Academic literature on the topic 'Seedlings growth parameters'

Light is a major environmental factor limiting the growth and survival of plants. The heterogeneity of the light environment after gap formation in forest influences the leaf chlorophyll contents, net photosynthetic rate (Pn), and chlorophyll fluorescence, thus influencing the growth and regeneration of Castanopsis kawakamii seedlings. The aim of this study was to explore the effects of weak light on the photosynthetic physiology of C. kawakamii seedlings in forest gaps and non-gaps. The results showed that (1) the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), and total chlorophyll (Chl-T) in forest gaps were lower than in non-gaps. Seedlings tended to increase chlorophyll content to absorb light energy to adapt to low light intensity in non-gap environments. (2) The Pn values of C. kawakamii seedlings in forest gaps were significantly higher than in non-gaps, and forest gaps could improve the seedlings’ photosynthetic capacity. (3) The C. kawakamii seedlings in forest gaps were more sensitive to weak light and control group treatment, especially the tall seedlings, indicating that seedlings require more light to satisfy their growth needs in the winter. The seedlings in non-gaps demonstrated better adaptability to low light intensity. The light intensity was not adequate in weak light conditions and limited seedling growth. We suggest that partial forest selection cutting could improve light intensity in non-gaps, thus promoting seedling growth and regeneration of C. kawakamii more effectively in this forest.

The experiment was conducted at the Agronomy research field of Bangladesh Agricultural University, Mymensingh from July to December 2013 to find out the effect of seedling age and storage duration on growth and yield of wet season rice. The experiment comprised of four ages of seedling (25, 30, 35 and 40-d-old) and four storage durations (0, 1, 2 and 3-days) of uprooted seedlings. Rice var. BRRI dhan52 was used as a test variety. The experiment was laid out in a split-plot design with 3 replications placing seedling age in the main plot and storage duration in the sub- plot. The effect of age and storage -duration of seedling, and their interaction were significant on growth parameters (shoot height, root length, number of tillers hill-1, leaf area index and crop growth rate), grain yield and straw yield. The growth parameters and yield exhibited a trend of decrease with the increase in seedling age and storage duration. All the growth parameters and yield showed highest value in the younger seedlings of 25-d-old with 0-day storage duration of uprooted seedlings while the lowest in the older seedlings of 40-d-old with 3-days of storage duration. The var.BRRI dhan52 produced the highest LAI (8.23), CGR (7.33 mg day-1 hill-1) and biomass (26.87 g) at 60, 45 and 60 days after transplanting. Grain yield reduced by 13, 19 and 37% of 30, 35 and 40-d-old seedlings, respectively compared to 25-d-old seedlings. In case of seedling storage, grain yield reduced by 5, 14 and 31% of 1, 2 and 3-d storage, respectively compared to 0-d storage. For optimum growth and yield of wet season rice, 25-d-old seedlings may be stored up to 1-day after uprooting taking into account the possible delay in transporting seedlings to the flood affected area from the nearby districts.Bangladesh Agron. J. 2017, 20(1): 45-56

This study was conducted during the growing season of 2021 and 2022 in horticulture station located at Akre city center Duhok Iraqi Kurdistan region, the study was aimed to investigate the effect of growth regulators on seedling growth of apricot and determined the best concentration of Gibberellin, Benzyl adenine and Kinetin to improve vegetative growth of seedling of apricot . so it consisted of three concentration of GA3 (0, 250 and 500 mg.L-1), BA (0,150 and 300 mg.L-1), KIN (0,150 and 300 mg.L-1) on some vegetative growth characteristics of apricot seedlings (Prunus armeniaca L.).The best results include the following. apricot seedlings sprayed with different concentrations of GA3 significantly affected and gave the seedling height, number of leaves, dry weight, single leaf area and total chlorophyll. Also, seedling sprayed with different BA concentration effected significantly and gave the highest seedling diameter, number of leaves, single leaf area, and dry weight. Whereas seedling spray with different KIN concentrations significantly affected on seedling diameter and total chlorophyll. Generally, interaction between GA3 and KIN and interaction between GA3 and BA and the interaction between BA and KIN was effected significantly on most growth parameters. The best result was in the treatment (GA3 500 mg.L-1 + BA 300 mg.L-1 + KIN 150 mg.L-1) which significantly affected on all growth parameters (seedling height, seedling diameter, single leaf area, total chlorophyll, number of leaves and dry weight)

Seedling quality is an important input affecting the outplanted seedling performance. Morphological attributes and association with symbiotic ectomycorrhizal (ECM) fungi belong to influential traits determining seedling quality. In this study, the effect of pre-sowing applied commercial additives Ectovit (containing hydrogel and ECM fungi), Mycorrhizaroots (ECM fungi and nutrients) and Vetozen (natural mineral fertilizer) on the growth and ectomycorrhiza formation of Norway spruce seedlings grown in nutrient-poor pure peat in an open nursery site was assessed. Two-year-old bareroot seedlings were transplanted into containers. No significant growth differences were detected between treatments for 1 + 0 seedlings but the values of growth parameters (root collar diameter; stem height; shoot, root and total dry weight) of Ectovit-inoculated seedlings were significantly higher than those in the other treatments including the control after the second (2 + 0 seedlings) and the third growing season (2 + 1). Root-to-shoot dry weight ratio and number of root tips were distinctly higher after the third year compared to the previous two years but they were not significantly different between treatments. Mycorrhizaroots and Vetozen did not have any significant effect on seedling development. Although the occurrence of treatment-specific ECM morphotype was detected in Ectovit-inoculated seedlings, the high total ECM colonization of roots in all treatments including the control indicated a crucial impact of naturally occurring fungi on ectomycorrhiza formation.

The study investigated the emergence and early seedling development of Monodora myristica in six different growth media viz: mixture of river sand/top soil, river sand/saw dust, top soil/saw dust, saw dust only, top soil only and river sand only. Results obtained recorded highest percentage germination (63%) in seeds sown in saw dust only. Early seedling growth was observed for four months. The results of this study showed that seedlings sown in mixture of top soil/saw dust recorded highest mean plant height (16.83cm), stem girth ( 2.50mm), and leaf area (46.18cm2) at the end of the experimental time. Seedlings on top soil only had the highest number of leaves (3.89). River sand had the least seedling performance in all the growth parameters examined; plant height (13.27cm), stem collar girth (1.99mm), leaf length (8.61cm), leaf width (4.77cm) and leaf area (30.83cm2). The study established that the % emergence of Monodora myristica seedlings was best in saw dust medium while mixture of top soil/saw dusts is recommended for enhancing early seedling growth of this plant in the nursery.

Raising vegetable seedlings in pro trays is becoming an innovative approach to produce quality seedlings in horticulture. The present investigation was conducted to evaluate the effect of AMF Funneliformis mosseae and K solubilizing bacterium Bacillus mucilaginosus singly and together in enhancing the growth of tomato seedlings raised in pro trays under polyhouse conditions. Different growth parameters like shoot and root length, total seedling length, stem diameter, dry weight of seedlings, biovolume index, plant strength, vigourindex, macro and micro nutrientuptake, mycorrhizal root colonization and the population of B. mucilaginosus in the root zone soil were monitored. Significantly higher shoot length,root length, stem diameter and biovolume indexwere recorded in the treatments inoculated with F. mosseae alone followed by B. mucilaginosus alone. Most of the plant growth parameters were significantly less in the dual inoculation treatment with F. mosseae + B. mucilaginosus compared to single inoculation with either of them. This brings out the negativeinfluence of the two inoculants on each other leading to a reducedeffect on plant growth.

A field experiment was carried out during summer season of 2004 to assess the effect of growth media, size and weight of seed and depth of seed sowing on the growth and quality of seedlings of Physic nut (Jatropha curcas Linn.). The analysis of data revealed that germination percentage (80.5%), final seedling stand before transplanting (75.6%), seedling height (90.50 cm), number of branches per seedling (1.93), collar diameter (2.61 cm), root total length per seedling (608 cm), leaf area per seedling (10597 cm2), total dry weight per seedling (164.2 g), total chlorophyll content (2.92 mg/g of tissue) and quality index (Dickson’s quality index and sturdiness quotient) of seedlings were significantly higher under raised seedbed of soil + FYM mixture (3:1 ratio) closely followed by raised seedbed of soil alone. Seedlings grown on polythene bags filled with soil + FYM mixture (3:1 ratio) recorded least values of all these parameters. Cost of nursery raising based on 5000 seedlings (Rs. 7660) was highest under polythene bags filled with soil + FYM mixture (3:1 ratio) while net returns (Rs. 6120) and benefit: cost ratio (1:21) was highest under raised seedbed of soil alone followed by raised seedbed of soil + FYM mixture (3:1 ratio). Negative net returns (Rs 1315) and benefit: cost ratio (-0.17) were recorded under polythene bags filled with soil + FYM mixture (3:1 ratio). Bold seeds sown at 3 to 4 cm depth produced significantly superior seedlings in terms of growth and quality parameters over the normal seeds sown at 5 to 6 cm depth. Bold seeds sown at 3 to 4 cm depth also improved economics of nursery raising over normal seeds sown at 5-6 cm depth.

Turnip (Brassica rapa L. subsp. rapa) is a type of root vegetable belonging to the Brassica subspecies of Cruciferae. Salt stress is one of the main abiotic stresses that causes water deficit, ion toxicity, and metabolic imbalance in plants, seriously limiting plant growth and crop yield. Two commercial turnip cultivars, Wenzhoupancai and Qiamagu, were used to evaluate the seed germination and physiological responses of turnip seedlings to salt stress. NaCl was used to simulate salt stress. Parameters of seed germination, seedling growth, osmoregulation substances content, chlorophyll content, antioxidant enzyme activity, and other physiological parameters of turnip seedlings were measured after 7 days of salt stress. The results showed that salt stress reduced the seed germination rate, and that the seeds of ‘Wenzhoupancai’ were more sensitive to salt stress. Salt stress inhibited the growth of turnip seedlings. With the increased NaCl concentration, the seedling dry weight, seedling fresh weight, and seedling length of turnip decreased gradually. Under the salt stress treatment, the osmotic regulatory substances and antioxidant enzyme activity in the seedlings of turnip increased significantly. The chlorophyll content increased at a lower NaCl level, but it decreased when the level of NaCl was higher. Growth parameters of turnip seedlings had significant negative correlations with the reactive oxygen content, osmoregulation substances, and antioxidant enzyme activities, but they had positive correlations with chlorophyll b and total chlorophyll content. These results indicated that salt stress-induced oxidative stress in turnip is mainly counteracted by enzymatic defense systems.

The quantity and quality of seedlings in the nursery has an impact on the success of re-establishment and later growth. High germination rates enable a sufficient number of seedlings, and their quality is assessed using a number of parameters, including seedling height and root collar diameter. These parameters are influenced in some species by seed size, but the correlation between them is species-specific. The model species in this research was sweet chestnut (Castaneasativa Mill.), and seeds from 12 populations from two distinct biogeographical regions of Croatia were collected. We examined the influence of seed size on four parameters: germination rate, seedling height, root collar diameter and sturdiness quotient. Seed size has been shown to have a positive influence on both seedling height and root collar diameter, whereas no such correlation was noted for germination rate and sturdiness quotient. Significant differences in nut size and seedling growth parameters were found between the Mediterranean and continental populations, with higher values observed in the coastal Mediterranean populations. We concluded that seed origin and seed size have a significant impact on seedling growth and are important factors to consider when choosing seed material. Further nursery operations should consider seed origin and local environmental conditions when choosing seedlings for reforestation efforts and general forest operations.

Abstract Both solid and liquid residues derived from activity of particleboard (PB)’srecycling were investigated. The solid was attempted to make recycle particleboard (rPB) while the liquid was tried to use as fertilizer to seedling of Acacia crassicarpa. Objective of this study was to compare quality between PB and rPB and to evaluate seedling growth of A.crassicarpa exposed to liquid disposal from PB’s recycling activity. Methods of this study were consisted of testing of physical and mechanicalproperties of industrial PB, manufacturing rPB, and comparing the properties between PB and rPB. Prior to manufacture rPB, liquid disposal from PB’s recycling activity was released through water immersion of industrial waste’s PB comprised of predominant trimming residues. The liquid disposal was measured its nitrogen (N) content and then it was kept in a gallon for further use as fertilizer. Observation on growth parameters (height, diameter, leaves number and seedling’s strength) of both treated and untreated seedlings was conducted weekly for 2 months. Results of this study showed: 1)rPB was feasible to be produced but their quality was slightly decreased. 2) Liquid disposal during cyclist test and water immersion of PB’s residues contained 0.69% N. 3) Growth parameters of A.crassicarpa seedling showed response positively and significant statistically between treated and untreated seedlings. These findings suggested that both residues originated from PB’s recycling can be utilized further; the solid can be used as raw material of rPB while the liquid can be utilized as fertilizer to seedlings.

Thesis (PhD)--Stellenbosch University, 2004.
ENGLISH ABSTRACT:Six experiments, five in the glasshouse and one in the field near Nelspruit, were carried out to ascertain the effect of factors related to shoot die-back, and of water treatments on the growth and physiological responses of Pterocarpus angolensis seedlings. The study was undertaken to broaden the knowledge and understanding of the phenomenon of shoot die-back in order to enhance our ability to regenerate the species. The following experiments were carried out (a) Assessment of biomass accumulation; anatomical characteristics of the shoot apical meristem; foliar, stem and root concentration of micro- and macronutrients associated with each phenophase, (b) Effect of seedling age and seed source on the occurrence of shoot die-back under field conditions; (c) Water treatment effects on ChI. afluorescence traits of£'. angolensis seedlings obtained by assessing the fluorescence yield of photosynthetic samples subjected to dark- and light-adaptation; (d) Genetic variation in shoot die-back and other traits of sixteen halfsib families of £.. angolensis from Malawi, Namibia and Zambia grown over two die-back seasons. Experiments conducted revealed the following 1. Patterns of growth observed in phenophases are indicators of seasonal changes in annual biomass allocation to the shoot and root. Phenophases such as leaf loss and stem senescence, whether shoot die-back occurs completely or not, are directly related to the decline in above-ground biomass and declined rate of increase in root biomass respectively. Leaf flush, expansion and maturation result in increased biomass accumulation whilst shoot die-back has a minimal downregulatory effect on root biomass accumulation compared to the shoot. Shoot dieback is not sudden, therefore from the first day of germination, seedlings synchronise growth and development with the occurrence of shoot die-back. 2. Phenophasic concentration of foliar N, Ca and Mg, stem Fe and Cu and root concentrations of P, K, Mg, Fe and B are associated with shoot die-back. Patterns of mineral nutrient concentration obtained in foliage and roots but to a lesser extent in the stem, may be related to nutrient remobilisation during shoot dieback. Higher relative mineral nutrient changes during leaf yellowing and shoot die-back may be an indication of the removal of significant volumes of mobile nutrients from senescing tissues. 3. The volume of the shoot apex of E. angolensis remains constant during different phenophases which points to seasonal uniformity in the size of the apical dome. Changes in phenology associated with declined growth, or shoot die-back, is revealed through declined cell number in the tunica which is a reflection of declined mitotic activity. 4. Shoot die-back occurs in all seedlings from nursery stock planted under field conditions and all seedlings of up to two years experience complete shoot dieback. Shoot die-back takes place irrespective of seed source or the age of nursery stock that is planted. Survival after the first shoot die-back is normally low. Water treatments had no significant effect on the function of PSIJ reaction centres of P. angolensis nursery seedlings. In the case of both dark- and light-adapted leaves, water treatment had no significant effect on the measured Chi. a fluorescence parameters or the calculated parameters (specific activities, phenomenological fluxes, structure-function and performance indexes and drivingforces). 5. Water treatments affect the shape of ChI. a fluorescence transients of lightadapted compared to that of dark-adapted photosynthetic samples of E. angolensis. No significant water treatment effect was obtained for extracted and technical Chi. afluorescence parameters, specific fluxes, quantum efficiencies and phenomenological fluxes. Quantum yield, relative electron transport and quantum yield limitation, de-excitation rate constants, structure-function, performance indexes and driving forces were also not significantly different across water treatments.6. Genetic variation was observed to exist among 16 halfsib families from Malawi, Namibia and Zambia. High heritabilities were obtained for shoot die-back and other traits, indicating that shoot die-back is genetically controlled. The trait is passed from parents to offspring and it is highly probable that it occurs, throughout its natural range, in all seedlings. Since shoot die-back is genetically programmed, it remains crucial to the ability of a seedling to regenerate in the following rainy season
AFRIKAANSE OPSOMMING:Ses eksperimente, vyf in die glashuis en een in die veld naby Nelspruit, is uitgevoer om die effek van faktore wat verwant is aan die terugsterwing van lote op saailinge, sowel as om die effek van waterstres op die groei en fisiologiese responsies van Pterocarpus angolensis saailinge, te ondersoek. Die studie is ondemeem om die kennis en begrip aangaande die regenerasie-dinamika van die spesies te verbeter. Die volgende eksperimente is uitgevoer: (a) Evaluering van die effek van jisiologiese veranderings op biomassa; blaar-, stam- en wortelkonsentrasies van spoor- en makro-voedingselemente, en anatomiese eienskappe van die apikale meristeem van die lote. (b) Effek van saailingouderdom en saadbron op die voorkoms van lootterugsterwing onder veldtoestande. (c) Waterbehandelingseffekte op Chi. ajluorisensie eienskappe van ,e. angolensis saailinge wat verkry is deur die jluorisensie te evalueer van fotosintesemonsters wat aan donker- en lig-adaptasies onderwerp is. (d) Genetiese variasie in loot-terugsterwing en ander groei-eienskappe van 16 halfsib families van ,e. angolensis vanaf Malawi, Namibia en Zambia wat gekweek is oor twee terugsterj-seisoene. Die eksperimente het die volgende aan die lig gebring: 1. Groeipatrone waargeneem gedurende die fenofases is indikatore van seisoenale veranderings in jaarlikse biomassa allokasies aan die loot en die wortels. Fenofases soos blaarverlies en lootafsterwing, ongeag of loot-terugsterwing volledig is of nie, is direk verwant aan die afname in bogrondse biomassa en afnemende tempo van toename in wortelbiomassa respektiewelik. Bottende blare, vergroting en rypwording van blare lei tot toenemende biomassa akkumulasie terwyl loot-terugsterwing 'n minimale afskalende effek op akkumulasie van wortelbiomassa het in vergelyking met die van die loot. Loot-terugsterwing is nie skielik, met ander woorde vanaf die eerste dag van ontkieming sinchroniseer saailinge groei en ontwikkeling met die voorkoms van loot-terugsterwing. 2. Fenofase konsentrasies van en veranderings in blaar N en Ca en loot Fe, asook veranderings in waargenome wortel N, K, Ca, Mn, Cu, Zn en B is sterk geassosieer met loot-terugsterwing. Patrone van minerale voedingselementkonsentrasies wat in blare en wortels, en in minder mate in die loot, verkry is, mag direk verwant wees aan hermobilisering van voedingselemente gedurende loot-terugsterwing. Hoe relatiewe minerale voedingselementveranderings gedurende die vergeling van blare en lootterugsterwing mag 'n indikasie wees van die verwydering van betekenisvoUe hoeveelhede mobiele nutriente vanaf sterwende weefsel. 3. Die volume van die groeipunt van r. angolensis bly konstant gedurende verskillende fenofases wat dui op seisoenale uniformiteit in die grootte van die apikale koepel. Veranderings in fenologie ge-assosieer met afnemende groei, of loot-terugsterwing, word gerejlekteer deur afnemende selgetaUe in die tunika wat dui op afnemende mitotiese aktiwiteit. 4. VoUedige loot-terugsterwing kom voor in aUe saailinge vanaf die kwekery wat in die veld geplant word tot op die ouderdom van twee iaar. Dit kom voor angeag van saadbron of ouderdom van saailinge ten tye van planting. Oorlewing na aanvanklike loot-terugsterwing is normaalweg laag. 5. Water behandelings het geen beduidende effek op die funksie van PSII reaksiesentra van r. angolensis kewekery-saailinge gehad. Vir beide donker- en lig-aangepaste blare is geen beduidende waterbehandelingseffek verkry vir waargenome ChI. a jluoresensie parameters of die berekende parameters (spes ifieke aktiwiteite, jenomenologiese jlukse, struktuur-funksie-indekse, "perjormance-indekse oj" driving forces" ). 6. Genetiese variasie tussen 16 halfsibfamilies vanaf Malawi, Namibie en Zambie is verkry vir loot-terugsterwing en ander groei-eienskappe. Dit dui op genetiese beheer van terugsterwing en dat die eienskap oorerjbaar is, en waarskynlik in die hele natuurlike verspreidingsgebied van die spesies in aUe saailinge voorkom. Aangesien loot-terugsterwing gene ties geprogrammeer is, is dit noodsaaklik vir die vermoe van die plant om in die volgende reenseisoen te regenereer.

Recent developments on environmental fate models indicate that as nano waste, engineered nanomaterials/nanoparticles (ENM/Ps) could reach terrestrial ecosystems thus potentially affecting environmental and human health. Plants can be therefore exposed to ENM/Ps but controversial data in terms of fate and toxicity are currently available. Furthermore, there is a current lack of information on complex interactions/transformations to which ENM/Ps undergo in the natural environment as for instance with existing toxic compounds. The main aim of current study is to evaluate potential toxicological risks due to the exposure of plants to ENM/Ps in their natural environment, and investigating different routes of exposure (i.e. water and soil). The aim of the first study reported in chapter 1 was to asses behavior and biological effects of titanium dioxide nanoparticles (n- TiO2) (Aeroxide P25, Degussa Evonik) and its interaction with cadmium (CdCl2) in plants using radish seeds (Raphanus sativus parvus) as model species. Radish seeds were exposed to different concentrations of n-TiO2 (range 1-1000 mg/L) and CdCl2 ( range 1-250 mg/L) alone and in combination using a seed germination and seedling growth toxicity test OECD 208. Percentages of seed germination, germination index (GI) and root elongation were calculated. Cell morphology and oxidative stress parameters as glutathione-S-transferase (GST) and catalase activities (CAT) were measured in radish seeds after 5 days of exposure. Z-Average, PdI and Z-potential of n-TiO2 in Milli-Q water as exposure medium were also determined. DLS analysis showed small aggregates of n-TiO2, negative Z-potential and stable PdI in seed’s exposure media. Germination percentage, GI and root length resulted affected by n-TiO2 exposure compared to controls. Exposure of CdCl2 significantly abolished germination % and GI compared to control seeds and a concentration dependent decrease on root elongation was observed against controls (p<0.05). As well, significant decrease of germination %, GI and root elongation was observed in seeds co-exposed to n-TiO2 and CdCl2 at the highest concentrations (1000mg/L n-TiO2 and 250 mg/L CdCl2) compared to co-exposed seeds at low concentration (1mg/L n-TiO2 and 1 mg/L CdCl2) and controls (p<0.05). Root elongation significantly increase compared to controls at the lowest co-exposure concentration (p<0.05). Similarly at intermediate concentrations of 10 and 100 mg/L in co-exposure conditions, n-TiO2 did not affect CdCl2 toxicity. Concerning antioxidant enzymes, a significant increase of CAT activity in seeds exposed to single high n-TiO2 concentration (1000 mg/L) was observed while n-TiO2 (1 mg/ L), CdCl2 (1 and 250 mg/L) and co-exposure resulted significantly decreased compared to controls (p<0.05). Regarding GST activity, a slight increase in seeds exposed to 1000 mg/L n-TiO2 but no significantly was observed, however both n-TiO2 and CdCl2 alone (1 and 250 mg/L, respectively) or in combinations caused a significant decrease in GST activity (p<0.05). Therefore, overall data support the hypothesis that the presence of n-TiO2 do not affect the toxicity of CdCl2 at least at the highest concentration (100 and 250 mg/L) in radish seeds. Morphological alterations in nuclei, vacuoles and shape of radish root cells were observed upon single Cd exposure and not abolished in the presence of n-TiO2. Nevertheless, although n-TiO2 seems not to reduce Cd toxicity at high concentration (up to 250 mg/L), interactions cannot be excluded based on obtained results. The aim of the second study reported in chapter 2 was to assess if the presence of n-TiO2 might affect elutriate toxicity to radish seeds (R. sativus parvus) seeds as a model species. Radish seeds were exposed to 11 soils (elutriates) alone and in combination with 1 mg/L of n-TiO2 collected from an industrial site located in Taranto area (South East of Italy). Exposure of seeds was performed according to OECD (208) guideline. Then, root elongation, percentages of seed germination and germination index% (GI) were analyzed. In addition, levels of several trace elements were also determined in soils in order to assess their level of contamination and effects on root elongation, seed germination and GI% further discussed. Main results revealed that the presence of n-TiO2 seems not affecting root length, GI % and germination% of seeds compared to seeds exposed to elutriates alone with the exception of only 2 sites. Moreover, the absence of any clear relationship between effects of elutriate on radish seed germination and trace elements levels was observed. Only slight but not significant changes based on levels of trace elements present in soil were observed in growth parameters. In particular levels of Co, Ni, Zn, Cu, Ti and Sn seem to affect radish seeds germination more than others. Regarding co-exposed seeds, the presence of n-TiO2 caused 100% of germination of radish seeds. Furthermore, in comparison to exposed seeds to elutriates alone, root length and GI % resulted more stimulated. Only slight effects on GI% and root length were observed which might be linked to interaction of these elements with n-TiO2. Likewise, it seemed that Co, Se, Sb and As in presence of n-TiO2 are responsible for changes on growth parameters. According on the overall results, soil elutriates alone could not be able to show real toxicity of a contaminated soil on seeds germination and future study should be performed in order to assess their suitability in real exposure scenarios. Therefore, based on observed data further investigations are required in order to assess real environmental scenarios where such particles could be present in soils together with existing contaminants such trace elements. The purpose of third study reported in chapter 3 chapter was to assess the impact of n-TiO2 alone and in combination with CdCl2 on germination and growth of radish seeds (R. sativus) exposed in vitro (experiment 1) and in vivo (directly into soils) (experiment 2). In experiment 1(in vitro) radish seeds were exposed to n-TiO2 (1 and 1000 mg/L and CdCl2) and CdCl2 (1 and 250 mg/L) alone and in combination (n-TiO2 1, 10, 100, 1000 mg/L and CdCl2 1, 10, 100, 250 mg/L) using a seed germination and seedling growth toxicity test OECD 208. In experiment 2 (in vivo), radish exposed only to water and then seedling transferred to soils contaminated with n-TiO2 (1 and 1000 mg/L and CdCl2) and CdCl2 (1 and 250 mg/L) alone and in combination (n-TiO2 1, 10, 100, 1000 mg/L and CdCl2 1, 10, 100, 250 mg/L), still following OECD 208 test conditions. Root length, shoot length and numbers of secondary leaves of all plants from the two experiments (1 and 2) were recorded at day 10 and day 21. Growth parameters of radish at both day 10 and day 21 showed that plants from seeds exposed during germination (experiment 1) resulted more affected by single and co-exposure to n-TiO2 and CdCl2 than those exposed directly in soil (experiment 2). Furthermore, presence of CdCl2 at 250 mg/L alone and in combination with 1000 mg/L of n-TiO2 seemed affect the root and shoot length in both experiments 1and 2 at day 10 and day 21. Growth parameter analysis of single and co-exposed groups in experiment 1 at day 10, showed a decrease in root length in all tested plants with exception of those exposed to n-TiO2 (1mg/L), co-exposed to n-TiO2 and CdCl2 (1mg/L and 1mg/L), (10 mg/L and 10 mg/L) and (100 mg/L and 10 mg/L) which showed slight increase compared to control. In experiment 2 at day10 only exposed plants to 1000 mg/kg of n-TiO2 revealed significant increase of root length while other all single and co-exposure groups showed a decrease of root length respect to control. Shoot length in exposed plants to all single and co-exposure groups in both experiments 1 and 2 at day 10 showed a decrease compared to control except plants exposed to n-TiO2 and CdCl2 (100 mg/kg and 10 mg/kg) in experiment 2 which showed an increase. Obtained results on day 21 showed a decrease of root length respect to control on tested plants to all single and co-exposure groups in both experiments 1 and 2 with exception of exposed radish to 1 mg/L of CdCl2 in experiment 1. Shoot length of all tested single and co-exposure groups in experiments 1 and 2 showed a decrease compared to control except radish exposed to 1000 mg/kg of n-TiO2 which revealed an increase in experiment 2. Regarding secondary leaves, in both experiments 1and 2 at day 10 no leaves were shown. On the opposite, (2 leaves) were present at day 21 in most plants exposed to single and in combination, while those exposed to CdCl2 (250 mg/kg), n-TiO2 and CdCl2 (10 and 100 mg/L) and (1000 mg/kg and 250 mg/kg) in experiment 1 showed no leaves. Likewise, exposure n-TiO2 (1000 mg/kg) and co-exposure of n-TiO2 and CdCl2 (10 mg/kg and 100) showed only one secondary leaf in experiment 2 at day 21.

- Ziele der Arbeit - Das primäre Ziel der vorliegenden Arbeit bestand in einer möglichst umfassenden Be-schreibung einzelner Entwicklungsstadien im Verjüngungszyklus von Betula pendula Roth. Dabei waren die lokalen Bestandes- und Standortsbedingungen im Untersuchungsgebiet in besonderer Weise zu berücksichtigen. Des Weiteren sollten Optionen zur waldbaulichen Integration der Sand-Birkenverjüngung in bestehende Behandlungskonzepte für in Auflösung befindliche Fichtenaltbestände aufgezeigt werden. - Untersuchungsgebiet - Der Tharandter Wald liegt im Freistaat Sachsen (50° 55’-50° 00’n. Br., 13° 25’-13° 35’ ö. L.) und umfasst eine Fläche von etwa 6.000 ha. Das von der Baumart Fichte dominierte Gebiet kolliner bis submontaner Höhenstufe (350 - 420 m ü. NN) wird der „Unteren Nordostab-dachung des Erzgebirges“ zugeordnet. Als Untersuchungsflächen wurden wechselfeuchte (wechselfrische) Standorte mittlerer Trophie gewählt, die von einschichtigen Fichtenbe-ständen in einem Alter von ≥ 80 Jahren bestockt waren. Einzeln bis truppweise eingemischte Samenbäume der Sand-Birke (B. pendula) bildeten eine Grundvoraussetzung für die Flächen-auswahl. - Methodisches Vorgehen - Das methodische Vorgehen konzentrierte sich auf die verjüngungsökologisch relevanten Entwicklungsstadien (fruktifizierender Samenbaum, Diaspore, Keimling, Sämling und eta-blierte Verjüngungspflanze) der Sand-Birke. Die Wachstumsparameter der vorhandenen Samenbäume wurden durch Untersuchungen zum Fruchtbehang unterlegt. Der mehrstufige Versuchsansatz zur Erfassung einzelner Verjüngungsstadien stützte sich auf Bestandesauf-nahmen, Gefäß- und Laborversuche. Erhebungen auf Bestandesebene erfassten die Diaspo-renausbreitung mithilfe von Samenfallen und dokumentierten die Keimlings- und Ver-jüngungsstadien von B. pendula auf entsprechend etablierten Aufnahmeplots (1 m x 1 m). Darüber hinaus umfassten die Aufnahmen Strahlungs- und Feuchtemessungen und die Charakterisierung der Bodenvegetation. Für die Einschätzung des mikrostandörtlichen Um-feldes wurden exemplarisch Bodendeckungsvarianten (Mineralboden, Nadelstreuauflage, Calamagrostis villosa CHAIX (GMEL.) und Deschampsia flexuosa L. (TRIN.)) ausgewählt, die als besonders repräsentativ für reine Fichtenbestände des Erzgebirges gelten. Für die räumliche Modellierung der Diasporen und Keimlinge auf Bestandesebene stand das Pro-gramm WALDSTAT (NÄTHER & WÄLDER 2003) zur Verfügung. Im Rahmen des Mitscherlich-Gefäßversuchs wurden gleichermaßen quantitative und qualitative Entwicklungen von Sand-Birkenkeimlingen und -sämlingen erhoben. Der Einfluss ausgewählter Bodendeckungs-varianten wurde in diesen Betrachtungen berücksichtigt. Neben zahlreichen Pflanzenpara-metern (Spross-, Blatt- und Wurzelentwicklung, Allokationen, Allometrien) war die kleinstandörtliche räumliche Verteilung dieser Verjüngungspflanzen von vorrangiger Be-deutung. Als Verteilungs- und Konkurrenzmaße auf Ebene des Mikrostandortes dienten Tessellationsmodelle, der Aggregationsindex nach CLARK & EVANS, der Gini-Koeffizient und das “Constant Yield Law“. - Ergebnisse - - Die Erfassung der Samenbaumparameter von B. pendula führte zu flächenspezifischen und signifikanten Unterschieden in der Dimension, Höhe und soziologischen Stellung. Für die Darstellung der Durchmesser-Höhenverteilungen erwiesen sich logarithmische und quadra-tische Funktionen gleichermaßen geeignet. Das Kronenprozent ereichte im Mittel Werte zwi-schen 37 % und 49 %. Die einzelnen Kronenparameter (Kronendurchmesser, Kronenlänge und Kronenmantelfläche) zeigten straffe lineare Zusammenhänge. Innerhalb der Kronen-strukturen (z. B. Blatt- und Zweigtrockenmasse) ließen sich zum Teil allometrische Be-ziehungen nachweisen. Im Rahmen der Vollbaumbeerntung war ein durchmesserabhängiger Fruchtbehang nachweisbar, der für den Einzelbaum eine Anzahl zwischen 2,3 und 4,2 Millionen Diasporen erreichte. - Mit den Erhebungen zur zeitlichen Ausbreitungsdynamik der Diasporen waren durch mehrjährige Untersuchungszeiträume, auch für eine Pionierbaumart wie B. pendula, stärkere Samenjahre nachzuweisen. Die räumliche Modellierung der anemochoren Diasporenaus-breitung belegte erwartungsgemäß bessere Modellanpassungen für den anisotropen (richtungsgebundenen) Modellansatz. Dennoch zeichneten sich sowohl jahres- als auch flächenspezifisch deutliche Unterschiede in der Modellgüte ab. Als maximale Diasporen-dichte pro m² wurde ein Wert von 20.700 Diasporen ermittelt. Die mittleren Ausbreitungs-distanzen (MDD - “Mean Dispersal Distances“) lagen nach Modellschätzung für die ge-samten Beprobungszeiträume und unter Berücksichtigung aller Versuchsflächen zwischen 37 m und 90 m. Die durchschnittliche Diasporenproduktion eines Einzelbaumes lag nach Anga-ben des Modells in einem Bereich von 180.000 bis 7.400.000. Die Qualitätsansprache an den Diasporen ergab einen Anteil von etwa 5 % bis 8 % äußerlich Schadhaften. Der unmittelbare Windeinfluss auf Hauptausbreitungsrichtung und -entfernung konnte ebenfalls nachgewiesen werden. - Untersuchungen zum Keimlingsstadium zeigten deutliche Abhängigkeiten zwischen den ausgewählten Bodendeckungsvarianten, der Keimlingsdichte und dem Keimlingswachstum. Sand-Birkenkeimlinge waren sowohl unter Bestandesbedingungen als auch unter den freif-lächenähnlichen Bedingungen des Mitscherlich-Gefäßversuchs auf der Variante mit Mine-ralboden besonders dicht aufgelaufen, blieben jedoch stark in ihrer weiteren Entwicklung zurück. Als besonders wüchsig erwiesen sich Keimlinge auf den Bodendeckungsvarianten mit Nadelstreuauflage und in D. flexuosa. Sand-Birkenkeimlinge der Bodendeckungsvarianten ohne Konkurrenz durch Bodenvegetation (Mb, Nd) besaßen eine längere Hauptwurzel und eine höhere Wurzelmasse (56 % - 60 % der Gesamtmasse). Die oberirdische Allokation (Blatt- und Sprossmasse) fiel hingegen für Sand-Birkenkeimlinge in den Bodendeckungs-varianten mit C. villosa und D. flexuosa höher aus. Verteilungs- und Konkurrenzerhebungen in den Gefäßversuchen erbrachten signifikante Zusammenhänge zwischen Keimlingsdichte, Standraum und Wachstum der Einzelpflanze. - Das Sämlingsstadium und die älteren Verjüngungspflanzen wiesen einen deutlichen Rückgang in der Mortalität auf. Die Erhebungen im Bestand ergaben ein unterschiedliches Durchschnittsalter für Sand-Birken auf den einzelnen Bodendeckungsvarianten (C. villosa 7,6 Jahre, D. flexuosa 6,2 Jahre und Nadelstreu 4,7 Jahre). Die wachstumsrelevanten Umweltbe-dingungen wie Strahlungsverfügbarkeit, Feuchteregime und Entfernung zum nächsten Alt-baum unterschieden sich außerdem in Abhängigkeit von den als repräsentativ eingestuften Bodendeckungsvarianten unter Bestandesbedingungen. Das bestandesbezogene Wachstum der Sand-Birken in einem Alter von 2 bis 6 Jahren ließ sich durch eine exponentielle Funktion mit hoher Anpassungsgüte (p ≤ 0,000) abbilden. Innerhalb des Mitscherlich-Gefäßversuchs haben sich ebenfalls Unterschiede in der Individuendichte, den Mortalitäts- und Wachstums-raten in Abhängigkeit von den Bodendeckungsvarianten ausgebildet. Höchste Verjüngungs-dichten wurden nach einem 2,5jährigen Entwicklungszeitraum auf der Bodendeckungs-variante Nadelstreuauflage erreicht. Die Allokationen in der Trockenmasse näherten sich hingegen in den unterschiedlichen Varianten stärker an. Ein dichteabhängiges Wachstum konnte in der letzten Aufnahme nicht mehr nachgewiesen werden. Abschließend bleibt festzuhalten, dass die ermittelten Untersuchungsergebnisse in Abhängig-keit vom jeweiligen Verjüngungsstadium die zeitliche und räumliche Präsenz, Konkurrenz- und Entwicklungsfähigkeit der Sand-Birke in Fichtenaltbeständen des Tharandter Waldes charakterisieren. Sie belegen eine kleinstandörtliche Heterogenität in den untersuchten Beständen, die sich nachhaltig auf die Etablierung der hier untersuchten Pionierbaumart auswirkt. Anhand der räumlichen Modellierung lässt sich die zu erwartende Verteilung von Diasporen und Keimlingen in Abhängigkeit von den Positionen der Samenbäume prognostizieren. Insgesamt ergibt sich aus den vorliegenden Ergebnissen ein vergleichsweise hohes Verjüngungspotenzial für B. pendula, das sich durch waldbauliche Maßnahmen effizient nutzen ließe. Ein detailliertes Wissen über die einzelnen Verjüngungsstadien bietet zudem die Möglichkeit einer gezielten waldbaulichen Steuerung der Baumart und zur Risikoabschätzung des Verjüngungserfolgs unter den gegebenen Rahmenbedingungen. Bei einer wachsenden waldbaulichen Unsicherheit im Umgang mit unterschiedlichsten Klima-prognosen, die sich in ihrer Wirkung regionalspezifisch erheblich unterscheiden können, sollte die Sand-Birke als Misch- und Vorwaldbaumart unbedingt berücksichtigt werden. Um dem viel zitierten Anspruch an die Nachhaltigkeit waldbaulichen Handelns gerecht zu werden, muss die Option zur Integration von B. pendula gewährleistet bleiben, auch für künftige Generationen und bei sich wandelnden Ansprüchen an den Wald
- Objectives - The main goal of this study was to describe comprehensively the particular stages of the regeneration cycle of Betula pendula Roth. Investigations were carried out in local stand and site conditions of a research area in South-East Germany (Tharandter Forest) are considered. In this context options for integrating Silver birch regeneration into silvicultural management concepts of old Spruce stands (Picea abies L.) with lacking vitality are pointed out. - Research area - The Tharandter Forest is located (50°00’N, 13°35’E.) in Saxony (South-East Germany) with an area of around 6.000 ha. It is dominated by Norway spruce stands, and ranges from colline to submontane altitudinal belt (350 to 420 m a.s.l.). These sites are part of the northern declivity of the Ore Mountains. Mono-layered Norway spruce stands with soils of medium trophy and well drained, but featured highly variable soil moisture levels during the growing season were selected for this study. The stand age was ≥ 80 years. Seed trees of Silver birch were mixed as single trees or small groups. - Methodical aspects - The methodical work was concentrated on relevant regeneration aspects like fructification of seed trees, seeds, seedlings, saplings and established regeneration of Silver birch. Growth parameters of seed trees and the amount of fructification were used to quantify allometric relationships. The multi-level research design was based on measurements under stand conditions, pot and laboratory experiments. Seed traps and plots (1m x 1m) were located in spruce stands with regard to different stages of Silver birch development. Therefore micro-environmental growth conditions like soil humidity and photosynthetic active radiation were measured, and plants of ground cover characterized. As examples of ground cover variants with highest presence in homogeneous spruce stands mineral soil, needle litter, Calamagrostis villosa CHAIX (GMEL.) und Deschampsia flexuosa L. (TRIN.) were chosen. Using the program WALDSTAT (NÄTHER & WÄLDER 2003) spatial distribution of dispersed seeds (diaspores) and seedlings could be modelled. Additionally pot experiments were done to compare quantitative and qualitative development of birch seedlings between stand and open site conditions. Regeneration density, number of leaves, shoot and root growth and allocations were measured as important growth parameters to evaluate single plant development under different environmental conditions. Finally, spatial distribution of seedlings in microsites and intraspecific competition were calculated by tessellation models, aggregation indices after CLARK & EVANS, Gini-coefficient and ‘constant yield law’. - Main results - - Measurements on seed trees of B. pendula indicate stand specific differences significantly in dimension, height and biosocial position of trees within the birch population (crown classes). For specific height-dbh curves logarithmic and quadratic equations were adapted. The relative crown length for seed trees was located between 37 % and 49 %. Allometric relationships between crown parameters (e.g. crown diameter, crown length and crown surface) were strongly correlated. In specific cases crown structures (e.g. dry mass of leaves and twigs) were also correlated, certainly with different grades. Direct seed counting of felled seed trees provided the relationships between dbh and number of seeds. Counted seeds for single Silver birch trees ranged between 2.300.000 - 4.200.000. - As one result of seed trapping huge varieties in seed production of Silver birch were detectable between years with different seed potential. Spatial modeling of seed dispersal supported strong influences caused by wind (direction and speed). Hence, best fitted model estimations were found for anisotropic scenarios. The maximum in seed density was recorded with 20.700 seeds per m². As data for ‘Mean Dispersal Distances’ (MDD) the program WALDSTAT calculated between 37 m and 90 m. Furthermore the amount of seeds produced by a single tree was estimated with 180.000 - 7.400.000 depending on dbh. Physical quality evaluations for seeds have shown a mean proportion of damaged and not germinable seeds between 5 % and 8 %. - Direct effects of ground cover variants have been identified for seedling density and growth. Seedling density was highest on mineral soil for both, stand conditions and pot experiment, but these birch seedlings developed slowly compared with individuals in the other ground cover variants. The best growth was realized by birch seedlings in needle litter and D. flexuosa. Regarding to root length and mass, birches in ground cover variants without grass competition (mineral soil and needle litter) have shown a significant better development of underground parts. Root dry mass of these birch seedlings reached proportions between 56 % and 60 % of whole plant dry mass. By contrast the aboveground dry mass (leaves and shoot) was higher for birches competing with grasses. Overall results of birch seedling distribution and competition were significant correlations between densities, space, and growth per single plant. - For saplings and established birch regeneration a notable decrease in mortality rates were found. According to regeneration analyses under stand conditions age distributions in Silver birch regeneration have been controlled by ground cover variants and their environment conditions. The average age of Silver birch seedlings was high in areas with C. villosa (7.6 years) and low in needle litter (4.7 years). Furthermore growth influencing environmental conditions like light, humidity, and distance of old spruce trees have shown differences between variants in ground cover. The growth of regenerated Silver birches at the age of 2 to 6 years under those stand conditions can be described by an exponential function with high degree of adaptation (p ≤ 0,000). There were also differences in sapling densities, mortality and growth rates caused by ground cover variants in the pot experiments. After 2.5 years maximum regeneration densities in pots were registered on ground covers with needle litter. Allocations in regeneration dry mass were less influenced by ground cover variants than in previous stages. Density dependent growth rates could not be proved during last measurements. Finally, the presented results provide the opportunity to characterize temporal and spatial presence of different regeneration stages of Silver birch, its potential of competition and further development in old Norway spruce stands of the Tharandter Forest. They document heterogeneous structures of micro-environmental conditions in these spruce stands, which have sustainable effects on regeneration establishment of this studied pioneer tree species. On the basis of spatial modeling it is possible to estimate spatial distribution of seeds and seedlings depending on seed tree positions. Overall the results involve a high potential of successful regeneration in Silver birch, which opens up promising vistas for silvicultural management. More detailed knowledge in particular regeneration stages induces possibilities for selective control in silviculture with Silver birch. Additionally, estimating the regeneration risks and the success under given surrounding conditions will be more precisely. Considering uncertainty in giving prognoses for climate change Silver birch should be integrated in silvicultural strategies because of its role as admixed tree species and pioneer crop combined with comparably high resilience against warming

- Ziele der Arbeit - Das primäre Ziel der vorliegenden Arbeit bestand in einer möglichst umfassenden Be-schreibung einzelner Entwicklungsstadien im Verjüngungszyklus von Betula pendula Roth. Dabei waren die lokalen Bestandes- und Standortsbedingungen im Untersuchungsgebiet in besonderer Weise zu berücksichtigen. Des Weiteren sollten Optionen zur waldbaulichen Integration der Sand-Birkenverjüngung in bestehende Behandlungskonzepte für in Auflösung befindliche Fichtenaltbestände aufgezeigt werden. - Untersuchungsgebiet - Der Tharandter Wald liegt im Freistaat Sachsen (50° 55’-50° 00’n. Br., 13° 25’-13° 35’ ö. L.) und umfasst eine Fläche von etwa 6.000 ha. Das von der Baumart Fichte dominierte Gebiet kolliner bis submontaner Höhenstufe (350 - 420 m ü. NN) wird der „Unteren Nordostab-dachung des Erzgebirges“ zugeordnet. Als Untersuchungsflächen wurden wechselfeuchte (wechselfrische) Standorte mittlerer Trophie gewählt, die von einschichtigen Fichtenbe-ständen in einem Alter von ≥ 80 Jahren bestockt waren. Einzeln bis truppweise eingemischte Samenbäume der Sand-Birke (B. pendula) bildeten eine Grundvoraussetzung für die Flächen-auswahl. - Methodisches Vorgehen - Das methodische Vorgehen konzentrierte sich auf die verjüngungsökologisch relevanten Entwicklungsstadien (fruktifizierender Samenbaum, Diaspore, Keimling, Sämling und eta-blierte Verjüngungspflanze) der Sand-Birke. Die Wachstumsparameter der vorhandenen Samenbäume wurden durch Untersuchungen zum Fruchtbehang unterlegt. Der mehrstufige Versuchsansatz zur Erfassung einzelner Verjüngungsstadien stützte sich auf Bestandesauf-nahmen, Gefäß- und Laborversuche. Erhebungen auf Bestandesebene erfassten die Diaspo-renausbreitung mithilfe von Samenfallen und dokumentierten die Keimlings- und Ver-jüngungsstadien von B. pendula auf entsprechend etablierten Aufnahmeplots (1 m x 1 m). Darüber hinaus umfassten die Aufnahmen Strahlungs- und Feuchtemessungen und die Charakterisierung der Bodenvegetation. Für die Einschätzung des mikrostandörtlichen Um-feldes wurden exemplarisch Bodendeckungsvarianten (Mineralboden, Nadelstreuauflage, Calamagrostis villosa CHAIX (GMEL.) und Deschampsia flexuosa L. (TRIN.)) ausgewählt, die als besonders repräsentativ für reine Fichtenbestände des Erzgebirges gelten. Für die räumliche Modellierung der Diasporen und Keimlinge auf Bestandesebene stand das Pro-gramm WALDSTAT (NÄTHER & WÄLDER 2003) zur Verfügung. Im Rahmen des Mitscherlich-Gefäßversuchs wurden gleichermaßen quantitative und qualitative Entwicklungen von Sand-Birkenkeimlingen und -sämlingen erhoben. Der Einfluss ausgewählter Bodendeckungs-varianten wurde in diesen Betrachtungen berücksichtigt. Neben zahlreichen Pflanzenpara-metern (Spross-, Blatt- und Wurzelentwicklung, Allokationen, Allometrien) war die kleinstandörtliche räumliche Verteilung dieser Verjüngungspflanzen von vorrangiger Be-deutung. Als Verteilungs- und Konkurrenzmaße auf Ebene des Mikrostandortes dienten Tessellationsmodelle, der Aggregationsindex nach CLARK & EVANS, der Gini-Koeffizient und das “Constant Yield Law“. - Ergebnisse - - Die Erfassung der Samenbaumparameter von B. pendula führte zu flächenspezifischen und signifikanten Unterschieden in der Dimension, Höhe und soziologischen Stellung. Für die Darstellung der Durchmesser-Höhenverteilungen erwiesen sich logarithmische und quadra-tische Funktionen gleichermaßen geeignet. Das Kronenprozent ereichte im Mittel Werte zwi-schen 37 % und 49 %. Die einzelnen Kronenparameter (Kronendurchmesser, Kronenlänge und Kronenmantelfläche) zeigten straffe lineare Zusammenhänge. Innerhalb der Kronen-strukturen (z. B. Blatt- und Zweigtrockenmasse) ließen sich zum Teil allometrische Be-ziehungen nachweisen. Im Rahmen der Vollbaumbeerntung war ein durchmesserabhängiger Fruchtbehang nachweisbar, der für den Einzelbaum eine Anzahl zwischen 2,3 und 4,2 Millionen Diasporen erreichte. - Mit den Erhebungen zur zeitlichen Ausbreitungsdynamik der Diasporen waren durch mehrjährige Untersuchungszeiträume, auch für eine Pionierbaumart wie B. pendula, stärkere Samenjahre nachzuweisen. Die räumliche Modellierung der anemochoren Diasporenaus-breitung belegte erwartungsgemäß bessere Modellanpassungen für den anisotropen (richtungsgebundenen) Modellansatz. Dennoch zeichneten sich sowohl jahres- als auch flächenspezifisch deutliche Unterschiede in der Modellgüte ab. Als maximale Diasporen-dichte pro m² wurde ein Wert von 20.700 Diasporen ermittelt. Die mittleren Ausbreitungs-distanzen (MDD - “Mean Dispersal Distances“) lagen nach Modellschätzung für die ge-samten Beprobungszeiträume und unter Berücksichtigung aller Versuchsflächen zwischen 37 m und 90 m. Die durchschnittliche Diasporenproduktion eines Einzelbaumes lag nach Anga-ben des Modells in einem Bereich von 180.000 bis 7.400.000. Die Qualitätsansprache an den Diasporen ergab einen Anteil von etwa 5 % bis 8 % äußerlich Schadhaften. Der unmittelbare Windeinfluss auf Hauptausbreitungsrichtung und -entfernung konnte ebenfalls nachgewiesen werden. - Untersuchungen zum Keimlingsstadium zeigten deutliche Abhängigkeiten zwischen den ausgewählten Bodendeckungsvarianten, der Keimlingsdichte und dem Keimlingswachstum. Sand-Birkenkeimlinge waren sowohl unter Bestandesbedingungen als auch unter den freif-lächenähnlichen Bedingungen des Mitscherlich-Gefäßversuchs auf der Variante mit Mine-ralboden besonders dicht aufgelaufen, blieben jedoch stark in ihrer weiteren Entwicklung zurück. Als besonders wüchsig erwiesen sich Keimlinge auf den Bodendeckungsvarianten mit Nadelstreuauflage und in D. flexuosa. Sand-Birkenkeimlinge der Bodendeckungsvarianten ohne Konkurrenz durch Bodenvegetation (Mb, Nd) besaßen eine längere Hauptwurzel und eine höhere Wurzelmasse (56 % - 60 % der Gesamtmasse). Die oberirdische Allokation (Blatt- und Sprossmasse) fiel hingegen für Sand-Birkenkeimlinge in den Bodendeckungs-varianten mit C. villosa und D. flexuosa höher aus. Verteilungs- und Konkurrenzerhebungen in den Gefäßversuchen erbrachten signifikante Zusammenhänge zwischen Keimlingsdichte, Standraum und Wachstum der Einzelpflanze. - Das Sämlingsstadium und die älteren Verjüngungspflanzen wiesen einen deutlichen Rückgang in der Mortalität auf. Die Erhebungen im Bestand ergaben ein unterschiedliches Durchschnittsalter für Sand-Birken auf den einzelnen Bodendeckungsvarianten (C. villosa 7,6 Jahre, D. flexuosa 6,2 Jahre und Nadelstreu 4,7 Jahre). Die wachstumsrelevanten Umweltbe-dingungen wie Strahlungsverfügbarkeit, Feuchteregime und Entfernung zum nächsten Alt-baum unterschieden sich außerdem in Abhängigkeit von den als repräsentativ eingestuften Bodendeckungsvarianten unter Bestandesbedingungen. Das bestandesbezogene Wachstum der Sand-Birken in einem Alter von 2 bis 6 Jahren ließ sich durch eine exponentielle Funktion mit hoher Anpassungsgüte (p ≤ 0,000) abbilden. Innerhalb des Mitscherlich-Gefäßversuchs haben sich ebenfalls Unterschiede in der Individuendichte, den Mortalitäts- und Wachstums-raten in Abhängigkeit von den Bodendeckungsvarianten ausgebildet. Höchste Verjüngungs-dichten wurden nach einem 2,5jährigen Entwicklungszeitraum auf der Bodendeckungs-variante Nadelstreuauflage erreicht. Die Allokationen in der Trockenmasse näherten sich hingegen in den unterschiedlichen Varianten stärker an. Ein dichteabhängiges Wachstum konnte in der letzten Aufnahme nicht mehr nachgewiesen werden. Abschließend bleibt festzuhalten, dass die ermittelten Untersuchungsergebnisse in Abhängig-keit vom jeweiligen Verjüngungsstadium die zeitliche und räumliche Präsenz, Konkurrenz- und Entwicklungsfähigkeit der Sand-Birke in Fichtenaltbeständen des Tharandter Waldes charakterisieren. Sie belegen eine kleinstandörtliche Heterogenität in den untersuchten Beständen, die sich nachhaltig auf die Etablierung der hier untersuchten Pionierbaumart auswirkt. Anhand der räumlichen Modellierung lässt sich die zu erwartende Verteilung von Diasporen und Keimlingen in Abhängigkeit von den Positionen der Samenbäume prognostizieren. Insgesamt ergibt sich aus den vorliegenden Ergebnissen ein vergleichsweise hohes Verjüngungspotenzial für B. pendula, das sich durch waldbauliche Maßnahmen effizient nutzen ließe. Ein detailliertes Wissen über die einzelnen Verjüngungsstadien bietet zudem die Möglichkeit einer gezielten waldbaulichen Steuerung der Baumart und zur Risikoabschätzung des Verjüngungserfolgs unter den gegebenen Rahmenbedingungen. Bei einer wachsenden waldbaulichen Unsicherheit im Umgang mit unterschiedlichsten Klima-prognosen, die sich in ihrer Wirkung regionalspezifisch erheblich unterscheiden können, sollte die Sand-Birke als Misch- und Vorwaldbaumart unbedingt berücksichtigt werden. Um dem viel zitierten Anspruch an die Nachhaltigkeit waldbaulichen Handelns gerecht zu werden, muss die Option zur Integration von B. pendula gewährleistet bleiben, auch für künftige Generationen und bei sich wandelnden Ansprüchen an den Wald.
- Objectives - The main goal of this study was to describe comprehensively the particular stages of the regeneration cycle of Betula pendula Roth. Investigations were carried out in local stand and site conditions of a research area in South-East Germany (Tharandter Forest) are considered. In this context options for integrating Silver birch regeneration into silvicultural management concepts of old Spruce stands (Picea abies L.) with lacking vitality are pointed out. - Research area - The Tharandter Forest is located (50°00’N, 13°35’E.) in Saxony (South-East Germany) with an area of around 6.000 ha. It is dominated by Norway spruce stands, and ranges from colline to submontane altitudinal belt (350 to 420 m a.s.l.). These sites are part of the northern declivity of the Ore Mountains. Mono-layered Norway spruce stands with soils of medium trophy and well drained, but featured highly variable soil moisture levels during the growing season were selected for this study. The stand age was ≥ 80 years. Seed trees of Silver birch were mixed as single trees or small groups. - Methodical aspects - The methodical work was concentrated on relevant regeneration aspects like fructification of seed trees, seeds, seedlings, saplings and established regeneration of Silver birch. Growth parameters of seed trees and the amount of fructification were used to quantify allometric relationships. The multi-level research design was based on measurements under stand conditions, pot and laboratory experiments. Seed traps and plots (1m x 1m) were located in spruce stands with regard to different stages of Silver birch development. Therefore micro-environmental growth conditions like soil humidity and photosynthetic active radiation were measured, and plants of ground cover characterized. As examples of ground cover variants with highest presence in homogeneous spruce stands mineral soil, needle litter, Calamagrostis villosa CHAIX (GMEL.) und Deschampsia flexuosa L. (TRIN.) were chosen. Using the program WALDSTAT (NÄTHER & WÄLDER 2003) spatial distribution of dispersed seeds (diaspores) and seedlings could be modelled. Additionally pot experiments were done to compare quantitative and qualitative development of birch seedlings between stand and open site conditions. Regeneration density, number of leaves, shoot and root growth and allocations were measured as important growth parameters to evaluate single plant development under different environmental conditions. Finally, spatial distribution of seedlings in microsites and intraspecific competition were calculated by tessellation models, aggregation indices after CLARK & EVANS, Gini-coefficient and ‘constant yield law’. - Main results - - Measurements on seed trees of B. pendula indicate stand specific differences significantly in dimension, height and biosocial position of trees within the birch population (crown classes). For specific height-dbh curves logarithmic and quadratic equations were adapted. The relative crown length for seed trees was located between 37 % and 49 %. Allometric relationships between crown parameters (e.g. crown diameter, crown length and crown surface) were strongly correlated. In specific cases crown structures (e.g. dry mass of leaves and twigs) were also correlated, certainly with different grades. Direct seed counting of felled seed trees provided the relationships between dbh and number of seeds. Counted seeds for single Silver birch trees ranged between 2.300.000 - 4.200.000. - As one result of seed trapping huge varieties in seed production of Silver birch were detectable between years with different seed potential. Spatial modeling of seed dispersal supported strong influences caused by wind (direction and speed). Hence, best fitted model estimations were found for anisotropic scenarios. The maximum in seed density was recorded with 20.700 seeds per m². As data for ‘Mean Dispersal Distances’ (MDD) the program WALDSTAT calculated between 37 m and 90 m. Furthermore the amount of seeds produced by a single tree was estimated with 180.000 - 7.400.000 depending on dbh. Physical quality evaluations for seeds have shown a mean proportion of damaged and not germinable seeds between 5 % and 8 %. - Direct effects of ground cover variants have been identified for seedling density and growth. Seedling density was highest on mineral soil for both, stand conditions and pot experiment, but these birch seedlings developed slowly compared with individuals in the other ground cover variants. The best growth was realized by birch seedlings in needle litter and D. flexuosa. Regarding to root length and mass, birches in ground cover variants without grass competition (mineral soil and needle litter) have shown a significant better development of underground parts. Root dry mass of these birch seedlings reached proportions between 56 % and 60 % of whole plant dry mass. By contrast the aboveground dry mass (leaves and shoot) was higher for birches competing with grasses. Overall results of birch seedling distribution and competition were significant correlations between densities, space, and growth per single plant. - For saplings and established birch regeneration a notable decrease in mortality rates were found. According to regeneration analyses under stand conditions age distributions in Silver birch regeneration have been controlled by ground cover variants and their environment conditions. The average age of Silver birch seedlings was high in areas with C. villosa (7.6 years) and low in needle litter (4.7 years). Furthermore growth influencing environmental conditions like light, humidity, and distance of old spruce trees have shown differences between variants in ground cover. The growth of regenerated Silver birches at the age of 2 to 6 years under those stand conditions can be described by an exponential function with high degree of adaptation (p ≤ 0,000). There were also differences in sapling densities, mortality and growth rates caused by ground cover variants in the pot experiments. After 2.5 years maximum regeneration densities in pots were registered on ground covers with needle litter. Allocations in regeneration dry mass were less influenced by ground cover variants than in previous stages. Density dependent growth rates could not be proved during last measurements. Finally, the presented results provide the opportunity to characterize temporal and spatial presence of different regeneration stages of Silver birch, its potential of competition and further development in old Norway spruce stands of the Tharandter Forest. They document heterogeneous structures of micro-environmental conditions in these spruce stands, which have sustainable effects on regeneration establishment of this studied pioneer tree species. On the basis of spatial modeling it is possible to estimate spatial distribution of seeds and seedlings depending on seed tree positions. Overall the results involve a high potential of successful regeneration in Silver birch, which opens up promising vistas for silvicultural management. More detailed knowledge in particular regeneration stages induces possibilities for selective control in silviculture with Silver birch. Additionally, estimating the regeneration risks and the success under given surrounding conditions will be more precisely. Considering uncertainty in giving prognoses for climate change Silver birch should be integrated in silvicultural strategies because of its role as admixed tree species and pioneer crop combined with comparably high resilience against warming.

AbstractSalinity is a major abiotic stress which decreases crop productivity. Salt stress also causes osmotic, water, ionic and oxidative stresses. Plants exposure to salt can check their growth by reduction in water and nutrient uptake, osmotic imbalance and cytotoxicity incited by sodium and chloride ions. Present study deals with the impact of salt on germination, growth and physiological components of fenugreek and its alleviation by the application of calcium silicate. The salt stress reduced fenugreek germination and growth but supplementation of calcium silicate to salt stressed seedlings mitigated deleterious impacts of salinity. Various parameters like germination, seedling length, biomass, pigment and protein contents of fenugreek seedlings were significantly improved with calcium silicate under salt stress. Maximum reduction 53.3% in protein amount was recorded in fenugreek seedlings treated with NaCl (10 mM) over control. Significant increase in total antioxidant content in fenugreek seedlings was observed with calcium silicate as it showed the following order: Ca2SiO4 > NaCl + Ca2SiO4 > NaCl > Control. Hence, application of calcium silicate can be useful for the fenugreek plants growing under saline conditions.

Abstract Coffee is one of the most commercially available raw materials, being the tropical product with the highest market value in the world. In Costa Rica it is the third most important product for agricultural exports and provides the main income for many families in the country. However, coffee is under threat due to coffee leaf rust disease (CLR). Mutation breeding in coffee is a promising approach to develop new varieties resistant to CLR. As a new technology for coffee, basic tests related to mutation induction need to be done. The plant material used was Coffea arabica var. 'Venecia' seeds, with a moisture content of 27.3%. The applied irradiation doses were 0, 80, 100, 120, 140, 160 and 180 Gy. For each treatment, three replicates of 200 g were used, with a seed number range of 765-808 units per replicate. The irradiated seeds were planted on the same day. Eighty days after treatment the number of seedlings was quantified, the hypocotyl height and radicle length were measured and the opening of cotyledons was determined for each dose. The effects of the radiation doses on seed germination frequency were recorded. At the dose of 80 Gy, germination was reduced over the control by 9.65%, at 100 Gy by 34.06%, at 120 Gy by 52.76%, at 140 Gy by 60.24%, at 160 Gy by 65.56% and at 180 Gy by 75.40%. Seedling growth was affected and a delay in opening of the cotyledons was observed at higher doses. This radiosensitivity test, based on seed germination as compared with unirradiated control, revealed that the LD₅₀ for the variety tested is in the range 100-120 Gy experimentally, and according to the regression is 125 ± 30 Gy. This dose will be used for further bulk experiments and is of great importance, because the LD₅₀ is considered as the range where the appearance of useful mutations in breeding programmes is favoured. The establishment of these parameters is a necessary advance to continue with measurements of genetic and phenotypical parameters to implement mutation breeding in coffee looking for new sources of resistance against CLR.

AbstractSeed vigour is an important aspect of seed quality. It is a quantitative trait which is responsible for overall seed performance in terms of rate and uniformity of seed germination, seedling growth, emergence ability under unfavourable environments and post storage performance. Seed vigour is controlled by genetic factors, initial seed quality, production environments, harvesting and storage conditions. Seed vigour tests provide a more sensitive index of seed performance per se than the germination test. Efforts have been focused on developing novel or improving existing methods of vigour estimation in different crops. The vigour tests are tools routinely used for in-house seed quality control programs, especially for field and vegetable crops. Some treatments can improve seed vigour, although the treatment effects are more evident under sub-optimum than optimum growing conditions. This chapter deals with different aspects of seed vigour and its effects on plant growth and discusses physiological and biochemical parameters to understand underlying mechanisms.

Vegetation growth peculiarities and morphological and physical-biochemical features of Prunus domestica L. Utro and Yaichnaya Sinyaya varieties leaves grafted on different growing strength rootstocks were studied. Low-growing clonal rootstocks 140–1 and Novinka decreased the trees growing strength on 15–20% in comparison with strong-growing stocks; medium-growing rootstocks OPA-15-2 and OP-23-23 reduced it on 10%. The longest growing activity and the largest sprouts length was stated on these rootstocks as well, i.e. 1.3–1.4 times more than on other ones. Stable sprouts average length decrease was registered on grafted stocks 140–1 and Novinka. Leaf surface index value on the trees grafted on clonal rootstocks OPA-15-2 and OP-23-23 was on 40% higher than on control, i.e. 4.3 leaves m2/crown projection area m2. Optimal values of total increment, sprouts average length, leaves area and the largest part of physiological-biochemical parameters were stated at medium-growing clonal rootstocks OPA-15-2 and OP-23-23 use. Plum leaves blades were hypostomatic; numerous stomata were located on the abaxial (bottom) side of leaves. Stomata were located in interveinal space irregularly. Stomata length size varied from 14.6 μm (Utro/seedlings) to 22.1 μm (Yaichnaya Sinyaya/OP-23-23). The rootstock has influence on the process of photosynthesis, antioxidant activity, accumulation of minerals and metabolic answerin the leaves.

This work is devoted to the development of technological methods for the production of grafted grape seedlings, which are based on new scientific developments and contribute to an increase in the yield of standard seedlings. For the production of grafted grape seedlings, we, for the first time, studied the effect of new biologically active complex preparations Radifarm, Bioglobin, Kornevin, Ukorenitel, Charkor, El–1, Potassium humate, Ecoorganics and Rost-concentrate at the technological stages – soaking of components and rooting of grafts. It has been established that their use has contributed to the intensive formation of circular callus on copulatory cuts of grafting components, active formation, and root growth of cuttings, grafts, and annual grape seedlings. The survival rate of grapes grafts treated with preparations in the open ground nursery exceeded the control indicator by 11.2–12.5%. For the successful rooting of grape grafts in the open ground nursery, we first investigated the effect of soil mulching with polymeric materials of various types on the parameters of the temperature and water regime, the indicators of the main physiological and biochemical processes in the leaf tissues, and the agrobiological indicators of the development of grafted seedlings. It has been established that a combined black-and-white film with a thickness of 30 microns is optimal. For the first time, scientific substantiation of the use of new materials (waxes and photodestructible films) was carried out to preserve water in the tissues of grafts at different technological stages and stimulation the development of callus tissue. To stimulate the development of callus tissue before stratification grafts, it is recommended to use waxes Proagrivax Hormone, Proagrivax White, Ant-002-7C, and Ant-001-6, Proagrivax Orange, Proagrivax Mediterranean, Ant-002-7 – before planting cuttings in the nursery. These materials ensured water retention in the apical parts of grafts at the level of 51.6 – 54.2% with 47.2% in the control 30 days after planting the grafts in the nursery. The use of photodegradable films «Buddy Tapе», «Medifilm», «Professional Grafting Tape» to protect the apical parts grafts from drying out, provided the yield of grafts with circular callus at the level of 80.0–90.0% with 70.0% in control, preservation water in tissues after 30 days of vegetation of grafts in nursery at the level of 49.0–50.0%, high survival rate of grafting grafts in the nursery (the difference between experimental and control variants for this indicator was 17.3–20.9%). Based on the results of many years of scientific research, it was found established that it is advisable to stratify grape grafts on water-retaining substrates. For the first time, for stratification and conservation, the influence of new water-retaining substrates was applied and studied – coco peat, its mixture with natural minerals – agroperlite, vermiculite, coconut substrates, kamka (sea grass), preparations of the hydroabsorbent group, a substrate for growing orchids, Polessky substrate. They contributed to the formation of circular callus in 70.0–80.0% of grafts grapes, swelling or the beginning of the opening the eyes of the scion, and the formation of a large number of root tubercles. The survival rate of grafts in the nursery was higher by 26.3–32.5% compared to the generally accepted open method on the water.

To understand the salinity tolerance mechanism in faba bean contrasting pair to salinity (cv. Chourouk as sensitive and cv. Najeh as tolerant), we evaluated the effect of high salt concentration (150 mM NaCl) on the photosynthetic, physiological, and biochemical parameters at short and long term of treatment (1 and 6 days, respectively) in the seedling stage. In general, the salinity affects the growth of plants. High salinity decreased all studied parameters, especially transpiration rate (E), stomatol conductance (gs), net CO2 assimilation (A), and substomatal CO2 concentration (Ci), and dramatic changes was registered in cv. Chourouk compared to cv. Najeh. Chlorophyll contents were also affected by salinity, especially in the sensitive variety. In addition, the synthesis of osmolytes (proline) was determinate, to understand whether the osmotic adjustment is a mechanism used by cv. Najeh to tolerate salt stress. Our research suggests that cv. Najeh should be introduced in a crossbreeding program as an elite salt-tolerant germplasm.

In Latvia one third of the total forest area is regenerated by planting tree seedlings and therefore it is important to choose the appropriate soil preparation method and the right type of regeneration material for each forest type. Usually the success of afforestation is evaluated by how high is the average seedling survival rate and growth parameters like height, annual increment, diameter at breast height while the location of the seedling is disregarded. This may be of great importance since in such stands the environmental conditions typically are not entirely homogenous. Micro topography differences impact seedling growth, because it modifies water regime, temperature, micronutrient availability, sun radiation and other factors. Therefore, aim of this work is to improve monitoring methods and determine the most efficient soil preparation and seedling preparation combination to improve the quality of forest regeneration. That could be done using ASTA documentation system originally developed to show seedling and mound location and density in planting area during mechanic planting. But it also allows to link the precise location of the seedling and growing conditions with its growing rate and survival and therefore it is easier to exclude seedlings that are affected by other factors than those that you are interested in, so you can gain more representative results. This also could be used in forest management. When using ASTA system it is also possible to display how different tree disease are distributed in the stand, if they have spread eventually or localized only in some parts of the stand, also it can be used for browsing and other tree damage monitoring in the stand. In conclusion: in harsh environmental conditions on unprepared forest soil and soil prepared in furrows made by disc trench larger seedlings show better survival rate. Survival of seedlings is significantly impacted by micro topography, whereas mounded micro sites equalize local environmental conditions that reduce impact of micro topography.

The aim of the study is to carry out a comparative assessment of biometric parameters and a preliminary analysis of the size and rate of initial growth of roots and stems of seedlings of the most common varieties of winter and spring forms of rape (Brassica napus L.) and brown mustard (Brassica juncea L.). The research was carried out at VNIIMK in 2019-2020. in the laboratory. The objects of the study were rape varieties Sarmat (winter) and Tavrion (spring), brown mustard Juna (winter) and Nika (spring). It was found that the length of the stem and root of seedlings of the spring form of rapeseed and brown mustard is 2 times higher than the parameters of seedlings of the winter form due to the physiological characteristics of their seeds.

The paper examines the influence of different salicylic acid concentrations on germination percentage, dynamics and uniformity of germination, elongation and biomass of maize (Zea mays L.) seedlings in the early phase of growth and development, as well as the effect of hormopriming by salicylic acid on overcoming salt stress. According to the obtained results, the stimulating effect of salicylic acid on the germination and growth parameters of maize seedlings was confirmed, as well as its protective effect in conditions of salt stress. The concentrations of 10-4 and 10-5 M had the greatest effect on the examined parameters.

In the course of the work, the hypothesis of the stimulating effect of combined laser radiation on the growth of watercress microgreens was tested. The doses of 0.6-18 J were used in the experiment, some biometric and biochemical parameters of seedlings were evaluated. It was found that a significant increase in biomass was observed when irradiated with doses of 2.4-4.2; 5.4-6.0 J.

We studied the effect of bacterization of seedlings of barley plants with strains of hormone-producing bacteria B. subtilis IB-22 and P. mandelii IB-Ki14. The parameters of plant growth, as well as RWС and the content of chlorophyll in their leaves were estimated.

The field experiment was carried out in 2016 on sandy soil in the forest nursery Białe-Błota (Bydgoszcz Forest Division, Poland). The effect of sprinkler irrigation on the growth Paulownia Shan Tong trees was investigated. The experiment was established as one factorial. The variability factor was the irrigation: S-sprinkler irrigation and C- without irrigation (control). The process included the controls of growth parameters: tree height, trunk diameter, number and surface of leaves. It was found that the sprinkled seedlings of Paulownia Shan Tong were significantly higher than those growing in the non-irrigated plots. The sprinkler irrigation applied in the experiment resulted in an increase in the number of leaves of the Paulownia and their surface area, which resulted in an increase in biomass yield. By analysing the results of the study on trunk diameter, leaf number and surface, it may be stated that irrigation watering significantly influenced the tested parameters. Irrigation significantly increased the height of Paulownia trees. The positive effect of the usage of sprinkler irrigation may indicate the possibility of effective application of this method in the field cultivation of Paulownia Shan Tong.

The water balance of agro ecological systems is a key parameter for most physical and physiological processes with the system soil–crop–climate. Therefore it is of great importance to calculate the water budget parameters in the required scale. The field study was conducted in the period of 2002–2005. Seedlings were planted in Irrigation engineering department experimental fields at the Lithuanian University of Agriculture. Seedlings were grown under standard nursery cultural practices until being transplanted into new fields in mid April 2002 and 2004. The research site contains evaporators and 8 lysimeters in which spruce seedlings were grown and studied. Lysimeters amount 42 m2 and 30 m2. At 2002, field No.1 was irrigated 8 times, irrigation norm was 250 m3 ha-1 and seedling got 2000 m3 ha-1 water. Field No.2 was irrigated 6 times, irrigation norm – 1500 m3 ha-1. In 2003 fields No. 1 and No. 2 were irrigated 4 times and seedlings got 1000 m3 ha-1 water. At 2004, field No.1 was irrigated 8 times, irrigation norm was 250 m3 ha-1 and seedling got 2000 m3 ha-1 water. Field No.2 was irrigated 6 irrigation norm – 1500 m3 ha-1. The total evapotranspiration of the first year seedlings planted in the field No.1 in 2004 made up 323 mm. The total evapotranspiration of the seedlings growing in variant No. 2 was 307 mm in 2004 and it is by 16 mm less as compared to variant No.1.

The aim was to determine the impact of Raskila bio-organic preparation on the productivity of winter rape ‘Sunday’ grown under conventional system, in order to activate and save the use of treatment Rovral aqua flo and to improve the wintering of plants. The scientific article presents the data of the conventional winter rape ‘Sunday’ growth intensity, plant formation, accumulation of dry matter, seed quality parameters, fertility data and the influence of the use of bioorganic fertilizers e. winter rape 'Sunday' seeds were coated with bioorganic preparations and synthetic treatments, and additionally sprayed with a bioorganic fertilizer solution. Agrotechnics was carried out according to the technology of winter rape growing at Aleksandras Stulginskis University Experimental station. Additional treatment of winter rape seeds and additional spraying with bioorganic fertilizers had a positive influence on the processes of growth and development of winter rape. By combining seed treatments and treatment with bio-organic Raskila fertilizers (3 l for 100 kg) and spray in autumn (3 l ha-1 ), the best results are achieved: the maximum rape seed yield was 3.87 t ha-1 and the best quality production. Bioorganic fertilizers and treatment Rovral aqua flo has significantly increased the following indicators of winter rape ‘Sunday’: the length of the plant (118.16-127.64 cm), the number of branches (6-10), seeds in the silique (28.27), the seed yield (3.16-3.87 t ha-1). The highest seed yield (3.87 l ha-1) was achieved, applying Nagro preparations in the autumn and the Rovral aqua flo treatment and spraying Raskila plants when the rape reaches a height of 5-7 cm (BBCH 10-19). Premium yield was 86.6 % compared to control. Raskila fertilizers and treatment Rovral aqua flo significantly increased the following parameters of winter rape seeds: content of fat (41.52-43.05 %), proteins (20.39-20.91%), glucosinolates decreased from 18.68 to 18.31 m mol g-1. This has improved seed quality. Treatment with Raskila and treatment Rovral aqua flo decreased seeds and seedlings infestation and morbidity due to Fusarium, Drechlera, Alternaria, Penicillium. Rates of treatment can be reduced if combined with bioorganic fertilizers. Application of bioorganic fertilizers and treatment in combination increases the effectiveness of treatment. Bio-organic fertilizer reduces plant stress caused by synthetic treatment.

A germination test of Vicia faba and Lens culinaris seeds under the effect of bleach and vinegar was conducted for seven days, and the observations were recorded daily. The completely randomized design (CRD) was used to examine the germination with three replicates at the lab conditions. Six germination parameters were measured, including germination percentage (GP), germination index (GI), mean germination time (MGT), mean germination rate (MGR), vigour index (VI), plus the fresh weight (FW) and dry weight (DW) of Vicia faba and Lens culinaris seeds. As a legume crop seeds model, the efficacy of four treatment levels from 0.005% to 0.5% of bleach and vinegar on the germination was tested. A chemical analysis was performed using the ion chromatography (IC) to evaluate the effect of chloride and acetate anions up-take on the seedling germination in addition to other essential nutrients. A significant inhibition in seedling growth was observed with increasing the treatment concentration. The maximum inhibition was recorded for both seeds at 0.5%, followed by 0.1% levels, while a positive effect was represented with the lower concentrations. The chemical analysis of the up-taking active ingredients was corroborated by the germination outputs.

Nonea pulla DC. is a promising perennial medicinal plant growing in the Crimea. Controlled in vitro cultivation of nonea seeds allows improving the up-to-date techniques of seedlings preparation. The conducted experiments confirmed the low germinating capacity of seeds (5–9 %). To increase this parameter and to speed up the introduction process, we investigated the Nonea pulla in vitro culture. The initial phases of germination were expectedly observed during seeds cultivation. The seed swelling, rupture of pericarp and seed hull, release of germ with cotyledons, dehiscence of cotyledons were detected. Moreover, in some cases, no subsequent development was observed. However, normal germs formed in 60% of cases. Seeds also sprouted without the prior cold stratification. For the following growth, plants required a relatively simple culture medium. The maximum development conditions were reached after 1.0–1.5 months of in vitro cultivation (26±2 °С, illuminance of 2000–3000 lux, 16-hour photoperiod).

Porphyra species (commonly known as ‘nori’ or ‘purple laver’) are edible red seaweeds rich in proteins, vitamins and other highly valued biogenic compounds. For years Porphyra has been cultured using seeded nets extended in the open sea, and its biomass consumed primarily in the Far East. While demands for international markets have increased steadily at an average of 20% per year, supplies are on the verge and not expected to meet future demands. Alternatively, land-based cultivation of seaweed has become attractive in the mariculture industry since (1) important growth parameters can be controlled, (2) is environmentally friendly and (3) perfectly matches with integrated aquaculture leading to sustainable, high quality products. During the last few years a tank cultivation technology for Porphyra has been developed at the Israeli institution. This technology is based on indoor production of asexual spores and their subsequent growth to 1-2 mm seedlings. The seedlings are then transferred to outdoor tanks and ponds when seawater temperatures drop to 20 °C, or below, and days become shorter during winter time. However, the current technology efficiently serves only about 100 m2 of ponds during one growth season. In order to produce seedlings in sufficient amounts, it is critical to address both technical and biological aspects of seedling production, securing optimal up-scale to commercial-size cultivation farms. We hypothesize that massive production of spores is related to thalli origin, thalli age and sporulation triggers, and that seedling survival and their subsequent growth potential is determined by the seawater quality and overall indoor growth conditions imposed. A series of bio-reactors were constructed and tested in which spore release and spore growth were separately studied. The main assessment criteria for optimal viability of the seedlings will be by determining their electron transport rate using PAM fluorometry and by subsequent growth and biomass yields in outdoor ponds. Altogether the project showed (1), controlled sporulation is possible in big outdoor/growth chamber settings provided initial stock material (small frozen seedlings) is at hand, (2), contamination problems can be almost completely avoided if stock material is properly handled (clean as possible and partially dehydrated prior to freezing), (3), spore release can significantly be enhance using high nutrient levels during thawing for P. yezoensis and P. haitanensis, but not for P. rosengurttii, (4), PAM fluorometry is an efficient tool to estimate growth capacity in both seedlings and juvenile thalli. The BARD funding also served to explore other aspects of Porphyra biology and cultivation. For example, the taxonomical status of Porphyra strains used in this study was defined (see appendix), and the potential use of this seaweed in bioremediation was well substantiated. In addition, BARD funding supported a number of opportunities and activities in the Israeli lab, direct or indirectly related to the initial objectives of the project such as: additional molecular work in other seaweeds, description of at least 2 new species for the Israeli Mediterranean, and continuous support for the writing of a book on Global Change and applied aspects of seaweeds. The technology for Porphyra cultivation in land-based ponds is readily available. This study corroborated previous know-how of Porphyra growth in tanks and ponds, and yet offers important improvements regarding seedling production and their handling for successful cultivation. This study supported various other activities opening additional important issues in the biology/cultivation/use of Porphyra and other seaweeds.

This one year BARD project was funded to develop methods to monitor promoter activity a gene expression patterns in citrus fruit. To fulfill this goal, we divided the research tasks between both labs so that the Israeli side evaluated the use of microprojectile bombardment ; a tool to evaluate transient gene expression in various citrus fruit tissues, and the US side optimized technical parameters required for Agrobacterium-mediated transformation of various citrus cultivars. Microprojectile bombardment appeared to be a very efficient method for transient gene expression analysis in citrus leaf tissues but was somewhat less applicable in fruit tissues. Nevertheless, we did succeeded to achieve significant levels of 35S-GUS gene expression in young green flavedo tissue. However, only single random spots of 35S-GUS gene expression were detected mature flavedo and in juice sacs and albedo tissue. Overall, we assume that following some more technical improvements particle bombardment could provide a useful technique to rapidly analyze promoter activity at least in the flavedo tissue. For Agrobacterium-mediated transformation, we found that shoot cultures of 'Washington' navel oranges,'Fairchild' mandarins,'Eureca' lemons,'Troyer' citrange and various grapefruits provided a more reliable and consistent source of tissue for transformation than germinated seedlings. Moreover, various growth media's (McCown, Quoirin & Lepoivre, DCR) further improved shoot and root growth relative to MS mineral media, which is commonly used. Also pure white light (using bulbs which do not emit UV or blue light) improved shoot growth in various citrus varieties, and paromomycin appeared to be a more efficient antibiotic for the selection of transgenic plants than Kanamycin. Overall, these optimizations improve transformation efficacy and shoot growth and rooting capacity. In addition to the development of transformation methods, both Israeli and US labs achieved progress in the identification of citrus fruit-specific promoters. In Israel, we isolated a 3.6 kb promoter fragment of the thiamine biosynthesis c-thi gene, which is highly expressed in fruit peel tissue, whereas in the US we isolated a 1.5 kb promoter fragment of the citrus seed-specific cDNA CssH. The identification of more fruit-specific cDNAs and their corresponding promoter regions is currently in progress.