GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Crop load management of newly planted Pinot gris grown in warm climate of California

Crop load management of newly planted Pinot gris grown in warm climate of California

Abstract

Context and purpose of the study – San Joaquin Valley accounts for 68% of Pinot gris acreage and produces 83% of Pinot gris wine in California. Strong demand for Pinot gris has prompted growers to restrict the nonbearing period to less than two years, if possible. This requires permanent vine structure establishment the first year with a crop expected in the second year. Precocious cropping raises the risk of overcropping with possible carry-over effects in subsequent years. To identify the optimum crop level and economic threshold for newly planted Pinot gris vines, a field trial was initiated in a commercial vineyard in 2016.  

Materials and methods – Bench grafted Pinot gris vines with Freedom rootstocks were planted in February of 2015. Quadrilateral cordons were established in the same year aiming for the first crop in 2016. Randomized complete block design was set up with four levels of inflorescence thinning in the spring of 2016, and each treatment was replicated in 5 times. Inflorescences were hand thinned approximately 3 weeks pre-bloom. No thinning was applied after 2016, but data were still collected to study the potential carry-over effect in 2017 and 2018. Four treatments included: 1) all fruit removed (0 cluster per shoot); 2) one cluster per two shoots; 3) one cluster per shoot; 4) no fruit removed. Five vines in each block were labeled as data vines and yield components, pruning weight and fruit chemistry were collected in 2016, 2017 and 2018.  

Results – inflorescence removal increased fruit set, average berry weight, and soluble solids in 2016. Increased cluster compaction on thinned vines did not cause excessive bunch rot, but did partially compensate for the potential yield loss associated with inflorescence removal. Yield in 2016 was reduced by 6%, 28% and 100% with the severity of inflorescence removal. No thinning was performed in 2017 and 2018, but yield, fruit chemistry, and pruning weight were still measured. The Ravaz Index (RI) from treatment of one inflorescence per two shoots was 8.3 in 2016 and vines in that treatment had the highest accumulated yield across 2016 and 2017. Vines with RI > 12 showed significant delayed sugar accumulation in 2016 and reduced yields in 2017. Thus, newly planted vines with an RI> 12 in their first crop year were overcropped and will likely see reduced yields the following year, whereas vines with RI of approximate 10 provide maximum yield without affecting fruit chemistry and the following year’s crop. In 2018, yield and fruit chemistry were monitored as well, however no difference has been found across various treatments. 

DOI:

Publication date: June 18, 2020

Issue: GiESCO 2019

Type: Poster

Authors

Shijian ZHUANG1, Kaan KURTURAL2, Matthew FIDELIBUS2

(1) University of California Cooperative Extension, Fresno County
(2) Department of Viticulture and Enology, University of California at Davis

Contact the author

Keywords

Pinot gris, Crop load, Carry-over, Newly planted vine

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Nutrients and heavy metals in a vineyard soil under organic, biodynamic and conventional management

Promoting sustainable agricultural practices is one of the challenges of the last decades. Organic and biodynamic viticulture can be an alternative to intensive viticulture, furthermore contributing to reduction of impact on environment and human health and guaranteeing soil preservation and quality products1. The aim of this experimentation was to evaluate the medium and long-term effects of different agronomic practices in viticulture on nutrient availability and heavy metal accumulation in soil.

Vegetative dose heights ‘Cabernet Sauvignon’ and its influence on fruit and wine quality

The leaf area is of fundamental importance so that the plant can realize adequate levels of photosynthesis for the accumulation of reserves and to reach a suitable maturation of
the berries. In this sense, the objective was to evaluate the effect of different lengths of the stalks from the first support wire, in the must and in the wine of ‘Cabernet Sauvignon’.

Piloting grape ripening in a global warming scenario: feasible techniques are available

Under the pressure of global warming, several wine grape growing regions around the world are increasingly suffering from advanced and compressed phenology; endangering wine character while also creating serious logistic problems. From a physiological standpoint, the issue of delaying ripening is not simple as, in several instances, only a few processes must be delayed (i.e. sugar accumulation into the berries) while other events such as pigmentation and accumulation of other important phenolic compounds should proceed at a normal rate. Thus, the issue of decoupling technological maturity from phenolic maturity is another important consideration. Over the last decades, several research groups have endeavored to establish alternate cultural practices aimed at addressing this decoupling. In some cases, special applications of quite robust and well known practices regarding physiological principles have been utilized, however some completely new techniques are also being studied. In figure 1 of the review, we offer a panorama of the available tools and in the text we elaborate on those having provided most reliable and consistent results under an array of genotypes and environmental conditions. Among these, primary focus is given to post‐veraison—apical to the cluster—leaf removal (that can also be suitably replaced by applications of anti‐transpirants); the use of kaolin against multiple summers’ stresses; and a drastic version of late winter pruning having the potential to postpone ripening into a cooler period with improved grape composition and a limited negative impact on yield and storage reserves replenishment. 

Impact of moderate water deficit on grape quality potential on Pinot Noir in Champagne (France)

Environmental factors like soil and climate influence grape quality potential. Their impact is often mediated through vine water and nitrogen status. Depending on the color of the grapes (red or white) and the type of wine produced, the desired level of vine water and nitrogen status for optimum wine quality is different. Little investigation has been carried out concerning these factors and their potential influence on sparkling wine quality on two vintages. In this study vine water and nitrogen status were assessed at a very high density and related to grape composition and berry weight. Through statistical analyses, the major factors driving grape quality potential on Pinot noir in Champagne were highlighted.

Georgian vitis germplasm: conservation, research and usage

Grapevine Vitis vinifera L. is a leader perennial crops for the Republic of Georgia, the South Caucasus. This is a region where the first wine making practice was initiated 8.000 years ago (McGovern et al. 2017) and a spot of grape domestication. The country of Georgia holds 525 local and more than 60 breeding varieties – they are preserved in 9 field collections inside the country.The list of recommended wine cultivars contains 34 names, including 27 old autochthonous varieties and covering 94% of the country’s vineyards.