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

Seed bacterization bl Pseudomonas fluorescens and P. aeruginosa alone and i n combination with aerial spray of their cell suspensions or Neemazal, a pr oduce of neem (Azadirachta indica), at different concentrations was tried u nder field conditions to control powdery mildew (Erysiphe pisi) of pea (Pis um sativum) through induced resistance in the host. Combination of seed bac terization with tither aerial sprays of bacterial cell suspensions or Neema zal was more effective in controlling the disease at all concentrations of Neemazal (50 mg/l being the optimum) than seed bacterization alone. Bacteri zation by both bacteria, and aerial spray of Neemazal increased the dry wei ght of aerial parts, number of nodes and pods as well as seed weight of pea planes. Colonization of the rhizosphere and rhizoplane was maximum by P. a eruginosa followed by strain Pf5 of P. fluorescens . The lower most leaves supported better survival of these two plant growth-promoting rhizobacteria (PGPR) than the upper leaves.