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 […]
What does a vine really experiences when it is in a good “terroir” or during a “good vintage”? To uncover the “terroir” or the “vintage” effect on vine activity, the best is simply to ask directly the plant. In other words, the best is to measure directly on the vine how it responds to the […]
The recent heat wave experienced after the rain last week (June 24th -25th) illustrated very well a classic misconception about vine water use. For years, people have considered that “drippy” leaves or “folded” leaves were a reliable sign of soil water deficit. However, after the last rainfall in Napa, while leaves were showing […]
