Abstract

EFFECT OF TIME OF INOCULATION AND DELIVERY SYSTEMS ON BIOLOGICAL CONTROL OF FUNGAL INFECTIONS OF TOMATO (SOLANUM LYCOPERSICUM) BY PSEUDOMONAS SPECIES

Balkrishna M. Sandikar*

Abstract

Six Pseudomonas isolates i.e. P. aeruginosa13, P. aeruginosa 58, P. putida71, P. fluorescens106, P. aeruginosa117, P. aeruginosa154 obtained from rhizosphere of healthy tomato plants with potent antifungal activity against the phytopathogenic Pythium and Fusarium species were used to study biocontrol of tomato (Solanum lycopersicum) plants by pot culture experiments. Active nutrient broth cultures of these Pseudomonas species were applied by three delivery systems- soil amendment, seed coating and foliar spray, at three different periods, i.e. before sowing, at the time of sowing and after the sowing of seeds. All the Pseudomonas cultures were proved successful to control tomato plants from Pythium and Fusarium infections, although with different efficiencies. Biocontrol of fungal infections of tomato was found to be more effective by soil amendment (>50%) while least effective by foliar spray (34-60%). Application of Pseudomonas cultures before sowing of seeds was found to be more effective in case of all the isolates. Biocontrol efficiency was found to be higher in case of P. aeruginosa 154, P. aeruginosa58 and P. aeruginosa13. We conclude that, application of these Pseudomonas cultures is more significant for biocontrol of fungal infections of tomato plants especially by soil amendment, before sowing of seeds.

Keywords: Biocontrol, Pseudomonas, Phytopathogens, Pythium, Fusarium.