Pepper (Capsicum annuum L.) is an important agricultural crop worldwide. A field experiment
was conducted under sandy soil conditions during two summer seasons of 2020 and 2021 at the Experimental
Farm of El-Kassasein, Hort. Res. Station, Ismailia Governorate, Egypt. Powdery mildew disease, caused by
Leveillula taurica anamorph Oidiopsis taurica is one of the most serious diseases attacking pepper plants under
greenhouse and open field conditions. In the present study, the effect of potassium salts and two bacterial
bioagents (Bacillus subtilis and Pseudomonas fluorescens) as foliar spray on growth, yield, fruit quality and
powdery mildew incidence and severity of pepper cv Bascara. Data revealed that, by combing potassium
silicate and mixture of P. fluorescens plus B. subtilis significant increase was noticed in shoot dry weight / plant,
K content and uptake by shoots, total chlorophyll in leaf tissues, average fruit weight, number of fruits/ plant,
yield / plant and yield /fad., dry matter percentage, total soluble solids, vitamin C and total capsaicin in fruits of
pepper. Regarding powdery mildew Incidence and severity, data revealed that the highest reduction in disease
incidence was obtained when mixture of the bacterial bioagents was combined with potassium silicate. Hence,
usage of bioagents and potassium salts are efficient as biocontrol method to manage disease and to improve
cropping systems together with saving the natural balance.