New sources of resistance to the stalk borers Busseola fusca (Fuller) and Chilo partellus Swinhoe in maize

A number of maize genotypes reportedly resistant to various stem borer species were evaluated for resistance to the maize stalk borer, Busseola fusca, and the spotted stem borer, Chilo partellus. Based on larval mass gain after two weeks of feeding on plants grown under greenhouse conditions, genotypes of both yellow and white kemel types were found to be significantly more resistant than the resistant standard Mp706. Pronounced resistance to both borer species was observed in breeding material developed by CIMMYT, whereas the Mississippi inbred line Mp708 was identified as a new source of resistance to C. partellus only. The level of resistance to B. fusca in Mp706 seemed to be negatively affected by reducing the photoperiod.