Optimization of delivery methods for Pseudomonas fluorescens in management of Rice root nematode, Hirschmanniella gracilis

In a field trial with rice, the plant growth promoting rhizobacterium, Pseudomonas fluorescens, was evaluated as seed treatment, seedling root dip and soil application individually and in different combinations for management of Hirschmanniella gracilis. All bacterial application methods reduced populations of H. gracilis in soil and roots. A combination of seed treatment, seedling root dip, and soil application of the bacterium was the most effective treatment and gave similar control as carbofuran 3G. There was significant increase in phenol, peroxidase and chitinase accumulation in plants treated with P. fluorescens. The bacterium also increased the plant growth parameters and grain yield. The highest grain yield resulted from the seed + seedling dipping + soil application and seed + seedling dip treatments.