Screening of Maize Inbreds against Maize Stem Borer, Chilo partellus (Swinhoe) Under Temperate Conditions of North Kashmir

The spotted stem borer, Chilo partellus (Swinhoe), is an important insect pest of maize (Zea mays L.), causing substantial damage to the crop and affecting its productivity. Host plant resistance offers an economical and environmentally sound approach to managing this pest. The present study was conducted to evaluate 102 maize inbred lines for their response to C. partellus under field conditions at the Division of Entomology, Faculty of Agriculture, Wadura, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, during the kharif seasons of 2024 and 2025. The genotypes were assessed using leaf injury rating (LIR), number of exit holes per plant, stem tunnel length and dead-heart incidence to identify promising sources of resistance. Based on the LIR, 56.86 % of the genotypes were classified as resistant in 2024, increasing to 63.73 % in 2025. A similar trend was observed for exit holes, with the proportion of resistant genotypes increasing from 56.86 % to 63.73 %, while the susceptible group declined from 18.63 % to 7.84 %. Stem tunnelling assessment revealed that resistant genotypes increased from 44.12 % in 2024 to 53.92 % in 2025, accompanied by a reduction in the susceptible group from 29.41 % to 24.51 %. Dead-heart incidence ranged from 0 to 80.00 % in 2024 and from 0 to 60.00 % in 2025, with mean incidences of 24.85 % and 17.58 %, respectively. Among the evaluated lines, G-82, G-22, BML-6, G-85, G-57, G-52 and G-55 showed promising resistance across multiple damage parameters. In contrast, IML-187 and BASI LOCAL generally exhibited greater susceptibility. Chi-square analysis revealed no significant differences between the two years in the frequency distribution of genotypes across the leaf injury rating, exit-hole and stem-tunnelling resistance categories. Overall, the study identified promising maize inbreds that could serve as valuable genetic resources for developing stem borer-resistant cultivars and strengthening integrated pest management strategies under temperate agroclimatic conditions.