The Cool Night Index The Cool Night Index was created to study nocturnal conditions of grapes ripening according to the different wine-making regions (Tonietto, 1999 ; Tonietto et Carbonneau, 2004). By convention, this index is also called nycthermal index and is equivalent in the North Hemisphere to the minimum temperature […]

This discussion is a follow up with our last blog on the 2017 maturation What is the situation end of september? A general disorder in sugar accumulation is observed in northern California. The trend is widespread and shows sluggish sugar accumulation rate across many different vineyards. The extend of the phenomenon indicates […]

Harvest decision 2017: A ripe Cabernet Sauvignon in Napa “should be worth the wait!” We discuss a preliminary analysis of the 2017 vintage effect on berry ripening dynamics. Our main conclusions are synthesized in this short summary below. If you are interested in the rationales and discussion points, please scroll down after the […]

If you read this blog you are probably interested in understanding the complexity of vine response to contrasted environmental conditions. Everyday scientific results shed new light on plant mechanisms which, if they are properly understood, can help the winegrower optimizing his practices. Today, we discuss the relationship between :root temperature, […]

How can a winegrower harness vineyard spatial variability to make better wines?   Numerous studies carried out since 2000, on irrigated and non-irrigated vineyards have shown that vineyards exhibit great spatial variability for many factors such as yield or berry quality components (Santesteban et al, 2013). This spatial variability can […]

One of the main challenges for a winegrower before harvest is : “where is it best to sample?” and “how many locations do I need to sample to get a reliable estimate?” In this blog we discuss how to design a sampling scheme to best capture vineyard spatial variability. The plant […]

What is sugar loading? The sugar loading of grape berries (evolution of the quantity of sugars per berry), widely described by Pr. Deloire during the last decade, constitutes a physiological marker integrating the functioning of the vine in its environment. The sugar loading includes two distinct periods: A first period […]

How much does vine transpiration increase during a heat wave? To address that question, a team of Australian researchers led by Edwards reported the following observations in 2011.While working in a greenhouse with Cabernet Sauvignon, researchers generated  a 2-day high-temperature event by imposing maximum daytime temperatures near 41°C.  Before imposing the […]