Supplementing host resistance for improvement of grain mold tolerance in Kharif sorghum across locations in India

Abstract

Grain mold of sorghum is an economically important disease causing significant loss of grain quality, market value and productivity worldwide during rainy season. Use of resistant cultivar is the most economical way for management of a disease. For grain mold, however, host resistance alone is not enough and resistance should be supplemented with suitable management practices. Eight bio-formulations of Trichoderma spp. were evaluated for their efficacy in management of this disease across four locations representing major kharif sorghum regions in India during consecutive three seasons. Evaluation was conducted under natural field conditions in grain mold screening block and the treatments were applied at 80% anthesis of panicle. Infection frequency of the major grain mold pathogens in India viz., Fusarium and Curvulatia species in 10-day-old tender grain (TG) were assesses by laboratory method. Grain mold severity at physiological (PM) and harvest maturity (HM) was assessed using a 1–9 disease rating scale. Frequency of infection in TG was significantly (p<0.05) less on any treated panicles compared to the control. Reduction of infection in TG had significant (R2>0.60, p<0.000) effects on decreasing mold severity at PM and HM. The PNS10LB was the best performing treatment that reduced TG infection by 56%, grain mold severity by 26.8% (panicle grain mold score or PGS) and 30.4% (threshed grain mold score or TGS) and produced 76% mold free grains. This study reports that supplementation of host resistance with suitable management practice can improve clean grain percentage in sorghum and resultant market value of the produce.