New strategies for Botrytis bunch rot control for a sustainable viticulture

Grapevine (Vitis vinifera L.) is cultivated throughout the world in a wide range of climates, from temperate to tropical ones. It’s highly susceptible to fungi, being Botrytis cinerea (Bc) among the most important pathogens causing bunch rot (BR), a disease mostly observed on ripe berries, normally controlled through use of chemicals. To date, the defence against Bc is still guaranteed by an intensive use of chemical fungicides. Consequently, the development of alternative strategies for Bc control with benefits both for human health and the environment is of high importance and a priority. In the last years, the concept of “integrated defence” against Bc is increasingly widespread, using defence protocols integrating agronomic control tools with interventions based on synthetic fungicides and natural antagonists to be carried out in the periods of higher susceptibility. In this project, a molecular method for monitoring Bc load in the field was setted-up in order to quantify the colonization by Bc of vineyards of V. vinifera cv Sangiovese and Trebbiano at different locations (hilly site vs plain site) and cultivated applying different integrated defence protocols against Bc. Samples at were collected at three different developmental stages (full flowering, bunch enclosure and veraison) from different biological replicates of different thesis of treatment and molecularly analyzed calculating the colonization coefficient for each sample. The correlation between molecular data with BcBR severity and incidence data at harvest in the different thesis for the two cultivars are here presented. The molecular assay will be useful both to quantify Bc load at the early season in order to predict BcBR severity at harvest, and more in general to evaluate the effect of disease management protocols adopted on the reduction of Bc inoculum.