Limiting carbohydrates to trunk and roots improves bud fruitfulness, fruit set and yield in cv. Malbec (original) (raw)
Related papers
Girdling of shoots at flowering reduces shatter in grapevine cv. Malbec
Australian Journal of Grape and Wine Research, 2020
Background and Aims: Some grapevine cultivars such as Malbec have unstable yield, due to poor fruitset or fruitlet abscission. The phenomenon is known as 'shatter' and this study aims to explore the potential of applying the shoot girdling technique at flowering, to direct the carbohydrate partitioning towards inflorescences and reduce shatter. Methods and Results: Fruitful Malbec shoots were girdled above the apical bunch, below the basal bunch, double girdled or not girdled (Control) during 2017 and 2018. Most vegetative growth parameters were unaffected, but shoots widened and the leaf expansion improved in the fruit zone. Fruitset doubled compared to that of the Control, ovary abortion was reduced, and fruit yield increased, mainly due to a greater number of small berries in the base and double girdled treatments. In addition, base girdling increased TSS per berry, reducing the concentration of phenolic substances in the normal size berries. Girdling effects were consistent during both seasons. Conclusions: Shoot girdling below the basal bunch proved to be effective in reducing shatter. The increase in carbohydrate supply available to the inflorescences during flowering was able to augment their weak sink strength relative to the perennial organs. Significance of the Study: The study contributes to an understanding of the importance of the photoassimilates flow towards inflorescences in reducing shatter and increasing yield in Malbec vines.
2015
Seasonal dynamics of total non-structural carbohydrates (TNC) in relation to the leaf-fruit ratio were measured over five years at different grapevine phenological stages in one- and two-year-old canes, trunks and roots of the cultivar 'Chasselas' ( Vitis vinifera L.). Carbohydrates were mainly stored as starch in different parts of the grapevine during the growing season. Soluble carbohydrates represented only a small part (< 7 % of dry weight, DW) of the TNC. In the roots and trunks, the starch content fluctuated during the growing season, reaching the lowest values between budbreak and flowering depending on the year, and the highest values between harvest and leaf fall. The soluble sugar content increased in the trunks and the two-year-old canes during the winter period with the decrease in temperatures. A negative correlation was established between the average air temperature recorded during the seven days before sample collection for carbohydrate analysis, and solu...
Biota Neotropica, 2010
The control of leaf to fruit ratio by the practice of entire clusters removal from the vine upon berry set has been used in traditional vineyards in order to regulate yield and to improve chemical composition of the berries. Although this practice has been settled in temperate zones, little is known about grapevines behavior in tropical growing areas. The aim of this work was to evaluate the biochemical and agronomical responses of two Vitis vinifera cultivars (Merlot and Cabernet Sauvignon) grown in Caldas, Minas Gerais, Brazil, a new winegrape region. Grapevines were submitted to cluster thinning (0%, 50% and 75% of cluster removal) and trimming treatments (trimmed and untrimmed) imposed at pea size stage. The source-sink alteration by fruit removal and shoot trimming had impact on yield, leaf sugar metabolism and grape composition. Although there was an improvement in color intensity of the berries with reduction of fruit load, the cluster thinning practice should be avoided in vineyards grown in the south of Minas Gerais State without impairment of wine grape quality. On the other hand, shoot trimming practice should be recommended only for Merlot in order to improve sugar grapes from vines with no cluster removal.
Journal International des Sciences de la Vigne et du Vin
Aim : The present study was conducted in grapevines to evaluate the influence of source/sink disturbance on reserve restoration in the entire plant (trunk, roots) and the consequences on reproduction, yield, sugar yield, potential alcohol content and total acidity over four successive years of treatment. Methods and results: At veraison, either total defoliation or total fruit removal was performed on Chardonnay plants grown in vineyards. The impact was measured each year on reproductive parameters and after four years on both plant weight and carbohydrate content. Defoliation induced an alteration in carbohydrate distribution in the entire plant, as revealed by decrease of starch content and parallel increase of soluble sugar content. These modifications affected the number of inflorescences/clusters per plant the year after. By contrast, fruit removal resulted in a significant increase of carbohydrate reserves in the whole plant, although the efficiency of sexual reproduction was ...
Water, 2021
Studying changes in partitioning of dry matter and nonstructural carbohydrates (NSC) content in both aboveground and underground perennial tissues in drought-affected grapevines could provide insights into plant response and carbon allocation strategies during stress periods. The analysis of soluble NSC and starch content in leaf petioles, due to their role in hydraulic segmentation, should also be considered. In the present research, these aspects have been investigated in Merlot grapevines grown in pots and subjected to progressive and increasing soil dehydration, and in well-irrigated vines. Drought conditions caused drastic reduction of shoot elongation and total plant leaf area development in favor of a greater biomass allocation and partitioning towards roots, where most of the NSC reserves were also conserved. Dry matter content of the perennial organs increased in stressed vines due to growth reduction, allocation of carbon reserves and possible anatomical modifications. Vines subjected to drought showed a higher NSC content in petioles, supporting the hypothesis that they are involved as compatible solutes in osmotic adjustments.
Frontiers in Plant Science, 2020
Girdling is a traditional horticultural practice applied at fruit set or other phenological stages, and is used mostly as a vine management. In grapevines, it is used primarily for table grapes to improve berry weight, sugar content, color, and to promote early harvest. The objective of this study was to evaluate the effect of trunk girdling applied at veraison, in 'Cabernet Sauvignon' wine grapes (Vitis vinifera L.), on agronomical and physiological parameters during vine development from the onset of ripening (veraison) to harvest, and additionally to quantify the effect of girdling on primary and secondary metabolism. Girdling was applied 146 days after pruning (dap) at veraison, when berry sampling for metabolomics and agronomical evaluations commenced, with a further three sampling dates until harvest, at 156 dap (30% maturation, 10 days after girdling-dag), 181 dap (70% maturation, 35 dag), and 223 dap (commercial harvest, 77 dag). Skin/pulp and seed tissues were extracted separately and metabolomics was performed using one-dimensional proton nuclear magnetic resonance (1D 1 H NMR) spectroscopy and high performance liquid chromatography (HPLC-DAD). At harvest, girdling significantly increased stomatal conductance (g s) in vines, decreased glutamine concentrations, and increased anthocyanin and flavonol concentrations in the skin/pulp tissues of grape berries. Berry weight was reduced by 27% from 181 dap to harvest, and was significantly higher in grapes from girdled vines at 181 dap. Sugars, organic acids, and other amino acids in skin/pulp or seeds were not significantly different, possibly due to extra-fascicular phloem vessels transporting metabolites from leaves
OENO One, 2005
Three-year-old grapevines of four cultivars (Garnacha tinta (Grenache noir), Tempranillo, Chardonnay and Airén) were grown on 35 L container under full irrigation and restricted irrigation conditions in order to determine the effect of water stress on carbohydrate allocation. Total grapevine dry matter was measured at pruning, fruitset, veraison and harvest. Roots, wood, shoots, leaves and clusters were dried separately. Shoots were the most affected organs by water stress, while wood was the least affected. Vines under water stress partitioned more dry matter to wood and roots to the detriment of fruits and shoots. The period from fruitset to veraison was the most active for dry matter accumulation under conditions of stress, whereas non-water stressed vines accumulated more dry matter from veraison to harvest. Under both irrigation treatments, fruits competed with roots for dry matter partitioning. Irrigation treatment and cultivar determined fruit size. Fruit size determined dry matter partitioning between organs and the dry matter accumulation pattern. Résumé : Quatre cépages (Grenache noir, Tempranillo, Chardonnay et Airén) greffés sur 1103 Paulsen ont été cultivés dans des conditions d'irrigation normale et sous contrainte hydrique. L'objectif du travail est de comprendre le rôle de l'eau en relation avec l'allocation du carbone dans les différents organes de la plante. Les bilans de matière sèche totale ont été réalisés en hiver (au moment de la taille), durant la croissance herbacée des fruits, à la véraison et à la maturité vendange. Les racines, le tronc, les sarments, les feuilles et les fruits ont été déshydratés séparément. Les vignes ont été cultivées en containers de 35 litres (l) dans un substrat homogène. Nous avons pu observer une différence importante de la répartition de la matière sèche entre les plants. L'effet de la contrainte hydrique sur l'allocation du carbone dépend du cépage. Les rameaux en croissance ont subi plus fortement la contrainte hydrique comparés aux parties pérennes aériennes. Les vignes sous contrainte hydrique ont réparti plus de matière sèche dans les organes pérennes au détriment des fruits et des bourgeons. Les vignes ayant subi une contrainte hydrique présentent une dynamique différente de répartition de la matière sèche. La période entre la nouaison et la véraison s'est avérée la plus active pour l'accumulation de la matière sèche en condition de contrainte hydrique, alors que les vignes sans contrainte hydrique ont accumulé plus de matière sèche dans les racines entre la véraison et la maturité vendange. Pour les vignes soumises aux deux types d'irrigation, les fruits ont fait concurrence aux racines pour la distribution de la matière sèche. La croissance du fruit dépend de la quantité d'eau apportée l'état hydrique de la plante et du cépage. L'allocation du carbone entre les organes dépend à la fois du niveau de la contrainte hydrique et du cépage.
Analysis of "Sink-Photoassimilation" Relationship in Field-Grown 'Cabernet Sauvignon' Grapevines
XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on the Effect of Climate Change on Production and Quality of Grapevines and their Products, 2012
Relationships between sink strength and leaf photoassimilation capability were evaluated on field-grown 'Cabernet Sauvignon' grapevines. Single shoots were subjected to cluster deprivation, girdling and defoliation treatments four weeks before harvest and compared to control untreated shoots. The capacity of grapevine leaves, irrespective of their type and age, to turn light into energy clearly depends on their ability to allocate the sugars produced via photosynthesis under daylight. While total defoliation of individual shoots obviously caused a remarkable reduction in stem starch accumulation, cluster deprivation as well as shoot girdling resulted in a notable accumulation of sugars as starch grains in the chlorenchyma cells, situated just below the epidermis of shoots. These two treatments elicited a severe drop in leaf photosynthesis imputable to an overall curtailment of sink strength. This inhibitory feedback mechanism of assimilate metabolism, which was also found in the leaves of laterals, highlighted a direct link between growth activity and sugar-storage sites on one hand and carbohydrate-formation sites (i.e., chloroplasts) on the other. Therefore, both primary and lateral leaves of grapevines fully activated the physiological processes involved in synthesis only if they can allocate their end products. If not, there is a marked down-regulation in CO 2 fixation and water transpiration processes, which lead to a substantial decrease in water loss. The lack of active metabolic sinks in grapevine, a situation that could arise in response to excessive cluster thinning or low bud load, can depress the photosynthetic activity of the entire vine and nullify the expected advantages, especially as to grape quality, from a particularly high leaf-tocluster ratio.
OENO One
Dormant cane pruning has a great impact on vineyard management both in terms of labour costs and the time required to complete this field operation in the absence of mechanisation. In this study, we investigated over three seasons the influence of five pruning dates on yield components, grape composition, phenology and carbohydrate reserves in the variety Merlot, grown in a warm climate area. Pruning was conducted soon after harvest, at the end of leaf fall, two bud dormancy stages and vine bleeding. Early pruning, carried out a few days after the grape harvest, did not significantly affect vine productivity or grape composition in the next season compared to full winter pruning. Similarly, non-structural carbohydrate concentration in trunk and roots showed no difference just before budburst, no matter the timing of pruning. Late winter pruning at vine bleeding slightly postponed budburst and flowering; it also delayed veraison in one out of two years of observation without affectin...