Milk stage kernel infection frequency in kharif sorghum at grain mold prone locations in India

Abstract

Milk stage kernel infection frequency has substantial effects on mold development in mature sorghum grain. Field experiments were conducted with 16 sorghum genotypes at four grain mold prone locations (Akola, Hyderabad, Dharwad and Surat) in India during kharif 2014 and 2015. The genotypes included grain mold susceptible, resistant, improved germplasm, breeding lines and released cultivars. The objective was to quantify natural infection frequency of fungi in milk stage kernel and study the response of various sorghum genotypes against this infection. Results revealed that Fusarium (16.1%) and Curvularia spp. (7.9%) were predominant fungal genera at the milk stage kernel at all the locations under study. Few other fungi namely Alternaria, Bipolaris, Aspergillus, and Penicillium spp. were detected sporadically in low frequency (~0.95%). There was significant negative association between infection frequency of Fusarium and Curvularia especially when intensity of infection was moderate to high (>25%). The genotypes B58586, GMR156-1, GMR166-1, SGMRN12-3-1 and IS25070 were found promising with low intensity (average total infection<10%) of infection across environments. The information can be useful for resistant breeding program against specific fungal component of grain mold.