Integrated control of Botrytis cinerea in blackcurrants

Abstract: In 2012 the efficacy of the biocontrol agents (BCAs) Serenade and Prestop was compared for control of botrytis fruit rot on blackcurrant cultivars Ben Hope and Ben Tirran to the fungicides Signum and UKA386a and an untreated control. Programmes based on the fungicides for the first three sprays followed by one, two or no sprays of Serenade were also included. The incidence of botrytis fruit rot pre-harvest on bushes was negligible. In post-harvest tests the incidence of botrytis rot on Ben Hope was significantly reduced by both Signum and UKA386a. Three sprays of UKA386a were as effective as four sprays with no additional benefit from late sprays of Serenade. The incidence of botrytis in post-harvest tests was higher in Ben Tirran (34% in untreated fruit compared to 11% in Ben Hope). Only UKA386a was effective in reducing botrytis. None of the BCAs were effective in reducing botrytis in either cultivar. In 2013 the efficacy of the elicitors Pretect, potassium phosphite and experimental A was compared for control of botrytis fruit rot on blackcurrant cultivars Ben Hope and Ben Tirran to a standard fungicide programme, UKA386a and an untreated control. In post-harvest tests the incidence of botrytis fruit rot on Ben Hope was negligible. On Ben Tirran, the best control of botrytis was achieved by UKA386a. However, elicitor A was as effective in reducing botrytis fruit rot as the standard fungicide programme. The economics of using fungicides, BCAs and elicitors for botrytis control in blackcurrants is discussed.