Efeito do fosfato monopotassico no controle do oídio do pimentao

Powdery mildew caused by Oidiopsis taurica (Lev.) Salmon is one of most limiting diseases of greenhouse sweet pepper crop. The effect of mono-potassium phosphate (MKP) on the control of sweet pepper powdery mildew was evaluated. Four genotypes were tested: one partially resistant hybrid HV-12 x 609, two susceptible hybrids Magali R and Margarita and a resistant cultivar HV-12. The trial was carried out under greenhouse conditions. Powdery mildew diseased plants were used to promote pathogen dissemination in the ratio of one pot for each three plots tested. A weekly MKP application was made for seven consecutive weeks, starting ninety days after sowing. Evaluation was done at the fruit harvest using a disease severity scale that varied from 1 (no symptoms) to 5 (with 51 % or more of foliar area affected). Disease severity was reduced in all treatments, but some phytotoxicity was observed. A synergistic effect was observed between the powdery mildew control with MKP and the partial resistance of the hybrid HV-12 x 609.