Use of biocontrol agents and botanicals in integrated management of Botrytis cinerea in table grape vineyards

BACKGROUND The increasing interest on biological control agents (BCAs) and botanicals (BOTs) is due to the increasing awareness on environmental and human health risks associated to the usage of synthetic plant protection products. The BCAs Bacillus subtilis strain QST713, Bacillus amyloliquefaciens strain D747 and Aureobasidium pullulans strains DSM14940 and DSM14941, and the BOTs Melaleuca alternifolia and terpenic extracts are proposed for the control of grey mould in vineyard. This study was aimed at evaluating their effectiveness in integrated crop management strategies and their outcomes in terms of management of fungicide resistance and residues. RESULTS In field trials carried out on table-grape in Southern Italy, alternations or mixtures of BCAs or BOTs with the SDHI fungicide fluopyram showed efficacy up to 96% against grey mould on bunches, comparable to the chemical-reference strategy (up to 87%), while the solo use of BCAs or BOTs (up to eleven sprays) were not enough effective (< 30%) under high disease pressure. The integrated use of BCAs or BOTs reduced the spreading of SDHI-resistant conidia as well as fungicide residues in grape. CONCLUSIONS Spray schedules based on integration of BCAs or BOTs with fungicides are effective against grey mould and reduce the risk of fungicide resistance in B. cinerea and fungicide residues in grape.