The long-term crop load study continued during 2017, the project’s sixth season. Eleven companies conducted the research on-site in 12 vineyards during 2017. Yields were the second highest in the six years of the study, second only to 2015. Average yield across all crop thinning treatments and sites was 1.13 lb/ft, which is higher than the 6-year mean of 0.93 lb/ft. Seasonal heat unit accumulation for 2017 was the lowest since 2012, and harvest was later than in recent years. However, fruit had sufficient ripening with total soluble solids (TSS) ranging from 21.0 – 25.0 °Brix. Analysis of harvest data across all sites in 2017 shows that fruit composition was affected by vineyard site and crop level. Treatment effects were tested within each vineyard site, and results show that only half of the sites (50%) had some treatment effect on fruit composition; however, the effects varied by site. There was no single fruit parameter that was affected by crop level at all sites, and the most common differences found by treatment were for TSS and pH in 2017. However, only 25% of vineyard sites had a difference in TSS with cluster thinning. Multiple regression analysis of data across the first five years (2012-2016) shows that crop load (yield: pruning weight, Y:PW) was related to TSS more than yield alone. Yield, however, was related to anthocyanin, pH and TA, with higher yields predicting lower pH, TA, anthocyanin, and tannin but higher TA. Fruit YAN was best predicted by pruning weights and Y:PW, not yield. Expert evaluation of wines from the 2012-2014 vintages show no yield effect on wine sensory perception, as wines did not group by yield level for descriptive analyses. According to industry collaborators surveyed, 43% had sufficient confidence in the study’s findings that they adopted higher yield targets in their vineyards beyond the research project, citing the ability to increase yield without compromising quality, and in recent warm years higher yields were preferred by winemakers.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF2018-05-18 09:43:122018-05-18 09:44:25A Researcher-Industry Partnership to Understand the Yield-Quality Relationship in Cool Climate Pinot noir and Chardonnay Production