Use of BCAs for effective control of Botrytis cinerea in vineyards

Botrytis bunch rot (BBR) – caused by Botrytis cinerea – is usually managed by a routine application of fungicides at: A, flowering; B, pre-bunch closure; C, veraison and D, pre-harvest. A 4-year experiment carried out in Italy showed that Trichoderma atroviride, Aureobasidium pullulans and Bacillus subtilis, applied at B, C and D, respectively, provide efficient control of BBR (Pertot et al., 2017). Recently, a new epidemiological model for B. cinerea was developed and validated (González-Domínguez et al., 2015). The validation showed that infections occurring during flowering play a key role in determining the severity of BBR on mature bunches. New experiments were performed to verify whether BCA applications, based on the disease model, could provide satisfactory disease control when applied in A too. This study shows that the application of BCAs in A significantly reduced the colonization rate of B. cinerea and the sporulation potential in bunch trash, as well as the incidence of latent infections of berries, similarly to a reference chemical fungicide and a botanical. Therefore, the use of BCAs for controlling BBR can be extended to early-season treatments based on the advice provided by the mathematical model, which account for weather data, crop phenology and different infection pathways.