Screening of Niger Cultivars/ Genotypes for Resistance to Leaf Spot Disease Under Natural Conditions

Abstract

Niger (Guizotia abyssinica L.) is a traditional minor oilseed crop of significant economic and nutritional value, especially in tribal and marginal farming regions of India. However, its productivity is adversely affected by biotic stresses, particularly leaf spot disease caused by Alternaria alternata, which leads to considerable yield and oil quality losses. In the present study, 21 cultivars/genotypes of niger were screened under natural epiphytotic conditions during kharif 2024 to identify sources of resistance to this disease. Observations on disease incidence were recorded using a 0–9 disease rating scale and per cent disease intensity (PDI) was calculated. Based on the disease intensity, genotypes were categorized into different resistance groups. Among the screened cultivars, GNNIG-3 (8.22%), CTPN-1 (4.44%), and ONS-188 (5.76%) were found resistant. Seven genotypes were moderately resistant, nine were moderately susceptible, and two were found susceptible. None of the cultivars exhibited highly resistant or highly susceptible reactions. The findings suggest that the resistant genotypes identified in this study can be utilized in future breeding programs and serve as promising candidates for sustainable disease management strategies in niger cultivation.