Control of powdery mildew (Erysiphe pisi) of pea (Pisum sativum) by combined application of plant growth-promoting rhizobacteria and Neemazal™.

Seed bacterization by Pseudomonas fluorescens and P. aeruginosa alone and in combination with aerial spray of their cell suspensions or Neemazal, a product of neem (Azadirachta indica), at different concentrations was tried under field conditions to control powdery mildew (Erysiphe pisi) of pea (Pisum sativum) through induced resistance in the host. Combination of seed bacterization with either aerial sprays of bacterial cell suspensions or Neemazal was more effective in controlling the disease at al concentrations of Neemazal (50 mg/l being the optimum) than seed bacterization alone. Bacterization by both bacteria, and aerial spray of Neemazal increased the dry weight of aerial parts, number of nodes and pods as well as seed weight of pea plants. Colonization of the rhizosphere and rhizoplane was maximum by P. aeruginosa followed by strain Pf5 of P. fluorescens. The lower most leaves supporte better survival of these two plant growth-promoting rhizobacteria (PGPR) than the upper leaves.