INDUCTION OF PLANT IMMUNE BY MICROBIAL INOCULANTS AGAINST TOMATO FRUIT WORM

Tomato (Lycopersicon esculentum Mill.) is one of the important and remunerative vegetable crops grown around the world for fresh market and processing. The production and productivity of the crop is greatly hampered by the fruit borer, Helicoverpa armigera (Hübner) which causes damage to the developing fruits and results in yield loss. The indiscriminate use of synthetic chemical pesticides to control this pest resulted in development of resistance and harmful pesticide residues in fruits. To avoid such problems caused due to indiscriminate use of insecticides, utilization of Host Plant Resistance (HPR) is an ecologically viable, alternate insect pest management strategy. The tomato accession Varushanadu Local along with a popular variety PKM1 was tested for induction of resistance by various microbial inoculants viz., Azospirillum, Phosphobacteria, Pseudomonas, K-solubilizer, Azospirillum + Phosphobacteria, Azospirillum + Pseudomonas, Azospirillum + K-solubilizer, Phosphobacteria + Pseudomonas, Phosphobacteria + K - solubilizer. and Pseudomonas. Based on the preliminary study, the promising microbial inoculants viz., Pseudomonas, K-solubilizer, Azospirillum, + k-solubilizer, pseudomonas + k-solubilizer, and phosphobacteria + Ksolubilizer were selected. Feeding preference of H. armigera to the leaves and fruits was the minimum towards the accessions Varushanadu Local treated with Pseudomonas + Ksolubilizer. Plants of the accessions Varushanadu Local supplied with Pseudomonas + Ksolubilizer exerted profound antibiosis effects against the life stages of H. armigera as evidenced by higher larval mortality, reduced pupation, reduced larval, pupal and adult duration.