Fruit set rate clonal variation explains yield differences at harvest in Malbec

The aroma of wine grapes is influenced by a complex metabolic network, with terroir factors, especially high temperatures, playing a critical role during berry development.

The timing of grape harvest is crucial factor to be considered in the winemaking process, as delayed harvest increases the content of varietal aromas, esters, aldehydes

Nitrogen (N2) is critical in grape berries, especially in organic wine making. After intake, N2 follows various metabolic and allocation routes and, from veraison, partly reallocates into berries. Water deficit affects the N2 nutrition due to a poor diffusion in soil solution and vascular mobilisation. Also, affects photosynthesis and the energy needed for metabolism, whose extent would depend on the stomatal sensitivity of the plant. We have assessed the effect of a moderate water deficit from pea size, in 3 years old field grown potted plants of Chardonnay (CH) and Cabernet Sauvignon (CS), differing in stomatal sensitivity, on the N2 status of plant parts. Water deficit reduced photosynthesis, leaf area and fresh and dry plant mass along the season, but up to a higher extent in CS.

The French grapevine breeding program for durable resistance to downy and powdery mildew (INRAE-ResDur) was initiated more than 20 years ago to help reduce the heavy use of plant protection products and provide a durable mean to cope with a strong pathogen pressure. This program has now proved to be effective, with about ten new varieties already officially registered. However, there is still a lot to be done (1) to reduce the duration of each breeding cycle, (2) to diversify disease factors’ pyramiding and anticipate emerging diseases, (3) to work towards larger adoption of the new resistant varieties. New breeding schemes incorporating for example genomic prediction of breeding values are being evaluated to accelerate genetic gains, saving cost and time while handling complex traits.

Le Muscat de Frontignan est bien connu pour ses fortes teneurs en composés terpéniques et par l’odeur florale et fruitée que ces composés confèrent aux vins qui en sont issus (1,2).