Freeze-thaw temperature oscillations promote increased differential gene expression during grapevine bud dormancy

This study presents the preliminary results obtained in 2022, of the evaluation of three new crossbreed winegrape genotypes and their parental varieties, grown under controlled irrigation (60% ETc) and rainfed conditions in a wine-growing area with scarcity of water and high temperatures (Murcia, southeast Spain). The genotypes MC16 and MC80 were obtained from crosses between the varieties ‘Monastrell’ and ‘Cabernet Sauvignon’, and MS104 from crosses between ‘Monastrell’ and ‘Syrah’ [1]. The objective of this study was to analyse the physiological response and vegetative development of the 6 genotypes under the two irrigation conditions, and to study their effect on the content of soluble sugars and chlorophyll in the leaf.

Botrytis bunch rot occurrence is one of the most important limitations for the wine industry in humid environments. A positive correlation between grapevine growth and susceptibility to fungal pathogens has been found. In theory the effect of grapevine vegetative growth on bunch rot expression results from direct effects (cluster architecture, nitrogen status among others) and indirect ones (via microclimate). However, a reduction in bunch rot incidence can be achieved in some circumstances without major vine growth reduction. The present study was aimed to test the general hypothesis that bunch rot susceptibility is affected by vine vigor, but other factors associated with grapevine vegetative expression could be even more relevant.

The quality of table grapes is critically influenced by several parameters, including sugar content, acidity, firmness, and overall appearance.

New Zealand viticulture has long been characterised by sustainable grape growing practices as promoted by Sustainable Winegrowing New Zealand (SWNZ) as well as by Organic Viticulture.

During alcoholic fermentation, nitrogen is an essential nutrient for yeast as it plays a key role in sugar transport and biosynthesis of wine aromatic compounds (thiols, esters, higher alcohols). The main issue of a lack in yeast assimilable nitrogen (yan) in winemaking is sluggish or stuck fermentations promoting the growth of alteration species which may lead to economic losses. However, correcting this nitrogen deficiency is sometimes not enough to restore proper fermentation performance. This suggests the existence of other nutritional shortages.