Field biocontrol efficacy of Trichoderma spp. in fresh and dry formulations against rice blast and brown spot diseases and yield effect

Abstract

This study set out to assess the antagonistic activities of isolated marine and endophytic Trichoderma in controlling rice blast and brown spot diseases in a field trial. All selected Trichoderma strains were fast-growing and able to grow over the rice pathogens tested within 4 days in dual tests. Twelve marine and endophytic Trichoderma strains were evaluated for their antagonistic activities against rice blast and brown spot diseases under greenhouse conditions. Five strains that displayed significant biocontrol activities against both diseases were selected, and their antagonistic activities were assessed under field trials in rice var. KMDL 105 in both their fresh and dry formulations. The results showed that the fresh formulations of all Trichoderma exhibited higher disease control performance than did the dry ones. Among the Trichoderma tested, the application of a fresh formulation of endophytic T. harzianum KUFA0405 showed the most effective biocontrol activity in suppressing leaf and neck blast diseases by 57.19 and 60.35%, respectively, while its dry formulation resulted in lower activity against blast disease, resulting in 51.26 and 46.66% disease reduction on leaf and neck blast diseases, respectively. Not only did endophytic T. harzianum KUFA0405 show the best biocontrol activity against the disease, but it also resulted in increasing the rice yield to 226 and 218 kg/ Acre when applied in fresh and dry formulations, respectively, compared with the control treatment, which resulted in a rice yield of only 158 kg/ Acre. Meanwhile, the application of endophytic T. harzianum KUFA0406 showed the most effective biocontrol activity in suppressing brown spot disease, causing a 39.23% and 29.64% disease reduction when applied as fresh and dry formulations, respectively, and increasing the rice yield up to 257 and 244 kg/ Acre when applied in fresh and dry formulations, respectively, compared with the control treatment, which resulted in a rice yield of only 184 kg/ Acre.