Control of brown rot blossom blight (Monilinia laxa) on apricot in organic agriculture

Abstract: The effect of copper, sulphur, sodium bicarbonate, lime sulphur and plant resistance improver based on algae extract (Alginure) on brown rot blossom blight on apricots was studied during spring 2011 and 2012. The small plot trials were conducted in two commercial apricot orchards (varieties: Pincot, Goldrich and Leskora) located in South Moravia (Czech Republic). Treatments were applied during the flowering period three times in 2011 and four times in 2012. Evaluation was done according to the EPPO 1/38(2) method. In 2011 all treated variants were significantly different from the untreated control. The most effective was copper 66% following by sodium bicarbonate 63%, Alginure 63%, sulphur 56% and lime sulphur 38%. In 2012 the brown rot blossom blight infestation vas very low. Therefore only variants of lime sulphur and combination of Alginure with copper were significantly different from untreated control. Efficacy of combination of Alginure with copper was 100% and combination of Alginure with lime sulphur reached 67.6%.