Results of late-wurmian to present-day climatic-geological evolution on to spatial variability of pedologic-geological characters of the AOC Gaillac terroirs (Tarn, Midi-Pyrénées)

Vigor declines in older vineyards and poor vine establishment in replant situations have been attributed to plant-parasitic nematodes. The northern root-knot nematode, Meloidogyne hapla, is the most prevalent plant-parasitic nematode species found in Washington wine grape vineyards. Management for nematodes in established vineyards is limited to the application of post-plant nematicides. We are evaluating new nematicides that are currently not registered in grape for their efficacy in controlling M. hapla and a part of that evaluation includes improving the alignment of nematicide application timing with the vulnerable second-stage juvenile (J2) life stage of M. hapla.

Grapevines are susceptible to freezing damage at temperatures below -5°F during the winter season. Preventing winter injury to grapevines is a major challenge in many grape-producing regions. Conventional methods such as hilling-up soil over graft unions have been developed as winter protection methods for preventing vine loss. However, these practices have drawbacks such as soil erosion, vine damage and crown gall development.

Volatile thiols contribute largely to the organoleptic characteristics and typicity of Sauvignon blanc wines. Among this family of odorous compounds, 3-sulfanylhexan-1-ol (3SH) and 4-methyl-4-sulfanylpentan-2-one (4MSP) have a major impact on wine flavor. These thiols are formed during alcoholic fermentation by the yeast from odorless and non-volatile precursors found in the berry and the must. The effect of vine nitrogen status on 3SH and 4MSP in Sauvignon blanc wine and on the glutathionylated and cysteinylated precursors of 3SH (Glut-3SH and Cys-3SH) was investigated in this study.

Grape downy mildew, caused by plasmopara viticola, is one of the main diseases affecting viticulture worldwide and its control usually relies on frequent sprays with agrochemicals. Grapevine varieties resistant to p. Viticola represent an effective solution to control downy mildew and reduce the environmental impact of viticulture. Loci of resistance to p. Viticola (Rpv) have been introgressed from wild vitis species and some of them, like Rpv1, Rpv3.1 and Rpv10, are currently the most utilized genetic resources in grape breeding.

Malolactic fermentation (MLF)¹, the decarboxylation of L-malic acid into L-lactic acid, is performed by lactic acid bacteria (LAB). MLF has a deacidifying effect that may compromise freshness or microbiological stability in wines² and can be inhibited by fumaric acid [E297] (FA). In wine, can be added at a maximum allowable dose of 0.6 g/L³. Its inhibition with FA is being studied as an alternative strategy to minimize added doses of SO₂⁴. In addition, wine yeasts are capable of metabolizing and storing small amounts of FA and during alcoholic fermentation (AF).