Improving shelf life of viticulture-relevant biocontrol and biostimulant microbes using CITROFOL® AI as liquid carrier

In winemaking, several antimicrobial peptides (AMPs) produced by different strains of Saccharomyces cerevisiae were found to be responsible for the inhibition of malolactic fermentation (MLF) carried out by some strains of Oenococcus oeni. However, only two AMPs produced by one of the yeast strains studied were totally identified and their mechanism of action was described. In an attempt to identify new AMPs, a 5-10 kDa peptidic fraction produced by an oenological strain of S. cerevisiae and previously shown to strongly inhibit MLF carried out by a strain of O. oeni was further purified.

In Portugal, the prospection and conservation of representative samples of intra-varietal variability of grapevine has been carried out for 46 years, and in 2010 an infrastructure was created for the conservation of all these genetic resources – the portuguese association for grapevine diversity (porvid) experimental centre for the conservation of grapevine diversity. the aim is to save the genetic identity of ancient varieties to prevent their imminent loss and to preserve the raw material for current and future selections, thus adding economic value and sustainability to the vine and wine sector.

The increasing vulnerability of food systems is a pressing challenge amplified by global interconnectedness.

Heatwave events, defined as 2 or more days reaching ≥ 38 °C, are an increasingly frequent phenomenon threatening grape production worldwide. Heat stress has been shown to have negative consequences on grapevine physiology, leading to increased evaporative demand and intensified water stress. Due to heatwaves overlapping with important stages of grapevine reproductive development, spanning from berry set to the ripening stage, severe heat can potentially compromise yield and grape quality. The physiological response of grapevine to heat stress suggests a potential use of irrigation to mitigate heatwaves, however there is limited information regarding the irrigation amounts and timings needed for this purpose. Following up on a pivotal trial conducted between 2019 and 2022, in this study irrigation treatments with varying intensity and timing of application were refined to determine their potential mitigation of heat-associated damage to yield and fruit composition.

Temperature has a decisive influence on the growth and development of plants (Carbonneau et al., 1992). In particular, in the case of the vine, the temperature is an omnipresent variable in the climatic indices (Huglin, 1986). For reasons of convenience, these indices use the temperature of the air measured under shelter in a meteorological station, making the implicit hypothesis of a concordance between this temperature and that of the sites of perception of the thermal stimulus by the plant. However, development may be more dependent on soil temperature than air temperature (Kliewer, 1975). Morlat (1989) thus verified that the variability in the precocity of the vine, positively correlated with the quality of the harvest and of the wine in the Loire Valley, was mainly explained by differences in temperature of the root zones.