Abstract
Traditional open-pollinated maize varieties grown by farmers in Kenya were evaluated for their reaction to the spotted stem borer (Chilo partellus Swinhoe) in three field trials under artificial infestation. Four resistance parameters were used to compute a selection index. Results obtained revealed the existence of very wide variability of reaction to C. partellus attack. Resistant genotypes were obtained from diverse agroecologies. Traditional Kenyan open-pollinated maize varieties are therefore, valuable sources of useful genes that can be exploited for improvement of maize.