Efficacy of marine antagonist, Trichoderma spp. as halo-tolerant biofungicide in controlling rice diseases and yield improvement

Abstract

Twelve stains of marine-derived Trichoderma namely, four of T. asperellum, three of T. harzianum, two of T. hamatum, two of T. viride and one of T. longibrachiatum, were evaluated their antagonistic activity against rice pathogens. Ten out of twelve Trichoderma strains showed potent in vitro antagonistic activities via high competition and their crude extracts displayed promising antifungal activity against Biopolaris oryzae and Rhizoctonia solani of 92.59–100% at 10 g L-1 and Fusarium semitectum and Curvularia oryzae of 62.35–100% at 50 g L-1 as well as significantly improving the germination and seedling growth when applied as a seed treatment. All selected Trichoderma strains exhibited tolerance to salt at 7% NaCl. Trichoderma hamatum KUFA 0077 displayed the most effective reduction in rice sheath blight severity of up to 92% in vivo. Moreover, T. asperellum KUFA 0042 showed the greatest biocontrol activity against dirty panicle disease, reducing the disease incidence by up to 64.50%, which was similar to the fungicidal activity of difenoconazole 15% + propiconazole 15 %EC when applied three times at the panicle initiation, flowering and milk stages in field trials. Treatment with marine Trichoderma strains also improved the rice yield by up to 21.73%. Three applications of Trichoderma strains resulted in better biocontrol effectiveness against dirty panicle disease and yield improvement than two applications. The results indicated that marine-derived Trichoderma are a novel source of biocontrol agents that show promising antagonistic activities and halo-tolerance in controlling rice diseases and significant improvement of rice yield and can be developed as new biocontrol agent alternatives to fungicide in rice disease management.