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.
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