Potential native Trichoderma strains against Fusarium verticillioides causing post flowering stalk rot in winter maize

Fusarium spp. complex, (Fusarium verticillioides, F. subglutinans, F. moniliforme, F. graminearum) causing post flowering stalk rot (PFSR), has been reported as a serious disease in southern Rajasthan, and eastern Gujarat in winter maize. In the present study, emphasis has been laid on the efficacy of twenty seven Trichoderma strains against F. verticillioides which is a major causal organism. Efficacy evaluation of Trichoderma strains was based on the radial growth of the pathogen in the presence of biological control agent (BCA). Based on per cent inhibition three potential native strains of Trichoderma spp (Trichoderma harzianum BThr29, T. asperellum BTas25, and T. erinaceum BTer43) were selected for biological control of PFSR in the field. T. harzianum BThr29, T. asperellum BTas25, and T. erinaceum BTer43 showed per cent inhibition of F. verticillioides by 87.8, 83.9, and 81.1 percent respectively. Maize plants were artificially inoculated with F. verticillioides, and three potential Trichoderma strains were delivered as soil application (Trichoderma enriched FYM 10 tones ha⁻¹), seed treatment (10 g/kg seeds), and drenching (10 g/liter water). Split stem observation at the harvest of crop showed a restricted lesion of T. harzianum BThr29 treated plant at par with fungicidal application with an average mean rating scale of 1–1.3, which showed less than 50% discoloration in inoculated internode. In control, the mean disease rating scale was 3–3.4 which showed 51–75% of the inoculated internode is discolored. Application of Trichoderma strains improved crop stand by reducing lodging from 42.1 to 71.1% in inoculated maize plants, and reduced PFSR disease severity from 17.58 to 62.37%, Fungicidal application reduced lodging of maize plant from 57.91 to 77.78% and PFSR disease by 58.24–64.35% as compared to untreated control. The results obtained suggested that Trichoderma harzianum BThr29 has the potential to be used as a non-chemical alternative for PFSR disease management in maize crops.