Unveiling the impact of varied growing seasons on Fusarium ear rot severity in maize under North Indian conditions

Fusarium ear rot (FER) caused by Fusarium verticillioides holds economical significance in maize due to its potential for mycotoxin contamination, which poses risk to the health of both humans and animals. Under Punjab conditions, FER poses a persistent threat to maize cultivation in spring and Kharif sown maize, thus significantly impacting crop yield and quality. In the present study, twenty isolates of Fusarium species associated with maize ear rot were collected from different maize growing areas of Punjab. The virulence spectrum of these isolates was studied on maize hybrid PMH 2 during spring 2022 and Kharif 2022 under field conditions. In the spring season, FER severity ranged from 35.16 to 75.88 per cent, while during Kharif season it varied from 52.75 to 80.50 per cent. On an average, ear rot severity was notably higher during the Kharif season (67.01 %) compared to the spring season (56.42 %). The presence of highly aggressive isolates resulted in higher mean ear rot severity of 70.17 per cent during Kharif season, as opposed to 66.40 per cent during the spring season. Additionally, the frequency of highly aggressive isolates was 80 per cent during the Kharif season, whereas, it was 40 per cent during the spring season. Weather conditions, including a temperature of 28°C, relative humidity of 67.13 per cent and total rainfall of 286 mm during the Kharif season’s reproductive stage, were found to be conducive to FER development. These results imply that the Kharif season, characterized by favourable environmental conditions, is best suited for screening germplasm against FER.