Abstract:
This study isolated 12 endophytic Trichoderma spp. from healthy rice leaves collected in intensively cultivated paddy fields in the Central Region of Thailand and tested for their antagonistic activity against rice disease. Four Trichoderma asperellum strains, and two strains each of Trichoderma harzianum, Trichoderma koningiopsis, Trichoderma longibrachiatum, and Trichoderma virens were identified and their biocontrol activity was evaluated. Among the endophytic Trichoderma tested, T. asperellum KUFA 0402, T. longibrachiatum KUFA 0409 and T. harzianum KUFA 0406 showed significant biocontrol activity against dirty panicle disease in field trials, reducing the disease by 60% when applied at 106 spores ml−1 three times at the panicle initiation, flowering, and milk stages. Moreover, the treatments of T. asperellum KUFA 0402 and KUFA 0403, T. harzianum KUFA 0406, and T. longibrachiatum KUFA 0409, when applied three times, displayed significant improvement of rice yield ranging from 198 to 209 kg Acre−1 which was similar to results from fungicide treatment, whereas the control (water) treatment yielded 178 kg Acre−1. The biocontrol activities of Trichoderma spp. included strong space and nutrient competition, and antibiotic production. The endophytic Trichoderma spp. proved to be potential biocontrol agents and could be developed for application in controlling rice diseases as alternative fungicides or as part of an integrated pest management in combination with treatments. Moreover, they showed compatibility with hexaconazole at the recommended rate at 375 ppm. © 2022, The Author(s), under exclusive licence to International Organization for Biological Control (IOBC).