S20 - Session O3 - Keynote : Development of alternative strategies to sustainably manage grapevine trunk diseases from nursery to vineyard

Authors: Florence Fontaine *, Catarina Leal, Vincenzo Mondello, Olivier Fernandez, Laura Gérard, Patricia Trotel-Aziz

Among grapevine declines, trunk diseases (GTDs) are a big threat for global viticulture. Without effective chemicals, ecofriendly strategies including biocontrol and the use of natural Plant Protection Products (PPPs) are developed as alternatives to better cope with environmental concerns. In our lab and since several years, we have been evaluating the efficacy of biocontrol agents (BCAs), alone or in combination, and natural products in vitro and in planta using plantlets, cuttings and established vines, to manage GTDs. For biocontrol strategies, the efficacy of fungi ( Fusarium proliferatum, Trichoderma atroviride ) and bacteria ( Bacillus subtilis , Bacillus amyloliquefaciens ) as BCAs has been evaluated and described as promising to sustainably manage GTDs in the short term, through complementary ways of protection. The induced resistance could therefore result from a direct antagonistic effect of BCA on GTD pathogens and/or indirect induction of plant defenses. Similar ways of protection have also been obtained with innovative PPPs such as LC2017, which combines 3.5% copper with the amphiphilic carrier hydroxyapatite and plant extracts. The main findings of these experiments will be presented to discuss the BCA and PPP incidence on GTDs, as fungicides or fungistatics, and as elicitors of the plant immune responses.