Evaluating maize genotypes for inherent resistance to maize stem borer, Chilo partellus Swinhoe

The identification of genes responsible for inbuilt resistance against insect pests and their integration into common cultivars for inclusion in Integrated Pest Management (IPM) programme for any area against any insect pest is gaining momentum in the present day agricultural system. The incorporation of insect-resistant lines into cultivation practices lowers the incidence of infestation of insect pests. This results in better economic gains for the farmers and safer ecological conditions, by minimizing use of insecticides. The maize stem borer, Chilo partellus Swinhoe is one of the devastating insect pests of maize crop. The infestation can range from 40 per cent damage to crop to total crop failure in dry season. Screening of the genotypes for identification of promising lines with inbuilt resistance against maize stem borer, C. partellus is one of the basic steps towards the implementation of IPM. A total of 20 maize genotypes were evaluated for their reaction against maize stem borer, C. partellus. Under natural infestation conditions at three different altitudes of Kashmir valley. The reaction was assessed as per Leaf Injury Rating (CIMMYT, 2011) and the cultivars ‘H-12’ and ‘H-8’ manifested less leaf damage and were categorised as resistant. The reaction of cultivars was unaffected by altitude. Leaf damage was positively correlated with number of pin holes and negatively with stem diameter, plant height, number of nodes per plant and leaf trichome density. The cultivars H-12 and H-8 can further be tested for inbuilt resistance under no choice conditions and incorporated in the stem borer resistant breeding programmes for Maize.