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Kirstein, Deon Louw. "Mechanical thinning of pome fruit." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97920.
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Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Thinning is an important practice in pome fruit production which aims to ensure an optimal yield of high quality, large sized fruit as well as an adequate return bloom. In South Africa, pome fruit thinning is generally done by means of chemicals, with follow-up hand thinning. When thinning is effective, set and thus the hand thinning requirement should be reduced. This is important as labor cost associated with hand thinning is high and continually rising. Chemical thinning is weather dependent and can be environmentally harmful, which has led to a shift towards environmentally acceptable methods of thinning such as mechanical thinning. From 2013 until 2015 the mechanical string thinners, viz. Darwin 300™, BAUM, and Bloom Bandit™, were evaluated. These machines are used to thin trees during full bloom and reduce the number of flowers before fruit set. The aim of the trials was to reduce fruit set and therefore hand thinning requirement, while increasing fruit size and quality, maintaining yield and return bloom. A range of tractor speeds and rotational rates were evaluated with the Darwin 300™ on ‘Forelle’ pears and ‘Cripps’ Pink’ apples, while the BAUM was evaluated only on ‘Cripps’ Pink’ apples. The hand-held Bloom Bandit™ was evaluated on ‘Forelle’, ‘Cripps’ Pink’, ‘Fuji’ and ‘Cripps’ Red’. The tractor-driven mechanical thinning devices gave erratic results. The most consistent results on ‘Forelle’ were obtained using the Darwin 300™ at 5.2 km·h-1 and 300 rpm, while the BAUM gave no consistent results. The unreliability of results were due to South African pome fruit orchards currently being unsuitable for tractor-driven mechanical thinning machines. The ‘Forelle’ orchard trained to a Palmette system was the most suited for thinning, which is reflected in the more positive results obtained, but further improvements are possible. The Bloom Bandit™ effectively thinned pear and apple trees and increased fruit size without a decrease in yield or return bloom. More time is spent on thinning with the device compared to tractor-driven machines and this should be taken into account when considering using the Bloom Bandit™. Thinning intensities of 25%, 50% and 75% of clusters or flowers was applied to mature ‘Forelle’ and ‘Cripps’ Red’ trees during full bloom. Variable effects were seen on fruit set, yield was reduced to acceptable levels, while fruit size was improved in ‘Forelle’ but not ‘Cripps’ Red’. Results showed that when thinning mechanically, the aim should be to remove between 25% and 50% of flowers clusters in ‘Forelle’ and 50% of flowers clusters in ‘Cripps’ Red’. These levels of thinning gave the best results in terms of the remaining hand thinning requirements and improved return bloom in ‘Forelle’. We, however, only evaluated full cluster thinning and not within cluster thinning, which might also occur during mechanical thinning.
AFRIKAANSE OPSOMMING: Vruguitdunning is 'n belangrike praktyk in kernvrugproduksie en het ten doel om voldoende opbrengs van hoë kwaliteit, groot vrugte en voldoende opvolgblom te lewer. In Suid-Afrika, word kernvrugte gewoonlik chemies uitgedun, opgevolg met handuitdunning. Effektiewe uitdunning verminder set en dus die benodigde handuitdunning. Dit is belangrik aangesien die arbeidskoste verbonde aan die handuitdunning hoog is en voortdurend styg. Chemiese uitdunning is afhanklik van weerstoestande en dit kan ook omgewing-onvriendelik wees. Hierdie nadele het gelei tot 'n verskuiwing na omgewingsaanvaarbare metodes van uitdunning soos meganiese uitdun. Vanaf 2013 tot 2015 is die meganiese Darwin 300™, BAUM en Bloom Bandit™ uitdunmasjiene geëvalueer. Hierdie masjiene word gedurende volblom gebruik om blomme uit te dun en verminder die aantal blomme voor vrugset. Die doel van die proewe was om vrugset en dus die handuitdunvereiste te verminder met ‘n gepaardgaande verbetering in vruggrootte en kwaliteit sonder om opbrengs en opvolgblom nadelig te beïnvloed. Trekker en rotasiespoed is gevarieer met die Darwin 300 ™ op 'Forelle' pere en ‘Cripps’ Pink' appels, terwyl die BAUM net op 'Cripps' Pink' appels geëvalueer is. Daarbenewens was die hand-draagbare Bloom Bandit™ geëvalueer op 'Forelle', 'Cripps' Pink’, ‘Fuji’ en ‘Cripps' Red’. Die trekkergedrewe uitdunmasjiene het wisselvallige resultate opgelewer. Die mees konstante resultate op 'Forelle' is verkry met die Darwin 300™ teen 5.2 km·h-1 en 300 rpm, terwyl die BAUM nie konsekwente resultate gegee het nie. Die wisselvallige resultate van die Darwin 300™ en die BAUM is te wyte aan die boorde wat nie vir trekkergedrewe uidunmasjiene geskik is nie. Die 'Forelle’ boord, wat as 'n Palmette stelsel opgelei is, was die meeste geskik vir uitdunning, soos duidelik uit die positiewe resultate wat verkry is, maar verdere verbeterings is steeds moontlik. Die Bloom Bandit™ het peer en appel bome effektief uitgedun deur die handuitdunvereiste te verminder en vruggrootte te verbeter sonder verlies in opbrengs of opvolgblom. Meer tyd word gespandeer tydens uitdunning met hierdie toestel in vergelyking met trekkergedrewe masjiene, en dit moet in ag geneem word met oorweging van die Bloom Bandit™. Uitdunningsintensiteite van 25%, 50% en 75% van die trosse of blomme is tydens volblom toegepas op volwasse 'Forelle’ en ‘Cripps’ Red' bome. Vrugset het aansienlike variasie getoon terwyl opbrengs tot aanvaarbare vlakke verminder en vruggrootte verbeter is in 'Forelle' maar nie in 'Cripps' Red’ nie. Resultate het getoon dat die doel moet wees om tussen 25% en 50% van alle blomme in trosse in 'Forelle’ en 50% van blomme in trosse in 'Cripps’ Red’ tydens meganiese uitdunnig te verwyder. Hierdie vlakke van uitdunning het die beste resultate gegee ten opsigte van die oorblywende handuitdunvereistes en het opvolgblom in 'Forelle’ verbeter. Ons het egter net volledige trosse uitdunning gedoen en nie blomuitdunning binne die tros wat ook tydens meganiese uitdun kan plaasvind nie.
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Steenkamp, Human. "New chemical thinning strategies for stone fruit." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/98026.
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Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Thinning of stone fruit, just as in any other deciduous fruit crop, plays an important role in producing fruit of the right size and quality. Hand thinning is highly labor intensive and time consuming, thus an alternative method of thinning is important to the industry. Chemical and mechanical thinning either alone or in combination could be the alternative. Two chemicals, 1-aminocyclopropane-1-carboxylic acid (ACC) and 6-benzyladenine (6-BA) were evaluated on Japanese plums, cling peaches and nectarines. In addition, the Darwin 300™, a mechanical string thinner, was also included in trials on early maturing ‘Alpine’ nectarine and ‘African Rose™’ plum. In all trials the objective was to reduce the required hand thinning during commercial hand thinning without compromising on yield and fruit quality. In Japanese plums we were able to reduce the hand thinning requirement significantly with both the ACC thinning and mechanical thinning strategies. Regarding ACC, cultivars differed in their sensitivity to the chemical and the recommended rate will differ for cultivars. ACC consistently reduced the required hand thinning linearly with increasing rate. The recommended rate of ACC for ‘African Rose™’ is 600 μl.L-1 and for ‘Laetitia’ 400 μl.L-1. For ‘Fortune’ a recommended rate could not be determined at this stage, thus further trials should be conducted. The Darwin 300™ reduced hand thinning significantly without reducing the yield significantly. Combining the Darwin 300™ with ACC 600 μl.L-1 in ‘African Rose™’ gave promising results with regard to hand thinning requirement and fruit size, without reducing yield efficiency significantly. No leaf drop was observed on Japanese plums, except in the pilot trial when applications were made at high temperatures, which should therefore be avoided. ACC was effective as thinning agent in cling peaches. In ‘Keisie’, the results were positive during both seasons, and ACC reduced the hand thinning requirement without reducing yield efficiency. The recommended rate of ACC for ‘Keisie’ is 600 μl.L-1. Slight leaf drop was observed. In ‘Sandvliet’, there was a significant reduction in fruit set, without reducing the required hand thinning. The reduction in fruit set led to a significant reduction in yield. Severe leaf drop was observed, indicating that cultivars differ in sensitivity to ACC. ACC would not currently be recommended for ‘Sandvliet’. In nectarines, ACC only thinned ‘Turquoise’ but not ‘Alpine’ or ‘August Red’ at the rates and phenological stage used, again indicating cultivar differences in sensitivity. In ‘Turquoise’, the highest ACC rate (500 μl.L-1) reduced fruit set per tagged shoot, as well as the hand thinning requirement, but this rate also reduced the total yield. The Darwin 300™ evaluated on ‘Alpine’ reduced fruit set significantly and the hand thinning requirement without reducing yield efficiency, indicating that mechanical thinning is a viable option in nectarines. Slight leaf drop was observed in all nectarine trials and ACC would not currently be recommended for nectarines. 6-BA was included to combat ACC-induced leaf drop and was partially successful. The reason for the differences observed in response to ACC between cling peaches and plums on the one hand, and nectarines on the other, cannot currently be explained.
AFRIKAANSE OPSOMMING: Uitdun van steenvrugte, net soos vir enige ander sagtevrugte soort, speel 'n belangrike rol in die produksie van vrugte met die regte grootte en gehalte. Uitdun van steenvrugte is hoogs arbeidsintensief en tydrowend, dus is dit belangrik om ʼn alternatief te vind vir die bedryf. Chemiese of meganiese uitdunning alleen of in kombinasie kan die alternatiewe wees. Twee middels, 1-aminosiklopropaan-1-karboksielsuur (ACC) en 6-bensieladenien (6-BA) is geëvalueer op Japanese pruime, taaipitperskes en nektariens. Daarby is die Darwin 300™, ʼn meganiese uitdunmasjien, ingesluit vir twee vroeë kultivars, nl. Alpine nektarien en African Rose™ pruim. Die doel van die proewe was om handuitdunning tydens kommersiële handuitdun te verminder, sonder om die opbrengs en vrugkwaliteit negatief te beïnvloed. Vir Japanese pruime kon ons die nodige handuitdunning beduidend verminder met beide die ACC en meganiese uitdun strategieë. Daar was wel ʼn verskil tussen die kultivars se sensitiwiteit teenoor ACC en die aanbevole konsentrasie sal verskil tussen kultivars. ACC het die benodigde handuitdunning vir al drie kultivars lineêr verminder met ʼn toename in konsentrasie. Die aanbevole konsentrasie van ACC vir ‘African Rose ™’ is 600 μl.L-1 en vir ‘Laetitia’ 400 μl.L-1. Vir ‘Fortune’ kan daar nog nie op hierdie stadium 'n konsentrasie aanbeveling gemaak word nie. Die Darwin 300™ behandeling het die benodigde handuitdunning beduidend verminder sonder om die opbrengs te beïnvloed. Die kombinasie van die Darwin 300 ™ met ACC 600 μl.L-1 het ook goeie resultate opgelewer wat handuitdunning en vruggrootte aanbetref sonder om die opbrengsdoeltreffendheid te verlaag. Geen blaarval was opgemerk by die pruime nie, behalwe in ʼn voorlopige proef toe die ACC toegedien is by hoë temperature, wat dus vermy moet word. Die effektiwiteit van ACC as uitdunmiddel van taaipitperskes was belowend. Vir ‘Keisie’ was die resultate positief vir beide seisoene, en ACC het handuitdunning verminder sonder om die opbrengs te beïnvloed. Die aanbevole ACC konsentrasie vir ‘Keisie’ is 600 μl.L-1. Effense blaarval is wel waargeneem. Vir ‘Sandvliet’ was daar 'n beduidende vermindering in vrugset, sonder dat handuitdunning verminder is. Daar was ook 'n beduidende afname in opbrengs en erge blaarval in die proef waargeneem. ACC sal tans nie aanbeveel word vir 'Sandvliet’ nie. Met nektariens het ACC net ‘n uitduneffek op ‘Turquoise’ getoon, maar nie teen die aangewende dosisse en ontwikkelingstadium op ‘Alpine’ of ‘Augustus Red’ nie. Dit dui daarop dat ACC kultivarspesifiek mag wees. In ‘Turquoise’ het die hoogste konsentrasie (500 μl.L-1) vrugset van gemerkte lote en die handuitdunning verminder, maar ook die totale opbrengs. Die Darwin 300 ™ het die vrugset van ‘Alpine’ asook die benodigde handuitdunning aansienlik verminder sonder om die opbrengs te verlaag. Effense blaarval was opgemerk in alle nektarien proewe. ACC sal nie aanbeveel word as uitdunmiddel vir nektariens nie. 6-BA was in die studie ingesluit om ACC-geïnduseerde blaarval teen te werk en was slegs gedeeltelik suksesvol. Die rede vir die verskille in respons tot ACC tussen pruime, perskes en nektariens kan nie tans verklaar word nie.
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De, Villiers Michiel Hendrik Jacobus. "Mechanical and chemical thinning of stone fruit." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95809.
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Thesis (MScAgric)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Producing fruit of the appropriate size and high quality is of the upmost importance to realize a profit in the fruit industry. This can be achieved through bloom or fruitlet thinning to reduce the number of fruit left on the tree. The cost of production is rising and labour cost forms a large part of the total production cost. Thinning of stone fruit is labour intensive and expensive, so an alternative to hand thinning needs to be found. Two alternatives are chemical and mechanical thinning. Chemical thinners are not routinely used in stone fruit as it is in pome fruit production and gibberellins were evaluated in this study. The Darwin 300TM was evaluated as a mechanical alternative to hand thinning. It thins flowers during bloom, before fruitlet thinning by hand is performed. In our trials on nectarines and Japanese plums the objective of reducing the time required for hand thinning was achieved, with the Darwin 300TM reducing the time required by up to 50%. When the time required to thin was reduced too much it also reduced the yield, but this could be overcome by lowering the rotor speed or using different strategies during supplementary hand thinning at the fruitlet stage. The bloom thinning and reduction in yield led to an increase in the fruit size. Care should be taken when using the Darwin 300TM as the earlier thinning could increase pit splitting and/or fruit cracking, especially in cultivars that are sensitive to these defects. The optimal rate of thinning needs to be determined for each cultivar individually. The application of gibberellic acid (GA3) and gibberellin A4+7 (GA4+7) at the pit hardening stage in the previous season could decrease the number of flowers for the following growing season. There was no effect on the yield at harvest or fruit size in the season of GA3 and GA4+7 applications, but the fruit firmness was increased. This effect was more pronounced for the GA4+7 applications. Our objective of reducing the time required for thinning was achieved in some but not all cultivars. The yield was not significantly reduced, with the fruit maturity only delayed in ‘African Rose’ plum. Again no increase in fruit size was found, but the fruit firmness was again increased. The GA-applications therefore were not satisfactory in their reduction of the time required for hand thinning. A positive effect is the increase in fruit firmness, which could possibly increase the storage potential of the fruit without having negative effects on the other aspects of fruit quality but this needs further evaluation.
AFRIKAANSE OPSOMMING: Produksie van vrugte met die verlangde vruggrootte en hoë vrug kwaliteit is baie belangrik vir die realisering van ‘n wins in die vrugte-industrie. Met hierdie mikpunt in gedagte, is blom- en vruguitdunning baie belangrik om die aantal vrugte per boom te verminder. Die kostes geassosieer met vrugte produksie is besig om te styg en arbeidskoste vorm ‘n groot deel van die totale produksiekostes. Uitdunning van steenvrugte is arbeidsintensief en baie duur, dus moet ‘n alternatief vir handuitdunning gevind word. Daar is twee alternatiewe naamlik chemiese en meganiese uitdunning. Chemiese uitdunmiddels word algemeen in kernvrugproduksie gebruik, maar daar is tans geen chemiese middels vir steenvrugte nie. In hierdie studie was gibberelliene ge-evalueer as potensiële uitdunmiddel. Die Darwin 300TM is ge-evalueer gedurende blomtyd as ‘n meganiese alternatief vir handuitdunning. Die masjien verwyder blomme en verminder so die vruguitdunning benodig. In ons eksperimente op nektarien- en Japanese pruimkultivars het ons gevind dat die tyd benodig vir handuitdunning met tot 50% verminder is deur die Darwin 300TM. Dit het ook daartoe gelei dat die totale oes per boom verlaag is. Hierdie effek kan vermy word deur die rotor spoed te verminder of die strategie vir aanvullende handuitdunning aan te pas. Die feit dat die grootste deel van die uitdunproses in blomtyd uitgevoer is en ook die feit dat die totale oes per boom verlaag is, het daartoe gelei dat die vrugte groter was. Die vroeër uitdunning met die Darwin 300TM kan egter lei tot ‘n verhoging in vrugkrake en gesplete pitte. Dit moet veral in gedagte gehou word by kultivars wat geneig is tot hierdie afwykings/defekte. Die optimum tempo van uitdunning moet vir elke kultivar individueel bepaal word. Wanneer gibberelliensuur (GA3) of gibberelien A4+7 (GA4+7) by pitverharding toegedien word in die vorige groeiseisoen, kan dit lei tot die vermindering van die hoeveelheid vrugte in die volgende seisoen. Daar was geen effek op die totale oes per boom en die vruggrootte tydens oes in die seisoen van aanwending nie, maar die vrugfermheid is verhoog. Die effek was hoër na die GA4+7 as na die GA3 aanwending. Die mikpunt om die tyd benodig vir handuitdunning te verminder, is in sommige kultivars bereik. Die oes per boom in die opvolgseisoen is weer eens nie verlaag nie, maar die vrug rypheid van ‘African Rose’ pruime is vertraag. Geen effek is op die vruggrootte opgemerk nie, maar die vrugfermheid was weer eens verhoog. Die GA-toedienings het dus nie bevredigend die tyd benodig vir handuitdunning verminder nie. ‘n Positiewe effek is die verhoging van die vrugfermheid, wat moontlik kan lei tot die verhoging van die opbergingspotensiaal van die vrugte sonder enige ander negatiewe effekte, maar hierdie aspek benodig verdere navorsing.
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Chabikwa, Tinashe Gabriel. "Chemical thinning of European pear cultivars (Pyrus communis L.)." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/2023.
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Belayneh, Teferi Yeshitela. "Effect of cultural practices and selected chemicals on flowering and fruit production in some mango (Mangifera indica L.) cultivars." Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-01142005-085139.
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Sagredo, Karen X. "Effect of rest-breaking and fruit thinning treatments on reproductive development in apple." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/2038.
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Zhu, Hong. "Investigation of Regulatory Mechanisms of Chemical-Mediated Fruit Thinning in Apple (Malus X Domestica Borkh.)." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/30220.
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Fruit thinning is critical to the success of apple industry because most apple trees are prone to biennial bearing characterized by heavy bloom and over-cropping in the â onâ year and low or no cropping in the â offâ year. Fruit thinning can improve fruit size, increase return bloom, and reduce alternate bearing habit of apple trees. Chemical thinning has been widely used as a horticultural practice by growers for years in apple and other fruit production. However, its thinning results are often variable and very difficult to predict since parameters as well as their interactions (e.g. concentration, environmental condition, cultivar response) that affect thinning effectiveness have been poorly defined and the regulatory mechanisms at molecular level remain to be illustrated. Therefore, the purpose of this study is to characterize the physiological and molecular responses of the apple trees to the thinning treatments, and then use key genes as molecular markers for screening potential thinning agents. The long-term goal is to understand how the applied chemicals and environmental factors interact and regulate key regulatory genes as well as the thinning effectiveness during thinning process, and establish a predictable model for the improvement of fruit thinning consistency and effectiveness in apple and other fruit trees.
Effects of naphthaleneacetic acid (NAA), shading, amimoethoxyvinylglycine (AVG) and 1-methylcyclopropene (1-MCP) on young apple fruit abscission, leaf and fruit ethylene production, and the expression of genes related to ethylene biosynthesis, perception and cell wall degradation were examined in â Golden Deliciousâ apples (Malus x domestica borkh.). NAA at 15 mgâ ¢L-1 and shading increased fruit abscission and ethylene production of leaves and fruit when applied at a 12-mm stage of fruit development, whereas AVG, an inhibitor of ethylene biosynthesis, at 250 mgâ ¢L-1 reduced NAA-induced fruit abscission and ethylene production of leaves and fruit. 1-MCP at 160 mgâ ¢L-1 had no effect on fruit abscission but induced ethylene production by both leaves and fruit.
Changes in the gene expression pattern responding to each treatment were analyzed by real-time quantitative PCR. NAA treatment was found to enhance the expression of genes related to ethylene biosynthesis (MdACS5A, MdACS5B and MdACO1) and perception (MdETR1, MdETR1b, MdETR2, MdERS1 and MdERS2). AVG reduced NAA-induced expression of these genes except for MdERS2 in the fruit abscission zone (FAZ). NAA increased the expression of a polygalacturonase gene (MdPG2) in the FAZ but not in the fruit cortex (FC), whereas AVG reduced NAA-enhanced expression of MdPG2 in the FAZ. These results suggest that ethylene biosynthesis, ethylene perception, and MdPG2 gene are involved in young fruit abscission caused by NAA. On the other hand, 1-MCP did not affect the expression of MdACS5A and MdACS5B in the FAZ, although it enhanced the expression of these two genes in the FC from 6 to 24 hours post-treatment. The expression of MdACO1 in both tissues was increased by 1-MCP after 3 or more days post-treatment. 1-MCP had only a small influence on the expression of most ethylene receptor genes, with the exception of MdETR1, which was up-regulated in the FC to a level similar to that observed for NAA treatment. In response to 1-MCP, in the FAZ, the expression of MdCel1 and MdPG2 was up-regulated at the beginning and the end, respectively, of the experiment, but otherwise remained at or below control levels. 1-MCP did not inhibit NAA-induced abscission of young apple fruit, suggesting that abscission does not solely depend on ethylene signal transduction, or that the periods of effectiveness for 1-MCP and ethylene were asynchronous in this study. Gene expression analysis also revealed that both NAA and shading enhanced the expression of gene related to ABA biosynthesis in the FAZ, which suggested the involvement of ABA in young fruit abscission.
Global gene expression profile during young fruit abscission was analyzed using an apple oligonucleotide microarray. More than 700 genes were identified with reproducible changes in transcript abundance in the FAZ after NAA treatment. Genes associated with abscission, ethylene, ABA, cell wall degradation, mitochondrial activity, glycolysis, lipid catabolism, secondary metabolism, abiotic stress, and apoptosis were upregulated, while genes involved in regulation of cell cycle, cell wall biosynthesis, photosynthesis, carbon fixation, chromatin assembly, auxin transport/efflux, cytoskeleton function, and flower development were generally downregulated. Comparison of changes in the gene expression patterns during NAA-induced fruit abscission with shading-induced fruit abscission revealed similarities, but also considerable differences. The data suggested that young fruit were shutting down growth and energy production and undergoing a certain kind of programmed cell death (PCD) induced by these different stimuli. Gene expression analysis in abscising young fruit revealed that photosynthesis, carbon utilization, and ABA/ethylene pathways appeared to operate in both NAA- and shading-induced fruit abscission. However, more sugar signaling genes were regulated in shading-induced fruit abscission, compared to NAA-induced fruit abscission.Ph. D.
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Alrashedi, Mubarak Mohammed. "Blossom thinning and managing bitter pit, storage life and fruit quality in organically grown apples." Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/1097.
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Blossom thinning and application of calcium influence storage life and apple fruit quality. Spray application of lime sulphur (4-5%) with olive oil (3%) and 0.05% synertrol oil as a surfactant at 75% bloom was most effective in reducing crop load with minimum leaf scorching and improved fruit quality in organically grown apple. Four spray applications of Biomin® calcium (3kg/ha) were highly effective in reducing bitter pit, scald and maintaining organic apple fruit quality.
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Rosa, Nídia Diana Heleno. "Comparison between benzyladenine and metamitron as chemical thinning agents in Gala, Kanzi, Pink Lady and Red Delicious apple cultivars." Master's thesis, ISA - Ul, 2016. http://hdl.handle.net/10400.5/12172.
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Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia - ULThis experiment was conducted in PCFruit Research Station orchards in Sint-Truiden, Belgium in 2015, in ‘Gala’, ‘Kanzi®’, ‘Pink Lady®’ and ‘Red Delicious’. Four treatments were tested: untreated, manual thinning, two applications of 165 ppm of metamitron at 8 and 12 mm and one application of 150 ppm of benzyladenine between 8 and 12 mm fruit diameter. All cultivars were sprayed on the same days. Fruit drop was counted, phytotoxicity evaluated after June drop, fruit growth rate was assessed and photosynthetic efficiency was measured. Fruit drop was higher in all cultivars with metamitron application than with benzyladenine (P<0.05). A greater growth rate in fruits treated with metamitron was registered, as well as, a positive correlation between the sum of the PSII efficiency and the thinning percentage (R2=0.98). A relation between the duration of the blocking effect of metamitron and phytotoxicity level in the trees was observed. At harvest, metamitron and manual thinning showed the best results in average fruit weight, in all cultivars. Despite the size improvements, the only influence in quality was observed in ‘Pink Lady®’ Brix° values. All cultivars thinned with 150 ppm benzyladenine were far from the ideal crop load for fruit size, probably due to the poor weather conditions after application, while with two times 165 ppm metamitron sprays had the same results as manual thinning. ‘Pink Lady®’ was the easiest cultivar to thin, with a slight over thinning effect, followed by ‘Gala’, that achieved the ideal crop load and ‘Red Delicious’ was the most difficult to thin. It was not possible to compare ‘Kanzi®’ with the other cultivars due to the poor fruitset observed before the product’s application. Metamitron doses can be adjusted to achieve optimum results; in ‘Pink Lady®’ the dose should be lower while in ‘Red Delicious’ higher. A simpler version of the Greene model was tested the percentage of error was 7.5% for fruits treated with metamitron while in benzyladenine treated fruits was 18%.
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Fernandes, Carla Maria Correia. "Monda em macieira Fuji. Comparação entre novas substâncias quimicas e a monda manual." Master's thesis, ISA/UTL, 2010. http://hdl.handle.net/10400.5/5362.
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Mestrado em Engenharia Agronómica - Hortofruticultura e Viticultura - Instituto Superior de AgronomiaThe chemical agents, ammonium thiosulphate (ATS) (1%), 6-benzyladenine (BA) (100 ppm) and metamitron (100, 175, and 350 ppm) were evaluated as thinning agents on 3 years old „Fuji‟ grafted on to M9 apples trees. The products were used alone, at single or double application or in combination. There were no differences between treatments regarding yield, mean fruit weight and number of commercial fruits (70 – 85 mm) but there were differences concerning the greater and smaller fruit size classes. The fruit set was reduced by metramitron, but when considering different crop loads its action was independent of the crop load for the 175 and 350 ppm concentrations, however, an over thinning effect was observed at 350 ppm in trees with low crop load. Probably, unfavourable weather conditions during the application period of ATS+BA has jeopardized its effectiveness. Hand thinning, leaving one fruit per cluster spaced of 15 cm, was the best option, but is often impossible because of labor costs and the limited supply of available labor
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Young, Deborah, Robert E. Call, Michael Kilby, and Tom DeGomez. "Backyard Fruit Production at Elevations 3500 to 6000 Feet." College of Agriculture, University of Arizona (Tucson, AZ), 2015. http://hdl.handle.net/10150/560973.
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Revised; Originally Published: 20007 pp.
The mid elevations (3,500 to 6,000 feet) in Arizona can be ideal for growing tree fruit. Site selection can make a pronounced effect on how well fruit will grow and produce. The warmer the site the greater the chance of success. Areas where cold air settles are a poor choice for tree fruit production. Variety selection is very important for good fruit production.February and March are the best months to plant bare root trees, although they can be planted anytime during the dormant season. Try to plant 30 days before bud break. Containerized plants are best planted in late September through early October. The open center pruning system allows for more sunlight to reach all the branches of the tree. Whereas the central leader is used with those trees that are less vigorous. Training trees when young is an important step in ensuring a strong scaffold system when bearing. Fruit thinning helps to control fruit size and consistent bearing. Proper fertilization, irrigation, and pest control will promote healthy productive trees.
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Queirós, Rui Jorge Lôro Valadares de. "Estudo de alternativas à monda de frutos em ameixeira japonesa (Prunus salicina L.) na qualidade e pós-colheita dos frutos." Master's thesis, Universidade de Évora, 2016. http://hdl.handle.net/10174/18425.
Full textAbstract:
As ameixas são maioritariamente consumidas em fresco, pelo que as condições de conservação em
pós-colheita e o estado fisiológico dos frutos quando é realizada a colheita assumem elevada importância
na sua comercialização. Este estudo sobre alternativas à monda de frutos em ameixeira japonesa
(Prunus salicina L.), compara quatro práticas culturais de regulação de carga, a extinção de esporões,
o desbaste mecânico de flores, a monda manual de frutos e a aplicação de GA3 (monda química),
e os seus efeitos na qualidade final dos frutos.
No presente estudo faz-se ainda uma comparação dos efeitos de duas colheitas desfasadas no tempo
sobre a qualidade final dos frutos quando conservados em câmara de frio, à temperatura de 4ºC e
humidade relativa alta, durante 15 dias; Abstract:
Evaluation of alternatives methods to hand-thinning in Japanese plum (Prunus salicina L.)
and its effects on final fruit quality
Plums are mostly consumed in fresh, therefore, the ripening period and the postharvest conditions
are important parameters that influence fruit quality and assume high importance in fruit
commercialization. The aim of this research work was to search for alternatives to fruit hand-thinning
in Japanese plum (Prunus salicina L.). Four cultural practices of yield regulation were implemented:
bud extinction, mechanical flower thinning, fruit hand thinning and GA3 application and it was
evaluated its effects on the final quality of fruits.
In this research it is also compared the effect of the harvest date in fruit quality, to reach this aim
fruits were harvested in two different periods (early harvest with 12% SSC and regular harvest with
16% SSC), stored at 4˚C and high Relative Humidity, and quality was evaluated during a 15 days
period.
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Grassi, Alexandre Manzoni. "Fenologia e qualidade de frutos de nespereira." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-15102008-075337/.
Full textAbstract:
A nespereira é uma planta rústica, que prescinde da utilização sistemática de defensivos, o que torna o cultivo atraente, para atender ao público que cresce, dia a dia, à procura de produtos naturais.O trabalho teve por objetivo realizar a caracterização fenológica da nespereira, estabelecendo os estádios fenológicos e o ciclo de produção de 5 cultivares e de uma seleção.Também estudou-se a melhor fase para o ensacamento dos frutos e a intensidade de raleio para a obtenção de frutos de alta qualidade. Foi estabelecida uma escala fenológica contendo sete estádios de desenvolvimento para a nespereira. Os estágios observados foram: 0 Desenvolvimento da Gema; 1 Desenvolvimento das folhas; 3 Desenvolvimento dos Brotos; 5 Emergência da Inflorescência; 6 Florescimento; 7 Desenvolvimento dos frutos; 8 Maturação dos frutos, de acordo com a escala BBCH. Mediante o estudo da escala fenológica das 5 cultivares e da seleção IAC NE3, verificou-se a existência de diferenças no ciclo de produção das cultivares estudadas e também da seleção, possibilitando a observação de três grupos. O primeiro grupo, mais precoce, foi formado pelas cultivares Mizuho e Mizumo, com ciclo médio de 195 dias contados a partir do início do desenvolvimento das gemas até a colheita dos frutos. As cultivares Néctar de Cristal e Centenária formaram um segundo grupo apresentando um ciclo intermediário com uma média de 203 dias. Já a cultivar Mizauto e a seleção IAC NE3 foram as mais tardias, uma vez que o ciclo foi concluído 208 dias, em média, após o início do desenvolvimento das gemas.A intensidade de raleio a ser adotada deve ser de 4 ou 6 frutos por panícula, levando-se em conta a safra esperada; o ensacamento dos frutos deve ser realizado nos estádios 1 (frutos com 1,0 cm de diâmetro) ou 2 (frutos com 1,5 cm de diâmetro).The Loquat is a rustic plant, which renounce the systematic use of defensive, which makes the cultivation attractive, to attend the public that grows, day by day, the demand for natural products. The study aimed to carry out the phenological characterization of loquat, setting the phenological stages and the cycle of production of 5 cultivars and a selection. Also studied is the best stage for the bagging of panicles and thinning intensity for obtaining fruits of high quality. Was established a scale containing seven phenological stages of development for loquat. The stages were observed: 0 - Development of bud, 1 - Development of the leaves, 3 - Development of shoot, 5 - Emergency of Inflorescence, 6 - Blooming; 7 - Development of fruit; 8 - Ripening fruits, according to the scale BBCH. Through the study of phenological scale from 5 cultivars and selection IAC NE3, there are differences in the production cycle of cultivars and the selection, enabling the observation of three groups. The first group, earlier, was formed by cultivars with Mizuho and Mizumo cycle average of 195 days counted from the beginning of the development of buds until the harvest fruit. Cultivars nectar of Cristal and Centenária formed a second group presenting a cycle intermediary with an average of 203 days. The cultivar Mizauto and the select IAC NE3 were the most late, since the cycle was completed 208 days on average after the start of the development of buds. The intensity of thinning to be used must be 4 or 6 fruits per raceme, considering the crop waited and the fruit price in the market. The fruit bagging must be realized in the harvest time 1(fruits with 1,0 cm of diameter) or 2(fruits with 1,5 cm of diameter).
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Leal, Luís Miguel Travessa. "Monda de frutos em macieira Fuji com matamitrão, ácido 1-naftilacético e 6-benziladenina." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5283.
Full textAbstract:
Mestrado em Engenharia Agronómica - Horticultura e Viticultura - Instituto Superior de AgronomiaThe effectiveness of 6-benzyladenine (6-BA, 150 mg/L), 1-naphthaleneacetic acid + 6- benzyladenine (ANA 10 mg/L + 6-BA 100 mg/L) and metamitron (165; 165+165; 247.5 mg/L) were analyzed in 6 years old apple ‘Fuji’ grafted on M7, considering simple, double or combined applications. Production per hectare, average fruit weight and commercial fruit production were not significantly different between the different methods however, there were significant differences between these treatments when considering the highest fruit size class. All the chemical thinning methods led to a reduction in the total number of fruits/BSA (cm2) and in the average number of fruits/100 fruit clusters. The methods ANA+6-BA and metamitron at 247.5 mg/L showed highest efficiency and metamitron at 247.5 mg/L resulted in the best global results: average fruit weight of 175.6 g and average diameter of 77 mm. The lower efficiency of 6-BA at 150 mg/L was due probably to adverse weather conditions that occurred 2-3 days after the product application. Chemical thinning is more favorable than manual thinning due to excessive cost of the second and to the lack of available labour.
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Mawdsley, Paul F. W. "The Effects of Cluster Thinning on Vine Performance, Fruit, and Wine Composition of Pinot Noir (Clone 115) in the Edna Valley of California." DigitalCommons@CalPoly, 2019. https://digitalcommons.calpoly.edu/theses/2090.
Full textAbstract:
A three-year study was conducted at a commercial vineyard site in California’s Edna Valley AVA to evaluate the physiological and agronomical effects of the timing of cluster thinning on Pinot noir (clone 115) grapevines. Vines were thinned to one cluster per shoot at three selected time-points during the growing season (bloom, bloom + 4 weeks, bloom + 8 weeks), and fruit from each treatment was harvested and made into wine. Across all growing seasons, yield decreased 43% in thinned vines relative to un-thinned control vines. No effect of cluster thinning or interaction with growing season was found in vine shoot diameter, internode length, fruit zone light level, or cluster weight. Growing season significantly affected more fruit and wine parameters than did cluster thinning treatment, with interactions between treatment and growing season found in fruit Brix, titratable acidity, and anthocyanins, as well as wine anthocyanins and wine b* (yellow component). For example, bloom + 8 and bloom + 12 thinning treatments advanced Brix in 2017 but had no effect in 2018. Cluster thinning treatments increased berry anthocyanins by 43% in 2017 and by 103% in 2018 relative to the control. Similarly, cluster thinning increased berry total phenolics by 87% in 2017 and by 140% in 2018 relative to the control, with no significant differences found between the different thinning treatments. However, the levels of anthocyanins and total phenolics were generally not affected by cluster thinning treatment in the resulting wines. The fact that different cluster thinning treatments resulted in nil or minor effects on fruit and wine suggests that the vines tested were at or below a balanced crop load prior to the application of cluster thinning. Edna Valley AVA could likely support higher crop loads than 3.2 on the Ravaz index without negatively impacting fruit or wine composition and reducing crop load below that level is unlikely to increase fruit or wine quality.
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Rosário, Ana Catarina Silva de Matos. "Monda em macieira Gala (Malus domestica Borkh.). Estudo de novas substâncias ativas." Master's thesis, ISA/UL, 2013. http://hdl.handle.net/10400.5/7396.
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PEREIRA, Auderlan de Macena. "Crescimento, produção e qualidade de frutos de melão cantaloupe em função da utilização do agrotêxtil e do numero de frutos por planta." Universidade Federal de Campina Grande, 2015. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/724.
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O meloeiro tem se destacado no Nordeste em razão das condições de solo e clima que favorecerem o cultivo dessa olerícola. É uma planta da família das cucurbitáceas que permite várias formas de manipulação da relação entre a fonte e o dreno por meio de seu manejo cultural. Uma possibilidade de alterar a relação fonte:dreno no meloeiro seria a utilização do agrotêxtil (tecido não tecido) em diferentes épocas, associada com a fixação de diferente número de frutos por planta. O trabalho teve como objetivo avaliar a partição de assimilados, a produtividade e a qualidade de frutos do meloeiro quando submetidos à retirada do agrotêxtil em diferentes épocas e fixação de fruto na planta. O experimento foi realizado no Centro de Ciências e Tecnologia Agroalimentar (CCTA/UFCG) durante o período de agosto a dezembro de 2014, com plantas do híbrido de melão Cantaloupe Hopey King, no espaçamento de 2,0 x 0,8 m em Pombal - PB. O delineamento experimental foi o de blocos casualizados com os tratamentos alocados em um arranjo em parcelas subdivididas (5x3), onde na parcela constaram de diferentes épocas de retirada do agrotêxtil (20, 24, 28, 32, e 36 dias após o transplante), e na sub parcela de diferentes fixações de frutos na planta (1 fruto, 2 frutos e fixação livre) em oito repetições, sendo quatro utilizadas para as avaliações de crescimento e quatro para a produção e qualidade dos frutos. Avaliou-se neste trabalho a quantificação da expressão do sexo, o crescimento e a partição de assimilados, a produção e a qualidade dos frutos. A retirada do agrotêxtil em diferentes épocas e o número de frutos por plantas afetaram significativamente a relação fonte:dreno. As épocas de retirada do agrotêxtil e a fixação fruto promoveram alterações no crescimento, produção e qualidade dos frutos do meloeiro. O atraso na retirada do agrotêxtil de 20,0 para 36,0 DAT proporcionaram maiores número de flores hermafroditas, massa seca da folha e da parte aérea, área foliar e redução nos sólidos solúveis totais. A frutificação livre na planta reduziu o número de flores hermafroditas e elevou a massa seca do fruto e índice de colheita. A massa do fruto e a produtividade da cultura atingiu o máximo valor com a retirada do agrotêxtil aos 26,6 e 25,1 DAT, respectivamente. Plantas com um e dois frutos apresentaram maior massa, porém com menor produtividade, se comparado a plantas com fixação livre de frutos. A utilização do agrotêxtil a partir dos 25 DAT dificultou as práticas culturais como capinas e penteamneto das plantas devido ao entrelaçamento de ramas dentro do túnel ocasionando maior queda de flores e reduzindo a produtividade da cultura.
The melon has excelled in the Northeast because of soil and climate conditions that favor the cultivation of this vegetable crop. It is a plant of the Cucurbitaceae family which allows various forms of manipulation of the relationship between the source and the drain by means of their cultural practices. A possibility to change the font ratio: drain the melon would be the use of the agrotextile (nonwoven fabric) at different times associated with fixing different number of fruits per plant. The study aimed to assess the assimilated partition, productivity and the quality of the melon fruit when subjected to removal of the nonwoven at different times and setting fruit in the plant. The experiment was conducted in the Science Center and Agrifood Technology (CCTA / UFCG) during the period from August to December 2014, with melon hybrid plants Cantaloupe Hopey King in the spacing of 2.0 x 0.8 m in Pombal - PB. The experimental design was a randomized block with treatments assigned to a split plot arrangement (5x3), which consisted in part of different periods of withdrawal of the row cover (20, 24, 28, 32, and 36 days after transplantation) and sub plot of different fruits fixings in the plant (1 fruit, 2 fruit and free) in eight repetitions, four used for the growth of reviews and four for the production and fruit quality. It was evaluated in this study to quantify the expression of sex, growth and assimilated partition, production and fruit quality. The withdrawal of agrotextile at different times and the number of fruits per plant significantly affected the supply relationship: drain. The withdrawal times of the nonwoven and fruit fixation promoted alterations in the growth, production and fruit quality of melon. The delay in the withdrawal of agrotextile 20.0 to 36.0 DAT provided higher number of hermaphrodite flowers, dry weight of leaf and shoot, leaf area and reduction in soluble solids. Free fruiting in the plant reduced the number of hermaphrodite flowers and raised the dry matter of the fruit and harvest index. The fruit mass and crop yield peaked with the removal of agrotextile to 26.6 and 25.1 DAT, respectively. Plants with one and two fruits presented greater mass but with lower productivity compared to plants with fruits of free determination. The use of nonwoven from 25 DAT difficult cultural practices as weeding and combing plants due to the intertwining branches into the tunnel leading to higher drop flowers and reducing crop yield
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Long, Robert Llewellyn, and bizarrealong@hotmail com. "Improving fruit soluble solids content in melon (Cucumis melo L.) (reticulatus group) in the Australian production system." Central Queensland University. Biological and Environmental Science, 2005. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20051019.144749.
Full textAbstract:
Total soluble solids (TSS) is a reliable indicator of melon eating quality, with a minimum standard of 10% recommended. The state of Australian melon production with respect to this quality criterion was considered within seasons, between growing districts and over seasons. It was concluded that improvement in agronomic practice and varietal selection is required to produce sweeter melons. The scientific literature addressing melon physiology and agronomy was summarised, as a background to the work that is required to improve melon production practices in Australia.
The effect of source sink manipulation was assessed for commercially grown and glasshouse grown melon plants. The timing of fruit thinning, pollination scheduling, the application of a growth inhibitor and source biomass removal were assessed in relation to fruit growth and sugar accumulation. Results are interpreted against a model in which fruit rapidly increase in weight until about two weeks before harvest, with sugar accumulation continuing as fruit growth ceases. Thus treatment response is very dependant on timing of application. For example, fruit thinning at 25 days before harvest resulted in further fruit set and increased fruit weight but did not impact on fruit TSS (at 9.8%, control 9.3%), while thinning at 5 days before harvest resulted in a significant (Pless than 0.05) increase in fruit TSS (to 10.8%, control 9.3%) and no increase in fruit weight or number. A cost/ benefit analysis is presented, allowing an estimation of the increase in sale price required to sustain the implementation of fruit thinning.
The effect of irrigation scheduling was also considered with respect to increasing melon yield and quality. To date, recommended practice has been to cause an irrigation deficit close to fruit harvest, with the intent of 'drying out' or 'stressing' the plant, to 'bring on' maturity and increase sugar accumulation. Irrigation trials showed that keeping plants stress-free close to harvest and during harvest, facilitated the production of sweeter fruit.
The maintenance of a TSS grade standard using either batch based (destructive) sampling or (non-invasive) grading of individual fruit is discussed. On-line grading of individual fruit is possible using near infrared spectroscopy (NIR), but the applicability of the technique to melons has received little published attention. Tissue sampling strategy was optimised, in relation to the optical geometry used (in commercial operation in Australia), both in terms of the diameter and depth of sampled tissue. NIR calibration model performance was superior when based on the TSS of outer, rather than inner mesocarp tissue. However the linear relationship between outer and middle tissue TSS was strong (r2 = 0.8) in immature fruit, though less related in maturing fruit (r2 = 0.5). The effect of fruit storage (maturation/senescence) on calibration model performance was assessed. There was a negligible effect of fruit cold storage on calibration performance.
Currently, the agronomist lacks a cost-effective tool to rapidly assess fruit TSS in the field. Design parameters for such a tool were established, and several optical front ends compared for rapid, though invasive, analysis. Further, for visualisation of the spatial distribution of tissue TSS within a melon fruit, a two-dimensional, or hyper-spectral NIR imaging system based on a low cost 8-bit charge coupled device (CCD) camera and filter arrangement, was designed and characterised.
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Shirahige, Fernando Hoshino. "Produtividade e qualidade de híbridos de tomate (Solanum lycopersicum L.) dos segmentos Santa Cruz e Italiano em função do raleio de frutos, em ambiente protegido." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-04082009-093752/.
Full textAbstract:
Os objetivos do trabalho foram determinar o efeito do raleio de frutos sobre o rendimento e seus componentes e caracterizar qualitativamente os frutos de híbridos de tomate dos segmentos Santa Cruz e Italiano de crescimento indeterminado, cultivados em ambiente protegido, visando ao consumo in natura. Utilizaram-se 12 cultivares de tomate de mesa, sendo seis híbridos experimentais e seis testemunhas comerciais. Usou-se delineamento em blocos completos ao acaso, com parcelas divididas, com 12 tratamentos e três repetições. As parcelas foram representadas pelas cultivares e as subparcelas pelo efeito de raleio, avaliando-se plantas com e sem raleio de frutos. Avaliaram-se a produção total (PT), comercial (PC) e de frutos nãocomercializáveis (PR), massa média do fruto (MM), número de frutos por planta (FP), número de frutos por inflorescência (FI), número de lóculos por fruto (LC), comprimento (CM), largura (LR) e relação entre comprimento e largura do fruto (CM/LR), tamanho da cicatriz peduncular (CP) e espessura da parede do fruto (EP). Para as análises qualitativas dos frutos, foram avaliados o teor de sólidos solúveis (SS), acidez titulável (AT), teor de ácido ascórbico (AA), pH, relação entre SS e AT (SS/AT) e teor de licopeno (LI). Nas condições em que o presente trabalho foi realizado e baseado nos resultados obtidos, conclui-se que o raleio dos frutos proporciona incremento da produção comercial, massa média, comprimento e largura do fruto para os híbridos THX-02 e THX-03, do segmento Santa Cruz, e THX-04, THX-05 e Netuno, do segmento Italiano e não mostrou vantagens para produção e seus componentes para os demais genótipos e características avaliadas. O raleio também não influencia a qualidade organoléptica dos genótipos avaliados, independentemente do segmento varietal. As diferenças entre elas se devem à constituição genotípica per se. Foi ainda concluído que Avalon apresenta maior teor de ácido ascórbico que Netuno e Sahel, e Débora Max, THX-01, THX-02 e THX-04, são semelhantes entre si quanto ao teor de licopeno, mas diferem de Giuliana, Sahel, THX-03, e THX-06.The objectives of this work were to determine the effect of cluster thinning on yield and its components on tomato hybrids of the Santa Cruz and Italian types of indeterminate growth, and to perform the qualitative characterization of the fruits, aiming at in natura growth. Treatments consisted of 12 indeterminate fresh-market tomato cultivars (six experimental hybrids and six commercial cultivars). A randomized complete block design was used in this trial, with split-plots, and 12 treatments replicated three times. The hybrid cultivars were allocated in the plots and the fruit thinning effect (with and without manual fruit thinning) was observed in the subplots. Total (PT), marketable (PC) and not marketable fruits (PR) yields, average fruit weight (MM), number of fruits per plant (FP), and, number of fruits per inflorescence (FI), number of locules per fruit (LC), fruit length (CM), fruit width (LR), length/width (CM/LR), size of the stem scar (CP), fruit wall thickness (EP) were measured. For quantitative characterization, soluble solids concentration (SS), ascorbic acid content (AA), tritable acidity (AT), pH, SS and AT ratio (SS/AT) and lycopene (LI) contents were measured. Based on the results of the trial carried out can be concluded that: a) the fruit thinning has increased marketable yield, average weight, length and width for the Santa Cruz hybrids THX-02 and THX-03, and THX-04, THX-05 and Netuno classed as Italian type. Furthermore, this practice did not provide benefits for production and its components for the other genotypes and characteristics evaluated, despite of the varietal type, and does not affect the organoleptic quality of the genotype. It was also concluded that regarding ascorbic acid content Avalon outperforms Netuno and Sahel, and Débora Max, THX-01, THX-02 and THX-04 are similar to each other as the content of lycopene, but differ from Giuliana, Sahel, THX-03, and THX-06.
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Campos, Antônio Marcos Diniz. "Espaçamentos e manejo na produção de híbridos de melancia em duas épocas." Universidade Federal de Uberlândia, 2014. https://repositorio.ufu.br/handle/123456789/12215.
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Although Brazil is the fourth watermelon (Citrullus lanatus) producing country in ranking position, its greatest challenge is the low yield average obtained (22.5 t ha-1). Such yield, places Brazil in the 38th position in the world rank, reflecting the amount of effort still needed to increase Brazilian yield efficiency. Thus, greater knowledge about the agronomic traits of new cultivars is relevant to obtain more yield efficiency. The constant search for yield increase demands for the optimization of crop practices associated to plant density, as a function of new cultivars, planting regions and market characteristics. Spacing variation can change plant development and its response to production factors. Presently, both for watermelon fruit thinning management and plant density, the recommendations are based on old varieties in greenhouses or in agreement with empirical observations of growers and technicians. Therefore, this study evaluated the effects of plant density and fruit thinning, in different plant positions, on watermelon yield and fruit quality, under dripping irrigation, in two experimental watermelon hybrids. The experiments were done at Bayer Vegetable Seeds Experimental Farm, in Uberlândia-MG, in two seasons, from April to July (Autumn-Winter) and from August to November (Winter-Spring), consisting of two watermelon experimental hybrids (X and Y); two fruit thinning management systems (A basal, or B distal), and four plant densities (3000, 4000, 5000 e 6000 plants ha-1). Fruit average weight, fruit density, brix, flesh firmness, flesh color, hollow heart and yield were evaluated. Average fruit weight was inversely proportional to the plant density up 5000 plants ha-1. Fruit size increases again, between 5000 and 6000 plants ha-1, probably due to better use of fertilizers. Therefore, greater yield was obtained with plant density of 6000 plants ha-1, with a commercial fruit size better accepted in the market (above 10 kg). Better performance was observed in all characteristics within management A (basal), season 2 (August-November), while some characteristics showed better performance in the season 1 (April-July) under the management B (distal). Thus, basal fruit thinning becomes relevant only if there is no adequate water supply and temperature for watermelon crop. Greater yield potential was observed in hybrid X, as well as greater qualitative traits potential, especially when weather conditions were more adequate for its development. Under less favorable weather conditions (season 1) hybrid X was more responsive to basal fruit thinning (management A) considering the trait average of fruit weight, with an increase of 2.5 kg per fruit and, consequently, more responsive to yield with an increase of 11.4 t ha-1.Apesar de o Brasil ocupar a quarta posição mundial no ranking dos países que mais produzem melancia (Citrullus lanatus), o maior desafio reside na baixa produtividade média alcançada (22,5 t ha-1). Com esta produtividade, o Brasil ocupa a 38o colocação no ranking mundial, o que reflete o quanto de esforços ainda precisa ser feito para aumentar a eficiência produtiva. Desta forma, o conhecimento aprofundado das características agronômicas das novas cultivares é muito relevante. A busca incessante pelo aumento de produtividade faz com que, em razão de novas variedades, novas regiões de plantio e de características de mercado, haja uma otimização de práticas culturais associada à adequação da densidade populacional. Variações no espaçamento podem alterar o desenvolvimento da planta e a resposta aos fatores de produção. Atualmente, tanto para o manejo do desbaste de frutos, quanto para a densidade populacional da melancieira, as recomendações são baseadas em variedades antigas sob cultivo protegido ou de acordo com observações empíricas de produtores e técnicos. Em razão do exposto, objetiva-se avaliar os efeitos da densidade de plantas e dos desbastes de frutos, em diferentes posições na planta, sobre a produtividade e qualidade da melancia, no sistema de gotejo, em dois híbridos experimentais de melancia. Os experimentos foram realizados na fazenda experimental da empresa Bayer Vegetable Seeds, no município de Uberlândia-MG. Estes foram conduzidos em duas épocas, entre Abril e Julho (Outono-Inverno) e entre Agosto e Novembro (Inverno-Primavera). O experimento constituiu-se de dois híbridos experimentais de melancia (X e Y); dois manejos de posição de frutos (manejos A-basal e B-distal) e de quatro densidades de plantas (3000, 4000, 5000 e 6000 plantas.ha-1). Peso médio de frutos, densidade de fruto, brix, firmeza de polpa, cor de polpa, presença de cavidade interna e produtividade foram avaliadas. O peso médio de fruto foi inversamente proporcional à densidade de plantas até 5000 plantas.ha-1. Entre 5000 e 6000 plantas.ha-1, o tamanho de fruto volta a aumentar, provavelmente, devido ao maior aproveitamento de fertilizantes. Portanto, maior produtividade foi obtida na densidade de 6000 plantas/ha com tamanho comercial de fruto mais aceitável no mercado (acima de 10 kg). Dentro do manejo A (basal), na época 2 (Agosto-Novembro) observou-se valores superiores para todas as características. Já no manejo B(distal), algumas características responderam melhor na época 1 (Abril-Julho). Portanto, o desbaste de frutos dos nós basais só é relevante se não houver água e temperatura adequadas para a cultura da melancia. Maior potencial produtivo foi observado no híbrido X, como também, maior potencial qualitativo, especialmente quando as condições de clima foram mais adequadas ao seu desenvolvimento. Em condições de clima não muito favoráveis (época 1), o híbrido X foi mais responsivo ao desbaste dos primeiros frutos (manejo A-basal) para a característica peso médio de fruto com um incremento de 2,5 kg por fruto e, consequentemente, mais responsivo à produtividade com um incremento de 11,4 t.ha-1.
Mestre em Agronomia
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Maurer, Michael A., and Kathryn C. Taylor. "Evaluation of thinning agents for "kinnow" mandarins." College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/222532.
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An experiment was designed to determine the effectiveness of foliar prebloom boron (B) sprays for thinning 'Kinnow' mandarins (Citrus reticulata). Treatments consisted of a control and foliar B applied at 1000, 1500, 2000, 2500 and 3000 ppm. Leaf tissue B levels were not significant between treatments. Likewise, fruit quality was similar for all treatments. Fruit weight and number were significantly greater for the control compared to the 1500, 2000, 2500 and 3000 ppm B treatments for the undersize fruit. There was a clear reduction in yield as the rate of B applied increased, however, the reduction was not statistically significant.
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Fallahi, Esmaeil, Michael Kilby, and John W. Moon. "Effects of Various Chemicals on Dormancy, Maturity and Thinning of Peaches." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/215745.
Full textAbstract:
Effects of 5 chemicals on the reduction of dormancy and early maturity of peaches were studied for 3 years under the desert climatic condition of Southwest Arizona. CuSO4, urea and particularly hydrogen cyanamide reduced the dormancy and enhanced blooming. Application of hydrogen cyanamide in October induced full bloom in November (1 month after application) and produced fruit. Late November was the most appropriate time for application of hydrogen cyanamide, and fruit were harvested 10 days before normal time in April. No difference was found between 5% and 3% (V/V) of hydrogen cyanamide in the time of blooming; however, rate at 5% always caused some phytotoxicity. Application of hydrogen cyanamide at 1% before bloom and at full bloom produced the same size of commercially packed fruit as hand-thinned ones.
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Yuan, Rongcai. "Effect of benzyladenine on fruit thinning and its mode of action on 'McIntosh' apples." 1998. https://scholarworks.umass.edu/dissertations/AAI9841934.
Full textAbstract:
6-benzylaminopurine (BA), which was applied at the 10 mm stage of fruit development at 50 and 100 mg.liter$\sp{-1}$ to 'McIntosh' apples (Malus domestica Borkh), effectively thinned fruit, and increased fruit size and caused seed abortion. Regardless of BA treatment, there were two distinguishable peaks of fruit abscission during 'June drop' on 'Morespur McIntosh' apples. There was a large peak about 14 days after treatment and a second smaller one 24 days after treatment. The first abscission peak was increased by BA, and approximately half of then existing fruit abscised from treated trees between 10 and 14 days after treatment, whereas only one fourth abscised from the control trees. The number of seeds per fruit was lower in abscising fruit than in persisting fruit regardless of BA treatment. Seed number of abscising fruit was increased linearly by BA application. BA enhanced the translocation of $\sp{14}$C-sorbitol from leaves to fruit when applied directly to the fruit, but not when applied directly to the leaves. Therefore, it is unlikely that BA thinned apple fruit directly through restricting the translocation of photosynthates moving from leaves to fruit. Net photosynthesis was decreased and dark respiration was increased when temperature following BA application was high (30$\sp\circ$C), whereas there was no effect when temperature was lower (20$\sp\circ$C). Total nonstructural carbohydrates, total soluble sugars, reducing sugars, and starch in the leaves decreased dramatically over the 12 or 13 day observation period, regardless of BA treatment. These carbohydrate levels were further lowered by BA application. Abscising fruit, based on specific reddening of pedicel, had higher reducing sugars, total soluble sugars, starch, and total nonstructural carbohydrates. The levels of these carbohydrates in fruit from BA treated trees were similar to that from untreated control trees. Foliar application of 5% sorbitol solution had no effect on fruit set. Removal of bourse shoot tip increased fruit set regardless of BA treatment. BA thinned fruit regardless of whether shoot tips were removed or not, and there was no interaction between BA application and shoot tipping. Experiments were conducted to evaluate the effects of BA on fruit set and fruit development on small fruiting branches supported by different numbers of leaves per fruit. BA thinned fruit only when one leaf per fruit was on the girdled small fruiting branch, but not when the leaf number was greater than two. Fruit weight and soluble solids content increased quadratically with increasing leaf number per fruit. BA reduced fruit growth rate when less than 16 leaves were present on the girdled branches between 3 and 7 days after treatment, but it did not affect fruit growth rate when 32 leaves were on the girdled branches. Increasing leaf number also increased normal seed number while decreasing the number of aborted seeds, but it had no effect on the number of total seeds per fruit. BA reduced the number of normal seeds per fruit only when the number of leaves per fruit was less than 4. These results were discussed in relation to carbohydrate supply and source-sink relationships.
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Yeh, You-Chiao, and 葉侑橋. "Effect of Harvest Date and Flower Thinning on Flowering and Fruit Growth of Kumquats (Fortunella spp.)." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/19241042927446816161.
Full textAbstract:
碩士國立臺灣大學
園藝學研究所
103
In this research, we discussed the possible effects of harvest timing on fruit quality of Fortunella margarita Swingle, Fortunella obovata Tanaka, and Fortunella crassifolia Swingle. We also discussed the effects of flower thinning to flowering time, fruit set timing, and fruit quality of F. margarita Swingle. These allow us to know the possibility of forcing through flower thinning in kumquat production. Kumquat flowers continuesouly during summer, therefore, the time for harvest lasts several months. Whether to harvest or not depends on fruit coloration. According to the criteria for harvest from local cultivators, we harvested fruits from orchards located in Jiaoxi, Ilan, every 15 days starting from Nov. 3rd, 2013. The measurement of total soluble solids and organic acid contents were made to better understand the appropriate time to harvest. Fruits of F. margarita were collected four times from Nov. 3rd to Dec. 18th. The fruits harvested on Dec. 3rd have higher ratio of total soluble solids to organic acid contents, which was 12.37, compared with the rest. The fruits harvested on Nov. 3rd have higher organic acid contents, which was 1.63%. The fruits harvested on Dec. 3rd have higher fruit weights and volume, which were 16.49 g and 17.73 cm3, when comparing to other time of harvest. The appropriate time for harvest starts from December for F. margarita. As for F. obovata, a total of seven times of harvest was done from Nov. 3rd to Feb. 1st next year. The fruits harvested from Nov. 18th to Dec. 18th have an average weight and volume of 37.85 g and 41.63 cm3, which was greater than fruit from other time for harvest. In the fruits harvested on Dec. 3rd, total soluble solid reached 9.24 °Brix, which is the highest in the entire harvest season. The appropriate harvest season for F. obovata is found from Nov. to Dec. As for F. crassifolia, a total of three times of harvest was done from Dec. 3rd to Jan. 2nd next year. The ratio of total soluble solid to organic acid contents decreased from 33.89 to 18.12 if the time for harvest delayed. In short, the appropriate harvest time for premium quality of F. margarita was later than that of F. obovata, with a month of poor fruit quality before the appropriate harvest time, which waste labour cost. If an increment in the number of fruit set can be imposed into the appropriate harvest time, it’s possible to raise grower’s income. From Jun. to Sep., 2014, eight flower thinning treatments were made to thirty-two F. margarita trees in the orchard in Jiaoxi, Ilan. F. margarita flowers four to five times a year, while the time for most flowers anthesis of F. margarita is mainly in first flowering time, an average of seven flowers and two fruits per shoot was observed, which contributed mainly to the total number of fruit set. Flower thinning was done on Jun. 30th, this caused a decrement in total fruit set. However, only flowers were thinned in the first flowering time, the amount of flower anthesis and fruit set in the second flowering time were significantly more than the second flowering time when untreated. If flowers were thinned for three flowering times, the next flowering time and main fruit set timing will be postponed to about two months, with an average number of flowers less than one flower per shoot and lower yield. After thinning, a delay was found in timing of both flowering and fruit set. The later thinning was done, the longer these periods postponed. Although, thinning gave a decrement in total number of fruit set. Relatively low rate of fruit set and drastic yield variation due to weather condition can be assumed, since large amount of flowers anthesis in the first flowering time. In summer, after the first flowering time, the second flowering time appeared for about two weeks later. Flower thinning in the first flowerinng time can asure a delay in the time for the second flowering time with certain amount of flowers and fruit set. In sum, flowering thinning in the 1st flowering time can postpone the time of fruit set for a month, reaching the goal of raising the number of fruit set in the appropriate harvest time for Fortunella margarita Swingle.
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Li, Sheng-Yang, and 李昇陽. "Bourse thinning effects on pear fruit growth and water balance of ‘Shinko’ under top-working system." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/23075390857591382941.
Full textAbstract:
碩士國立臺灣大學
園藝學研究所
99
In the annual top-working system, bourse shoots sprout from auxiliary vegetative buds after bloom. At early fruit growth period, growing bourse shoots may compete with fruitlets on a top-working unit for carbohydrates and thus affecting fruit growth and development. On the other hand, upon maturity bourse shoots may not only be an important source for supporting carbohydrates for further growth of fruit but also regulating fruit water balance. Pear growers practicing annual top-working usually thin bourse shoots off the top-working unit before bagging fruit at mid growing season. The main hypothesis of this study was that bourse shoot thinning results negative effect on fruit growth and final fruit size. This hypothesis was tested in field and potted ‘Hengshan’ trees top-worked with ‘Shinko’ bud chips. Bourse shoots from the bud chip were subjected to thinning treatments and fruit growth was measured. Bourse shoot thinning did not reduce final fruit size but relative fruit growth was temporary declined after bourse shoot thinning. Bourse shoot thinning reduced nocturnal expansion of fruit diameter but did not affect day-time fruit contraction. Effects of bourse shoot thinning on diurnal fruit size fluctuation were also temporary and not were detectable in raining days. Skin texture of ‘Shinko’ pears changes from smooth to russet skin toward full maturity. It was hypothesized that the surface transpiration of a ‘Shinko’ pear fruit changes along with the growth of the skin. To test this hypothesis, fruit in a commercial orchard practicing annual top working were periodically sampled and surface transpiration was measured in a controlled environment. The surface transpiration based on surface area of a growing ‘Shinko’ pear fruit decreased toward fruit maturity but total water loss through surface transpiration increased due to rapid increase in surface area. Considering the simultaneously rapid increase in fruit weight, the influence of surface transpiration of ‘Shinko’ pear fruit on fruit water balance were at its maximum when fruit was young. Along with fruit growth and skin texture change, influence of surface transpiration quickly declined.
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Pescie, Maria. "Effect of time and severity of thinning on fruit quality and yield in hardy kiwifruit (Actinidia arguta) /." 2001. http://hdl.handle.net/1957/7123.
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Chiang, Chih-Hsiang, and 姜志祥. "Effects of Girdling and Inflorescence Thinning on Plant Nutrition and Fruit Yield in Litchi (Litchi chinensis Sonn.)." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/zdjuyh.
Full textAbstract:
碩士國立屏東科技大學
農園生產系所
105
Low and irregular yields have been reported as the major problems in litchi (Litchi chinensis Sonn.) production in Taiwan. These problems are attributed either to a failure to poor flowering or to a failure to set and retain fruit. The goal of this research is to elucidate the effects of girdling and inflorescence thinning on the content of carbohydrate and yield in field-grown ‘Yu Her Pau’ and ‘Tainung No.2’ litchi. Different parts of trees including mature stems, mature leaves, root, bark and inflorescences were sampled before/after girdling and inflorescence thinning. And, their total soluble sugar and starch contents were analyzed in order to reveal the change patterns of the carbohydrate in various organs. Fruiting shoots were selected before full bloom to monitor fruit set weekly, and fruit yield and quality after harvest were recorded. After girdling, the carbohydrate content of the girdling treatment increased in mature stems, mature leaves and bark (above girdling) compared with control (non-girdling). And, starch was the major carbohydrate pattern accumulated in them. In the first experiment, the numbers of fruit set were significantly decreased from 5 to 8 week after inflorescence thinning, while both retention number of fruits and yield per cluster in the girdling group were still higher than the one in control. In the second experiment, the treatment of inflorescence pruning was finished before the beginning of the first flowering wave. And, they were hand thinned and respectively retained base 1/2 (IT1), mid 1/3 (IT2) and base 1/3 (IT3) of the inflorescence length. After ‘Yu Her Pau’ litchi anthesis, the total soluble sugar, starch and carbohydrate contents in the inflorescences were increased, and IT3 was the highest among the treatment. However, all of analysis contents in the inflorescences were declined with fruits development at fruit set stage, and it was still the highest in IT3 treatment. And, IT3 treatment has the most abundant on the fruit retention number per cluster (12 fruits). After ‘Tainung No.2’ litchi anthesis, the change trend of total soluble sugar, starch and carbohydrate contents in the inflorescences were the same as ‘Yu Her Pau’ litchi. At fruit set stage, IT3 treatment has the significantly most of total soluble sugar (6.21%), starch (7.18%) and carbohydrate (13.39%) content contents in the inflorescences. However, CK (non-inflorescence thinning) has the most of the fruit retention number per cluster (14.5 fruits), and it is significantly higher than inflorescence thinning groups. In the third experiment, non-pruned part of inflorescence has more than pruning inflorescence treatment on the fruit number and fruit weight per cluster in ‘Tainung No.2’ litchi. Similarly, compared with the non-girdling group, the fruit number per cluster of the girdling group is higher. The results indicated that girdling combined with non-inflorescence thinning treatment could get the best number of fruit and total fruit weight in ‘Tainung No.2’ litchi.
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Tsai, Bi-Cheng, and 蔡弼丞. "Effects of Fruit and Flower Development and Hand Flower Thinning on Growth of Tea (Camellia sinensis (L.) O.Kuntze)." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/54431083978593923012.
Full textAbstract:
碩士國立臺灣大學
園藝暨景觀學系
103
This study is to explore Taiwan main cultivars ‘TEES No. 12’ and ‘Chin-Shin Oolong’ reproductive characteristics, and its effect on growth and yield. It is divided into eight stages from labeling to flowering. In stage 1-4, each length and width of flower is less than 5 mm and 4 mm. Flowers grow slowly in this period. In stage 5-7, flowers enter rapid growth period and petals turn to white. Color of stamens turn to yellow from transparent. In stage 8,flowers enter anthesis period. ‘TEES No. 12’ and ‘Chin-Shin Oolong’ flowers both appear single sigmoid growth curve. ‘TEES No. 12’ needs 102 days and ‘Chin-Shin Oolong’ needs 114 days from labeling to anthesis. Investigating fruit height, width and fresh weight of ‘TEES No. 12’ and ‘Chin-Shin Oolong’ that show fruits both belong to single sigmoid growth curve. Weight of ripe fruits with single seed, double seeds and triple seeds of ‘TEES No. 12’ and ‘Chin-Shin Oolong’ is 4.37 ± 1.7 g, 6.27 ± 1.33 g, 6.51 ± 0.71 g, and 4.7 ± 0.8 g,7.0 ± 1.3 g, 11.8 ± 0.6 g individually. In order to understand the effect of pot’s size and hand flower thinning treatment on top and root growth, planting ‘TEES No. 12’ annual cutting in 30 cm and 60 cm pot, and utilize 50％ hand flower thinning, 100％ hand flower thinning and control treatment. Results indicate that 50％ hand flower thinning and 100％ hand flower thinning can advance roots growing. Pot’s size treatment and hand flower thinning treatment have an interaction on total root length and root weight. Which planting in 60 cm plot cuttings, hand flower thinning treatment promote roots fresh weight, roots dry weight, total root length and total dry weight. Further investigating the effect of hand flower thinning treatment on tea yield, character, nutrient content and fruit yield. Using ‘TEES No. 12’ as material, and comparing the effect of 0％ hand flower thinning, 25％ hand flower thinning, 50％ hand flower thinning, 75％ hand flower thinning, and 100％ hand flower thinning on autumn tea, winter tea, spring tea, and summer tea. Using 50％ hand flower thinning treatment advances leaves’ weights of winter tea and spring tea. Summing four season yield, 50％ hand flower thinning treatment is 281.1 g/m2 ,and control is 195.9 g/m2. Yield will increase 0.85 ton every hectare and per year. Using 25％ and 50％ hand flower thinning treatment increase 2nd leaf thickness, 3rd leaf width, and 3rd leaf thickness. Using 75％ and 100％ hand flower thinning treatment promote bud elongation. Except 100％ hand flower thinning treatment, other treatments maintain fruit yield. 100％ hand flower thinning has the highest score in winter tea quality, which has relatively bright color. 50％ hand flower thinning on spring tea has rich fragrance. In nutritional analysis of leaves, using 50％ hand flower thinning increases nitrogen content of autumn tea, potassium content of autumn tea, phosphorus content of winter tea and phosphorus content of summer tea. Based on the above results, using 50％ hand flower thinning can promote tea yield, character, and quality.
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Campos, Catarina Alexandre. "Mecanismo de acção do ácido 1-naftalenoacético (ANA) na monda de frutos de nespereira (Eriobotrya japonica Thunb. Lindl.)." Master's thesis, 2009. http://hdl.handle.net/10400.5/1900.
Full textAbstract:
Mestrado em Engenharia Agronómica - Instituto Superior de AgronomiaThe mode of action of naphthaleneacetic acid (NAA) (20 mg/l) in fruit thinning of loquat was studied through the action of NAA on both female and male gametophyte of ovules and pollen grains cultured in vitro. Additionally, in vivo treatments with NAA to the panicles of different growth stages were carried out. The flowers of these panicles were observed with fluorescence microscopy in order to evaluate the effect of NAA in the ovule’s development and in the pollen grain germination. In vitro results showed that NAA prevents pollen germination, pollen tube growth and ovule’s development from flowers of panicles in the stage 609-700 BBCH. In vivo, NAA also prevents pollen germination and pollen tube growth for 7 days after the treatment. In flowers near the stage 609 BBCH, NAA interrupts the ovule’s development, resulting in the emergence of callose in the chalazal part of the ovule. Ovules in previous or later stages than 605- 700 BBCH are insensitive to NAA, therefore, if this treatment is carried out earlier or later becomes ineffective.---------------------------------Neste trabalho, estudou-se o mecanismo de acção do ácido 1-naftalenoacético (ANA) (20 mg/l) sobre a monda de frutos de nespereira, para tal analisou-se a acção do ANA sobre o gametófito masculino e feminino, procedendo-se à cultura de grãos de pólen e de óvulos in vitro. Paralelamente, foram feitos tratamentos com ANA in vivo, a panículas de diferentes estados fenológicos. As flores destas panículas foram observadas através de microscopia de fluorescência para avaliar o efeito do ANA no desenvolvimento dos óvulos e na germinação de grãos de pólen. Os resultados mostram que o ANA, em condições in vitro, impede a germinação dos grãos de pólen, o crescimento do tubo polínico e o desenvolvimento de óvulos provenientes de flores de panículas no estado 609-700 da escala BBCH. In vivo, o ANA impede a germinação de grãos de pólen e o crescimento do tubo polínico durante 7 dias após o tratamento e nas flores próximas do estado 609 BBCH interrompe o desenvolvimento dos seus óvulos, levando ao aparecimento de calose na calaza do óvulo. Os óvulos em estados anteriores e posteriores a 605-700 BBCH são insensíveis ao tratamento com ANA, consequentemente, se este tratamento for efectuado antecipada ou tardiamente torna-se ineficaz.
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Yeshitela, Teferi Belayneh. "Effect of cultural practices and selected chemicals on flowering and fruit production in some mango (Mangifera indica L.) cultivars." Thesis, 2005. http://hdl.handle.net/2263/23181.
Full textAbstract:
Although mango (Mangifera indica L.) has been studied for many years, numerous problems still elude researchers. The objectives of the current trials were to study the effects of some cultural practices (fruit thinning, panicle/ bud/ renewal/ post-harvest pruning) and chemicals (Corasil.E, potassium nitrate/urea, paclobutrazol) on various vegetative, floral, yield and quality parameters. The study meant to address problems of both South African and Ethiopian mango growers. The thinning (on ‘Sensation’) and pruning (on ‘Tommy Atkins’ and ‘Keitt’) experiments were conducted for two seasons (2001-2003) at Bavaria Fruit Estate in South Africa. Effects of Paclobutrazol and Potassium nitrate were studied on ‘Tommy Atkins’ during 2002-2003 season at Upper Awash Agro-industry Enterprise in Ethiopia. Complementary effects of paclobutrazol and potassium nitrate on floral induction were studied in growth chamber experiments at the experimental farm of University of Pretoria on ‘Tommy Atkins’ and ‘Keitt’ mango. Where fruit on ‘Sensation’ were thinned to one and two fruit per panicle, a significant increase was obtained for most of the fruit quantitative parameters. The treatments where one fruit and two fruit per panicle were retained and 50% panicles removed, produced a significant increase in size of the fruit, fruit qualitative parameters and fruit retention percentage. Corasil.E produced very small sized fruit with a considerable percentage of “mules” (fruit without seed). Trees subjected to severe thinning intensities showed earlier revival of starch reserves and better vegetative growth. Applications of paclobutrazol (1- (4-chlorophenyl) –4,4-dimethyl-2- (1,2,4- triazol-1-yl) pentan-3-ol) at rates of 5.50 and 8.25 g a.i. per tree, both as a soil drench and spray applications, on ‘Tommy Atkins’ mango were effective in suppressing vegetative growth as compared to the control. Consequently, the trees from these treatments had higher total non-structural carbohydrate in their shoots before flowering which led to higher results of percentages of shoots flowering, number of panicles produced, percentages of hermaphrodite flowers, yield and quality of the fruit. Trees that received panicle pruning (during full bloom) treatment at the point of apical bud attachment, were observed to be induced for synchronized re-flowering and also attained more fruit per panicle. On the other hand, trees on which renewal pruning (early in the season) and post-harvest pruning (especially for early cultivars) treatments were applied, have been observed for the development of an adequate number of productive inflorescences. Post-harvest pruning treatments also resulted in greater vegetative growth on both cultivars. The responses to pruning treatments were greater especially in ‘Tommy Atkins’ than ‘Keitt’. The trend for the interaction of duration and chemicals in Tommy Atkins and Keitt mango cultivars revealed the possible floral induction complementary effect of PBZ after the trees were induced only for 15 days at 10/15 oC temperature. Higher potassium nitrate concentrations especially in combination with urea (5 litre solution of 4% KNO3+0.5 g urea tree-1 and 5 litres of 4% KNO3+1 g urea tree-1 ) produced higher results for most of the flowering and yield parameters in ‘Tommy Atkins’.Thesis (DPhil (Horticulture))--University of Pretoria, 2006.
Plant Production and Soil Science
unrestricted
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Wang, Yi-Han, and 王藝翰. "Effects of Inflorescence Thinning and Types of Reproductive Shoots on Flower Sex Ratio,FruitSetand Fruit Quality of ‘No Mai Taz’ (73-S-20)Litchi(Litchi chinensis Sonn.)." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/59802716315326358682.
Full textAbstract:
碩士中興大學
園藝學系所
103
Poor yield and unstable of flowering have been reported as the major production problems of‘No Mai Tsz’(73-S-20)litchi in Taiwan. The objective of this study was to document the effect of inflorescences thinning and types of reproductive shoots on the flower sex ratio, fruiting and fruit quality. 1/2 to 2/3 flowers per inflorescences were removed by hand right before 1 and 3 weeks of anthesis (female flower is full blooming). That inflorescence thinning before 3 weeks of full anthesis could affect flower sex ratio, but could not promote fruit set and fruit quality in ‘No Mai Tsz’ (73-S-20) lithci. We investigate the axis length of inflorescences, leaf length, chlorophyll readings and gas exchange rate at 1 week after leaflet unfolding of mixed shoot. In second experiment we investigate the generative shoots, mixed shoots and transition shoots on field growth tree. The gas exchange rate were determined at over fruit growing period. That concluded that photosynthetic capacity comapred within leaflet of leafy inflorescences and generative shoot are no difference, but leaflet of mixed has a samller size than leaflet of generative shoot. Generative shoots had highest flower numbers (588), while mixed shoots (459) and transition shoots (221) followed respectively, suggesting that it had a gradual reduction of flower numbers associated with the attribute of leafy reproductive shoots. No difference was recorded in sex ratio of M1, F and M2 flowers among all types of shoots. The major wave of fruit drop, more than 80%, occurred within 5 weeks after full bloom, regardless of the types of shoots. The number and proportion of fruit retained at harvest in generative, mixed and transition shoots were 1.4、0.7%, 2.3、1.5% and 2.1、2.4%, respectively. There was no difference in fruiting and yield performance among all types of shoots. Most characteristics of matured fruit, including weight of fruit, aril and seed as well as aril sweetness, did not vary with types of shoots, besides the pericarp weight of transition shoots was inferior to that of other two types of shoots. defoliate of mixed shoot on difference inflorescences growth stage, undefoliate on mixed shoot and generative shoot are control. Our results indicated that inflorescences leaf of mixed shoot inhibit inflorescences development, resulting in Total flower number of mixed shoot were much less than that of generative shoot. Whihe inflorescences leaf of mixed shoot have potential of stabilizing fruit set and does not affect fruit quality.
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Domingos, Sara Nobre Gonçalves. "O ensombramento como técnica de monda na macieira 'Gala' (Malus domestica Borkh.). Caracterização agronómica e ecofisiológica." Master's thesis, 2009. http://hdl.handle.net/10400.5/627.
Full textAbstract:
Mestrado em Engenharia Agronómica - Hortofruticultura e Viticultura - Instituto Superior de AgronomiaIn this study, carried out in 2007, at the University of Bologna Experimental Farm, a new thinning method via shading in ‘Gala’ apple trees is proposed. The two treatments compared were: chemical thinning (NAA 12 ppm + 6-BA 120ppm, at 14 DAFB) and artificial shading (with a polypropylene 90% shading cloth, at 30 DAFB, for one week). Fruit drop, fruit growth rate via caliper and electronic gauges, and whole tree gas exchange were measured before, during and after shading. Fruit daily growth patterns changed and greatly reduced under shading, as well as net carbon exchange rates, total and per unit of light intercepted by the trees, decreased more than 50% during shading. This work supports the hypothesis that C-deficit may induce fruit abscission around 30 DAFB. The effects of chemical thinning and shading on fruit abscission (58,4±1,98 and 56,3±2,42%), crop load (4,17±0,44 and 4,14±0,27 fruitscm-2TCSA), yield density (0,58±0,06 and 0,60±0,03 Kgcm-2TCSA), final fruit weight and size (164,89±1,97 and 165,37±1,39 g, 73,01±0,26 and 72,33±0,23 mm), were the same. Fruits quality was superior in shading, with higher sugar content, flesh firmness and titrable acidity.
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Vance, Amanda J. "Impacts of crop level and vine vigor on vine balance and fruit composition in Oregon Pinot noir." Thesis, 2012. http://hdl.handle.net/1957/30290.
Full textAbstract:
Vineyard management strategies, including vineyard floor management and crop level management, can be used to influence vine vigor and fruit composition. Two studies were conducted to evaluate the impact of these practices on Pinot Noir in Oregon's Willamette Valley. Managing crop levels is common in cool climate vineyard production though it is a costly practice. With economic pressures, the premium winegrape industry is questioning whether they can reduce production costs and increase yields without compromising quality. A crop thinning trial was conducted in 2010 and 2011 to address these concerns and to better understand the role of vine balance on fruit composition. Crop levels were moderately (35% crop removed) or severely (65% crop removed) thinned at pre-bloom, fruit set, lag phase, or véraison and compared to full crop treatments. In both years, crop thinning reduced yields but had no effect on berry weight or cluster size. In 2010, poor fruit set reduced overall yields, and thinning treatments resulted in very few differences in vine growth, cluster architecture or fruit composition, including total soluble solids (TSS), pH, titratable acidity (TA), yeast assimilable nitrogen (YAN), anthocyanins, phenolics and tannins. In 2011, yields were much higher due to high fruit set and larger cluster size. No differences were found in vine growth (leaf areas or pruning weights) or fruit YAN, but thinned vines had higher TSS and pH and lower TA than full crop vines at harvest. Fruit thinned at lag phase and véraison had higher TSS and lower TA than fruit thinned pre-bloom. Intensity of thinning had a
stronger influence on anthocyanin and tannin concentration than timing, while phenolics were not impacted by either factor. Ravaz index values (fruit yield/pruning weight) below 2.25 and leaf area to yield ratios of 2.25 to 3.25 m²/kg improved fruit composition in 2011 as did later season thinning, though data from the remaining years of this study will provide more insight into appropriate crop load metrics for cool climate Pinot Noir. A second study was implemented in 2011 to determine the impact of crop thinning in vines with different levels of vegetative vigor caused by three vineyard floor management techniques: permanent grass (Festuca rubra spp. rubra) cover (grass), alternating grass cover and tillage (grass & tilled), and tillage of every alleyway (tilled). Crop was thinned at the BB stage of berry development (EL stage 73) to one cluster per shoot (half crop) or not thinned (full crop); all cluster wings were removed at the time of thinning. Tillage treatments had been in place four years prior to the start of the study and competition for nitrogen in grass caused reduced early season vine growth, leaf chlorophyll and canopy size at both bloom and véraison while crop thinning increased canopy size at véraison. Yields were altered by tillage and crop thinning treatments, as grass had fewer clusters per shoot and berries per cluster, and crop thinning reduced yields to 64.7% of full crop across all tillage treatments. At harvest, grass had the lowest TA while TSS and pH were not affected by tillage. Crop thinning increased TSS but did not impact pH or TA. Anthocyanins were affected by both tillage and thinning and were found to be related to vine yield, YAN, leaf N, and leaf area index. Tannins were highest in grass but were not affected by crop thinning, and phenolics were not changed by either factor. Few interactions between tillage and crop thinning were found, but as variables such as yield per vine were impacted by both treatment factors, monitoring long term effects of cropGraduation date: 2012