GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Utility of leaf removal timing and irrigation amounts on grape berry flavonoids under climate change

Utility of leaf removal timing and irrigation amounts on grape berry flavonoids under climate change

Abstract

Context and purpose of the study – The dormant and growing season temperatures in California USA have been increasing with more clear sky days. A consequence increasing temperatures and clear sky days is water deficit conditions. Viticulturists must determine appropriate balances of canopy management and irrigation budgeting to produce suitable yields without compromising berry chemistry. In response, a study designed to test the interactive effects of leaf removal timing and applied water amounts on Cabernet Sauvignon/110R in Napa Valley, CA.

Material and methods – We performed a field experiment with 7‐year‐old Cabernet Sauvignon grafted on 110R (Vitis berlandieri × Vitis rupestris) rootstock. A factorial design with leaf removal timing (pre‐ bloom and post‐fruit set, compared to an untreated control) and applied water amounts (1.0, 0.5 and 0.25 of crop evapotranspiration replacement (ETc)) was used. We measured plant water status, leaf gas exchange, primary and secondary metabolites in response to treatments.

Results – Stem water potential was lower in the 0.25 ETc regardless of leaf removal treatments. A 40% reduction in net carbon assimilation was evident in the 0.25 ETc treatments, as well. Likewise stomatal conductance was lower with 0.25 ETc. Leaf removal timing did not affect leaf gas exchanges. There was no effect of leaf removal on components of yield, including the number of berries set. The 0.25 ETc treatment reduced berry mass and yield, but 0.5 and 1.0 ETc treatments were not different from each other. Stem water potential integrals were well related to speed of total soluble solids accumulation. There was a significant interaction of leaf removal and irrigation on pruning weight and Ravaz Index. Reducing the irrigation resulted in a significant increase of anthocyanin concentration; however, there was no increase in its biosynthesis. The ratio of 3’4’5‐OH to 3’4’‐OH anthocyanins was greater with 0.25 and 0.50 ETc compared to 1.0 ETc. Leaf removal affected flavonol content, specifically kaempferol‐3‐o‐ glucoside concentration well as its content a per berry basis which was greater with leaf removal regardless of its timing. Berry skin proanthocyanidins in either concentration or content, or mean degree of polymerization were not affected by treatments applied. Clear skies and longer periods with minimal precipitation paired with reduction in irrigation had a stronger influence on berry chemistry than leaf removal application. Our results indicated that cluster microclimate without leaf removal was already optimized within the confines of this study. Although not as impactful, there still appears to be potential for understanding leaf removal influence on berry physiology and its effect on vine balance in premium regions.

DOI:

Publication date: June 19, 2020

Issue: GIESCO 2019

Type: Article

Authors

Johann MARTíNEZ‐LUSCHER (1) , Constance Cunty (2), Luca BRILLANTE (3), Runze Yu (1), Gregory Gambetta (2), S. Kaan KURTURAL (1)

(1) Univeristy of California Davis 1 Shields Ave. Davis, CA 95616 USA
(2) UMR EGFV ISVV, 210 Chemin de Leysotte – CS 50008 33882 Villenave d’Ornon Cedex, France
(3) California State University Fresno 2360 E. Barstow Ave. Fresno, CA 93704 USA

Contact the author

Keywords

anthocyanins, flavonol, carbon assimilation, canopy management, proanthocyanidins

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Organic recycled mulches in sustainable viticulture: assessment of spontaneous plants communities and weed coverage

In recent years, developing more efficient and sustainable viticulture management has been essential due to the impact of climate change in semiarid regions. For this reason, the use of recycled organic mulching (ROM) in the vineyard has become an interesting strategy to cope with water stress, isolated soil from extreme temperatures and improving soil humidity, control the presence of weeds and therefore reduce the inputs of herbicides and improve soil fertility. This work aimed to analyse the effect of three different organic mulches [straw (S), grape pruning debris (GPD) and spent mushroom compost (SMC)] and two traditional soil management techniques [herbicide (H) and interrow (IN)] on weed coverage and the spontaneous plant communities’ presence. Data sampling was collected throughout the vine vegetative cycle of 2021 in La Rioja, Spain. The different soil management techniques had a clear effect on weed coverage and his development during the vine vegetative cycle. SMC and H were the treatments with the highest and the lowest coverage percentage, respectively. IN had a delayed weed emergence at the beginning of the vine vegetative cycle, but finally it reached maximum values nearby SMC. GPD and S had similar effects on weed emergence, reaching 25-30% of the maximum coverage values. A total of 29 herbaceous species were identified during the vegetative cycle, some of them very isolated and occasional. Principal component analysis (PCAs) showed a good association between spontaneous species and treatments, furthermore, specific species-treatment associations were found. Moreover, three clear groups of herbaceous communities were identified by cluster analysis. This study provides interesting information about the effect of different alternative soil management on herbaceous plant coverage and weed species communities which could contribute to making more sustainable viticulture.

Desorption of phenolic compounds bound to lees by combining hydrolytic enzymes and ultrasounds

he final concentration of phenolic compounds in the wines is usually lower than what might be expected given the phenolic concentration measured in grapes

Closure permeability modulates the aroma expression of monovarietal white wines during bottle ageing

Bottle ageing is a critical period for wine quality, as it undergoes various chemical and sensory changes during storage. Ideally, a phase of qualitative ageing, during which wine sensory quality improves, is followed by a decline of quality. Understanding how different oenological variables influence these phases is a key challenge in modern winemaking. Recent studies highlighted the significant role of oxygen in modulating reactions involving volatile and non-volatile components, impacting aroma evolution during bottle aging. Oxygen exposure of wine during bottle ageing is mediated by closure.

Variety and climatic effects on quality scores in the Western US winegrowing regions

Wine quality is strongly linked to climate. Quality scores are often driven by climate variation across different winegrowing regions and years, but also influenced by other aspects of terroir, including variety. While recent work has looked at the relationship between quality scores and climate across many European regions, less work has examined New World winegrowing regions. Here we used scores from three major rating systems (Wine Advocate, Wine Enthusiast and Wine Spectator) combined with daily climate and phenology data to understand what drives variation across wine quality scores in major regions of the Western US, including regions in California, Oregon and Washington. We examined effects of variety, region, and in what phenological period climate was most predictive of quality. As in other studies, we found climate, based mainly on growing degree day (GDD) models, was generally associated with quality—with higher GDD associated with higher scores—but variety and region also had strong effects. Effects of region were generally stronger than variety. Certain varieties received the highest scores in only some areas, while other varieties (e.g., Merlot) generally scored lower across regions. Across phenological stages, GDD during budbreak was often most strongly associated with quality. Our results support other studies that warmer periods generally drive high quality wines, but highlight how much region and variety drive variation in scores outside of climate.

Melatonin priming retards fungal decay in postharvest table grapes 

Postharvest losses of fruits may reach in some cases 40% in developed countries. This food waste has a significant carbon footprint and makes a major contribution toward greenhouse gas emissions so sustainable postharvest strategies are being investigated.
Melatonin, a well-known mammalian neurohormone, has been investigated as a priming agent to slow down fungal decay progression in postharvest climacteric and some non-climacteric fruits. However, the molecular and metabolic mechanisms responsible for such enhancement of disease tolerance are largely unknown.