Efficacy of Pseudomonas fluorescens and Paecilomyces lilacinus against Meloidogyne graminicola infecting rice under system of rice intensification

Abstract

The talc-based formulations of the plant growth promoting rhizobacterium, Pseudomonas fluorescens and egg parasitic fungi, Paecilomyces lilacinus, were evaluated as seed treatment, soil application and combination of both for the management of M. graminicola in fields of rice grown under system of rice intensification. Both the bioformulations significantly reduced the root invasion and soil populations of M. graminicola but P. fluorescens was most effective when applied as seed cum soil application and seed treatment alone. Effect of these treatments was comparable with the standard chemical carbofuran application. The introduced P. fluorescens survived significantly in rice roots when applied as seed cum soil application and seed application alone than as soil application. There was significant increase in phenol, peroxidase and chitinase accumulation in plants treated with P. fluorescens. Application of bioagents had positive influence on growth parameters such as plant height, root length, shoot weight, root weight and number of tillers per hill. Application of P. fluorescens as seed cum soil treatment resulted in higher grain yield, which was 20.6%–26.9% increase over control followed by P. fluorescens as seed treatment alone that increased grain yield of rice by 10.7%–11.2% than control. However, economic returns per investment was higher when P. fluorescens was applied as seed treatment alone (1:8.8–1:12.0 incremental cost benefit ratio) followed by the P. fluorescens as seed cum soil treatment (1:6.2–1:9.7 incremental cost benefit ratio).

Key words:

• Pseudomonas fluorescens
• Paecilomyces lilacinus
• Meloidogyne graminicola
• rice

Acknowledgement

The author thanks Dr P.M.M. David, Professor and Head, Department of Plant Protection, Agricultural College and Research Institute, Killikulam, India, for his valuable suggestions during execution of the field trials. He thanks Dr R. Samiyappan, Director, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore, India, for providing the laboratory facilities to carry out the biochemical assays.