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


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. 


Publication date: June 18, 2020

Issue: GiESCO 2019

Type: Poster



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

Contact the author


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


GiESCO | GiESCO 2019 | IVES Conference Series


Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.