Response of yard long bean (Vigna unguiculata var. sesquipedalis (L.) Verdcourt) to application of pgpr consortium-farmers’ participatory research

Yard Long Bean (Vigna unguiculata var. sesquipedalis (L.) Verdcourt) known as ‘Achinga Payar’ in Malayalam is one of the important vegetable of Kollam district of Kerala state owing to its greater market prize and consumer preference. But its cultivation is at risk in the recent past especially in Kollam district with the incidence of disease and its poor response to fertilizer due to soil problems. In this context Krishi Vigyan Kendra, Kollam has undertaken a farmer participatory on farm trial to rejuvenate the soil microbial population for enhancing the response to the nutrients applied and protecting the plant from many pathogens by using the plant growth promoting rhizobacteria consortium developed by Kerala Agricultural University during 2011–2012 in seven randomly selected farmers’ fields in Kollam District of Kerala through participatory approach. This trial consisted of three technology options viz., farmers's practice i.e. unscientific use of chemicals(T1), soil test based liming + Rhizobium + Pseudomonas application (technology option 1., T2), and soil test based liming + application of PGPR consortium Mix I + Mix II (Technology option 2 ie., T3). The results revealed that both technologies (technology option 1, T2 and technology option 2, T3) had a positive influence in determining the yield of yard long bean. The technology option 2(T3) recorded the highest yield (16.25 t/ha) nearly 27% increase over farmer's practice. The technology option 1(T3) enhanced the yield by 19% over Farmers Practice. Disease incidence was to the tune of less than 5% when bioagents were used. Better control of disease was observed in PGPR applied plots (disease incidence of 1%) whereas incidence of disease was 22.4% in the plots maintained under Farmers Practice. The trail undertaken conclusively proved the use of plant growth promoting rhizobacteria, as an economic and effective management method to reduce chemical fertilizers and pesticide load in crop production with the advantages of growth promotion and disease management effect.