Bio-intensive Management of Soil-borne Diseases of Sunflower

In vitro all the bio-agents were able to inhibit the growth of test organisms where Trichoderma viride exerted maximum against Pythium aphanidermatum (27.8%), Rhizoctonia solani (38.2%), Sclerotinia sclerotiorum (33.4%) and Sclerotiorum rolfii (36.9%). Under pot conditions, maximum seed germination, shoot and root length were observed in those treatments where formulation of T. viride was applied except for S. sclerotiorum. Maximum reduction in disease severity (17.1%) and higher yield (13.52 q/ha) were observed when seeds were treated with a combination of T. viride (4 g/kg seed) + vitavax (1 g/kg seed). Soil treatment with T. viride (2.5 kg/ha) was much better as compared to seed treatment (4.0 g/kg seed) regarding yield of sunflower. Mixed formulation of T. viride (5 g) + Pseudomonas fluorescens (1.50 g) was found best as seed and soil applicant in reducing disease severity and increasing yield. In validation trials at farmers field, T. viride (4 g) + vitavax (1 g) proved as a best seed dresser. T. viride (2.5 kg) alone as a soil applicant gave maximum reduction in disease severity (20.0%) with maximum yield (13.5 q/ha.)