Efficacy of fungicides, botanicals and bioagents against Rhizoctonia solani inciting leaf blight on turmeric (Curcuma longa L.)

Abstract

Leaf blight caused by Rhizoctonia solani is a serious diseases of turmeric crops. Fifty percent disease incidence was obsd. in turmeric growing areas of India. The antifungal efficacy of botanicals, biol. agents, and fungicides was tested against R. solani in vitro. Seed ext. and oil cake of mahua (Madhuca longifolia) suppressed the mycelia growth (34.81; 49.63 %), sclerotial formation (100%), and prodn. of biomass (2.18; 2.41 mg) of R. solani, followed by leaf exts. of Azadirachta indica and Littorina littorea. Among the biol. agents, native isolates of BSoya1 of Bacillus spp., Cg1 of Chaetomium spp., Pf1 of Pseudomonas spp., and Tv1 of Trichoderma spp. showed >50% antagonistic effect on mycelial growth and 100% on sclerotial formation. The complete fungal growth inhibition was obsd. in media with added Nativo and Bavistin fungicides. The basal soil application of mahua cake and Trichoderma viride in the ratio of 1:2 (1 g of mahua cake mixed with 2 g T. viride per kg of pot soil) was followed by foliar spray of Nativo at 0.5% in mitigating the leaf blight (8.6%) over the inoculated control (50.51%) in the pot culture expts. [on SciFinder(R)]