Greater Vegetative Growth Research Articles

Substrato à base de resíduos agroindustriais e coloração de bancadas de cultivo influenciam a produção de Zinnia elegans

Abstract Among the various technologies that can be used to modify the environmental conditions in protected cultivation, the use of agricultural waste and the use of cultivation benches of different colors can be beneficial to plants, providing adequate plant development and giving greater sustainability to the production system. The study aimed to identify the potential for using substrate based on agro-industrial waste and colored benches as alternatives for the production of Zinnia elegans. The experiment was conducted in the experimental area of the Mato Grosso do Sul State University (UEMS), in the Unit of Cassilândia, using a completely randomized design arranged in a 3 x 5 factorial scheme (three bench colors x five substrate doses), with three replications of four plants for each treatment. The treatments consisted of three colored benches (white, red, and control - metal bench) and five substrate mixtures with different concentrations of agro-industrial waste (SBRA) and Ecosolo® (0, 25%, 50%, 75%, and 100%) in which Zinnia elegans was grown. The variables analyzed were plant height, length of internodes, the number of leaves, relative chlorophyll content (SPAD), stem diameter, flower diameter, number of petals, time required for flowering and shoot dry mass. It was found that the composition of the substrate affected most of the characteristics evaluated, except for internode length and stem diameter. The benches resulted in significant differences in relative chlorophyll content and number of petals. Adding increasing proportions of SBRA, provides greater vegetative growth and flower development in Zinnia elegans plants.

Male fertility advantage within and between seasons in the perennial androdioecious plant Phillyrea angustifolia.

Androdioecy, the co-occurrence of males and hermaphrodites, is a rare reproductive system. Males can be maintained if they benefit from a higher male fitness than hermaphrodites, referred to as male advantage. Male advantage can emerge from increased fertility owing to resource reallocation. However, empirical studies usually compare sexual phenotypes over a single flowering season, thus ignoring potential cumulative effects over successive seasons in perennials. In this study, we quantify various components of male fertility advantage, both within and between seasons, in the long-lived perennial shrub Phillyrea angustifolia (Oleaceae). Although, owing to a peculiar diallelic self-incompatibility system and female sterility mutation strictly associated with a breakdown of incompatibility, males do not need fertility advantage to persist in this species, this advantage remains an important determinant of their equilibrium frequency. A survey of >1000 full-sib plants allowed us to compare males and hermaphrodites for several components of male fertility. Individuals were characterized for proxies of pollen production and vegetative growth. By analysing maternal progeny, we compared the siring success of males and hermaphrodites. Finally, using a multistate capture-recapture model we assessed, for each sexual morph, how the intensity of flowering in one year impacts next-year growth and reproduction. Males benefitted from a greater vegetative growth and flowering intensity. Within one season, males sired twice as many seeds as equidistant, compatible hermaphroditic competitors. In addition, males more often maintained intense flowering over successive years. Finally, investment in male reproductive function appeared to differ between the two incompatibility groups of hermaphrodites. Males, by sparing the cost of female reproduction, have a higher flowering frequency and vegetative growth, both of which contribute to male advantage over an individual lifetime. This suggests that studies analysing sexual phenotypes during only single reproductive periods are likely to provide inadequate estimates of male advantage in perennials.

Optimizing Hydroponic Management Practices for Organically Grown Greenhouse Tomato under Abiotic Stress Conditions

Hot and humid conditions create challenges for tomato production under a controlled environment. Low tomato productivity is related to the lack of stress tolerance of existing cultivars and their ability to maximize fruit set and yield. The aim of this study was to evaluate the effectiveness of three management strategies, cultivar selection, grafting, and plant density, for the growth and production efficiency of organically grown hydroponic tomatoes under adverse environmental conditions in Qatar. The experiment used a split-split plot design with ‘Velocity F1’ and ‘Sigma F1’ as the main plot treatments and a factorial arrangement of grafting combinations and planting densities (3.5 and 5.5 plants/m2) as subplots. Tomato cultivar Velocity F1 grafted on Maxifort F1 resulted in greater vegetative growth and improved phenological attributes than nongrafted Velocity F1. Grafted ‘Velocity F1’ plants grown at 3.5 plants/m2 had an increase in leaf photosynthetic rates (18%), less transpiration loss (16%), and less electrolyte leakage (15%) while maintaining stomatal conductance and intercellular CO2 concentrations. At 9 weeks after transplanting, canopy growth was higher (24%) and flowering occurred earlier (3 days) with grafted ‘Velocity F1’ transplants than with nongrafted transplants. Higher fruit sets (20%), pollen viability (22%), and fewer flower drops (17%) were also observed for grafted ‘Velocity F1’ transplants than for nongrafted transplants. Marketable fruit yields were higher (26%) with grafted ‘Velocity F1’ grown at 3.5 plants/m2 than with nongrafted ‘Velocity F1’. Both grafted ‘Velocity F1’ and ‘Sigma F1’ fruits retained acceptable fruit color (L*, a*, b*, C*, °h), firmness, °Brix, titratable acidity, weight, and prolonged shelf life by 4 additional days than nongrafted ones. We conclude that grafted tomato ‘Velocity F1’ grown at a plant density of 3.5 plants/m2 was the best management strategy for enhancing seedlings quality, plant growth, and postharvest quality and alleviating abiotic stresses under this protected environment and hydroponic system.

Effect of Different Foliar Fertilizer Applications on Esca Disease of Grapevine: Symptom Expression and Nutrient Content in the Leaf and Composition of the Berry

Esca disease, the most common grapevine wood disease in Europe, causes yield losses correlated with the foliar symptoms’ expression. In two vineyards located in the Abruzzo Region of Italy, each of which were investigated for esca symptoms after 1994, different applications of macro- and microelements were performed in two consecutive growing seasons. The main aim of the work consisted of verifying the effects of the fertilizer applications on the foliar symptoms’ expression, in order to deepen knowledge of the nature of the symptom, which is still unclear. For each treatment, in each year, the leaf content of macro- and microelements and the composition of berries and musts were assessed. The effects of these applications on vegetative growth and yield quantity were also verified. The trials were carried out on symptomatic, asymptomatic and apparently healthy vines. All applications, in particular those with microelements, increased the foliar symptoms’ expression, and a greater vegetative growth was detected only in vines treated with NPK fertilizers. The symptoms’ increase was always associated in the leaf with a decrease of calcium, and to a lesser extent, magnesium, reinforcing the hypothesis of the plant’s hypersensitive reaction in the development of foliar symptoms, given the role of calcium in the defense response. The vineyards were in nutritional balance regardless of the fertilizer applications. The general increase in foliar symptoms and the decrease in sugars in the musts of asymptomatic treated vines underlined the importance of the vegetative-productive balance, in Esca infected vineyards especially, in order to limit the symptoms’ expression and the decrease in yield.

Liquid Nitrogen as promotor of seeds germination and seedling growth in tropical legumes

Introduction: The hard seed is the main cause of dormancy in most of the Leguminoseae species. Seed scarification methods, where physical damage is sought to break hard seed coat without diminishing quality, have been modified over time to make them more effective. The most commonly used seed scarification methods include heat, mechanical scarification, and freeze-thaw. Some methods for freeze-thaw scarification include ultra-low temperature immersion in liquid nitrogen (LN, -196 ° C). Objective: Determine the effectiveness use of Liquid nitrogen (LN) as a scarification method to overcome dormancy in seeds of species of the Leguminoseae family. Methodology: The physiological quality of all freshly harvested seeds was determined and scarified by direct immersion in LN for 30 minutes. Total germination was determined under laboratory conditions, as well as the time required for the seeds to reach 50% germination (T50) and the total number of seeds that remained hard at the end of the experiment. The percentage of emerged seedlings and their vegetative growth was evaluated for 21 days after sowing. Results: The seeds of all species evaluated showed a high physiological quality at the time of harvest. Scarification with LN improved germination, emergence and vegetative growth in the species Desmodium scorpiorus, Teramnus labialis, Neonotonia wigthii and Phueraria phaseoloides. Conclusions: Dormancy was effectively overcome in the seeds of the species D. scorpiorus, T. labialis, N. wigthii and P. phaseoloides. It was possible to increase the percentage and speed of germination and emergence, managing to obtain plants with greater vegetative growth during the first 21 days after sowing.

NPK, calcário e gesso na produção de mudas de Ochroma pyramidale

O pau de balsa ( Ochroma pyramidale (Cav. Ex Lam.) Urb.) É uma espécie amazônica, pioneira, de rápido crescimento e com diversas potencialidades de uso. Objetivou-se avaliar mudas desta espécie submetidas a solid de nitrogênio, fósforo e potássio (NPK), calcário e gesso agrícola. O delineamento experimental utilizado foi inteiramente ao acaso com oito tratamentos, cinco repetições e quatro mudas por repetição, num total de 160 plantas, tratados testados foram: Testemunha; NPK; NPK + Calcário; NPK + Calcário + Gesso Agrícola; N; N + calcário; N + Gesso Agrícola e N + Calcário + Gesso agrícola. As mudas foram conduzidas em casa de vegetação, em sacolas plásticas com capacidade de 2,38 dm -3e, aos 70 dias após transplante avaliou-se: altura da planta (h), comprimento da raiz (CR), diâmetro do coleto (Dc), número (NF) e área de folhas (AF), Índice de Clorofila Falker (ICF) ), matéria seca da raiz (MSR), da parte aérea (MSPA) e total (MST), relação altura da planta com diâmetro do coleto (RAD), relação da matéria seca da parte aérea com matéria seca das raízes (RPAR) , relação altura e massa seca da parte aérea (H / MSPA) e Índice de Qualidade de Dickson. A adubação com NPK, independente da presença do calcário e gesso agrícola, proporcionou maior crescimento vegetativo e qualidade das mudas de pau de balsa.

Stimulation of photosynthesis and enhancement of growth and yield in Arabidopsis thaliana treated with amine-functionalized mesoporous silica nanoparticles

Mesoporous silica nanoparticles (MSNs) of 50 nm diameter particle size with a pore size of approximately 14.7 nm were functionalized with amino groups (Am-MSNs) and the effects of exposure to these positively charged Am-MSNs on each of the life cycle stages of Arabidopsis thaliana were investigated. After growth in half strength MS medium amended with Am-MSNs (0–100 μg/mL) for 7 and 14 days, seed germination rate and seedling growth were significantly increased compared with untreated controls. The seedlings were then transferred to soil and irrigated with Am-MSNs solutions every 3 days until seed harvesting. After four weeks growth in soil, Am-MSNs treated plants showed up-regulation of chlorophyll and carotenoid synthesis-related genes, an increase in the content of photosynthetic pigments and an amplification of plant photosynthetic capacity. All these changes in plants were closely correlated with greater vegetative growth and higher seed yield. In all the experiments, 20 and 50 μg/mL of Am-MSNs were found to be more effective with respect to other treatments, while Am-MSNs at the highest level of 100 μg/mL did not result in oxidative stress or cell membrane damage in the exposed plants. To the best of our knowledge, this is the first report evaluating both physiological and molecular responses following exposure to plants of these specific Am-MSNs throughout their whole life cycle. Overall, these findings indicate that following exposure Am-MSNs play a major role in the increase in seed germination, biomass, photosynthetic pigments, photosynthetic capacity and seed yield in A. thaliana.

Adaptations of Three Cash Crops to Climate Change

Climate change is likely to lead to adaptations among important crop species. Elevational gradients can be used to illustrate the effects of climate change on crop adaptation patterns. The research aimed to determine adaptation patterns in crop species across an elevational (and therefore temperature and humidity) gradient. A factorial design was applied with two factors within a simple Randomized Complete Block Design, wherein the primary factor was elevation (10 – 1,000 m). Three crop species (long bean, common bean, and winged bean) were used as test species. Growth rate and flower number were used as adaptation parameters. The results indicated that these three cash crop species showed different adaptation patterns. Common bean showed the greatest vegetative growth at approximately 600 m in elevation, long bean at 400 m in elevation, and winged bean at 10 m in elevation. The results of this study indicate that the three tested agricultural crops have different adaptation patterns, and these results was the first finding to be published in Indonesia. For agriculture practices, it can be recommended that planting of these cash crops be adapted to the elevation of the planting area.

Photosynthetic performance is determined by scion/rootstock combination in mango seedling propagation

This study aimed to identify the most promising rootstock for the development of ‘Uba’ mango seedlings. We used three polyembryonic Mangifera indica L. rootstock cultivars (‘Oleo’, ‘Uba’ and ‘Imbu’) and one ‘Uba’ scion cultivar, 'Uba Clone 2′ ('UC2′). The chlorophyll a fluorescence, gas exchange, proline content and growth of the rootstocks and their respective scion/rootstock combinations (UC2/Oleo, UC2/Uba and UC2/Imbu) were analyzed. The parameters selected for the PSII photochemical system by chlorophyll a fluorescence kinetics (F2, F3, dV/dt0, DI0/RC, DFABS and DFTOTAL) were suggested as physiological indicators and the leaf proline content was suggested as a biochemical indicator for identifying the higher PSII quantum efficiency, increased water use efficiency and greater vegetative growth in UC2/Oleo. With these results, it was possible to better understand the potential effects of ‘Oleo’, ‘Uba’ and ‘Imbu’ rootstocks on ‘Uba’ mango scion performance, distinguish the grafted plants on the ‘Oleo’ rootstock and confirm the superiority of this rootstock in the production of ‘Uba’ mango seedlings under optimal environmental conditions. Thus, measuring chlorophyll a fluorescence, a fast and nondestructive method, can be highly useful for identifying the most promising rootstock for the production of 'Uba' mango seedlings, replacing time-consuming methods in crop management.

Plant phenological asynchrony and community structure of gall-inducing insects associated with a tropical tree species.

The dynamics of occurrence of target organs in plant populations produces windows of opportunity that directly and indirectly affect the structure of herbivore communities. However, mechanisms that drive herbivore specialization between resource patches are still poorly known. In this study, we tested three hypotheses related to variation in host plant phenology and community structure (i.e., composition, richness, and abundance) of gall‐forming species: (a) plants with early leaf‐flushing in the season will have greater vegetative growth and high contents of secondary chemical compounds; (b) gall‐inducing insect community structure changes among temporary resource patches of the host; and (c) interspecific competition is a probable mechanism that drives gall‐inducing insect community structure on Copaifera langsdorffii. We monitored daily a total of 102 individuals of the super‐host C. langsdorffii from August 2012 to May 2013, to characterize the leaf flushing time of each host plant. The leaf flushing time had a positive relationship with the number of folioles per branch and a negative relationship with branch growth. We sampled a total of 4,906 galls belonging to 24 gall‐inducing insect species from 102 individuals of C. langsdorffii. In spite of some gall‐inducing species presented high abundance on early leaf‐flushing plants, direct and indirect effects of plant phenology on galling insect abundance was species dependent. At the community level, our study revealed that the quality and quantity of plant resources did not affect the richness and abundance of gall‐inducing insects associated with C. langsdorffii. However, the richness and composition of gall‐inducing species varied according to the variation in leaf flushing time of the host plant. The results of null model analysis showed that galls co‐occurrence on C. langsdorffii trees differ more than expected by chance and that interspecific competition can be one potential mechanism structuring this gall‐inducing insect community.

Linking species abundance and overyielding from experimental communities with niche and fitness characteristics

Abstract So far, the principal force shaping local plant abundance patterns remains unclear. Rarity can result not only from poor competitive ability or from small vegetative or generative reproduction, but also from strong self‐limitation. The same mechanisms can drive species‐specific overyielding, that is, increased species productivity at high community diversity. Rare species can then benefit more (i.e., overyield to a larger extent) from growing in species‐rich communities because of altered competitive hierarchies or smaller conspecific frequencies. Here, we test which mechanism is the most important determinant of species rarity and of species‐specific productivity across a diversity gradient ranging from 1‐ to 60‐species plots. For that, we measured vegetative growth, competitive ability (competitive effect), and negative frequency dependence for 49 perennial grassland species from Central Europe. We then linked these characteristics with species abundance (measured as species biomass from 60‐species plots) and with species‐specific overyielding in The Jena Experiment. Species with higher rates of vegetative growth (when grown without neighbours) were also more abundant in the Jena Experiment. Larger species‐specific overyielding was then associated with a stronger negative frequency dependence. As species with greater vegetative growth were also more self‐limited, larger overyielding in species‐rich communities was characteristic for common rather than for rare species, refuting our initial hypothesis. Finally, path analysis indicated that species with poor capacity to suppress neighbours also profited more from growing in diverse communities. Synthesis. Our results identify key mechanisms driving abundance and productivity of species in synthetic communities differing in species richness. While vegetative reproduction was closely associated with abundance, intraspecific interactions (strength of negative frequency dependence) shaped species productivity across a richness gradient. Our study sheds light on the abundance patterns of species and their influence on community functions, such as biomass production, of species‐rich and ‐poor vegetation.

Morphological, physiological and biochemical responses of two Australian biotypes of Parthenium hysterophorus to different soil moisture regimes.

Parthenium weed is a problematic invasive species in several countries around the world. Although it is considered to be a highly invasive species within Australia, not all biotypes of parthenium weed exhibit the same ability in regard to aggressive colonization and distribution. Differences among biotypes, particularly in regard to environmental ranges as a possible basis for this variation, have not always been elucidated. To determine whether drought tolerance could be a factor in biotype demographics, we quantified the biological responses of two Australian parthenium weed biotypes known to differ in invasive ability Clermont ("high") and Toogoolawah ("low") to 100, 75 and 50% of soil water holding capacity (WHC). The Clermont biotype had greater vegetative growth, seed production and chlorophyll content than Toogoolawah, across all moisture levels. Net photosynthesis, stomatal conductance, internal CO2 concentration, seed production per plant, 1000 seed weight and subsequent germination percentage were also higher for Clermont than for Toogoolawah and were maximum at 75% WHC. Clermont plants also had higher total soluble sugar, phenolics and free proline content than Toogoolawah, and a significant increase in the levels of all of these biochemicals was observed at 50% WHC. In conclusion, Clermont grew and reproduced better than Toogoolawah across all moisture regimes consistent of enhanced invasive ability of this biotype. Overall, the ability of parthenium weed to maintain good growth, physiology and seed production under moisture stress may enable it to colonize a wide range of Australian environments.

Yield of sugarcane submitted to nitrogen fertilization and water depths by subsurface drip irrigation

ABSTRACT Water is limiting for growth and essential for photosynthesis. Crop yield depends on the available amount of this resource and on the efficiency of its use by the plant. This study aimed to evaluate the vegetative growth and the gross yield of sugar and ethanol from sugarcane along cane-plant and ratoon cane cultivation, under different irrigation depths for water replenishment, with and without nitrogen (N) application by subsurface drip irrigation. The experimental design was randomized blocks, analyzed in a split-plot scheme, with four replicates, in which the plots were represented by the interaction: irrigation depths (0, 25, 50, 75 and 100% water replenishment of the field capacity), with and without N fertigation, and subplots were represented by 9 evaluation periods (90, 120, 150, 180, 210, 240, 270, 300 and 330 days after planting/days after the first cutting for ratoon cane). The gross yields of sugar and alcohol for water replenishments below 93 and 97%, respectively, are higher in sugarcane of first year than in sugarcane of second year. Fertigation provided greater vegetative growth of ratoon cane.

Response of KDML105 and RD41 rice varieties grown on a Typic Natrustalf to granulated pig manure and chemical fertilizers

A study on the effect of composted pig manure and chemical fertilizers on the yield and plant nutrients uptake of the KDML105 and RD41 rice varieties grown on a Typic Natrustalf was carried out in a field of the Farmer Occupational Research and Development Centre, Ban Panead, Khok Samrong district, Lopburi province in 2013. The soil on the experimental area contained some soil constraints that adversely gave a low rice yield; therefore, the study investigated the response of two rice varieties to the application of composted pig manure and chemical fertilizers. A factorial, randomized, complete block design with three replications was employed. The first factor comprised the two rice varieties while the second factor consisted of six treatments consisting of no added fertilizer, sole and a combination of composted pig manure and chemical fertilizers. The results showed that both rice varieties produced similar amounts of grain yield—1.32 t/ha for the KDML105 variety and 1.28 t/ha for the RD41 variety. The KDML105 variety had greater vegetative growth than the RD41 variety. The application of 50% composted pig manure plus 100% chemical fertilizers highly significantly promoted the rice grain yield to the highest level achieved (1.88 t/ha), whereas the sole application of chemical fertilizer (T2) as commonly used by local farmers and 50% composted pig manure (T4) gave much lower yields, albeit greater than the control without manure added or fertilization. Almost all major and minor plant nutrients were statistically more concentrated in the grain of RD41 than in KDML105, while some micronutrients accumulated more in KDML105. In general, the application of 50% composted pig manure together with 100% chemical fertilizer (T5) effectively promoted the highest uptake of most plant nutrients in both the grain and straw, which coincided with the highest grain yield. While there were no statistically significant differences, RD41 with the addition of 50% composted pig manure together with 100% chemical fertilizer tended to give the highest grain yield of 2.29 t/ha when grown on this poor soil.

Grafting with an Interspecific Hybrid Squash Rootstock Accelerated Fruit Development and Impaired Fruit Quality of Galia Melon

Interspecific hybrid squash (Cucurbita maxima × Cucurbita moschata) is a well-known cucurbit rootstock for controlling soilborne diseases and improving abiotic stress tolerance. However, reduced fruit quality has been reported on certain melon (Cucumis melo) cultivars when grafted with squash rootstocks. In this study, a field experiment was designed to explore fruit development and quality attributes of galia melon ‘Arava’ by grafting with hybrid squash rootstock ‘Strong Tosa’. Grafted plants with ‘Strong Tosa’ showed delayed anthesis of female flowers by ≈8–9 days, but harvest dates were unaffected compared with non- and self-grafted ‘Arava’ plants. Early and total yields were not significantly different between grafted and nongrafted plants. Grafted plants with ‘Strong Tosa’ rootstock exhibited accelerated fruit development and greater vegetative growth. During the harvest period, ≈27% of grafted plants with ‘Strong Tosa’ wilted, which was determined as nonpathogenic. Grafting with ‘Strong Tosa’ rootstock resulted in reduced fruit total soluble solids (TSS) and consumer rated sensory properties.

Eucharis Grandiflora Planch. and Linden Development Fertirrigated with Different Osmotic Potentials

Eucharis grandiflora Planch. and Linden is a tropical climate Amaryllidacea, commonly known as lily, which develops a bulbous stem and is considered an indoor ornamental plant for its evergreen foliage and inflorescence. The aim of this study was to evaluate the vegetative development of the Lily, in response to the treatment with of the Steiner solution at different concentrations. The plants were acclimated under greenhouse conditions and the bulbs selected by a completely randomized design. Plants were treated with various concentrations of the Steiner solution, to develop the following potential osmotic: −0.018, −0.036, −0.054, −0.072, and 0 Mpal. The production of bulbils, development and leaf area, stomatal density, chlorophyll quantification, and osmotic potentials were evaluated. The results showed that treatment with solutions of −0.054 and −0.072 MPa induced a greater vegetative growth, 29.5% more stomata developed, and synthesized 29% more chlorophyll “b” than the control.

Irrigation Frequency during Container Production Alters Rhododendron Growth, Nutrient Uptake, and Flowering after Transplanting into a Landscape

One deciduous cultivar of Rhododendron L., Gibraltar (AZ), and two evergreen cultivars, P.J.M. Compact (PJM) and English Roseum (ER), were grown in containers for 1 year to determine the effects of irrigation frequency during container production on plant performance the next spring when the plants were transplanted into the landscape. While in the containers, each cultivar was irrigated once or twice daily, using the same amount of water per day, and fertilized with complete nutrient solutions containing 0, 35, 70, or 140 mg·L−1 nitrogen (N). Three months after transplanting into the landscape, nutrient uptake, growth, and flowering were evaluated. In general, the effects of irrigation frequency in containers on performance in the landscape differed between the deciduous cultivar and the evergreen cultivars. In AZ, less frequent irrigation in containers had a pre-conditioning effect that resulted in greater vegetative growth in the landscape but less reproductive growth. In contrast, less frequent irrigation reduced vegetative growth of evergreen cultivars in the landscape and improved flowering. Different growth responses to irrigation frequency between deciduous and evergreen cultivars appeared to be related to differences in timing of nutrient uptake and mobilization. In the deciduous cultivar, less frequent irrigation increased nutrient reserves and improved the ability of the plants to absorb and use nutrients after transplanting, but in the evergreen cultivars, it generally decreased nutrient uptake after transplanting. Less frequent irrigation also altered plant attributes that are important to consumers, including developing a sparser canopy in ER and a fuller canopy in PJM, and producing more but smaller inflorescences in both cultivars. Landscape performance was related to plant nutrition in containers; however, irrigation frequency in containers disrupted relationships between nutrition and performance in all three cultivars. Our results indicate that irrigation frequency during container production of Rhododendron results in a tradeoff between vegetative and reproductive growth the next spring when the plants are in the landscape.

Influence of retained node number on Sauvignon Blanc grapevine vegetative growth and yield

Background and Aims The potential yield of grapevines is often inexpensively manipulated by altering the number of nodes retained per vine after pruning. In the context of Sauvignon Blanc in Marlborough New Zealand the influence of node number on grapevine performance is not well documented. To address this void a multi-year field study examined the effect of node number on Sauvignon Blanc grapevine growth and yield. Methods and Results A replicated field experiment was established by winter pruning the same grapevines to 24–72 nodes per vine (two, three, four, five or six 12-node canes per vine) over a 4-year period. Increasing the number of nodes resulted in a linear increase in vine yield in 2007. In subsequent years, the yield response decreased and from 2009 onwards, increasing the number of nodes beyond 36 per vine did not increase yield. Fewer nodes per vine were associated with greater vegetative growth and cane vigour. Pre-flowering shoot length, leaf number and shoot diameter along with end of season mean cane mass were greatest in vines with fewer nodes. Conclusions The dynamic interseasonal yield responses were caused by a combination of changes in bunches per vine and bunch mass, although the contribution of each yield component altered during the course of the experiment. Changes in cane vigour and bunches per shoot (fruitfulness) suggest that they are part of the mechanisms by which vines moderate yield over time in response to altered node number. Significance of the Study Increasing or reducing node number per vine does not result in sustained yield increases or reductions respectively. Grapegrowers should expect the level of yield compensation to change after the first year of a change in node number. Therefore, adjustment of nodes per vine and the selection of appropriate cane vigour at pruning should be considered carefully when setting the annual yield potential of Sauvignon Blanc grapevines.

Clonal growth and plant species abundance

Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf-height-seed) traits and by actual performance in the botanical garden. Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area - height - seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially underlying clonal growth effects on abundance. Garden performance parameters provide a practical approach to assessing the roles of clonal growth morphological traits (and LHS traits) for large sets of species.

Restoration of Herbaceous Woodland Plants: Persistence, Growth, and Reproductive Success of Local and Non-local Propagules

Restoring the forest herbaceous layer in remnant forests throughout the Midwestern United States (U.S.) is limited by the lack of seed and propagules for many plant species. As a result, restorationists often have limited material to work with and must seek out plant material at a regional rather than a local scale, without knowing whether regional provenances are ecologically appropriate. We conducted greenhouse and field experiments to examine persistence, growth, and reproduction of three herbaceous perennials (wild ginger, Virginia waterleaf, and James’ sedge) that could be used for restoration. The greenhouse experiment represented a common garden and was conducted to identify whether there were genetic differences in morphological characters between local plants and non-local transplants from commercial nurseries. The two-year field study was conducted to determine whether any genetic differences noted in the greenhouse persisted in a natural setting, and also to determine what planting density (two or five individuals in a 0.25 m2 plot) would be sufficient for the plants to establish. In the greenhouse, growth and reproductive measures for non-local plants were generally equal to or greater than those of local plants. However, we found the reverse for many traits, particularly related to reproduction, in the field during year two. In natural field conditions local plants had equal or greater vegetative growth and reproduction than non-local plants, although both had similar persistence. Further, similar persistence and growth in low- and high-density field plots suggested that a limited number of transplants would be adequate for successful establishment of non-local transplant stock.