Foliar application of calcium chloride and calcium silicate decreases white mold intensity on dry beans

Abstract

White mold (Sclerotinia sclerotiorum) is the most important common bean disease during the fall-winter season in Brazil. Different control strategies are necessary to control this disease and increase bean yield in infested areas. The aim of this research was to evaluate the effect of application of calcium chloride (CaCl 2 ) and calcium silicate (CaSiO 3 ) on white mold control on common bean. The experiment was carried out during the 2006 fall-winter season in Viosa MG, Brazil, in a field naturally infested with sclerotia. Both CaCl 2 and CaSiO 3 were applied at 45 days after emergence (DAE) (early bloom) over the plants with a hand sprayer (800 L ha -1 ) at the rates of 100, 200, 300 and 400 mg L -1 or at 45 and 55 DAE at 300 mg L -1 . Two additional treatments were used: water (untreated control) and the fungicide fluazinam (0.5 L ha -1 ) applied at 45 and 55 DAE. Both incidence and severity of white mold were significantly reduced with application of CaCl 2 and CaSiO 3 , but there was no effect on yield. Fluazinam reduced significantly the disease incidence and severity by 52% and 73%, respectively, and increased the yield by 31%.