Dissertations / Theses on the topic 'Fruit trees'

6 pp.
Training and pruning newly-planted deciduous fruit trees is one of the most important steps in developing trees with a strong framework (scaffold branches). Trees with a good framework of branches can support heavy crops without limb breakage and will help to bring the young tree into production at an early age. Selection and arrangement of these branches determines the type of development and growth in later years. The goal of pruning and training is to balance vegetative and fruiting wood growth.

Fruit-tree borer, Maroga melanostigma (Wallengren), is a native Australian pest in many species of trees. It is of particular economic importance in prune (Prunus domestica) trees because the presence of this wood boring insect can reduce productivity by an average of 5% per tree. Large areas of orchards can be affected. There are currently no chemicals registered for control of this pest. Young, New South Wales is the second largest prune-growing district in Australia and the area most seriously affected by M. melanostigma. Prune growers in the district utilise integrated pest management and were supportive of a project to investigate biological control options for this economically damaging pest. The two main objectives of the project were 1) to understand the life cycle of M. melanostigma, so biological controls could be timed appropriately; and 2) to investigate biological control options for this pest. Life cycle studies were commenced in the first season (2003/04) using field cages and light trapping. These investigations continued throughout the project. In Young, moths were found to emerge from wood over a two month period (December and January). Oviposition was assumed to be during this period however, even after extensive searches of trees, no eggs were observed. Historical data were collated to determine locations and timings of moth emergence elsewhere in Australia. The data showed that M. melanostigma has been found in every state and territory Australia, with moths observed from October through to March. The biological control options reviewed were egg parasitoids (Trichogramma species only), entomopathogenic nematodes and entomopathogenic fungi. Trichogramma were favoured because of previous research undertaken against the same pest in pecans in Moree, NSW. Entomopathogenic nematodes were also investigated due to research indicating their effectiveness in cryptic situations, such as borer tunnels in trees. Fungi were considered but dismissed due to lack of literature supporting their effectiveness in reducing lepidopteran pest damage in trees. A major field trial was designed with the assistance of a biometrician and the trial blocks laid out based on this advice. There were three trial sites, each containing four blocks of approximately 200 trees (~800 trees/site). Two blocks were designated as release blocks and two as non-release blocks to correspond with the trial’s two treatments. In the first season (2003/04) an initial visual assessment of borer damage was undertaken after leaf fall on each of the trees in the trial. This information was used as baseline data, to compare against damage levels following biological control releases in the second and third years of the project. Natural parasitism in the field was assessed using cultured eggs of Helicoverpa armigera (Hübner) before and between Trichogramma carverae (Oatman and Pinto) releases. Temperature and relative humidity were recorded in each of the trial sites, for the duration of the trial, using commercially available data loggers. In the second season (2004/05), Trichogramma releases were made during the period of moth activity and H. armigera eggs were used to monitor parasitism in the trial orchards. Parasitised eggs were reared through and all parasitoids were identified as T. carverae. Damage assessments were again carried out after leaf fall to compare release versus non-release blocks, as well as to determine if there was any change in borer activity. Early instar larvae were collected from non-trial blocks and exposed to the entomopathogenic nematode Steinernema carpocapsae in a laboratory investigation. Results from this limited bioassay were inconclusive. In the third season (2005/06), Trichogramma releases were again made during the period of moth activity and H. armigera eggs were used to monitor parasitism in the trial orchards. Parasitised eggs were reared through to emergence. The emerged parasites were identified as T. carverae, T. pretiosum and T. nr brassicae. Damage assessments were again made of all the trees in the trial. Results were statistically analysed to detect any differences between treatments. There was no statistically significant evidence that the releases of T. carverae reduced damage from M. melanostigma over the duration of the trial. Although damage increased across both release and non-release treatments in most blocks during the trial investigations, the increase was slightly lower in trees in which Trichogramma had been released. It should be noted that the experiments were affected by serious drought conditions which prevailed during the three seasons of the trial.

Thesis (M.Sc.(Hons.)) -- University of Western Sydney, 2007.
A thesis submitted in fulfilment of the requirements for the degree of Master of Science (Hons) to the University of Western Sydney, College of Health and Science, Centre for Plant and Food Science. Includes bibliography.

Thesis (M.Sc. Agric. (Horticulture)) --University of Limpopo, 2008
The mineral nutrition of indigenous crop species is not well documented like other known crop species, thus making it difficult for one to know how to plant and maintain the crops. Mmupudu (Mimusops zeyheri), which, happens to be a wild crop, is one of the indigenous trees of interest to the Discipline of Plant Production, University of Limpopo. The current study gives baseline information that will be important in various environmental physiology studies of this plant. Physiological studies will be necessary to assess the importance of “limiting” mineral nutrients in the accumulation of certain mineral nutrients in Mmupudu in relation to its productivity. The experiment was arranged as a 2 x 3 factorial in RCBD, with the first and second factors being time of sampling and location, respectively. The three locations where data were collected were Chuenespoort, Bochum and Sekgosese. In each location, the experiment was replicated 10 times. Data were analyzed using ANOVA and means were separated using the least significant difference test. The two-factor interaction was nonsignificant (P ≥ 0.10) for both pH and electrical conductivity. Soil pH was not affected by time in all three locations suggesting that abscised flowers and fruitlets have no effect on pH. Leaf K experienced an increase of 65% at Chuenespoort and a decrease of soil K after fruiting by 44%. Leaf and soil P decreased after fruiting in all locations as was the case with Cu. Chuenespoort and Sekgosese experienced a decrease in leaf Mn after fruiting while soil Mn decreased in all whereas leaf Mg decreased in all locations.
the National Research Foundation and the Department of Water Affairs and Forestry

Temperate Region fruit and nut trees, and many other perennial plants, require cool winter temperatures (chilling hours) to ensure leaf and flower bud production in the following season. Temperate Regions are characterized by variable winter and spring temperatures. Failure of meeting sufficient chilling requirement results in deformed fruits, unequal maturation, and other plant deformities, thereby reducing quality and yields. Chilling requirements are expressed as number of accumulated hours within a range of approximately 32º to 45ºF or 0º to 7.2ºC. These requirements are specific for level of temperature, length of temperature period, and species and cultivar of plants. Information on chilling hour production by the diverse Kentucky environments and chilling requirements of its plants is limited. Global warming is reducing the occurrence and length of chilling conditions, thereby negatively impacting perennial fruit production (IPCC, 2014). There is increasing interest in fruit crops by the state’s producers and consumers. The Kentucky Mesonet Weather System provides temperature data, which can readily be converted to chilling units. Also, commercial nurseries are beginning to publish chilling requirement data for their fruit stocks. The present study included data collected over A 5-years period at 33 Mesonet sites. The average number of chilling hours overall years and sites was 1544, year means ranged from 1427 to 1842, sites means ranged from 1422 to 1682. Chilling hour production exceeded chilling requirements of fruit and nut crops commonly grown in Kentucky.

Thesis (MScAgric (Plant Pathology))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: A survey was undertaken on apple and pear trees in the Western Cape Province to determine the aetiology of trunk diseases with reference to trunk diseases occurring on grapevine. Grapevine trunk diseases cause the gradual decline and dieback of vines resulting in a decrease in the vine’s capability to carry and ripen fruit. In recent years, viticulture has been expanding into several of the well established pome fruit growing areas. The presence of trunk pathogens in pome fruit orchards may affect the health of the pome fruit trees as well as cause a threat to young vineyards planted in close proximity to these potential sources of viable inoculum. Several genera containing species known to be involved in trunk disease on pome fruit and grapevine were found, including Diplodia, Neofusicoccum, Eutypa, Phaeoacremonium and Phomopsis. Diplodia seriata and D. pyricolum, were isolated along with N. australe and N. vitifusiforme. Four Phaeoacremonium species, P. aleophilum, P. iranianum, P. mortoniae and P. viticola, two Phomopsis species linked to clades identified in former studies as Phomopsis sp. 1 and Phomopsis sp. 7, and Eutypa lata were found. In addition, Paraconiothyrium brasiliense and Pa. variabile, and an unidentified Pyrenochaetalike species were found. Of these the Phaeoacremonium species have not been found on pear wood and it is a first report of P. aleophilum occurring on apple. This is also a first report of the Phomopsis species and Eutypa lata found occurring on pome trees in South Africa Two new coelomycetous fungi were also found including a Diplodia species, Diplodia pyricolum sp. nov., and a new genus, Pyrenochaetoides gen. nov. with the type species, Pyrenochaetoides mali sp. nov., were described from necrotic pear and apple wood. The combined ITS and EF1-α phylogeny supported the new Diplodia species, which is closely related to D. mutila and D. africana. The new species is characterised by conidia that become pigmented and 1-septate within the pycnidium, and that are intermediate in size between the latter two Diplodia species. Phylogenetic inference of the SSU of the unknown coelomycete provided bootstrap support (100%) for a monophyletic clade unrelated to known genera, and basal to Phoma and its relatives. Morphologically the new genus is characterised by pycnidial with elongated necks that lack setae, cylindrical conidiophores that are seldomly branched at the base, and Phoma-like conidia. The phylogenetic results combined with its dissimilarity from genera allied to Phoma, lead to the conclusion that this species represents a new genus. A pathogenicity trial was undertaken to examine the role of these species on apple, pear and grapevine shoots. N. australe caused the longest lesions on grapevine shoots, while Pyrenochaetoides mali, Pa. variabile, D. seriata and P. mortoniae caused lesions that were significantly longer than the control inoculations. On pears, D. pyricolum and N. australe caused the longest lesions, followed by D. seriata and E. lata. On apples, the longest lesions were caused by N. australe and P. iranianum. D. seriata, D. pyricolum, E. lata, N. vitifusiforme, Pa. brasiliense, P. aleophilum and P. mortoniae also caused lesions on apple that were significantly longer than the control. The study demonstrated that close cultivation of grapevine to apple and pear orchards may have inherent risks in terms of the free availability of viable inoculum of trunk disease pathogens.
No Afrikaans abstract available.

Thesis (MScAgric)--University of Stellenbosch, 2000.
ENGLISH ABSTRACT: The understanding of pear branching and bearing habits is required to optimise management practices. The objective of this study was to quantify the branching and bearing habits of pear cultivars under South African conditions of sub-optimal winter chilling. Two-year-old branches of Pyrus communis L. were classified into groups according to the proleptic (from dormant buds) branching habit. In Winter 1998 upright and flat, two-year-old branches were randomly sampled from trees of seven pear cultivars, i.e., Forelle (on Quince A and BPI rootstocks), Abaté Fetel, Flamingo, Packham's Triumph, Golden Russet Bose, Rosemarie and Beurre D'Anjou (all on BPI rootstock). Laterals were classified according to length « lem, 1-5cm, 5-20cm and >20 cm) and position (distal to proximal quadrants on the two-year-old axis). The number of shoots per cm of quadrant length, per length class for each cultivar was subjected to a cluster analysis, then a canonical and a stepwise discriminant analysis. The cultivars were grouped into four groups from Group 1 (Flamingo) which resembles a spurred growth habit with strong apical control, to Group 4 (Packham's Triumph and Golden Russet Bose) which resembles a spreading growth habit and weak apical control. The bearing habits of the same pear cultivars were quantified. In Winter 1998 ten unpruned branches were tagged on trees of each of the seven cultivars. The description started with the development of the main fruiting branch, forming several leaves in the first year of growth (designated year Y), with meristems developing in the leafaxils. In the following season (year Y+1), these axillary meristems have five alternatives: to remain as a latent bud (L), to develop as a vegetative bud (V), to become a flower bud not setting fruit (F), to become a flower bud producing a fruit (P) or to abort and leave a scar (S). Each year the development of these axillary buds were observed and classified anew, giving rise to a sequence. Between 50% ('Forelle/QA') and 75% ('Rosemarie') of buds remained in the growing phase (comprising of V, F or P buds) during the years of monitoring. It was shown that the predominant bud state in the growing phase was V. Although flower formation was low for all cultivars throughout the trial period, 'Packham's Triumph' and 'Rosemarie' displayed a relatively high proportion ofF and P buds in year Y+1. The latter two cultivars also displayed the bourse-over-bourse bearing phenomenon (PP), producing flowers and fruit terminally on bourse shoots. Artificial extinction of reproductive buds was applied in Winter 1999 to individual branches of the pear cultivar Doyenne du Cornice. This pear variety bears on spurs and is prone to biennial bearing. The objective was to reduce the number of growing buds, thereby increasing the allocation of assimilates to remaining reproductive structures. Three thinning intensities, i.e. 0%, 33% and 66% removal of reproductive buds and two methods, i.e. removal of proximal reproductive buds and removal of reproductive buds situated distally on spurs (by means of cutting back) were utilised. Autonomy of fruiting structures was not enhanced, but results warrant the repetition of this trial using whole trees as experimental units.
AFRIKAANSE OPSOMMING: Dit is belangrik om die vertakkings- en drawyses van pere te verstaan, aangesien bestuurspraktyke hierdeur bepaal word. Die doel van hierdie studie was om die vertakkings- en drawyses van pere onder Suid-Afrikaanse toestande van sub-optimale winterkoue te kwantifiseer. Tweejaar-oue Pyrus communis L. takke is volgens hul proleptiese (vanuit dormante knoppe) vertakkingswyse in groepe geklassifiseer. Regop en plat takke van die peerkultivars Forelle (op Kweper A and BPI onderstamme), Abaté Fetel, Flamingo, Packham's Triumph, Golden Russet Bose, Rosemarie en Beurre D'Anjou (almalop BPI onderstam) is in die winter van 1998 gemonster. Jaarlote is volgens lengte « l cm, 1-5cm, 5-20cm and >20 cm) en posisie (distale tot proksimale kwadrante op die tweejaar-oue draer) geklassifiseer. Die getal lote per cm, per lengte klas per kwadrant vir elke kultivar is toe onderwerp aan 'n groep analise en daarna aan 'n kanoniese en 'n stapsgewyse diskriminant analise. Kultivars is in vier groepe gegroepeer vanaf Groep 1 (Flamingo) wat 'n spooragtige vertakkingswyse en sterk apikale kontrole toon, tot Groep 4 (Packham's Triumph en Golden Russet Bose) met 'n spreidende vertakkingswyse en swak apikale kontrole. Bogenoemde peerkultivars is ook gebruik vir die kwantifisering van drawyses. In die winter van 1998 is tien ongesnoeide takke per boom gemerk. Die beskrywing van die drawyses het begin met die ontwikkeling van die hoof tak van die dra-eenheid. In die eerste jaar van groei (genoem jaar Y) ontwikkel meristeme in die blaar oksels. In die daaropvolgende seisoen (jaar Y+1) is daar vyf ontwikkelings moontlikhede vir die oksellêre knoppe: om latent te bly (L), om vegetatief te ontwikkel (V), om te blom sonder die set van 'n vrug (F), om te blom en 'n vrug te set (P) of om te aborteer en 'n letsel te los (S). Die ontwikkeling van hierdie oksellêre knoppe is elke jaar gemonitor en opnuut geklassifiseer om sodoende 'n reeks te vorm. Gedurende die moniteringstydperk het tussen 50% ('ForelleIKweper A') en 75% ('Rosemarie') van die knoppe in die groeifase (G) (bevattende V, F ofP knoppe) gebly. Die proporsie knop tipes per jaar vir die onderskeie kultivars het getoon dat die oorheersende knop tipe in die G-fase V-knoppe is. Alhoewel blom inisiasie laag was gedurende die hele proeftydperk, het 'Packham's Triumph' en 'Rosemarie' relatiefhoë verhoudings F en P knoppe in jaar Y+1 getoon, wat gepaard gaan met dié kultivars se vermoë om vrugte op een jaar-oue lote te dra. Die beurs-oor-beurs verskynsel (PP) het ook by dié twee kultivars voorgekom. Reproduktiewe knoppe van die peerkultivar Doyenne du Comice is in die winter van 1999 verwyder (kunsmatige abortering) vanaf indivuduele takke. Hierdie peerkultivar dra op spore en is geneig tot alternatiewe drag. Die doel was om die hoeveelheid groeiposisies te verminder en sodoende die allokasie van reserwe assimilate na oorblywende reproduktiewe strukture te verhoog. Drie uitdun intensiteite (0%,33% en 66% van reproduktiewe knoppe verwyder) en twee metodes (verwydering van proksimale spoorknoppe en verwydering van distale spoorknoppe) is gebruik. Outonomiteit van reproduktiewe strukture was nie verhoog nie, maar resultate regverdig die herhaling van dié eksperiment. Daar word aanbeveel dat volledige bome dan as eksperimentele eenhede gebruik word.

L'aplicació de Reg Deficitari Controlat (RDC) en parcel·les comercials d'arbres fruiters s'enfronta a una
problemàtica variada. En primer lloc cal buscar una metodologia fiable que permeti caracteritzar l'estrès
en la planta i en segon lloc, cal valorar quin nivell de dèficit és permisible assolir en un cultiu, de
manera que els efectes d'aquest estrès no esdevinguin indesitjables. El treball que es presenta pretén
aprofundir en el coneixement de les relacions hídriques en arbres fruiters amb la intenció de millorar la
gestió del RDC.
Un dels factors que ajuda a l'èxit en l'aplicació d'una determinada estratègia de RDC és que el cultiu en
qüestió presenti certa tolerància al dèficit hídric. Comparant la resposta fisiològica de l'avellaner
respecte la de l'ametller quan han estat sotmesos a un període de 2.5 mesos (15 juny a 31 agost) de
limitació progressiva en les aportacions de reg, s'ha demostrat, en l'avellaner, l'alta dependència de la
seva capacitat fotosintètica sobre el potencial hídric de la fulla medit abans del alba. L'avellaner ha
mostrat, a més, una limitada capacitat d'experimentar potencials hídrics de fulla baixos, la qual cosa el
converteix en un cultiu amb molt poca habilitat d'aprofitament del recurs hídric en condicions limitants,
tot al contrari que en l'ametller. Tot això condueix a que les possibles estratègies de RDC a aplicar en
avellaner s'hagin de dissenyar amb la màxima precaució.
La posada a la pràctica de RDC necessita d'un seguiment de l'estat hídric de la planta durant el període
de reg deficitari. En presseguer els treballs realitzats s'han enfocat sota aquesta perspectiva, en l'àmbit
d'una sèrie de tractaments de reg, basats en l'aplicació de reg deficitari en dos estadis diferents del cicle
anual del cultiu. Un període de reg deficitari es va aplicar durant la fase II de desenvolupament del fruit
(fase d'alentiment del creixement), i l'altre període a postcollita. En aquests treballs s'ha fet avinent que
el potencial de fulla al migdia en condicions de mesura estandaritzades (dies complerts sense núvols, en
fulles que reben radiació directa) pot ser un indicador aconsellable per ajudar a la programació de RDC
en presseguer, sobretot en RDC de fase II, degut al alt nivell explicatiu d'aquest paràmentre sobre el
comportament estomàtic. En postcollita, el cultiu esdevé més tolerant al dèficit hídric (el potencial hídric
de fulla de pèrdua de turgència és més negatiu que durant la fase II) i per sobre d'un determinat nivell
d'estat hídric de la fulla, el potencial de fulla al migdia sembla menys determinant sobre l'activitat
d'intercanvi de gasos de la fulla. Durant la fase III de desenvolupament del fruit (fase de creixement
ràpid del fruit) el potencial hídric de fulla al migdia va estar poc lligat amb la seva activitat estomàtica,
el que fa més aconsellable l'ús del potencial hídric de fulla mesurat abans de la sortida del sol.
En perera, una part dels treballs s'han encaminat a avaluar la resposta de la planta al dèficit hídric a
nivell de relacions hídriques en la fulla. L'objectiu és el de fonamentar la possible adequació de
estratègies de RDC a la perera. Per tal cosa es van aplicar dos cicles de dessecament progressiu
mitjançant maneig de l'aigua de reg. Un cicle es va aplicar durant el mes de maig (durant 27 dies) i l'altre cicle durant el juliol (durant 23 dies). En el cicle de primavera no es va evidenciar amb prou
claredat cap mecanisme d'aclimatació al dèficit hídric, però durant el cicle d'estiu es va fer palesa
l'existència d'un augment en la fracció d'aigua a l'apoplasma del teixit foliar, que es va traduir en una
major baixada del potencial hídric de la fulla dels arbres en dèficit, respecte els de no dèficit, per igual
valor de contingut d'aigua relatiu. Aquest major gradient però, solament es produiria a partir de la
pèrdua de turgència de la fulla, la qual cosa condueix més a la supervivència de la planta que al
manteniment dels processos productius.
En l'altra part dels estudis en perera, s'ha volgut comprobar la resposta del fruit a l'aplicació d'un RDC
aplicat en la fase I de creixement del fruit (fase de creixement linial) en unes condicions concretes de
cultiu en contenidors de gran capacitat (120 litres). Durant la fase I, els fruits del tractament RDC van
augmentar la seva mida a un ritme inferior que els dels arbres Control (tractament de no estrès). En
restituir la dosi òptima amb l'inici de la fase II (fase de creixement exponencial del fruit) i durant 2-3
setmanes, els fruits del tractament RDC van experimentar un ritme superior en l'augment del volum de
la pera en comparació amb el Control. Aquest ritme però, no es va mantenir durant la resta de la fase II,
durant la qual els fruits del tractament Control van tornar a mostrar un creixement superior. S'especula
amb el fet que durant la fase I s'afectés negativament el procés de divisió cel·lular del fruit; això
explicaria la limitació en la potencialitat del creixement del fruit al final de fase II. Les condicions
específiques de l'assaig, amb restricció radicular produïda pels contenidors, ús de portempelts poc
vigorosos o el nivell d'estrès hídric assolit durant la fase I del creixement del fruit, podrien també tenir el
seu paper en aquesta resposta del fruit al RDC aplicat.

Boron was applied as a foliar spray to pecan trees in a pecan orchard located in Cochise County. Single or repeated application prior to pollination did not affect nutlet set. Leaf analysis indicated that the boron levels in all trees were in the sufficient range for optimum growth and production.

Thesis (MSc)--Stellenbosch University, 2000.
Full text to be digitised and attached to bibliographic record.
ENGLISH ABSTRACT: Enhancement of vegetative growth in young citrus plantings The establishment of citrus involves high input costs, with break-even usually only attained after six years, making early returns imperative for economic survival. Early production is inseparably associated with good growth of the trees in the non-bearing years. In cool and cold production regions, coupled with a high frequency of wind, the initial tree growth is unsatisfactory. Trials were conducted to evaluate the effect of foliar application of Progibb® (GA3), Promalin'" (G~+7 + BA), Kelpak® (seaweed extract containing auxins and cytokinins) and soil applications of Temik® (aldicarb) as a means to promote vegetative growth. GA3 and/or aldicarb significantly increased tree height, without increasing the stem diameter in comparison to the control trees on 'Eureka' lemon, but not on 'Lisbon' lemon. G~+7 + BA or Kelpak® treatments did not have an effect on tree growth or fresh weight distribution. In conclusion, growth stimulation by GA3 and/or aldicarb could lead to quicker filling of the allotted space, and consequently higher, earlier yields, but further trials are required to verify these results. Insufficient carbohydrate and nitrogen reserves are often implicated in poor establishment performance of nursery trees. The effect of tree size at planting and different topping heights on early growth in the field were evaluated; also the physical and chemical profile of tall nursery whip trees were quantified. Significant correlations were found between the initial stem diameter and final stem diameter and initial tree height and final tree height at the end of the first growing season. Stem diameter increase was significantly reduced in topped trees relative to untopped trees. Roots comprised approximately 22%, and the aboveground portion about 78% of total dry weight. Roots nearly always contained higher concentrations of carbohydrates and nitrogen reserves. However, the aboveground sections, comprising a higher proportion of total dry weight, contained more than two thirds of total carbohydrates and nitrogen reserves. Topping of nursery whip trees at 60 cm aboveground thus would result in a loss of 33 to 37% dry matter, 29 to 33% carbohydrates and 37 to 46% nitrogen. Therefore, planting large, untopped nursery trees enhance initial tree growth in the orchard. The use of well-branched nursery trees for orchard planting can shorten the time to commercial fruit production. Citrus nursery trees do not develop lateral shoots adequately in the nursery or in the field and therefore necessitate various branch induction techniques. Two trials on newly-planted (one or five months after planting) trees were conducted to evaluate various branch induction techniques, viz., girdling, Promalin® (G~+7 + BA) (at 1000 or 2000 mg/I) and/or leaf removal and notching either to individual buds or the whole trees. The first trial, on l-month-old trees did not yield significant results. In the second trial, notching and girdling significantly increased the number and total length of lateral branches, but notching was the most effective technique. As the first trial, on the very young trees, yielded no significant results, it seems that trees have to be well established before they will respond. In young, non-oearing trees a lot of energy is invested in the flowering process, which results in an inhibition of vegetative growth. Gibberellic acid (GA3) and heavy mineral oil (Bac-oil) treatments, either individually or in combination, applied during early winter were evaluated as a means to reduce flowering levels in young nonbearing citrus trees. GA3 and mineral oil either separately or in combination were sprayed from April to July to the whole tree. GA3 and mineral oil either individually or in combination applied late in May to late June markedly reduced flowering. GA3 application in mid April had a minimal effect on flowering levels. Peak responses to GA3 coincided with a significant reduction in bud sprouting. Although optimum application time proved to be around May to July, this time is likely to vary from year to year depending on the influence of the prevailing temperature and other climatic conditions. The winter application of GA3, specifically, and possibly in combination with mineral oil to inhibit flowering and early vegetative growth may be utilised commercially. However, response may vary dramatically from season to season. Effect of time of application and concentration of 2,4-dichlorophenoxypropionic acid (2,4-DP) and l-naphthaleneacetic acid (NAA) as potential fruit thinning agents to reduce fruit set soon after flowering and enhance vegetative growth were evaluated over a two year period. 2,4-DP at 150 and 300 mg/I and NAA at 200 and 400 mg/! were sprayed on 2- and 4-year-old 'Mihowase' Satsuma, as well as on 2-year-old 'Marisol', 'Nules' and 'Oroval' Clementine trees at two times (late October and early November). The higher concentration of 2,4-DP and NAA generally did not result in increased fruit abscission in the first year. However, in the case of 2,4-DP the higher concentration resulted in stronger thinning in the second year. 2,4-DP and NAA can be used as potential fruit thinning agents to reduce fruit set on young non-bearing trees.
AFRIKAANSE OPSOMMING: Verbetering van vegetatiewe groeie by jong sitrus-aanplantings Die vestiging van sitrus behels hoë insetkoste en die gelykbreekpunt word gewoonlik eers na ses jaar bereik. Vroë opbrengste is dus noodsaaklik vir ekonomiese oorlewing. In koel en koue produksie-areas, met baie wind, is die aanvanklike boomgroei onvoldoende. Studies is uitgevoer om die effek van blaarbespuitings van Progibb'" (GA3), Promalin® (G~+7 + BA), Kelpak (seewier-ekstrak wat ouksien en sitokiniene bevat) en grondtoedienings van Temik® (aldicarb), as metodes om vegetatiewe groei te verbeter te evalueer. GA3 en/of aldicarb het boornhoogte betekenisvol laat toeneem, sonder om stamdeursnit te bevoordeel op 'Eureka' suurlemoen, maar nie op 'Lisbon' suurlemoen nie. G~+7 + BA of Kelpak'" behandelings het geen effek op boomgroei of varsmassa-verspreiding gehad nie. Groeistimulasie deur GA3 en/of Aldicarb kan lei tot vinniger vul van spasie, en hoër en vroeër oeste, maar verdere studies is nodig om die resultate te bevestig. Onvoldoende koolhidraat- en stikstofreserwes word dikwels gekoppel aan swak vestigingsprestasie van kwekerybome. Die effek van boomgrootte by planttyd en verskillende tophoogtes op vroeë groei in die veld is geëvalueer; die fisiese en chemiese profiel van lang ongetopte kwekerybome is ook gekwantifiseer. Betekenisvolle korrelasies is gevind tussen die aanvanklike stamdeursnit en en finale stamdeursnit en tussen aanvanklike boomhoogte en finale boomhoogte aan die einde van die eerste groeiseisoen. Stamdeursnit-toenarne is betekenisvol verminder in getopte bome relatief tot ongetopte bome. Wortels het uit ongeveer 22% en die bogrondse porsie ongeveer 78% van die totale droë massa bestaan. Wortels het bykans altyd hoër konsentrasies koolhidrate- en stikstofreserwes bevat. Die bogrondse gedeeltes, wat ook 'n hoër proporsie van die totale droë massa bevat, het meer as twee derdes van die totale koolhidraat en stikstofreserwes. Die top van kwekerybome op 60 cm bo die grond sal lei tot 'n verlies van 33 tot 37% droë massa, 29 tot 33% koolhidrate en 37 tot 46% stikstof. Dus, die plant van groot, ongetopte kwekerybome sal die aanvanklike boomgroei in die boord verbeter. Die gebruik van goedvertakte kwekerybome by planttyd kan die tyd tot komrnersieële vrugteproduksie verkort. Sitrus-kwekerybome gee nie voldoende laterale vertakking in die kwekery of in die boord nie. Twee studies op pas-aangeplante bome (een en vyf maande na plant) is uitgevoer om verskillende tegnieke om laterale lootgroei te stimuleer te evalueer, nl. Promalin® (G~+7 + BA) (teen 1000 of 2000 mg/I) en/of blaarverwydering, en die maak van kerfies op individuele knoppe of op bome as geheel. In die eerste studie, op die een-maand-oue bome, is geen betekenisvolle resultate verkry nie. In die tweede studie het kerfies en ringelering die hoeveelheid en lengte van laterale takke betekenisvol vermeerder, maar kerfies was meer effektief. Die bome moet egter blykbaar goed gevestig wees voor dit reageer. In jong, nie-draende bome word baie energie gebruik in die blomproses en dit lei tot die inhibisie van vegetatiewe groei. Gibberelliensuur (GA3 ) en 'n swaar mineralolie (Bac-oil) wat individueel of in kombinasie toegedien is tydens die vroeë winter is geëvalueer as 'n tegniek om blomvlakke in jong nie-draende sitrusbome te verminder. GA3 en minerale olie individueel of in kombinasie, is gespuit vanaf April tot Julie op die bome as geheel. GA3 en minerale olie toegedien individueel of in kombinasie laat in Mei tot Junie het blomvlakke verminder. GA3 toegedien in middel April het 'n minimale effek gehad. Die beste reaksie op GA3 het saamgeval met 'n betekenisvolle vermindering in die bot van knoppe. Alhoewel die optimum tyd van toediening rondom Mei tot Julie is, mag hierdie tyd wissel van jaar tot jaar afhangende van die effek van heersende temperature en ander klimaatstoestande. Die wintertoediening van GA3, spesifiek en moontlik in kombinase met minerale olie om blomvlakke en vroeë vegetatiewe groei te verminder kan kommersieel gebruik word. Die reaksie op hierdie behandelings mag egter drasties wissel van seisoen tot seisoen. Die effek van die tyd van toediening en konsentrasie van 2,4- dichlorofenoksipropioonsuur (2,4-DP) en 1-naftaleenasynsuur (NAA) as potensiële vruguitdunagente om vrugset kort na blom totaal te verminder en om vegetatiewe groei te verbeter, is geëvalueer oor 'n twee-jaarperiode. 2,4-DP teen 150 en 300 mg/l en NAA teen 200 en 400 mg/l is gespuit op 2- en 4-jaaroue 'Mihowase' Satsuma, en ook op 2-jaaroue 'Marisoi', 'Nules' en 'Oroval' Clementines op twee tye (laat Oktober en vroeg November). Die hoër konsentrasies van 2,4-DP en NAA het oor die algemeen nie gelei tot 'n verhoging in vrugafsnoering in die eeste jaar nie. Met 2,4- DP het die hoër konsentrasie gelei tot strawwer uitdunning in die tweede jaar. 2,4-DP en NAA kan as potensiële vruguitdunagente op jong, nie-draende bome gebruik word.

Cupuassu (Theobroma grandiflorum), one of the most profitable crops of Amazonia, is now attracting world-wide attention as an exotic fruit, used in juices, ice cream and sweets. It is a shade tolerant tree that can be grown as a component of agroforestry systems. Nevertheless it is still a wild species and little is known about its biology. Floral biology of cupuassu was studied in Belem-Brazil during 2 floweringfruiting seasons between June 1991 and December 1993. Flowering occurs in the drier period of the year. Flowers commence opening at any time of the day, but open fully at the end of afternoon. The anthers dehisce and the stigmas are receptive as soon as the flowers are fully open. Stigmas remain receptive until 10:00 am the following day. Throughout this period, the pollen grains remain viable. The flowers have a complex morphology which favours allogamy. The species is also self-incompatible. Experimental pollinations, using compatible pollen grains, have shown that a flower which receives 60 compatible pollen grains has 20% probability of setting fruit; a flower which receives more than 400 pollen grains always sets fruit. However, only around 2% of naturally pollinated flowers receive more than 60 pollen grains. A stingless bee, Plebeia minima, is considered an effective pollinator of cupuassu. Another stingless bee, Trigonisca pediculana, also visits cupuassu flowers. Both bees are small insects, which are unlikely to fly very far. Ants (Wasmannia sp.) and weevils (Baris sp.) were considered secondary pollinators, unlikely to promote effective pollinationsFruits mature during the wet period of the year, approximately 5.5 months after the flowers open. The limited and irregular fruit set is probably caused by scarcity of pollinators. The transformation of cupuassu to a plantation crop will therefore require conditions which favour natural pollinators and their access to receptive and compatible flowers

This study investigated the potential of some indigenous fruit trees as high value crops for use as shade trees in cocoa farms and the interactions between the cocoa and the indigenous fruit trees with the aim of maximising productivity. A survey on farmers' knowledge on Theobroma cacao-Chrysophyllum albidum agroforestry in the Suhum-Kraboa-Coaltar District using a structured questionnaire revealed challenges in propagation of C. albidum and the need to address them. The study also showed that the use of indigenous fruit trees in cocoa farms could bring economic gains to the farmer. A range of pre-sowing treatments were evaluated to determine the most effective method to break the dormancy of C. albidum hard seed coats. The results of the investigation showed that mechanical scarification was the best treatment for mass and uniform germination of C. albidum seeds with a percentage of 73.8% Experiments were also conducted to optimise vegetative propagation of C. albidum. In this study the effects of leaf area treatments, IBA concentrations and propagating media were examined. The results showed that stem cuttings with 40 cm2 leaf area on Sawdust medium gave optimum rooting with a percentage of 88.5%. A field experiment to study the interactions between the cocoa and indigenous fruit trees of C.albidum, Irvingia gabonensis and Oacryodes klaineana agroforestry was set up at Afosu in Ghana. The experiment showed that at 15 months, the species allocated varying percentages of plant resources to root, stem and leaves biomass. This showed the growth strategies of the various plants. From these early measurements, C. albidum showed the initiation of a tap root system which could be expected to be less competitive with cultivation with cocoa. An on-farm study confirmed little competition for soil water between T. cacao and C. albidum both in the wet and dry seasons. On-farm data collection enabled stocking of C. albidum fruit tree per hectare to be calculated based on series of allometric equations. The key recommendations for the study are optimal planting distances and density for different age and class sizes of C. albidum trees in cocoa farms as well as pruning of fruit trees and cocoa trees to increase percentage light interception for higher yield.

In farming of fruit trees it is of interest to know the light interception of the trees. Therefore, in this project, a geometric model of the trees was derived using LiDAR data and this was combined with a sky model to estimate the light interceptionof orchard trees. The light interception was estimated by first synthesising a discrete model of the hemispherical sky, which holds a measure of global lightradiation in each node. The light interception of the trees was then estimated by ray tracing from the sky, applying a radiation absorption model where rays passed the point cloud representation of the trees. Comparing the interception model to measurements of photosynthetically active radiation (PAR) underneath a tree, the qualitative agreement was high and the quantitative analysis showed a reasonable, albeit noisy, correspondence between the model output and the real world measurements. When comparing the estimations produced by the solar-geometry model and the tree volume (estimated also with LiDAR), a correspondence between the surface area of the tree and the interception was found. When comparing tree volume and light interception against actual yield numbers (total weight, average fruit weight and fruit count per tree), the observable trend was that light interception did better in predicting the average fruit size, while the volume did a better job of estimating the two others. The results were encouraging, however, because ground truth data were only available for 18 trees, future work will have to compare with a greater number of measurements over multiple growing seasons.

Standardised systems of food production where food is brought into cities from far away is accompanied with high emissions from both production and transport. Simultaneously, food growing in the urban surroundings is not picked and left to rot. This thesis is concerned with urban foraging, the practice of picking edibles in the urban landscape, a practice often overlooked by research and policymakers. The case study area is Skarpnäck, southern Stockholm and the focus is specifically on foraging of fruit and berries from public vegetation. Using a qualitative mixed methods approach where a questionnaire was followed by interviews, the aim has been to assess how the practice is perceived in the case study area and if there are certain cultural norms that limit picking activities. Results suggest that foraging is perceived to be out of place in the urban area. Although some people do pick, others feel it is inappropriate and do not want to be seen picking fruit or berries and therefore limit picking. The thesis concludes that urban foraging has the potential to increase urban sustainability, but efforts are needed for foraging to be a culturally accepted practice.

Thesis (PhD(Agric))--Stellenbosch University, 2009.
ENGLISH ABSTRACT: The global movement in agriculture is towards more environmentally friendly, sustainable production practices, since the role of soil microbial functions in ensuring crop production and soil fertility has become more evident in agricultural systems. Furthermore, with the impeding phase-out of methyl bromide, apple replant disease (ARD) is becoming an increasingly important problem and biological management practises are needed. Since microbial activity is generally carbon-limited in agricultural soil, it is widely accepted that management practices providing a range of organic compounds on a regular basis will tend to maintain an active and diverse microbial population. It was hypothesised that the application of various biological amendments can affect soil microbial numbers and function, thereby having a positive effect on fruit tree growth and yield. The effect of continued applications of organic material, various microbial inoculants and biostimulants on tree performance were evaluated in conventional management systems. Field trials were established in a conventional pear orchard, potential apple replant disease sites, as well as an optimally managed, high density apple orchard under controlled fertigation. The use of compost, compost extracts, a Bacillus inoculant and humates were investigated intensively. Furthermore, to improve our understanding of soil biological systems a combination of simple, practical methods were used to evaluate the effect of biological amendments on soil microbial properties and effects were related to tree performance. Regular application of compost extract in combination with compost showed the most significant effect in improving tree performance in commercial pome fruit orchards under various conditions. In the pear orchard, cumulative yield over the first two seasons was improved by more than 50% compared to controls, while in the fertigated orchard yield was improved by 22%. Biological amendments also showed improved growth in orchards suffering from stunted growth symptoms typical of ARD. However, in severe ARD cases methyl bromide fumigation showed the most consistent effects. Other biological amendments which showed positive effects on yield were application of Bacillus inoculants (Biostart®) in combination with a labile C source and a low dosage humate product, as well as a combination of compost and humates. It was clear that a combination of labile organic matter and a diverse group of microorganisms showed most promise. Although for some specific treatments increased microbial numbers and activity may have resulted in improved tree performance, in general, changes in culture-based plate counts, soil enzyme activity and carbon utilisation profiles could not be used as an indicator of yield. It was suggested that improved synchronisation of nutrient release and plant uptake, as well as microbial phytohormone production, may play an important role in improving tree performance with application of biological amendments. More research is needed on the exact mechanisms through which compost extracts improve yield and studies on root growth proliferation, as well as effects in the rhizosphere are recommended.
AFRIKAANSE OPSOMMING: Binne lanbouverband is daar tans wêreldwyd die neiging om die uitwerking van produksie-praktykte op die omgewing in ag te neem en sodoende meer verantwoordelik op te tree. Omdat die belangrike rol wat grondmikro-organisme funksionering in volhoubare verbouingspraktyke speel nou deeglik besef word, word meer volhoubare bestuurspraktyke bepleit. Hiermee saam, noodsaak aspekte soos die uitfasering van metielbromied vir die beheer van appelhervestigingsiekte, dat biologiese bestuurspraktyke meer aandag geniet. Daar word geredelik aanvaar dat gereelde toediening en aanvulling van organiese materiaal ‘n aktiewe, diverse mikrobe populasie in die grond tot gevolg sal hê. Die hipotese is gestel dat die toediening van ‘n verskeidenheid biologiese produkte grondmikrobe getalle en werking gunstig kan beïnvloed. Dit kan moontlik weer aanleiding gee tot positiewe reaskies wat die groei en drag van vrugtebome betref. In hierdie studie is die uitwerking van voortgesette toedienings van organiese materiaal, mikrobiese inokulante, asook biostimulante, op die prestasievermoë van vrugtebome ondersoek. Veldproewe is uitgelê in ‘n konvensionele peerboord, verskeie boorde met moontlike appelhervestigingsiekte probleme, asook ‘n hoëdigtheidsaanplanting appelboord onder optimale bestuur. ‘n Deeglike ondersoek is gedoen met betrekking tot die gebruik van kompos, komposekstrak, Bacillus-inokulante en humate. Eenvoudige, praktiese metodes is aangewend om vas te stel hoe biologiese toevoegings grondmikrobe eienskappe beïnvloed en of dit verband hou met veranderinge in boomprestasie. Die studie het aangetoon dat die gereelde toediening van komposekstrak saammet kompos, betekenisvolle verbetering in boomprestasie van kernvrugboorde teweeg bring onder verskeie omstandighede. Die kumulatiewe opbrengs van ‘n peerboord is oor twee seisoene met meer as 50% verhoog teenoor die kontrole. In ‘n optimaal bestuurde appelboord onder sproeibemesting, is opbrengs met 22% verhoog in vergelyking met die kontrole. Biologiese toevoegings het ook groei verbeter in boorde waar appelhervestigingsiekte bome se groei vertraag het. In die geval van ernstige appelhervestigingsimptome het metielbromied egter steeds die mees konstante positiewe uitwerking gehad. Ander biologiese toevoegings wat ‘n gunstige uitwerking op opbrengs getoon het, was ‘n kombinasie van Bacillus inokulante, ‘n lae dosis humaat en ‘n aktiewe koolstofbron, asook kompos in kombinasie met humate. Dit is duidelik dat ‘n kombinasie van ‘n maklik afbreekbare koolstofbron (soos kompos) tesame met ‘n diverse groep mikroorganismes mees belowend is vir gebruik in biologiese verbouingssisteme. Resultate toon dat veranderings in aantal organismes gemeet deur plaattellings, die aktiwiteit van grondensieme, en verbruikspotensiaal van verskillende koolstofbronne, nie as ‘n aanduiding van boomprestasie gebruik kan word nie. Daar is voorgestel dat verbeterde sinkronisasie van voedingselementvrystelling en plantopname, sowel as produksie van plantgroeihormone deur mikrobe, moontlik ‘n rol speel by boomreaksies op biologiese toevoegings. Meer navorsing wat verband hou met die meganisme waardeur komposekstrak opbrengs verbeter, is nodig. Verder word studies op fynwortelontwikkeling sowel as aspekte van die wortelrisosfeer aanbeveel.

A major concern related to agricultural management systems used by the man lies on the effects on biological processes in the soil, whose action within ecosystems aiming at the farm, modifies the intensity of these processes under use of techniques that exclusively aim to maximize crop yield. One of the challenges of research in soil biology is precisely understand the impacts on the complex interactions of all soil organisms at the community level by the management that are critical in maintaining soil quality. The objective of this work was to evaluate the influence of management practices on fruit trees (mango, guava and coconut trees) in the composition and distribution of soil arthropods (edaphic macrofauna, mesofauna) and on microbial biomass, the activity and interaction with the chemical, physical and environmental attributes. The study of soil arthropods began in July 2013 and followed until May 2014, with measurements at four periods. Microbiological soil activities were evaluated by the determination of microbial soil properties (RBS, CBM, NBM, NBM / N, qCO2 and qMIC). It was found that the soil arthropods were sensitive to changes arising from different soil tillage systems, allowing it to be used as an important tool to apply as bio-indicators of the quality of edaphic system. The system with guava cultivation proved to be unstable over time in relation to the structure of the community of soil arthropods. The system with coconut tree cultivation allows for better soil quality, increase in abundance and species richness of invertebrate macrofauna. The microbial biomass carbon (MBC), microbial biomass nitrogen (NBM) and the metabolic quotient (qCO2) were the main microbiological soil properties responsible for identifying dissimilarities between areas. Correlations between microbiological and faunal characteristics of the soil were low with significant correlations only between Collembola, NBM and NBM / N.
Uma das grandes preocupaÃÃes relacionadas aos sistemas de manejo agrÃcola adotado pelo homem reside nos efeitos sobre os processos biolÃgicos que ocorrem no solo, cuja aÃÃo dentro dos ecossistemas visando à exploraÃÃo agrÃcola, modifica a intensidade desses processos em virtude do emprego de prÃticas que objetivam exclusivamente a maximizaÃÃo da produÃÃo vegetal. Um dos desafios da pesquisa em biologia do solo à justamente entender os impactos do manejo sobre as complexas interaÃÃes de todos os organismos edÃficos ao nÃvel de comunidade que sÃo fundamentais na manutenÃÃo da qualidade do solo. Objetivou-se avaliar a influÃncia dos manejos em cultivos de fruteiras (mangueira, goiabeira e coqueiro) na composiÃÃo e distribuiÃÃo dos artrÃpodes de solo (mesofauna e macrofauna edÃfica) e sobre a biomassa microbiana, sua atividade e interaÃÃo com os atributos quÃmicos, fÃsicos e ambientais. O estudo dos artrÃpodes edÃficos teve inÃcio em julho de 2013 e seguiu atà maio de 2014, com coletas realizadas em quatro perÃodos. As atividades microbiolÃgicas do solo foram avaliadas mediante as determinaÃÃes dos atributos microbianos do solo (RBS, CBM, NBM, NBM/N, qCO2 e qMIC). Constatou-se que os artrÃpodes de solo mostraram-se sensÃveis as alteraÃÃes ocasionadas pelos sistemas de manejos do solo, possibilitando a sua indicaÃÃo como importante ferramenta para aplicar-se como bioindicadores da qualidade do sistema edÃfico. O sistema com cultivo de goiabeiras mostrou-se instÃvel ao longo do tempo em relaÃÃo à estrutura da comunidade dos artrÃpodes de solo. O sistema com cultivo de coqueiros propicia melhores caracterÃsticas do solo e aumento na abundÃncia e riqueza de espÃcies da macrofauna invertebrada. O carbono da biomassa microbiana (CBM), nitrogÃnio da biomassa microbiana (NBM) e o quociente metabÃlico (qCO2), foram os principais atributos microbiolÃgicos do solo responsÃveis por identificar dissimilaridades entre as Ãreas. CorrelaÃÃes entre as variÃveis microbiolÃgicas e faunÃsticas do solo foram baixas, com correlaÃÃes significativas somente entre Collembola, NBM e NBM/N.

La coltura in vitro, applicata alla propagazione e miglioramento genetico della biodiversità vegetale, può rappresentare uno strumento efficace per affrontare i problemi attuali come i cambiamenti climatici, le nuove esigenze dei consumatori e indirettamente lo sviluppo delle aree rurali. Inoltre, può assumere un ruolo strategico nel miglioramento genetico e nella propagazione delle cultivar al fine di ottenere genotipi resistenti, con frutti migliori dal punto di vista organolettico e piante capaci di adattarsi ai cambiamenti climatici. Il miglioramento genetico attraverso i metodi convenzionale è limitato da molti fattori infatti, gli alberi da frutto sono caratterizzati da un lungo periodo di giovanilità, elevata eterozigosi e molto spesso incompatibilità sessuale. La tecniche in vitro della coltura di antere e/o microspore isolate, per ottenere piante aploidi o doppi aploidi, riescono a superare alcuni limiti del miglioramento genetico tradizionale e fornire in un solo passaggio linee completamente omozigoti interessanti per studi di genomica, mutazioni, mappatura e trasformazione genetica. La tecnologia in vitro oltre ad essere applicata al miglioramento genetico, risulta un metodo complementare ai metodi convenzionali di propagazione agamica, in quanto, il materiale vegetale risulta protetto da eventuali attacchi di patogeni, il processo è indipendente dalle condizioni stagionali, permette uniformità genetica ed elevati tassi di moltiplicazione in uno spazio ridotto. La coltura in vitro è resa possibile dal fenomeno della totipotenza; cioè la capacità che hanno le cellule, organi o tessuti di de-differenziarsi e acquisire capacità meristematiche dando origine ad organi, tessuti o a un individuo intero, anche diverso da quello di partenza. Questa ricerca ha avuto come obiettivo l’induzione dell’embrio enesi ametica in vari genotipi di agrumi, tramite coltura in vitro di antere. Inoltre, si è studiata la messa a punto di un efficiente protocollo di conservazione e propagazione, attraverso la tecnologia del seme sintetico, rispettivamente in Fico, Luppolo e Cappero. Gli esperimenti sono stati condotti nel 2017, 2018 e 2019 presso l’Universit de li Studi di Palermo (UNIPA) e l’Instituto Valenciano de Investi aciones A rarias (IVIA). Per quanto riguarda la coltura di antere di agrumi è stata ottenuta embriogenesi somatica nella varietà Moro (2x), portando alla rigenerazione di embrioni che dopo le analisi della ploidia e molecolari sono risultati tetraploidi eterozigoti; nei genotipi Marisol (4x), Clemenules (4x), Moro Los Valles (4x), Sanguinelli (4x) e Sanguinelli (2), è stata osservata divisione simmetrica del nucleo, strutture multinucleate e la formazione di embrioni che in se uito all’analisi citofluorimetrica sono risultati per la maggior parte diploidi. L’analisi molecolare, effettuata con i marcatori SSR invece, ha rilevato risultati singolari, infatti, nei genotipi Marisol, Clemenules e Sanguinelli (2x e 4x), anche se sono state osservate microspore multinucleate e la maggior parte dei rigenerati erano diploidi, dall’analisi sono risultati tutti eterozi oti, mentre in Moro Los Valles, imarcatori hanno rilevato che dei diploidi rigenerati tre erano omozigoti, due omozigoti mutati (variabilità gametoclonale) e due eterozigoti mutati. La tecnologia del seme sintetico è stata applicata alla varietà Houmairi di Ficus carica L., in particolare, è stato valutato l’effetto di due Regolatori di crescita (PGR): 6-benzilaminopurine (BAP) e meta-Topolina (mT), aggiunti all’endosperma artificiale, e della conservazione a 4° C per 30 iorni delle microtalee incapsulate. La più alta percentuale di semi vitali e che hanno portato ad una maggiore ripresa vegetativa si è avuta nella tesi che non ha previsto conservazione a freddo prima della semina e quando l’endosperma artificiale veniva addizionato con il BAP. In maniera diversa, la percentuale maggiore di conversione si è avuta, sia per i semi conservati che non quando l’endosperma veniva addizionato con mT. La propagazione in vitro, è stata applicata anche, alla varietà Cascade di Humulus lupulus L. con l’obiettivo di realizzare un protocollo efficiente di micropropagazione. Partendo dal prelievo in campo del materiale vegetale, si è proceduto alla sterilizzazione, stabilizzazione della coltura asettica nonché alla moltiplicazione, radicazione e acclimatazione alle condizioni ex vitro. Per la moltiplicazione sono stati testati 3 PGR: BAP, mT e Thidiazuron (TDZ) in diverse combinazioni, mentre per la radicazioni 2 PGR auxinici: Acido indol-3-acetico (IAA) e Acido indol-3-butirrico (IBA). L’interazione TDZ/BAP ha mostrato il più alto tasso di germogliamento anche se con un maggiore sviluppo di callo tale da considerare il mezzo con 2mg Lˉ¹ di TDZ il migliore nonostante dia un germogliamento inferiore così come per la presenza di callo. Per quanto riguarda la maggiore percentuale di radicazione si è avuta nel mezzo contenente 2 mg Lˉ¹ di IBA anche se differiva per pochi punti percentuali dal mezzo che conteneva 1 mg Lˉ¹ di IAA. Infine, è stata valutata l’influenza del rivestimento di alginato di calcio e di tre diversi regolatori di crescita (PGR): 6-benzilaminopurina (BAP), meta-topolina (mT) e zeatina (ZEA), sulla vitalità, la ricrescita e la conversione dei propaguli. di due genotipi siciliani di Capparis spinosa (L.). Le microtalee di cappero sono state sezionate e collocate in diversi endospermi artificiali a base di sali e vitamine Murashige e Skoog, arricchiti di mT o ZEA o BAP. I semi sintetici ottenuti sono stati seminati su un mezzo MS addizionato con 0,4 mg / Lˉ¹ di acido acetico naftalenico e 0,7 mg / Lˉ¹ di acido gibellerico. Dopo 60 giorni, sono stati rilevati i seguenti parametri: vitalità, ricrescita, numero e lunghezza dei germogli e delle radici, conversione. I risultati confermano che l'incapsulamento non ha influito negativamente sulla vitalità, che ha mostrato la percentuale più alta con BAP in Tracino e con ZEA in Scauri. Risultati simili sono stati ottenuti nella ricrescita, con differenze statisticamente significative tra i tre PGR testati: Tracino ha mostrato la migliore ricrescita in capsule arricchite con BAP, Scauri con ZEA. Inoltre, la conversione dei semi sintetici è stata fortemente influenzata dalla PGR ed era più elevata nell'endosperma artificiale addizionato con BAP in Tracino e ZEA in Scauri.
In vitro culture, applied to the propagation and genetic improvement of plant biodiversity, can be an effective tool to face current problems such as climate change, and new consumer needs. Moreover, it can take on a strategic role in genetic improvement and propagation of cultivars in order to obtain genotypes resistant to biotic and abiotic stresses, with fruits improved from an organoleptic point of view and plants able to adapt to climate change. Genetic improvement through conventional methods is limited by many factors. Fruit trees are characterized by a long period of juvenitlity, high heterozygosity and, very often, by sexual incompatibility. The in vitro techniques of the cultivation of isolated anthers and/or microspores, to obtain haploid or double haploid plants, are able to overcome some limits of traditional genetic improvement and provide in a single step completely homozygous lines of interest for genomic studies, mutations, mapping and genetic transformation. In addition, in vitro technology is a complementary method or can even support conventional methods of agamic propagation, since the plant material is protected from possible attacks by pathogens, their production is independent of seasonal conditions, this tecquique allows genetic uniformity and high multiplication rates, in a small space. In vitro culture is made possible by the phenomenon of totipotency, that is, the ability of cells, organs or tissues to de-differentiate and acquire meristematic skills, giving rise to organs, tissues or to an entire individual, even different from the original one. This research had as its objective the induction of gametic embryogenesis in various citrus genotypes through in vitro culture of anthers, and the development of an efficient protocol for Fig, Hop and Caper through synthetic seed technology and micropropagation, respectively. The experiments were conducted in 2017, 2018 and 2019 at the University of Palermo (UNIPA) and the Valencian Institute of Agricultural Research (IVIA). As far as the cultivation of citrus anthers is concerned, somatic embryogenesis was obtained in the Moro variety (2x), leading to the regeneration of embryos which after ploidy and molecular analyzes were heterozygous tetraploids; and Marisol (4x), Clemenules (4x), Moro Los Valles (4x), Sanguinelli (4x) and Sanguinelli (2) genotypes, symmetric division of the nucleus, multinucleated structures and formation of embryos that following the analysis was observed cytofluorimetric results for the most part were diploid, molecular analysis, carried out with SSR markers instead, found singular results, in fact, in the Marisol, Clemenules and Sanguinelli genotypes (2x and 4x), even if multinucleated microspores and the most regenerated were diploid, from the analysis they were all heterozygous, while in Moro Los Valles, the markers found that three regenerated diploids were homozygous, two mutated homozygotes (gametoclonal variability) and two mutated heterozygotes.In this research, synthetic seed technology has been applied to the Houmairi variety of Ficus carica L., in particular, the effect of two “Plant rowth Re ulators” (P R): 6-benzylaminopurine (BAP) and meta-Topolina (mT), added to the artificial endosperm, and of the preservation at 4 ° C for 30 days of the encapsulated microcuttings. The highest percentage of viable seeds that led to a greater vegetative recovery occurred in the thesis that it did not foresee cold storage before sowing and when the artificial endosperm was added with BAP. In a different way, the highest percentage of conversion occurred, both for the stored seeds and not when the endosperm was added with mT. In vitro propagation was applied to the Cascade, variety of Humulus lupulus L. with the aim of achieving an efficient micropropagation protocol. Starting from the collection in the field of the plant material, sterilization, stabilization of the aseptic culture as well as the multiplication, rooting and acclimatization to ex vitro conditions were carried out. For the multiplication 3 PGR were tested: BAP, mT and Thidiazuron (TDZ) in different combinations, while for the rooting 2 PGR auxinic: indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA). The TDZ / BAP interaction showed the highest germination rate even though with a greater callus development such as to consider the medium with 2 mg lˉ¹ of TDZ the best despite giving a lower budding as well as for the presence of callus. As regards the greater percentage of rooting, it occurred in the medium containing 2mg lˉ¹ of IBA without significant difference from the medium that contained 1 mg L of IAA. Finally, the influence of the calcium alginate coating the cuttings along with the three different growth regulators (PGR) were evaluated: 6-benzylaminopurine (BAP), meta-topolina (mT) and zeatin (ZEA), on vitality, regrowth and the conversion of the propagules of two Sicilian genotypes of Capparis spinosa (L.) (Tracino and Scauri, from Pantelleria Island). Caper microcutting have been sectioned and placed in different artificial endosperms based on Murashige and Skoog, enriched with mT or ZEA or BAP. The synthetic seeds obtained were seeded on an MS medium added with 0.4 mg / L of naphthalene acetic acid and 0.7 mg / L of gibelleric acid. After 60 days, the following parameters were detected: vitality, regrowth, number and length of shoots and roots, conversion. The results confirm that encapsulation did not negatively affect vitality, which showed the highest percentage with BAP in Tracino and with ZEA in Scauri. Similar results were obtained in regrowth, with statistically significant differences between the three PGRs tested: Tracino showed the best regrowth in capsules enriched with BAP, Scauri with ZEA. Furthermore, synseed conversion was strongly influenced by PGR and was higher in artificial endosperm added with BAP in Tracino and ZEA in Scauri genotype.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Foi avaliado o efeito da presença de uma árvore que possui nectários extraflorais (Inga sp., Fabaceae) no controle do bicho-mineiro do cafeeiro (Leucoptera coffeella) e broca- do-café (Hypothenemus hampei) em cafeeiros sob sistemas agroflorestais. A disponibilidade de néctar em árvores de Ingá aumentou o parasitismo do bicho-mineiro e diminuiu os danos em plantas de café. Para elucidar os mecanismos envolvidos no controle das pragas do café em sistemas agroflorestais foi avaliado o efeito do néctar, como uma fonte de alimento, no fitness de inimigos naturais das pragas do café. Em laboratório, foi avaliado o efeito de um alimento rico em açúcar, semelhante ao néctar, na biologia de um tripes predador que foi encontrado dentro de frutos brocados de café e se alimentando nos nectários dos Ingás nos sistemas agroflorestais. Além disso, foi avaliado o efeito da predação do tripes na população de brocas no interior de frutos brocados. A sobrevivência do tripes aumentou com a fonte de alimento rica em açúcar. No entanto, o tempo de desenvolvimento das larvas aumentou e eles não atingiram a idade adulta, a não ser quando foram alimentados com a broca-do-café. A predação do tripes não foi suficiente para diminuir a população de brocas-do-café no interior dos frutos. O efeito do néctar extrafloral do Ingá na sobrevivência de inimigos naturais do bicho-mineiro também foi avaliado. A sobrevivência de quatro espécies de parasitoides e de uma espécie de crisopídio aumentou quando se alimentaram de néctar extrafloral. Por fim, foi realizado um experimento em campo para comparar a produção do café, os danos no cafeeiro e o parasitismo e a predação das pragas entre café em monocultivo e café consorciado com árvores de Ingá. Para avaliar o efeito da proximidade das árvores na proteção do café, a produção e o controle de pragas foram avaliados ao longo de transectos de 50 m se estendendo a partir das árvores Ingá. O peso dos frutos do café aumentou quando o café foi consorciado com árvores Ingá. Os danos causados pelo bicho-mineiro e pela broca-do-café também foram menores no café consorciado e aumentou com a distância das árvores. O parasitismo e predação das pragas do café não respondeu significativamente à presença das árvores, mas mostrou a tendência esperada. Portanto, árvores de Ingá com nectários extraflorais aumentam o controle natural de pragas e a produção em cultivos cafeeiros.
The effect of the presence of an extrafloral nectary-bearing tree (Inga sp., Fabaceae) on the control of coffee leaf miner (Leucoptera coffeella) and coffee berry borer (Hypothenemus hampei) in agroforestry coffee systems was assessed. The availability of nectar from Inga trees increased parasitism of coffee leaf miner and decreased damage on coffee plants. To uncover mechanisms behind enhanced pest control in agroforestry systems we assessed the effect of nectar feeding on fitness of natural enemies of coffee pests. Through a laboratory experiment, we assess the effect of a sugar-rich food source resembling nectar on life-history traits of a predatory thrips that was found inside bored coffee fruits and feeding on extrafloral nectar of Inga trees during surveys in coffee agroforestry systems. Also, we assessed the effect of the thrips predation on coffee berry borer population inside the berries. The predatory thrips benefited from feeding on sugar-rich food through increased survival. However, the developmental time of larvae was increased and they did not reach adulthood unless fed on coffee berry borers. Thrips did not decrease the abundance of coffee berry borer inside the berries. The effect of nectar from Inga trees on natural enemies of coffee leaf miners was also assessed. Four parasitoid species and one green lacewing species increased their survival when feeding on extrafloral nectar. Subsequently, we performed a field experiment comparing coffee yield, coffee damage and parasitism and predation of coffee pests between coffee plots with or without Inga trees. To evaluate the effect of nectar source proximity on coffee protection, we also assessed pest control and production along transects of 50 m extending from the Inga trees. Coffee fruit weight was increased when coffee was consorted with Inga trees. Damage caused by coffee leaf miners and coffee berry borers were also lower in consorted coffee plants and increased with distance from the trees. Parasitism and predation of coffee pests did not increase significantly when coffee was associated with Inga trees, but showed the proper trends. Therefore, Inga trees bearing extrafloral nectaries enhanced natural pest control of pests and production in coffee crops.

Thesis (MScAgric (Horticulture))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: Persimmon production is new to South Africa with about 700 ha planted to the dioecious, parthenocarpic Triumph cultivar since 1998. Little local expertise is available to assist growers in achieving high yields of high quality fruit and previous research has shown that recipes that are followed in Israel, from where ‘Triumph’ was introduced to South Africa, do not necessarily have any beneficial effect in South Africa. ‘Triumph’ orchards in South Africa are often late in reaching full production. Persimmon trees are generally vigorous and prone to excessive fruit drop, partly due to excessive vegetative growth, especially when young and grown on the very vigorous Diospyros lotus seedling rootstock. The first objective of this study was to evaluate the use of growth retardants and various severities of girdling to increase flower formation, fruit set and yield in vigorous, young ‘Triumph’ orchards. Scoring and girdling improved fruit set and yield in two such orchards and are recommended as tools to improve yield in ‘Triumph’ in South Africa. Strapping, prohexadione-Ca (P-Ca) and paclobutrazol (PBZ) did not increase yield whereas 5 mm bark removal was too severe a treatment and decreased fruit quality in the current season and yield in the following season. None of the treatments had an effect on flower formation or decreased vegetative growth. PBZ, especially as foliar spray, appears to advance fruit maturity. P-Ca at 125 mg L-1 and 250 mg L-1 induced phytotoxicity symptoms and decreased yields in both orchards. However, further research is required before P-Ca and PBZ are completely discarded as treatments to manage vigor in ‘Triumph’ persimmon in South Africa. In contrast to the negative effect of excessive vigor on fruit production, the profitability of orchards is dependent on the rapid growth of trees after planting in order to fill the allotted canopy volume and achieve full production as quickly as possible. Hence, the second objective of this study was to determine optimum levels of irrigation and fertilizer application rates to attain early, high yields in newly planted ‘Triumph’. Fertigation was applied at three levels, viz. ½X, 1X and 2X with 1X being the commercial standard application rate. Irrigation was also applied at these levels without addition of fertilizer. In addition, fertilizer was applied at 0X, ½X and 1X at 1X irrigation level. Tree size increased with an increase in water application rate. Yield also increased linearly with an increase in water application rate due to a linear increase in fruit size. Fertigation and ½X water as well as an increase in fertilizer application rate at 1X irrigation substantially delayed fruit ripening. Hence, careful management of fertilizer and water application rate could be used to extend the harvesting period and, therefore, the marketing window of South African ‘Triumph’. We recommend that the trial be continued for a further few seasons so that the effect of water and fertilizer application rates on fruit quality and storability can be assessed. Fruit set may also be affected as trees reach their mature size with a concomitant increase in shading.
AFRIKAANSE OPSOMMING: Persimmonverbouing is ‘n nuwe bedryf in Suid-Afrika met ongeveer 700 ha van die tweeslagtige, partenokarpiese Triumph cultivar wat sedert 1998 aangeplant is. Min plaaslike kundigheid is beskikbaar om produsente van raad te bedien oor hoe om te werk te gaan om hoë opbrengste van hoë kwaliteit te verkry. Vorige navorsing het getoon dat resepte wat ‘Triumph’ van Israel na Suid-Afrika gevolg het, nie noodwendig suksesvol hier toegepas kan word nie. ‘Triumph’ boorde in Suid-Afrika neig om lank te neem alvorens hul hul maksimum produksievermoë bereik. Persimmons is oor die algemeen baie groeikragtig en geneig tot hoë vrugval, deels as gevolg van hul geil groei, en veral terwyl hulle jonk is en op die uiters groeikragtige Diospyros lotus saailingonderstam geënt is. Die eerste doelwit van hierdie studie was om die invloed van groei inhibeerders en verskillende grade van strafheid van ringelering op blomvorming, vrugset en oesopbrengs in jonk, sterk-groeiende ‘Triumph’ boorde te evalueer. Insnyding en ringelering met ‘n handsaag het vrugset en oeslading in twee groeikragtige boorde verbeter en word aanbeveel as geskikte ingrepe om die oeslading van ‘Triumph’ te verhoog. Draad-ringelering, en aanwending van prohexadione-Ca (P-Ca) en paclobutrazol (PBZ) het nie die opbrengs verhoog nie terwyl die verwydering van `n 5 mm strook bas té aggresief was en die vrugkwaliteit in die seisoen van toediening en opbrengs in die daaropvolgende seisoen verlaag het. Geen van die behandelings het blomvorming geaffekteer of vegetatiewe groei verminder nie. Dit wil voorkom asof PBZ, veral as blaartoediening, vrugrypwording kan versnel. Blare het tekens van fitotoksisiteit getoon na aanwending van P-Ca teen 125 mg L-1 en 250 mg L-1. P-Ca het ook die opbrengs in beide boorde aansienlik verlaag. Verdere navorsing is egter nodig alvorens P-Ca en PBZ sondermeer verwerp word as behandelings om die groei van ‘Triumph’ te beheer. Die winsgewendheid van boorde is afhanklik daarvan dat bome aanvanklik vinnig groei ten einde die toegekende boomryvolume so spoedig moontlik te vul en sodoende so vinnig as moontlik hul vol produksievermoë bereik. Bogenoemde is natuurlik teenstrydig met die negatiewe effek van uitermatige geil vegetatiewe groei op vrugproduksie. Die tweede doelwit van hierdie studie was dus om die optimale vlakke van besproeiing en bemesting te bepaal wat die vroeë aanvang van hoë opbrengste in nuwe ‘Triumph’ boorde sal verseker. Vloeibare bemesting is in kombinasie met besproeiing teen drie vlakke toegedien nl. ½X, 1X en 2X met 1X die kommersiële standaard vlak van toediening. Besproeiing is ook teen hierdie vlakke toegedien sonder dat kunsmis bygevoeg is. Addisioneel hiertoe is bemesting ook toegedien teen ½X, 1X en 2X teen 1X besproeiing. Boomgrootte het toegeneem met `n toename in die vlak van besproeiing. `n Lineêre toename in vruggrootte met ‘n toename in die vlak van besproeiing het ‘n oorsaaklike lineêre toename in opbrengs tot gevolg gehad. Bemesting in kombinasie met besproeiing, ½X besproeiing sonder bemesting, asook `n toename in die bemestingsvlak by 1X besproeiing het vrugrypwording substansieel vertraag. Die omsigtige bestuur van bemesting- en besproeiingsvlakke kan moontlik gebruik word om die oesperiode, en dus die bemarkingsvenster, vir Suid-Afrikaanse ‘Triumph’ te verleng. Ons beveel aan dat die proef vir ‘n vêrdere aantal seisoene voortgesit word sodat die effek van bemesting- en besproeiingsvlakke op vrugkwaliteit en -houvermoë bepaal kan word. Verhoogde oorskaduwing soos wat bome van sekere behandelings hul toegekende spasie bereik en oorskry, kan ook in die toekoms ‘n invloed op vrugset uitoefen.

Many species of plants that produce fleshy fruits depend on birds for seed dispersal, and many of the birds that disperse seeds rely on fruits for a substantial proportion of their diets. From an ecological and evolutionary standpoint, it is important to understand why frugivorous birds feed in the particular plants they do. Intrinsic plant characteristics (e.g., crop size) influence the foraging patterns of birds; however, these factors cannot be fully understood outside the context of the communities within which birds and plants find themselves. Here I report on spatial patterns of bird use of fruiting plants in central Puerto Rico and its relationship to plant distributions and fruit abundance. From Feb.-Jun. 1998 I quantified frugivorous bird visitation to fruiting trees of Schefflera morototoni in a secondary forest-shade coffee plantation mosaic. Visitation rate was positively related to crop size and negatively related to conspecific fruit abundance within 30 m of focal plants. The presence or abundance of heterospecific bird-consumed fruits had mixed relationships with visitation: four species were positively related to visitation; one was negatively related. The fruit neighborhood explained most variation in visitation to focal trees, suggesting that such variables might help explain the high variability seen in other fruiting plant frugivore systems. In order to evaluate spatial dependency in tree distributions, fruiting, and frugivory over a range of tree species and spatial scales, I mapped bird-consumed fruiting plants on a 4.05 ha study grid in secondary wet forest and monitored fruiting and frugivory from Aug.-Nov. 1999. I focused analyses on four tree species: Dendropanax arboreus, Guarea guidonia, Miconia serrulata, and Schefflera morototoni. All of these were intraspecifically aggregated at scales < 80 m, but differed markedly in degree of crowding experienced by individuals. G. guidonia was the most, and M. serrulata the least crowded. Distributions of visited trees and autocorrelation in the number of frugivory observations at trees suggested that individuals of some species (e.g., S. morototoni) facilitated visitation to one another at small spatial scales (< ~30 m). Frugivory was positively correlated with fruit abundance on trees for all species; spatial variation in fruit abundance appeared to have reduced, and in some cases outweighed (e.g., M. serrulata), facilitative benefits of visited neighbors. Evidence of facilitation was especially weak for G. guidonia and may have reflected its particularly high density in the study area. Consideration of interspecific tree distributions showed S. morototoni to be aggregated with M. serrulata at scales > 69 m, and G. guidonia to be aggregated with D. arboreus at scales < 5 m. All other pairs were randomly or regularly distributed with respect to one another. Spatial patterns of fruiting and frugivory of M. serrulata appeared linked to the distribution of fruiting S. morototoni. Spatial patterns of frugivory also overlapped for other species and generally suggested facilitation at larger scales. Interspecific interactions were probably strongest at larger scales because of shifts in the relative abundances of conspecifics and heterospecifics at those scales. These findings highlight the potentially large size of plant neighborhoods with respect to use by avian frugivores and the dependence of neighborhood effects on local plant densities and crop sizes. From the perspective of birds, spatial patterns of frugivory suggested birds closely tracked fruit abundance. I observed few agonistic interactions between birds and found little evidence of their negatively influencing one another?s use of fruiting trees. Similarity in spatial patterns of frugivory between bird species, and positive cross-correlation in frugivory of different species at patch boundaries, suggested birds may have assisted one another (via calling) in locating new foraging patches. This could explain mixed-species flock formation.

Thesis (MscAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Alternate bearing is a common phenomenon in most commercial perennial fruit trees. In citrus, the “on” year consists of a heavy crop load with mostly small fruit, often followed by an “off” year with few, large and coarse fruit. Carbohydrates play an important role in affecting alternate bearing, especially during fruit set, but also flowering and fruit maturation, and are essential in maintaining a regular bearing habit. Changes in starch and total sugar accumulation in the leaves of the alternate bearing prone „Nadorcott‟ mandarin were followed over an entire season for both “on” and “off” trees to evaluate the possibility of using carbohydrate levels to predict bearing potential. Starch accumulation followed a distinct pattern with differences between “on” and “off” trees visible in April and May. Starch concentrations in April showed a moderate negative correlation with yield and a moderate positive correlation with return bloom. Rapid starch accumulation started prior to harvest with a peak at the beginning of flowering. Thereafter a sharp decrease in starch levels occurred until after full bloom followed by a steady decrease from physiological fruit drop towards fruit maturity. “On” trees bore 53% more fruit than “off” trees, but the return bloom of “off” trees was 140% more than “on” trees, thus illustrating the negative effect that a large crop has on the next season‟s bloom. It was concluded that for „Nadorcott‟ mandarin, leaf starch concentration in April can be used as an indication of bearing potential the following season. Pruning is a well-established management tool to control alternate bearing. Summer pruned trees had more spring flush vegetative shoots, more nodes per shoot and also more growth per parent shoot overall, compared to unpruned, control trees. Control trees had higher light levels inside the tree compared to summer pruned trees. However, no differences in leaf starch or total sugar levels during April were measured between treatments. Production of new bearing sites should therefore be considered in this experiment. It was concluded that pruning during November followed by early regrowth management gave the best balance between light penetration and production of new bearing units. Pruning in November, rather than during winter, also allowed selective pruning of shoots with or without flowers, depending on whether it was an “on” or an “off” year. When fruit thinning chemicals are applied at the optimum time and concentration, it is an effective way of moderating an alternate bearing cycle. Unfortunately no significant differences were obtained in this experiment even though the thinning treatments did show slightly higher starch levels in April 2012, indicating that the demand for energy was lower in these trees. This response was most likely due to the slightly lower yield and fruit number of the thinning treatments compared to the control. The dichlorprop treatment also showed a higher fruit growth rate, and future research should focus on timing of chemical thinning sprays in late mandarin cultivars
AFRIKAANSE OPSOMMING: Alternerende drag is 'n algemene verskynsel by die meeste meerjarige kommersiële vrugtebome. In die “aan” jaar by sitrus word 'n swaar oeslading gedra wat hoofsaaklik uit klein vrugte bestaan gevolg deur 'n “af” jaar met minder, groter en growwer vrugte. Koolhidrate speel 'n belangrike rol, veral gedurende vrugset, maar ook tydens blomtyd en vrugrypwording, en is noodsaaklik om ‟n reëlmatige drasiklus te verseker. Veranderinge in stysel- en totale suiker akkumulasie in die blare van „Nadorcott‟ mandarynbome, is deur die loop van 'n volle seisoen gevolg op beide “aan” en “af” bome om die moontlikheid te ondersoek dat koolhidraatvlakke gebruik kan word om dragpotensiaal te bepaal. Verskille tussen “aan” en “af” bome was in April en Mei sigbaar. Styselvlakke in April het 'n matige negatiewe korrelasie met drag getoon en 'n matige positiewe korrelasie met die volgende seisoen se blom. Styselvlakke het voor oestyd begin toeneem en aan die begin van blomtyd 'n piek bereik waarna 'n skerp daling voorgekom het tot na volblom. Dit is gevolg deur 'n geleidelike afname vanaf fisiologiese vrugval totdat die vrugte ryp was. “Aan” bome het 53% meer vrugte gedra as “af” bome, maar die volgende seisoen se blom van “af” bome was 140% meer. Dit illustreer die negatiewe effek wat ‟n groot oes op die volgende seisoen se blom het. Die gevolgtrekking is dat styselvlakke in blare gedurende April gebruik kan word as 'n aanduiding van die drag-potensiaal vir die komende seisoen vir „Nadorcott‟ mandarynbome. Snoei is 'n gevestigde manier om alternerende drag te beheer. Bome wat in die somer gesnoei is, het 'n groter aantal vegetatiewe lote in die lente, meer knoppe per loot en ook meer groei op ouer-lote gehad in vergelyking met die kontrole bome wat nie gesnoei is. Kontrole bome het hoër ligvlakke binne-in die boom gehad in vergelyking met die bome wat in die somer gesnoei is. Daar is egter in April geen verskille gemeet in die blare se stysel- en totale suikervlakke tussen behandelings nie. Produksie van nuwe dra-posisies moet dus vir hierdie eksperiment in ag geneem word. Die gevolgtrekking was dat, deur in November te snoei en vroeë bestuur van nuwe groei toe te pas, die beste boomvorm verkry is. Deur in November te snoei eerder as in die winter, kon daar ook selektief gesnoei word aan lote met of sonder blomme, afhangende of dit ‟n “aan” of “af” jaar was. Korrekte chemiese vruguitdunning is een van die mees effektiewe maniere om ‟n alternerende drag-siklus te verminder. Ongelukkig is geen betekenisvolle verskille in hierdie eksperiment verkry nie, ten spyte van die feit dat die uitdunningsbehandelings wel ietwat hoër styselvlakke in April 2012 getoon het. Dit dui daarop dat die behoefte aan energie in hierdie bome laer was. Die reaksie was waarskynlik te wyte aan die effens laer oes en vruggetalle as gevolg van die uitdunningsbehandelings in vergelyking met die kontrole. Die dichlorprop-behandeling het ook ‟n hoërvruggroeitempo gestimuleer. Navorsing in die toekoms behoort te fokus op die tydberekening waarvolgens die chemiese uitdunningsmiddels op laat mandarynkultivars toegedien word.

Includes bibliographical references
Seed dispersal is a key process. It is important in plant population biology because it influences the fate of seeds and the probability of recruitment, in plant biogeography since dispersal mode can influence the distribution range and rate of response to environmental change and habitat fragmentation, and in animal ecology since fruits can be an important dietary item (Wang and Smith, 2002). The majority of trees in the tropics (70 – 90%) and a large proportion of trees in temperate regions (up to 60%) rely on vertebrates for their dispersal (Howe and Smallwood, 1982; Fleming et al., 1987, Willson, 1990). Vertebrate dispersers range in size from 5g mistletoe birds (Dicaeidae) to 7,500,000g elephants (Elephantidae). The range and distribution of frugivore sizes is not uniform across ecosystems or geographical regions (Mack, 1993). These differences, one might suspect would be mirrored in the range and distribution of fruit size. This is not the case; in South America where the largest frugivorous mammal is the tapir (300kg; Hansen and Galetti, 2009), there is a subset of fruit that are conspicuously large. The paradoxical existence of such large fruit in the lowlands of Costa Rica was first noted by Janzen. In collaboration with Pleistocene faunal expert Paul Martin they conjectured that these fruit were ecological anachronisms that had evolved in the presence of large terrestrial vertebrates (>1000kg - megafauna) but had remained long after their demise (Janzen and Martin, 1982).

Thesis (MScAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Three field trials were conducted to investigate the effects of mulching on the chemical and biological aspects of the soil as it is reflected by tree performance and fruit quality in ‘Cripps’ Pink’ orchards. In the two trials at Lourensford Estate, where only the soil type differed between sandy silt loam (sandy) and heavy silt loam (heavy), mulches where used as an additive to the soil surface together with a standard, commercial, inorganic fertilization program. Four different mulch types: compost, wood chips, vermi-compost and a geotextile fabric, were compared to a bare surface control in a randomized complete block design. At the heavy silt loam site (site 1), the wood chips treatment was the most effective in regulating diurnal soil temperatures in the top 10 cm of soil (2009/10), whereas all mulches regulated average diurnal soil temperature similarly and more effectively than the control at the sandy silt loam site (site 2). After two seasons of treatment at site 1, the vermi-compost treatment significantly increased soil phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), manganese (Mn), zink (Zn) and boron (B) significantly compared to the control. The wood chips treatment increased Na, K and Ca and compost only increased soil K significantly compared to the control. For site 2, only wood chips (Na and K) and vermi-compost (Na, K and Mg) showed significant increases in soil nutrient elements compared to the control. Yield efficiency was significantly increased by the wood chips (both seasons) and vermicompost (only 2009/10) treatments compared to the control in site 1. In site 2, none of the treatments differed significantly in yield efficiency compared to the control treatment. The number of roots and fine feeder roots were increased (not sign) by the wood chips and geotextile treatments compared to the control. In site 1, all treatments improved the number of roots compared to the control treatment, in contrast with site 2, where the number of roots of the control, compost and vermi-compost treatments was more similar. Fruit quality showed significant differences between the wood chips and vermi-compost treatments compared to the geotextile and control treatments for malic acid, at site 1, at harvest in 2009. This did not differ significantly from the compost treatment. Leaf mineral analysis only showed significant differences at site 2, in 2010, with significantly increased for the following minerals and treatments: Mn (compost and geotextile treatments versus other treatments), Fe (control treatment compared to all treatments except compost), Zn (compost compared to all other treatments) and B (control and compost versus vermicompost, wood chips and geotextile). Fruit mineral analyses showed no differences between treatments at harvest 2009 for either site and 2010, for site 1. At site 2, the Ca percentage of fruit from the wood chips treatment was significantly higher than that of all treatments, except the geotextile treatment. Only in the 2010 analysis at site 2, the mycorrhizal colonization was significantly influenced, where all the mulching treatments showed an increase compared to the control. However, the same trend was observed at site 1. At site 1and 2, the compost, wood chips and vermi-compost treatments in general showed a decreasing trend in percentage plant parasitic and increasing trend in percentage free living nematodes from 2009 to 2010. In general, the geotextile and control treatments showed an increasing trend in the percentage plant parasitic and decrease in percentage free living nematodes. However, this was not the case at 0 – 15 cm soil depth for site 1. In the third trial, at Elgin Experimental Farm (Elgin), bare surface chemical control was compared to mulching in the tree row (mulch) and mulching together with regular application of compost tea (mulch + compost tea). All treatments were combined with different inter row management practices to compose a total of eight different treatments. In the tree row, the control treatment received standard rates of inorganic fertilizer, which was compared to the mulched only treatment. Both the percentage of soil carbon and cation exchange capacity was significantly increased by all the mulch treatments compared to the control. Furthermore, all the mulches increased various soil minerals significantly, however of which only P was significantly increased in both the leaves and fruit. The rate of soil microbial activity and mycorrhizal root colonization was significantly increased by mulching treatments, but resulted in a significantly lower yield efficiency compared to the inorganic control treatment. This can be ascribed partly to the microbial activity of the compost mulch during spring, although it was not quantified per se and to the increase in tree vigour at the end of the trial. The slow rate of N mineralization was reflected indirectly by the significantly lower fruit N for the mulched treatments and the lower rate of microbial activity during spring at this site. With regards to the addition of the compost tea, no significant contributions were evident in terms of tree performance, soil minerals or microbial activity over a period of seven years, compared to the application of mulch only. Compared to the trial at Lourensford Estate, with no significant differences in fruit mineral composition between treatments after two years, fruit mineral analyses of the Elgin trial showed significant differences between treatments after six (2009) and seven (2010) seasons for P for some treatments. Only in 2010 more treatments showed significant differences for N, Mn, Fe and Zn as well. Regarding fruit quality, in agreement with the results at Lourensford Estate, differences were not persistent across all seasons for treatments.
AFRIKAANSE OPSOMMING: Veldproewe is geloods om die effek van verskillende deklae op grond chemiese en – biologiese aspekte en die effek daarvan op boom prestasie en vrugkwaliteit in ‘Cripps’ Pink’ appelboorde te ondersoek. In die eerste twee proewe te Lourensford Landgoed, waar slegs die grondtipe verskil het tussen die sanderige slik leem (ligter) en swaarder slik leem (swaar) gronde, is deklae toegedien saam met ‘n standard bemestingsprogram en mikro-besproeiingstelsel. Vier deklaagtipes: kompos, houtspaanders, vermi-kompos en geotekstiel material, is vergelyk met die onbedekte, skoon bewerkte, kontrole in ‘n total ewekansige blokontwerp. By die swaar grondtipe (perseel 1), was die houtspaanderbehandling die effektiefste om die daaglikse skommelings in grondtemperatuur te reguleer in die boonste 10 cm, teenoor die sanderige perseel (2), waar al die deklae die daaglikse grondtemperatuur meer effektief as die kontrole behandeling gereguleer het. By perseel 1, het die vermi-behandeling ‘n betekenisvolle toename getoon teenoor die kontrole behandeling in grond fosfaat (P), kalium (K), kalsium (Ca), magnesium (Mg), natriuim (Na), mangaan (Mn), sink (Zn) en boor (B). Alhoewel dit nog nie tans gekwantifiseer kan word nie, is ‘n gedeelte van die toename heel moontlik te wyte aan die samestelling van die deklaag. Die houtspaander- en komposbehandelings het ‘n betekenisvolle verskil in toename tot gevolg gehad in grond K en Na in vergelyking met die kontrole. In die geval kan die toename van die komposbehandeling aan die invloed van die sampestelling van die deklaag toegeskryf word, maar nie in die geval van die houtspaanderbehandeling nie. Die geotekstielbehandeling het, soos verwag, nie betekenisvolle verskille ten opsigte van die kontrole getoon nie, aangesien die samestelling van die geotekstielmateriaal nie voedingstowwe tot die grond kan toevoeg nie. By perseel 2, het beide die houtspaander- en geotekstielbehandelings betekenisvolle toenames in grond elemente (K, Mg) getoon teenoor die kontrole behandeling. Die ander elemente het nie noemenswaardige verskille teenoor die kontrole getoon nie. Weer eens kan die toename in die vermi-kompos toegeskryf word aan die samestelling van die deklaag, maar nie in geval van die houtspaanders nie, wat ‘n moontlike rol van ander faktore soos temperatuur en grondvog in die opname en beskikbaarheid van voedingselemente toon. Op 30 cm diepte in perseel 1, het die vermi-kompos behandeling betekenisvolle hoër Na, K, Mg en P getoon as die kontrole. Die houtspaanderbehandeling het betekenisvolle hoër Na, K en Ca getoon as die kontrole. Geen een van die ander behandelings het enige betekenisvolle veranderinge ten opsigte van voedingselemente getoon nie. Vir perseel 2 by die gronddiepte, het die houtspaanderbehandeling betekenisvolle toenames in grond Na en K getoon teenoor die kontrole. Geen van die ander behandelings het enige betekenisvolle veranderinge ten opsigte van voedingselemente getoon nie. By hierdie dieper gronddieptes is ‘n soortgelyke verandering in elemente waargeneem as by die vlakker gronddieptes vir perseel 1, in geval van P en K. Mg en Na het volgehoue verandering vir die vermi-komposbehandeling in die dieper gronddieptes getoon vir die makro-elemente, maar nog nie in geval van mikroelemente nie. In perseel 2 – het toenames in K en Mg in die vermi-komposbehandeling ook voortgeduur en die veranderinge vir beide persele mag toegeskryf word aan die samestelling van die deklae per se. Dit blyk dat die veranderinge in die komposbehandeling nie so konstant voorgekom het in die materiaal wat in die proewe toegedien is nie. Nietemin kan die kompos- en vermi-komposbehandelings ook ander grond faktore beïnvloed en die bydra van die minerale elemente afkomstig uit die samestelling van die deklaag moet eers bereken word alvorens afleidings gemaak word. By beide persele het die komposbehandeling die opbrengseffektiwiteit verminder in vergelyking met die kontrole behandeling. Die opbrengseffektiwiteit is betekenisvol verhoog in die houtspaanderbehandeling (beide seisoene) en vermi-komposbehandeling (net 2009/10) in vergelyking met die kontrole in perseel 1. In perseel 2 het teen behandeling betekenisvol in opbrengseffektiwiteit verskil ten opsigte van die kontrole nie. Die aantal wortels en fyn, voedingswortels het ‘n dramatiese (nie-betekenisvolle) toename getoon by die houtspaander- en geotekstielbehandelings. In perseel 1 het alle behandelings die aantal wortels verhoog ten opsigte van die kontrole in kontras met perseel 2, waar die aantal wortels in die kontrole, kompos- en vermi-komposbehandelings ongeveer dieselfde was. Stamwaterpotensiaal het onveranderd gebly ongeag van die behandeling, wat moontlik beïnvloed is deur die hoë besproeiingskedulering siklus. Geen verskille tussen behandelings of persele is gevind nie. Alhoewel dit net in die tweede seisoen (2010) gemeet is, was daar geen betekenisvolle verskille in gemiddelde loot groei van eenjaarlote tussen die behandelings of persele nie. Vrugkwaliteit het betekenisvolle verskille getoon in appelsuur (malic acid) in die houtspaander- en vermi-komposbehandelings teenooor die geotekstie- en kontrole behandelings in perseel 1, by oes 2009. Laasgenoemde het nie betekenisvol van die kontrol behandeling verskil nie. Hierdie verskille het nie na opberging voortgeduur nie. Geen betekenisvolle verskille in vrugkwaliteit het voorgekom by perseel 2, tydens oes, of na opberging nie. Gedurende oes 2010, asook na opberging, is geen verskille in vrugkwaliteite van enige persele opgemerk nie. Behandelingsverskille in blaar-analises is waargeneem tussen vermi-kompos- en die ander behandelings, met uitsondering van die geotekstielbehandeling in Februarie 2009, perseel 1. Geen ander betekenisvolle verskille vir enige element het voorgekom tussen behandelings in perseel 2 nie. Gedurende 2010 is geen betekenisvolle verskille tussen behandelings ten opsigte van blaar-analises gevind vir perseel 1 nie. Betekenisvolle verskille in blaar- en vrugmineraal-analises was in perseel 2 teenwoordig as volg: Mn (kompos- en geotekstielbehandelings teenoor al die ander behandelings), Fe (kontrolebehandeling teenoor alle ander behandelings behalwe die komposbehandeling), Zn (komposbehandeling teenoor al die ander behandelings) en B (kontrole en komposbehandelings teenoor vermi-, houtspaander- en geotekstielbehandelings (gedurende 2010. Die vrugmineraal-analises het geen verskille getoon tussen behandelings by oes 2009 vir enige perseel, of 2010 vir perseel, 1 nie. By perseel 2 was die Ca persentasie in die vrug in die houtspaanderbehandeling betekenisvol hoër as die van die ander behandelings, uitgesonder die geotekstielbehandeling. By perseel 1, het al die behandelings die persentasie mycorrhiza-kolonisasie verhoog in vergelyking met die kontrole, alhoewel dit nie betekenisvol was nie. By perseel 2 was daar wel ‘n betekenisvolle toename in die persentasie mycorrhiza-kolonisasie by al die deklaagbehandelings in vergelyking met skoonbewerking van die kontrole behandeling. Die persentasie plant-parasitiese nematodes was baie variëerend met gronddiepte by beide persele. Die houtspaander- en vermi-komposbehandelings in perseel 1 het ‘n afwaartse tendens getoon in die persentasie plant-parasitiese en toename in persentasie vry-lewende nematode vanaf 2009 na 2010, in die 0-15 cm diepte. In teenstelling, het die geotekstiel- en komposbehandeling ‘n toenemende tendens getoon in die persentasie plant-parasitiese en klein afname in persentasie vrylewende nematodes vanaf 2009 tot 2010. Geen betekenisvolle verskille in nematode getalle is waargeneem in gronddiepte 15 -30 cm grond in die perseel nie. In perseel 2 is geen betekenisvolle verskille in aantal nematodes gevind gedurende die twee seisoene tussen behandelings of binne persele op 0-15 cm gronddiepte nie. Nietemin het die houtspaander-, kompos- en vermi-komposbehandelings die persentasie plant-parasitiese verlaag en die van die vry-lewende nematode verhoog vanaf 2009 tot 2010, in vergelyking met die kontrole in die 15-30 cm gronddiepte. Slegs die houtspaanderbehandeling het betekenisvolle verskille getoon teenoor die kontrole. Die geotekstiel- het dieselfde tendens as die kontrole behandeling getoon, met ‘n toename in persentasie parasities- en afname in persentasie vry-lewende nematode. Die kontrole en geotekstielbehandelings het nie betekenisvol van mekaar verskil nie. Die aantal erdwurms en meso-fauna was baie laag tydens die eerste twee jaar by beide die persele en data is daarom nie statisties verwerk nie. By die derde proef, is ‘n skoonbewerkte oppervlak, wat chemiese beheer (kontrole) behels het, vergelyk met deklaagbehandelings in die boomry (deklaag) en behandelings waar kompostee saam met die deklaag toegedien was in die boomry (deklaag + kompostee). Al die behandelings is gekombineer met verkillende tussenry behandelings wat ‘n totaal van agt verskillende behandelings behels het. Hierdie verslag konsentreer slegs op die behandelings in die boomry, waar die kontrole behandelings wat ‘n standaard bememestings program ontvang het, vergelyk word met die deklaag behandelings, wat geen alternatiewe bemesting ontvang het nie en as organise alternatiewe beskou word in ‘n ‘Cripps’ Pink’ appelboord. Klem in die verslag is gelê op die hoof effekte van die behandelings op vrugkwaliteit. Beide die persentasie grondkoolstof en die katioonuitruilkapasiteit het ‘n betekenisvolle toename getoon by al die deklaagbehandelings in vergelyking met die kontrole behandeling. Terselfdetyd, het al die deklaagbehandelings ook verskeie grondminerale betekenisvol verhoog, waarvan slegs P betekenisvol in beide die blare en vrugte verhoog is. Die tempo van grondmikrobe aktiwiteit en micorrhiza-kolonisasie van die wortels is betekenisvol verhoog deur die deklaagbehandelings, maar het gerealiseer in ‘n betekenisvolle laer opbrengseffektiwiteit in vergelyking met die anorganiese, kontrole behandeling. Dit kan onder andere toegeskryf word aan die mikrobe aktiwiteit van die komposdeklaag gedurende die lente – alhoewel dit nie per se in die studie gekwantifiseer is nie, sook die toename in vegetatiewe groeikrag aan die einde van die proeftydperk. Dit is wel indirek gereflekteer deur die betekenisvolle, laer vrug N van die deklaagbehandelings en die laer tempo van mikrobe aktiwiteit gedurende die lente by die deklaagbehandelings op die perseel. Wat die toedienning van kompostee betref, het dit geen betekenisvolle bydra gelewer in terme van gewasprestasie, grondminerale of microbe-aktiwiteit oor ‘n tydperk van sewe jaar in vergelyking met die behandelings waar die deklaag geen kompostee ontvang het nie. In vergelyking met die proef by Lourensford Landgoed, met geen betekenisvolle verskille in vrug mineral-analises tussen die behandelings oor ‘n tydperk van twee jaar nie, het die proef te Elgin wel betekenisvolle verskille tussen behandelings na 6 (2009) en 7 (2010) jaar getoon in geval van P, vir sekere behandelings (4,7,8 versus 1,2,6). Slegs in 2010 het meer behandelings betekenisvolle verskille getoon vir N, Mn, Fe en Zn. Rakende vrugkwaliteit - in ooreenstemming met resultate van 2009 vir perseel 1 te Lourensford Landgoed - het beide seisoene betekenisvolle verskille ten opsigte van appelsuur getoon in Elgin. Die verskille het egter nie konstant in al die behandelings voorgekom nie. Stysel afbraak, totaal oplosbare stowwe en fermheid het ook betekenisvolle verskille tussen behandelings getoon in Elgin – maar dit was nie konsekwent oor behandelings of seisoene nie en het ook nie voorgekom in die Lourensford Landgoed persele nie.

Thesis (m.s.)--University of Kentucky, 2004.
Title from document title page (viewed Jan. 7, 2005). Document formatted into pages; contains viii, 80p. : ill. Includes abstract and vita. Includes bibliographical references (p. 74-79).

Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2005.
This study is about marketing of Uapaca kirkiana fruit in Zambia, a fruit that has great economic value especially among the rural and urban poor. It contributes to general food security. In southern Africa, farmers and other stakeholders have identified Uapaca as a priority species for domestication. Current agroforestry initiatives are promoting integration of indigenous trees into farming systems to provide marketable products for income generation. Domestication of trees however, depends on expanding the market demand for tree products. There is considerable evidence that expanding market opportunities is critical for the success of domestication innovations but farmers have been introduced to domestication with little consideration for marketing. The existing market potential can be achieved through sound knowledge on markets and marketing. Information on the marketing of Uapaca fruit is inadequate. This study, therefore, aimed at generating information on the marketing of Uapaca kirkiana fruit, including the basic conditions of demand and supply of the fruit. The main study was conducted in Chipata and Ndola districts in the Eastern and Copperbelt provinces respectively, while fruit pricing was conducted in Lusaka district in Lusaka Province. Questionnaires and participatory research methods were used to collect the data. A total of 37 markets involving 49 collectors, 59 retailers, 189 consumers and 20 government forest workers are included in the study. The study reveals that there is demand for the fresh and secondary products of the fruit and hence substantial fruit trading exists in Zambia. However, the marketing system is characterised by underdevelopment. There is insufficient capacity to satisfy the demand for the fruit and institutional /policy support to Uapaca fruit market expansion. Currently, only basic technology for product development exists. The results suggest a need to address policy and capacity development for expansion of Uapaca kirkiana fruit industry. To improve the Uapaca trade industry, the study proposes developing and scaling up policy strategies, fruit processing sector, research-extension-trader-agribusiness linkages, infrastructure development and knowledge generation for improved understanding of the Uapaca fruit markets.

Thesis (MScAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Limited research is available on the effect of mulches on established orchards. Most of the information available stems from research conducted in newly planted orchards or on annual crops such as green peppers and strawberries under greenhouse conditions. To increase the current knowledge on the effect of mulches in established orchards, two field trials were conducted on 14 year old „Cripps‟ Pink‟ orchards. The one trial concentrated on the influence of mulches on the root environment and the other trial on the effect of mulches on growth, yield and fruit quality. Both trials were conducted at Lourensford Estate near Somerset West, but the sites differed in soil texture between lighter soil (Tukulu) and heavier soil (Clovelly). Four different mulches were used viz. compost, wood chips, vermi-castings (topped with thin layer of woodchips) and a woven geotextile fabric. These four treatments were compared to an un-mulched control, managed according to industry norms. After reducing irrigation volume in the 2010/2011 season, with a further reduction in the 2011/2012 season, more significant differences were obtained in nutrient levels of fruit and leaves compared to the 2008/2009 and 2009/2010 seasons of the trial. Leaf and fruit nutrients showed significant differences in both sites, but the differences were more pronounced on the lighter soil. At the heavier soil site, the vermi-castings, woodchips and compost treatments increased fruit phosphorus (P) during 2010/2011 and the control treatment increased fruit boron (B) during 2011/2012. Only leaf magnesium (Mg) was increased by woodchips and vermi-castings in 2011/2012 at this site. In the lighter soil site, the control treatment had the highest fruit B levels in 2010/2011 while the vermi-castings and the woodchips treatments had the highest fruit P levels in 2011/2012. For the same site, vermi-casting and compost treatments improved leaf potassium (K) uptake in 2010/2011 and 2011/2012, whereas woodchips and geotextile significantly improved leaf copper (Cu) uptake in 2010/2011 compared to the control. To determine if applied nutrients were trapped in the organic mulches over time, leading to a deficiency in the soil and eventually the tree, a mineral analysis was conducted on the organic mulches at the end of each season. Results of the two seasons indicated that vermi-castings contained higher total nutrient levels than the other two organic mulches, but the difference in nutrient levels were shown not to be directly related to the fertilisers applied during each season. In the case of vermi-castings, nutrient quantities in the original material applied at the beginning of each season were higher than those of the other organic mulches. The higher nutrient levels in organic in comparison to inorganic mulches were however not reflected in the fruit and leaf mineral analysis of these treatments. The overall treatment effect in terms of changes in nutrient levels in the tree became less significant when trees were over irrigated. This became evident as the differences between mulching treatments increased as the irrigation was reduced during the season, indicating the masking effect of irrigation on mulching. Evaluating the effect of mulches on growth, yield and fruit quality showed significant differences only at the heavier soil site. The vermi-casting treatment had significantly higher yield efficiencies than the control for the 2010/2011 season. Compost had the lowest yield efficiency at both sites, also during the previous two seasons that formed part of an earlier study (Kotze 2012). In 2011/2012, the compost treatment also showed significantly higher shoot growth than the control. Compost therefore could increase vegetative growth in established orchards on a heavier soil after application for four seasons. Taking the cost of mulching into account, wood chips are the only treatment that can be recommended without compromising fruit quality. Wood chips will sustain or even improve yield efficiency in an established orchard on especially heavier soil. Future research should study the effect of different amounts of irrigation on the various mulches, as the effect of irrigation was not evaluated in this study.
AFRIKAANSE OPSOMMING: Beperkte navorsing is beskikbaar oor die effek van deklae op bestaande boorde. Die meeste bestaande inligting is gegrond op proewe wat uitgevoer is op nuut aangeplante boorde of op eenjarige gewasse, soos groenrissies en aarbeie, onder kweekhuis toestande. Om bestaande kennis aan te vul rakende die effek van deklae op vrugproduksie en -kwaliteit in bestaande boorde, is twee veldproewe geloots in 14-jaar-oue „Cripps‟ Pink‟ appelboorde. Die een proef het gekonsentreer op die invloed van deklae op die wortel omgewing en die ander proef, op die effek van deklae op groei, opbrengs en vrugkwaliteit. Beide proewe is uitgevoer op Lourensford Landgoed naby Somerset-Wes en twee verskillende grondtipes is hiervoor gebruik: „n ligte grond (Tukulu) en swaarder grond (Clovelly). Vier verskillende deklaagtipes is gebruik naamlik: kompos, houtspaanders, „vermi-castings‟ (bedek met „n dun lagie houtspaanders) en geweefde geotekstiel materiaal. Hierdie vier behandelings is vergelyk met „n onbedekte kontrole wat volgens industrie norm bestuur is. Nadat die besproeiingsvolume verminder is in 2010/2011 en daarna weer in 2011/2012, het meer betekenisvolle verskille tussen behandelings voorgekom in nutriënt-vlakke van vrugte en blare in vergelyking met die eerste twee jaar van die proef (2008/2009 en 2009/2010). Blaar en vrug nutrient-vlakke het betekenisvolle verskille in beide persele getoon, maar die verskille was meer duidelik in die ligte grondtip. In die swaarder grond perseel het die „vermi-castings‟, houtspaanders- en kompos behandelings die vrug fosfaatvlakke (P) betekenisvol verhoog in 2010/2011. In die kontrole behandeling was vrug boorvlakke (B) betekenisvol hoër as die ander behandelings in 2011/2012. In hierdie perseel is net magnesium-vlakke (Mg) in die blare betekenisvol verhoog deur die houtspaanders- en „vermi-castings‟ behandelings in 2011/2012. In die ligte grond perseel het die kontrole behandeling die hoogste vrug B-vlakke in 2010/2011 gehad en die „vermi-castings‟ en houtspaander-behandelings gesamentlik, die hoogste vrug P-vlakke in 2011/2012. Die „vermi-casting‟ en kompos behandelings het kalium-vlakke (K) opname in die blare in 2010/2011 en 2011/2012 verbeter, terwyl die houtspaanders- en geotekstiel behandelings die koper-vlakke (Cu) in die blare in 2010/2011 verbeter het. Om te bepaal of die toediening van voedingstowwe oor tyd kan lei tot die „vashou‟ daarvan in „n organiese deklaag en dan tekorte van sekere nutriënte in die grond en uiteindelik die boom kan veroorsaak, is „n mineral analise van die organiese deklae uitgevoer aan die einde van beide seisoene. Resultate van die twee seisoene het getoon dat „vermi-castings‟ hoër totale nutrient-vlakke gehad het as die ander organiese deklae, maar die nutrient-vlakke was nie direk verwant aan die toegediende voedingstowwe nie. In die geval van „vermi-castings‟, was nutrient-vlakke van die moedermateriaal, wat toegedien is aan die begin van die seisoen, hoër as die van die ander organiese deklae. Hierdie hoër nutrient-vlakke van die organiese teenoor anorganiese behandelings, is nie gereflekteer in hoër nutrient-vlakke in die vrug- en blaar mineraal analises van die bome nie. Behandelings effekte rakende veranderinge in nutrient-vlakke in die boom, nadat die besproeiing verminder is, het verander in vergelyking met die van die vorige twee seisoene en is „n aanduiding van die verbloemende invloed van besproeiing op die prestasie van deklae. Evaluasie van die effek van deklae op groei, opbrengs en vrugkwaliteit het net betekenisvolle verskille in die swaarder grond perseel getoon. Die „vermi-casting‟-behandeling het „n betekenisvolle hoër opbrengseffektiwiteit as die kontrole getoon in 2010/2011. Kompos het die laagste opbrengseffektiwiteit in beide persele gehad en het resultate van die vorige twee seisoene van Kotze (2012) bevestig. Die betekenisvolle hoër lootgroei van kompos as die ander behandelings het net in 2011/2012 voorgekom. Kompos kan dus groei verhoog in „n gevestigde boord, in „n swaarder grond, indien besproeiing optimaal is. In terme van kostes, word die gebruik van houtspaanders as deklaag voorgestel vir „n gevestigde boord met „n swaar slik leem grond, aangesien daar geen nadelige effek op vrugkwaliteit was met die behandeling nie en die opbrengseffektiwiteit van die bome gehandhaaf en selfs verbeter is. Toekomstige navorsing kan die effek van besproeiing op verskillende deklaag tipes bestudeer, aangesien die bestaande proef dit nie kon aanspreek nie.

Cameroon needs healthy citizens to archive emergence by 2035. Malnutrition and undernourishment is the highest burden in the World in recent times and a silent crisis facing most rural communities in forest areas of Cameroon. Its abstruseness makes extremely fragile political, social and economic planning to foster development in such areas. Therefore, it is time we bring appropriate understanding and new strategies on unpacking the complexities of food and nutritional security and define practical solutions to food insecurity. Working in the context of increasing deforestation, this thesis brings evidence on the situation of household food insecurity (FIS) access experience in forest areas which is not reported in current discussions at the national level. It further investigates the knowledge and awareness of households on the availability, accessibility, utilisation, vulnerability and consumption of nutrient rich food items using the example of fruits from trees. Thus, the aim of this research was to investigate strategies for addressing household FIS through increased domestic supply and consumption of fruits from trees in the context of deforestation in Cameroon. Data were collected through four rounds of structured interviews completed between August 2013 and October 2014. Analysis was done using simple citations and ordering, Principal Component Analysis (PCA), Likert scale, χ2-test of association and Cramer's V coefficient to test the strength of the association and means and ANOVA. The HFIAS approach used to determine household FIS. Only 1% of the population were food secure and the moderately deforested zone showed the worst trends in food insecurity. Therefore, the effect of deforestation was nuanced. Diverse fruit trees were registered. Households said they required fruits only 2.4 ± 1.5 times per week. Recently, the intake of 400 g of fruit per person per day for good health was announced as a priority of international recognition. However, households were not aware of the importance and frequency of fruit consumption with less than 50% of households eating fruits daily during the harvesting season. Fruit tree nurseries where scarce and seeds where obtained from local sources. Fruit tree diseases where rampant and up to 50% harvest lost was registered for some fruits species. This study has shown that food availability does not necessarily mean adequate food intake. Three opinions about fruit trees and the prevalence of food insecurity in Cameroon has been raised in this thesis. First, there is ineffectiveness in the eradication of FIS because even in agricultural conducive environments, hunger and food insecurity are still prevalent at high rates. Therefore, effective and efficient targeting of food insecured groups need to be promoted in all clusters of the population. Secondly, the national nutrition program is neglecting sensitisation on food consumption patterns and therefore people are not making use of nutrient rich foods even when this maybe found around their environments - taking the case of fruits from trees. Thus, very few people ate fruits and at irregular frequencies of consumption. Thus, there is need to design special campaign programs to promote the consumption of fruits from trees. Thirdly, the word-of-mouth or neighbour-to-neighbour dissemination approach on fruit trees planting has not been efficient across communities. As such nurseries where scarce and people obtained fruit trees plants from natural regeneration or found them on the field when establishing the field. Therefore, in this research, it is postulated that no matter the nature of efforts and level of intervention, what is certain is that addressing FIS requires effective targeting of the vulnerable population and the implementation of novel and practical approaches on promoting access to and consumption of fruits in the right frequencies. This research further revealed that poor eating habits was a problem and lack of knowledge about the frequency and intake of nutrient rich food was serious. For instance, people were not aware on the recommended frequency of fruit consumption and people ate infested fruit while reserving the healthy ones for sale. This is the trap of the food insecurity problem in some regions – knowledge about foods and ways of food utilisation. This is neither a problem of availability nor accessibility, but rather a problem of lack of knowledge and lack of sensitisation. From FAO reports on the state of food insecurity in the world and other studies of food intake in most developing nation, poor food consumption is a global problem in most poor regions and even in rich areas affected by obesity. Thus, there is a need to establish a high level policy framework maybe in the form of a convention or an intergovernmental panel at the level of the United Nations and/or the African Union on ‘reducing malnutrition in all its forms (rates, drivers and consequences on human health and the environment)’. This structure will promote setting priorities, strategies, monitoring on peoples eating habits, setting nutritional standards, and principles and indicators for observing under nutrition, over nutrition and associated problems within all population strata.

Thesis (MScAgric)--University of Stellenbosch, 2002.
ENGLISH ABSTRACT: Excessive shoot growth of fruit trees may have various negative effects. These include a decrease in fruit set, fruit size, red colour and in return bloom. Cultural practices that are currently in use, such as the use of dwarfing rootstocks, girdling and pruning do not always give sufficient shoot growth control. The use of plant growth retardants, in combination with these cultural practices, offer additional possibilities. Trials were conducted to evaluate the effect of the new plant growth retardant prohexadione-calcium (P-Ca) on apple, pear and plum shoot growth. In addition, the effect of P-Ca on fruit set, fruit size, yield, fruit quality and return bloom were also evaluated. During the 1999/2000 season P-Ca was applied to full bearing twelfth leaf 'Golden Delicious' trees on M793 rootstock, twenty-sixth leaf 'Granny Smith' trees on seedling rootstock, ninth leaf 'Royal Gala' trees on M793 rootstock, seventh leaf 'Rosemarie' trees on seedling rootstock and eighth leaf 'Songold' trees on 'Marianna' rootstock in the Villiersdorp area in the Western Cape (33°59' S, 19°17' E; ca. 365 m a.s.l.; Mediterranean climate). P-Ca was applied at concentrations of 3 x 50, 4 x 50 and 3 x 67 mg.l' to the apple trees. The first application was at petal drop with no surfactant added with any of the treatments. P-Ca was applied at concentrations of2 x 62.5,125,250 and 2 x 125 mg.l" to the pear and plum trees. The first application was at petal drop and pit-hardening for the pear and plum trees respectively. Agral-90 was used as surfactant only with the first spray applied to the pear trees. During the 2000/2001 season the same 'Golden Delicious' and 'Royal Gala' trees were used as in the 1999/2000 season. Thirteenth leaf 'Granny Smith' trees on M793 rootstock in the Villiersdorp area were used. Sixth leaf 'Rosemarie' trees on BP3 rootstock, fifth leaf 'Golden Russet Bose' trees on BP3 rootstock, seventh leaf 'Forelle' trees on BP3 rootstock and 16th leaf 'Packham's Triumph' trees on seedling rootstock in the Wolseley area in the Western Cape were used. P-Ca was again applied at concentrations of 3 x 50,4 x 50 and 3 x 67 mg.l' to the apple trees. The first application in the 'Golden Delicious' and 'Granny Smith' trees was at full bloom and at petal drop in the 'Royal Gala' trees. The last application was at 45 days before harvest. No surfactant was added with any of the sprays. P-Ca was applied at concentrations of 50, 75, 150, 2 x 50,2 x 75 and 3 x 50 mg.l" to the pear trees with the first spray when 4 to 5 leaves were unfolded and the last one 45 days before harvest. Agral-90 was added as surfactant with all the pear sprays. The pear trial also included a girdling treatment. P-Ca effectively inhibited shoot growth of all three apple cultivars in both seasons. Regrowth occurred in both seasons in all the cultivars, therefore it is not clear which treatment(s) is optimal for reducing shoot growth. P-Ca increased fruit size in 'Royal Gala' in the 1999/2000 season and decreased yield expressed as kg fruit harvested 1 em trunk circumference in 'Golden Delicious' in the 2000/2001 season. This reduction in yield can be attributed to the low number of flower clusters in the spring of 2000 following P-Ca treatment in 1999. P-Ca decreased the number of developed seeds in 'Royal Gala' in both seasons and increased the number of seeds with aborted embrios in the 200012001 season. After four weeks of cold storage (± 5°C) and one week at room temperature (± 20°C), P-Ca had no effect on the occurrence of bitter pit in 'Golden Delicious'. The 'Granny Smith' trees were harvested before fruit analysis could be done in the 2000/2001 season. In pear, girdling was not effective in inhibiting shoot growth in any of the cultivars, but P-Ca proved to be an effective inhibitor of shoot growth of 'Rosemarie' and 'Golden Russet Bose', and to a lesser degree 'Packham's Triumph', but not 'Forelle'. Despite the re-growth that occurred ca. four weeks after harvest in 'Rosemarie' in the 2000/20001 season, it appears that a single high rate (250 and 150 mg.l' for the 1999/2000 and 2000/2001 seasons respectively) P-Ca application is more effective than a single low rate or multiple low rates in inhibiting shoot growth. In the 200012001 season P-Ca increased fruit set in 'Rosemarie' and 'Forelle'. In both seasons P-Ca reduced 'Rosemarie' fruit size while girdling increased 'Forelle' and 'Packham's Triumph' fruit size in 2000/2001. P-Ca increased 'Rosemarie' fruit firmness and 'Forelle' fruit colour in the 2000/2001 season and decreased the percentage of 'Packham's Triumph' fruit with cork spot. Girdling increased 'Packham's Triumph' fruit colour and TSS concentration while decreasing fruit firmness in 2000/2001. P-Ca reduced return bloom in 'Forelle' and 'Packham's Triumph' in 2001, while girdling increased 'Golden Russet Bose' and 'Forelle' return bloom. Due to poor flowering and thus low fruit number in 'Golden Russet Bose', fruit set in 2000 could not be determined and no fruit analysis could be done. In 'Songold' all four P-Ca treatments inhibited shoot growth, but the 2 x 125 mg.l' treatment were the most effective, both in terms of total shoot growth and in reduction of the re-growth that occurred ca. two weeks before the first commercial harvest date. P-Ca increased fruit firmness and decreased TSS concentration both at harvest and after four weeks of cold storage at dual temperature (10 days at -O.soC + 18 days at 7.S°C). In conclusion P-Ca is an effective inhibitor of shoot growth of the apples 'Golden Delicious', 'Granny Smith' and 'Royal Gala', the pears 'Rosemarie', 'Golden Russet Bose' and 'Packham's Triumph' and the plum 'Songold', but more work is needed to control re-growth.
AFRIKAANSE OPSOMMING: Oormatige lootgroei van vrugtebome kan verskeie negatiewe effekte tot gevolg he, insluitende 'n afname in vrugset, vruggrootte, rooi kleur en 'n verlaging in die daaropvolgende jaar se blom. Boordpraktyke soos die gebruik van dwergende onderstamme, ringelering en snoei, beheer nie altyd lootgroei doeltreffend nie. Die gebruik van groeireguleerders, in kombinasie met hierdie boordpraktyke, bied bykomende geleenthede. Proewe is uitgevoer om die effek van die nuwe groeireguleerder proheksadioon-kalsium (PCa) op appel, peer en pruim lootgroei te evalueer. Die effek van P-Ca op vrugset, vruggrootte, opbrengs, vrugkwalitiet en die daaropvolgende jaar se blom is ook geevalueer. Gedurende die 1999/2000 seisoen is P-Ca toegedien aan voldraende twaalfde blad 'Golden Delicious' bome op M793 onderstamme, ses-en-twintigste blad 'Granny Smith' bome op saailing onderstamme, negende blad 'Royal Gala' bome op M793 onderstamme, sewende blad 'Rosemarie' bome op saailing onderstamme en agste blad 'Songold' bome op 'Marianna' onderstamme in die Villiersdorp area in die Wes Kaap (33°25' S, 19°12' 0; ligging ong. 270 m.; Meditereense klimaat). P-Ca is aan die appelbome toegedien teen konsentrasies van 3 x 50, 4 x 50 en 3 x 67 mg.l' met die eerste toediening by blomblaarval. Geen benatter is by enige van die toedienings gevoeg nie. P-Ca is aan die peer- en pruimbome toegedien teen konsentrasies van 2 x 62.5, 125, 250 en 2 x 125 mg.l' met die eerste toediening by blomblaarval en pitverharding vir onderskeidelik die peer- en pruimbome. Agral-90 is as benatter gebruik slegs saam met die eerste toediening op die peerbome. Tydens die 2000/2001 seisoen is dieselfde 'Golden Delicious' en 'Royal Gala' bome gebruik as in die 1999/2000 seisoen. Derde blad 'Granny Smith' bome op M793 onderstamme in die Villiersdorp area is gebruik. Sesde blad 'Rosemarie' bome op BP3 onderstamme, vyfde blad 'Golden Russet Bose' bome op BPI onderstamme, sewende blad 'Forelle' bome op BP3 onderstamme en sestiende blad 'Packham's Triumph' bome op saailing onderstamme in die Wolseley area in die Wes Kaap is gebruik. P-Ca is weereens aan die appelbome toegedien teen konsentrasies van 3 x 50, 4 x 50 en 3 x 67 mg.l". Die eerste toediening aan die 'Golden Delicious' en 'Granny Smith' bome was by volblom en die eerste toediening aan die 'Royal Gala' bome by blomblaarval. Die laaste toediening is 45 dae voor oes gedoen. Geen benatter is met enige van die toedienings bygevoeg nie. P-Ca is aan die peerbome toegedien teen konsentrasies van 50, 75, 150,2 x 50, 2 x 75 en 3 x 50 mg.l' met die eerste toediening toe vier tot vyf blare ontvou was en die laaste een 45 dae voor oes. Agral-90 is as benatter gebruik met al die peer bespuitings. By die peer proef is ook 'n ringeleer behandeling ingesluit. In beide seisoene het P-Ca die lootgroei van al drie appel kultivars verminder. Hergroei het in beide seisoene in al drie kultivars plaasgevind. Dit is dus onduidelik watter behandeling(s) optimaal is vir lootgroei beheer. In die 1999/2000 seisoen het P-Ca 'Royal Gala' vruggrootte verbeter. In die 2000/2001 seisoen is 'Golden Delicious' opbrengs, uitgedruk as kg vrugte geoes / cm stamomtrek, verlaag. Hierdie verlaging in opbrengs kan toegeskryf word aan die lae blom aantal in die lente van 2000 wat gevolg het op die P-Ca behandeling in 1999. In beide seisoene het P-Ca die aantal ontwikkelde sade in 'Royal Gala' verminder terwyl die aantal sade met geaborteerde embrios verhoog is in die 2000/2001 seisoen. Na vier weke koelopberging (± 5°C) en een week by kamertemperatuur (± 20°C) het P-Ca geen effek op die voorkoms van bitterpit in 'Golden Delicious' gehad nie. Die 'Granny Smith' bome is in die 2000/2001 seisoen geoes voordat enige data ingesamel kon word. Ringelering het geen effek op lootgroei gehad in enige van die peer kultivars nie, maar P-Ca het lootgroei effektief beheer in 'Rosemarie' en 'Golden Russet Bose' en tot 'n mindere mate 'Packham's Triumph', maar het geen effek op 'Forelle' lootgroei gehad nie. Ten spyte van die hergroei wat voorgekom het in die 'Rosemarie' bome ongeveer vier weke na oes in die 2000/2001 seisoen, wil dit voorkom asof P-Ca toegedien teen 'n enkele hoe konsentrasie (250 en 150 mg.l' vir die 1999/2000 en 2000/2001 seisoene onderskeidelik) meer effektief was om lootgroei te beheer as 'n enkele lae konsentrasie of veelvuldige lae konsentrasies. P-Ca het vrugset in 'Rosemarie' en 'Forelle' verhoog in die 2000/2001 seisoen. In beide seisoene het P-Ca 'Rosemarie' vruggrootte verlaag terwyl ringelering 'Forelle' en 'Packham's Triumph' vruggrootte verbeter het in die 2000/2001 seisoen. P-Ca het 'Rosemarie' vrugfermheid en 'Forelle' vrugkleur verhoog in die 2000/2001 seisoen en die aantal 'Packham's Triumph' vrugte met kurkvlek verlaag. Ringelering het 'Packham's Triumph' vrugkleur en TSSkonsentrasie verhoog, maar vrugfermheid verlaag in die 2000/2001 seisoen. P-Ca het die aantal blomme in 'Forelle' en 'Packham's Triumph' verlaag in 2001, terwyl ringelering blom in 'Golden Russet Bosc' en 'Forelle' verhoog het. As gevolg van 'n lae blom- en dus vruggetal in 'Golden Russet Bosc' kon vrugset In 2000 nie bepaal word nie en geen vrugontledings kon gedoen word nie. Al vier P-Ca behandelings het lootgroei in 'Songold' beheer, maar die 2 x 12S mg.l' toediening was die effektiefste, beide in terme van totale lootgroei en in beheer van die hergroei wat ongeveer twee weke voor die eerste kommersieele oesdatum plaasgevind het. PCa het vrugfermheid verhoog en die TSS-konsentrasie verlaag, beide tydens oes en na vier weke koelopberging by dubbel temperatuur (10 dae by -O.soC + 18 dae by 7.S0C). Om saam te vat kan gese word dat P-Ca 'n effektiewe inhibeerder van lootgroei van die appels 'Golden Delicious', 'Granny Smith' en 'Royal Gala', die pere 'Rosemarie', 'Golden Russet Bosc' en 'Packham's Triumph' en die pruim 'Songold' is. Meer werk is egter nodig om die hergroei te beheer.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A presente pesquisa teve o objetivo de estudar os efeitos da adubação nitrogenada sobre caramboleiras (cv. B-10) em implantação, através de análises químicas do solo, da determinação do crescimento, da amostragem de folhas e inflorescências, da avaliação do estado nutricional, em relação ao nitrogênio, através do uso do clorofilômetro, além do início da produção de frutos. Para tanto, foi instalado um experimento na Fazenda Manga Rosa, no município de Bonfim Paulista - SP, Brasil, sobre um Latossolo Vermelho eutroférrico, que foi conduzido de janeiro/2003 a fevereiro/2006. O delineamento experimental adotado foi em blocos ao acaso, com cinco tratamentos que corresponderam a doses de nitrogênio (uréia) e quatro repetições. Na implantação as doses utilizadas foram iguais a zero, 30,60, 90 e 120 g de N planta-1 e, nos 1°, 2° e 3° anos de experimentação utilizou-se o dobro, o triplo e o quádruplo das doses iniciais. A aplicação do fertilizante nitrogenado, a partir do segundo ano de experimentação, promoveu diminuição significativa do pH que aumentou a acidez potencial e diminuiu as concentrações de potássio, cálcio e magnésio, bem como a soma de bases e a saturação por bases. As caramboleiras do tratamento testemunha não floresceram e apresentaram menor teor foliar de N, em relação àquelas que receberam o adubo. O estado nutricional das plantas, em relação ao nitrogênio pode ser avaliado com o uso do clorofilômetro, pois, houve correlação positiva entre a leitura SPAD e o teor foliar de N determinado pela análise química, e uma dose próxima de 120 g de N planta-1 proporcionou os melhores resultados para a caramboleira na fase de implantação.
The present work was conducted to study the effect of nitrogen fertilization on star fruit (cv. B-10) at establishment, through soil nitrogen chemical analyses, plant growth, leaf and inflorescence sampling, nitrogen nutrition evaluation with a chlorophylometer, as well as the beginning of fruit production. The experiment was set at Manga Rosa Farm, in Bontim Paulista, SP, Brazil, under Eutrustox soil from January 2003 to February 2006. The experiment design was randomized blocks, with tive treatments corresponding to nitrogen (urea) rates, with four replications. At the plant establishment, N rates utilized were zero, 30, 60, 90 and 120 9 of N planr1 and, at the 1st, 2nd and 3rd years of experimentation, two fold, three fold and four fold of initial rate. The nitrogen fertilizer application, afier the second year of experiment, resulted in significant pH reduction which increased potential acidity and decreased potassium, calcium and magnesium concentrations, as well as the sum of bases and base saturation. Control star fruit did not flower and showed lower foliar N concentration in relation to those which received fertilizer. The plant nitrogen nutritional state can be evaluated with a chlorophylometer, because a positive correlation was observed between SPAD and N in leaves determinated by chemical analisys, and a rate near of 120 9 of N planr1 showed the best results for star fruit at orchard establishment.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Recentemente foi demonstrado que o boro exibe rápida e significante mobilidade no floema de algumas espécies produtoras de polióis. Os polióis como os açúcares alcoóis sorbitol, dulcitol e manitol possuem a capacidade de complexar o B conferindo a esse elemento alguma mobilidade dentro da planta. As espécies selecionadas foram o cajueiro (não produtora de sorbitol) e o pessegueiro (produtora de sorbitol). O trabalho teve por objetivo verificar a mobilidade de B aplicado via foliar em mudas de cajueiro e pessegueiro. As espécies foram conduzidas separadamente em dois experimentos em casa de vegetação pertencente a UNESP/FEIS no município de Ilha Solteira-SP. O delineamento experimental foi em blocos ao acaso, com três repetições, em parcelas subdivididas, em duas épocas (30 e 60 dias). Foram avaliados nas parcelas cinco tratamentos e nas subparcelas dois tipos de folha (folhas velhas e folhas novas). Os tratamentos estudados constituiram-se da adubação via solo e/ou via foliar com boro marcado ou não com 10B, da seguinte forma: sem adubação via solo e foliar com B (Sol -B Fol -B); sem adubação via solo com B e adubação foliar com 10B (Sol -B Fol 10 B); adubação via solo com B e sem adubação foliar (Sol B Fol -B); adubação via solo com B e foliar com 10B (Sol B Fol10B) e adubação via solo com 10B e foliar com B (Sol10B Fol B). Na adubação via solo o mesmo foi acrescido de B na dose de 0,5 mg kg-1 de solo e na adubação via foliar aplicação de solução com B na doses de 255 mg L-1, utilizando-se como fonte de B o ácido bórico e ácido bórico enriquecido com átomos de 10 B (99%). Foram avaliados quinzenalmente a altura e o número de folhas e o teor total de B e a porcentagem de B na folha velha e folha nova proveniente do fertilizante aos 30 e 60 dias após a aplicação dos tratamentos
Recently it was demonstrated the boron mobility in the phloem of some species producing polyols. The polyols or such alcohols sugar as sorbitol, mannitol and dulcitol are capable of complexing B giving to this element some mobility within the plant. This work had the objective to study the effect of fertilization with boron in the soil and leaves of cashew and peach seedling. They were conducted two experiments for 120 days in the greenhouse at UNESP, Ilha Solteira/SP. The experimental design was randomized blocks with three replications in a split plot, in two times for collection of leaves (30 and 60 days after application of treatments). We studied five treatments in plots and two ages of leaves in the subplots (old leaves and new leaves). The treatments studied were: no fertilizer with B in the soil and leaves (Sol -B Fol -B); without fertilizer with B in the soil and leaves with 10B (Sol - B Fol10B); fertilizing in the soil with B and leaves without B (Sol B Fol -B); fertilizing in the soil with B and leaves with 10B (Sol B fol10B) and fertilizing in the soil with 10 B and leaves with B (Sol10B Fol B). Were evaluated the height and the number of leaves biweekly and B total content and B percentage at the leaf from the fertilizer (% Bfopf) at 30 and 60 days. There was no fertilization effect with boron in the cashew seedling growing . The foliar fertilization with boron showed higher increase in the leaves number on peach seedlings at 60 days after fertilization. Boron foliar application is restricted or intermediate mobility in mobile cashew and peach evaluated at 30 and 60 days after fertilization

Orientador: Antonio Baldo Geraldo Martins
Banca: José Antônio Alberto da Silva
Banca: Carlos Ruggiero
Banca: Dalmo Lopes de Siqueira
Banca: João Alexio Scarpare Filho
Resumo: O trabalho foi realizado nas Fazendas Santo Antônio e Jurupema, localizadas no Município de Taquaritinga -SP, Brasil, de abril de 2003 a dezembro de 2005, com o objetivo de estudar a influência da temperatura, anelamento e alguns reguladores de crescimento sobre a floração e a produção de lichieiras cultivar Bengal. Foram registrados dados de produção e temperaturas, precipitação e horas acumuladas com temperaturas inferiores a 15,5° C, e correlacionados para entender o grau de interação. Foi realizado anelamento de ramos de diferentes diâmetros, para conhecer o seu efeito sobre a floração e a frutificação. O anelamento não teve efeito sobre a brotação vegetativa após a colheita, mas as maiores concentrações de PBZ reduziram significativamente a brotação vegetativa e o comprimento dos ramos. O uso de ANA provocou queimaduras nas inflorescências e queda de frutos, mas os que permaneceram, não apresentaram alterações nas características físicas e nos sólidos solúveis. Não foi observado efeito significativo da aplicação de GA3, sobre a fixação de frutos. A queda de frutos, a partir de uma massa de 2 g até a colheita, é de 50%.
Abstract: The work was carried through on Santo Antonio and Jurupema farms, located in Taquaritinga, São Paulo State, Brazil, in the period from April 2003 to December 2005, with the objective to study the influence of temperature, girdling and some growth regulators on the flowering, fruiting and production of lychee trees cultivar Bengal. It was registered production data and temperatures, precipitation and accumulated hours with inferior temperatures to 15.5°C, and correlated to understand the interaction degree. Girdling of branches of different diameters was carried through, to know its effect on the flowering and fruiting. The girdling didn't have effect on the vegetative flushes after the harvest, but the biggest concentrations of PBZ reduce the vegetative flushes and the length of shoots significantly. Spray with NAA provoked burns in the panicles and drop of fruits, but the ones that had remained did not have present alterations in the characteristics and in the soluble solids. Beneficial effect of the application of GA3 on the fruit set was not observed. The drop of fruits, starting from a weight of 2 g to the harvest, is of 50%.
Doutor

Resumo: A presente pesquisa teve o objetivo de estudar os efeitos da adubação nitrogenada sobre caramboleiras (cv. B-10) em implantação, através de análises químicas do solo, da determinação do crescimento, da amostragem de folhas e inflorescências, da avaliação do estado nutricional, em relação ao nitrogênio, através do uso do clorofilômetro, além do início da produção de frutos. Para tanto, foi instalado um experimento na Fazenda Manga Rosa, no município de Bonfim Paulista - SP, Brasil, sobre um Latossolo Vermelho eutroférrico, que foi conduzido de janeiro/2003 a fevereiro/2006. O delineamento experimental adotado foi em blocos ao acaso, com cinco tratamentos que corresponderam a doses de nitrogênio (uréia) e quatro repetições. Na implantação as doses utilizadas foram iguais a zero, 30,60, 90 e 120 g de N planta-1 e, nos 1°, 2° e 3° anos de experimentação utilizou-se o dobro, o triplo e o quádruplo das doses iniciais. A aplicação do fertilizante nitrogenado, a partir do segundo ano de experimentação, promoveu diminuição significativa do pH que aumentou a acidez potencial e diminuiu as concentrações de potássio, cálcio e magnésio, bem como a soma de bases e a saturação por bases. As caramboleiras do tratamento testemunha não floresceram e apresentaram menor teor foliar de N, em relação àquelas que receberam o adubo. O estado nutricional das plantas, em relação ao nitrogênio pode ser avaliado com o uso do clorofilômetro, pois, houve correlação positiva entre a leitura SPAD e o teor foliar de N determinado pela análise química, e uma dose próxima de 120 g de N planta-1 proporcionou os melhores resultados para a caramboleira na fase de implantação.
Abstract: The present work was conducted to study the effect of nitrogen fertilization on star fruit (cv. B-10) at establishment, through soil nitrogen chemical analyses, plant growth, leaf and inflorescence sampling, nitrogen nutrition evaluation with a chlorophylometer, as well as the beginning of fruit production. The experiment was set at Manga Rosa Farm, in Bontim Paulista, SP, Brazil, under Eutrustox soil from January 2003 to February 2006. The experiment design was randomized blocks, with tive treatments corresponding to nitrogen (urea) rates, with four replications. At the plant establishment, N rates utilized were zero, 30, 60, 90 and 120 9 of N planr1 and, at the 1st, 2nd and 3rd years of experimentation, two fold, three fold and four fold of initial rate. The nitrogen fertilizer application, afier the second year of experiment, resulted in significant pH reduction which increased potential acidity and decreased potassium, calcium and magnesium concentrations, as well as the sum of bases and base saturation. Control star fruit did not flower and showed lower foliar N concentration in relation to those which received fertilizer. The plant nitrogen nutritional state can be evaluated with a chlorophylometer, because a positive correlation was observed between SPAD and N in leaves determinated by chemical analisys, and a rate near of 120 9 of N planr1 showed the best results for star fruit at orchard establishment.
Orientador: William Natale
Coorientador: Renato de Mello Prado
Banca: Takashi Muraoka
Banca: Ben-Hur Mattiuz
Mestre

Thesis (MSc (Forest and Wood Science))—University of Stellenbosch, 2007.
The utilization and commercialization of indigenous fruit trees has in the past been overlooked by extension agencies due to the misconception that they do not play a major role in contributing to the rural livelihoods. There is new and increasing emphasis on the contribution of non-timber forest products (NTFPs) on improving the livelihoods and sustainable management of forest ecosystems of the Miombo woodlands. This study was conducted around Mwekera area in the Copperbelt province, Zambia to determine the role of indigenous fruit trees in the rural livelihoods. A total of 70 households were interviewed in the survey using semi-structured questionnaires, in-depth open ended interviews and focus group meetings to collect information on the use of indigenous fruits. The study revealed that 99% of the households experience ‘hunger’ during the rainy season from November to April every year. Ninety seven percent (97%) of the households collect indigenous fruit, with the most collected fruits being Uapaca kirkiana (74%), Anisophyllea boehmii (71%) and Parinari curatellifolia (67%). Additionally, there is very little selling of indigenous fruit (31%) but that Uapaca kirkiana and Anisophyllea boehmii account for 95% of the fruits sold. Forty six percent (46%) of the households process fruits of U. kirkiana, A. boehmii and P. curatellifolia into juice and/or porridge. Furthermore IFTs are also used as traditional medicine. Sixty three percent (63%) of the households used IFTs for medicinal purposes with two-thirds of the respondents citing Anisophyllea boehmii as an important medicinal tree species. The study also showed that 85% of the respondents have seen a change in the forest cover resulting into loss of biodiversity with 70% of the respondents indicating that the change is with respect to reduction in forest size and scarcity of some species; and that charcoal production and clearance of land for cultivation are the major causes of the scarcity of indigenous fruit trees. It is concluded that the major contribution of IFTs in the study area is in filling the gap during times of hunger rather as being a source of income through selling. Charcoal production and clearance for agriculture are the main contributing agents for the loss of biodiversity and scarcity of IFTs. It is recommended that domestication of IFTs and sustainable forestry and agricultural management practices be employed to ensure that future generations continue to benefit from the forest resource.

Thesis (MSc)--Stellenbosch University, 2004.
Full text to be digitised and attached to bibliographic record.
ENGLISH ABSTRACT: The control of excessive vegetative growth is important in deciduous fruit orchards. Currently the plant growth regulator prohexadione-calcium (p-Ca) is used to control apple shoot growth in the Untited States of America and some European countries. The effect of P-Ca on the shoot and fruit growth of apples (Malus domestica B.), pears (Pyrus cummunis L.), plums (Prunus sa/icina L.) and nectarines (Prunus persica L.) was evaluated. Inhibition of shoot growth can effect fruit growth. Therefore I did a literature review on the fruit growth of pome- and stone fruit. Split pit, a physiological disorder associated with an increased fruit growth rate in stone fruit, was also investigated. During the course of the 2001 / 2002 season two trials were conducted in the Villiersdorp area of the Western Cape on 'Golden Delicious' and 'Granny Smith' apple trees. Single and multiple applications of P-Ca at different rates, with and without the surfactant Dash®, were applied. One of these trials was continued during the 2002 / 2003 season. In the 2001 / 2002 season, P-Ca reduced shoot growth in both trials on 'Golden Delicious'. The shoot growth of 'Granny Smith' was reduced in both trials where PCa was applied three or four times. There was an improvement in the fruit size of 'Golden Delicious' in both trials, but there was no improvement in the fruit size of 'Granny Smith'. In the 2002 / 2003 season, the single P-Ca application did not reduce shoot growth. Unfortunately 'Golden Delicious' was harvested before any data were obtained. Once again P-Ca had no effect on the fruit size of 'Granny Smith'. Dash® did not improve the effect ofP-Ca. In the 2002 / 2003 season we replicated one trial on five different pear cultivars in the Wolsely area of the Western Cape. Single and multiple applications of P-Ca at different rates were compared to a girdling treatment (2 weeks after full bloom). 'Early Bon Chretien', 'Rosemarie', 'Flamingo', 'Forelle' and 'Packham's Triumph' pear trees were used and Dash®was added to all 0f the treatments. P-Ca reduced shoot growth in all of the pear cultivars. Girdling reduced shoot growth only in 'Forelle'. P-Ca increased fruit set of 'Early Bon Chretien', 'Rosemarie' and 'Forelle', however, this was associated with a reduced fruit size of 'Early Bon Chretien' and 'Rosemarie'. Girdling did not increase fruit set, but increased fruit size of 'Flamingo' and 'Early Bon Chretien'. P-Ca reduced return bloom of 'Packham's Triumph' and 'Forelle', whereas girdling increased return bloom in all the cultivars except 'Packham's Triumph'. In the 2002 / 2003 season, trials were also conducted on 'Pioneer' and 'Songold' plums and 'May Glo' nectarine in the Wemmershoek and Stellenbosch area of the Western Cape. Single applications at different rates of P-Ca were applied. Dash® was added to all of the treatments. The higher rates of P-Ca reduced the shoot growth of 'Pioneer'. P-Ca only reduced shoot growth of 'Songold' initially and but did not reduce shoot growth of 'May Glo'. P-Ca had no influence on fruit size of 'Pioneer', 'Songold' or 'May Glo'. P-Ca did not aggravate the occurrence of split pit. In conclusion, P-Ca reduced shoot growth in apples and pears when applied at the appropriate rates. Although P-Ca reduced shoot growth of 'Pioneer' plum, more research needs to be done on stone fruit to optimise timing and rate of P-Ca applications.
AFRIKAANSE OPSOMMING: Die beheer van oormatige lootgroei is van kardinale belang in vrugtebome. Tans word die plantgroeireguleerder proheksadioon-kalsium (P-Ca) gebruik om die lootgroei van appels te beheer in die Verenigde State van Amerika en sekere lande in Europa. Die effek van P-Ca op lootgroei en vruggrootte is in proewe op appels (Malus domestica B.), pere (Pyrus cummunis L.), pruime (Prunus salicina L.) en nekatriens (Prunus persica L.) geëvalueer. Aangesien lootgroei inhibisie moontlik vruggroei kan vesnel, is 'n literatuurstudie oor die vruggroei van kern-en steenvrugte gedoen. Die ontwikkelling van gesplete pit by steenvrugte ('n fisiologiese defek geassosieer met versnelde vruggroei) is ook ondersoek. Gedurende die 2001 / 2002 seisoen is P-Ca in twee afsonderlike proewe in die Villiersdorp area van die Wes Kaap geëvalueer. Enkel en veelvuldige toedienings van verskeie konsentrasies P-Ca, met en sonder die benatter Dash", is op 'Golden Delicious' en 'Granny Smith' bome toegedien. Een proef is herhaal gedurende die 2002 / 2003 seisoen. In die 2001 /2002 seisoen het die P-Ca behandelings in beide proewe die lootgroei van 'Golden Delicious' verminder. Die lootgroei van 'Granny Smith' is in beide proewe verminder waar P-Ca 3 of 4 keer toegedien is. Die vruggrootte van 'Golden Delicious', maar nie 'Granny Smith' nie, is in beide proewe deur die P-Ca verbeter. In die 2002 / 2003 seisoen kon die enkeltoedienings van P-Ca nie die lootgroei verminder van 'Golden Delicious' of 'Granny Smith' nie. 'Golden Delicious' is geoes voor enige inligting oor die vruggrootte ingesamel kon word. Weereens het PCa geen invloed op die vruggrootte van 'Granny Smith' gehad nie. Dash® het nie die effek van P-Ca verbeter nie.In die 2002 / 2003 seisoen is proewe met P-Ca gedoen op 5 verskillende peer kultivars in die Wolsely area van die Wes Kaap. P-Ca is teen verskillende konsentrasies, met enkel en veelvuldige bespuitings toegedien en vergelyk met 'n ringelerings behandeling (2 weke na volblom). 'Early Bon Chretien', 'Rosemarie', 'Flamingo', 'Forelle' en 'Packham's Triumph' bome is gebruik en die benatter Dash® is by al die behandelings gevoeg P-Ca toedienings het lootgroei verminder in 'Early Bon Chretien', 'Rosemarie', 'Flamingo', 'Forelle' en 'Packham's Triumph'. Ringelering kon slegs die lootgroei van 'Forelle' verminder. P-Ca het die vrugset van 'Early Bon Chretien', 'Rosemarie'en 'Forelle' verhoog. Die toename in vrugset het gelei tot 'n afname in die vruggrootte van 'Early Bon Chretien' en 'Rosemarie'. Ringelering het die vruggrootte van 'Flamingo' en 'Early Bon Chretien' verbeter. P-Ca het 'n afname in die hoeveelheid reproduktiewe knoppe in die volgende seisoen, van 'Packham's Triumph' en 'Forelle' veroorsaak. Ringelering het 'n toename in die hoeveelheid vegetatiewe knoppe in die volgende seisoen gehad vir al die kultivars, behalwe 'Packham's Triumph'. Geduerende dieselfde seisoen is daar ook proewe gedoen op 'Pioneer' en 'Songold' pruime en 'May Glo' nektarienbome in onderskeidelik die Wemmershoek en Stellenbosch areas van die Wes Kaap. Bome is met enkel toedienings van verskillende konsentrasies P-Ca behandel en die benatter Dash® is by al die behandelings bygevoeg. Die hoër dosisse P-Ca het die lootgroei van 'Pioneer' verminder. P-Ca kon slegs die aanvanklike lootgroei op 'Songold' verminder en kon nie lootgroei van 'May Glo' beperk nie. P-Ca het geen invloed op die vruggrootte van 'Pioneer', 'Songold' of 'May Glo' gehad nie. P-Ca het nie die voorkoms van gesplete-pit vererger nie. Om saam te vat kan gesê word dat P-Ca lootgroei op appels en pere goed beperk teen die regte konsentrasies. Alhoewel P-Ca lootgroei suksesvol beheer het op 'Pioneer', moet daar meer werk gedoen word op steenvrugte.