Combined application of Pseudomonas fluorescens and Purpureocillium lilacinum liquid formulations to manage Globodera spp on potato

Potato cyst nematodes (PCN), Globodera rostochiensis and Globodera pallida are major limiting factors to potato cultivation globally. Effective use of nematode antagonistic bio-agents is a potentially important component of the eco-friendly agro-farming. Pseudomonas fluorescens and Purpureocillium lilacinum are known for their nematode antagonistic potential and plant growth promotion ability. The effect of seed treatment with liquid suspension of P. fluorescens at 1 l/ton seeds and soil drenching with suspension of P. lilacinum at 5 l/ha, singly and jointly, was studied to minimize the damage caused by PCN in potato plants under field conditions in two regions in India. Both applications showed significantly greater PCN suppression and better plant growth promotion in comparison to solo application. The both application showed the highest reduction of cyst population (75.7%) in soil, female population (79.9%) in root and egg numbers per soil of each location (84%). The potato plants from P. fluorescens-seed treatment and P. lilacinum-soil drenching both applied plots were 33.5% taller with 45.6% more number of tubers than untreated plants. The tuber yield was also significantly higher (35.9%) in both application than untreated control. There was no significant difference on the root colonization of P. fluorescens and P. lilacinum in solo and both treatments.