Several definitions exist to characterize grape berry maturity: technological, aromatic, polyphenolic, and enological: Technological maturity is the time point beyond which berries do not accumulate more sugar and do not lose any more acidity. Phenolic maturity takes into account the quantitative and qualitative evolution of the berry polyphenols in the skin (anthocyanin […]
As season goes by and the first berries enter veraison, 2015 promises to be a very hot and dry vintage. Despite a late bud break early April, the 2015 season is now turning into a very early vintage, catching up with 2011. This catch up is explained by temperatures in […]
Thanks to a grant received from the Water Metropolitan District of Southern California, we set up an experiment last year with the help of 6 independent wineries, under contrasted California climates. The goal of the experiment was to evaluate how much irrigation water could be saved and how was affecting yield and maturation compared to […]
As we enter veraison, we observe that the window during which berries are changing color is stretching due to the weather cooling off. What does this mean for the uniformity of ripening? Traditionally it is assumed that the rate of ripening is uniform between berries. Consequently, when a berry turns […]
Predicting the onset of budbreak, bloom, and other phenological stages, is a very active topic of research. Recently, new results regarding the effect of winter temperature at hastening the onset of budbreak have been reported. Parker et al (2013) have suggested that the effect of heat accumulation on vine phenology […]
California is experiencing its fourth consecutive year of drought. So far 2015 vintage is even earlier than last year, which is logical considering the faster heat accumulation recorded during the first four months of the year. Consequently dates of budbreak and bloom are on average 2 weeks earlier than 2014. […]
Highlights of the Xth Terroir Congress (7/7 – 7/10) in Tokaj, Hungary At Terroir Congress, participants from all over the world discussed the most recent findings in viticulture. Attendees came from diverse backgrounds (PhD students, UNESCO and OIV members, vineyard owners, full-time researchers or winemakers) and from diverse fields (viticulture, […]
The purpose of this discussion is to sharpen critical views of new methods as they arise. It aims at understanding the limitations and benefits of new techniques to improve our ability to optimize water use. Surface renewal (SR) is an interesting and powerful method, particularly for large acreage showing a […]
Is it really such a good idea? Except in situations where root reservoir is subjected to high drainage (for instance sand situations) or when rooting depth is physically limited, common sense considerations make you wonder if this is really the best idea to adapt to drought and to get the […]
Over the last weeks many Napa vintners have been wondering whether they should be irrigating to prevent possible forthcoming effects caused by the drought statewide. Following the rain over the week-end, the cumulated amount of water received during winter is now around 10 inches, which is typically the case by […]
