Mechanisms of Resistance in Tropical Maize Inbred Lines to Spotted Stem Borer (Chilo Partellus)

This study examined the mechanisms of stem borer resistance in CIMMYT tropical inbred maize. Kenya is a producer of maize, but cannot satisfy its domestic needs. The maize stalk borers are among the production constraints that are responsible for the low maize yields in Kenya. One hundred and twenty CIMMYT tropical inbred lines were planted at Kiboko Field Station in October 2011 and March 2012. Ten (10) plants from each entry were artificially infested with Chilo partellus neonates three weeks after planting; 17 plants were protected from borer damage using an insecticide. The experiment was designed as an alpha lattice and replicated 3 times. Data were collected from five of the infested plants through destructive sampling. Data were collected on several borer resistance attributes and also on grain yield. There were significant (P<0.05) differences among germplasm for the different resistance mechanisms, with genotypes expressing one or a combination of the different mechanisms. Canonical discriminant analysis indicated that trichome density was the most important trait conferring resistance. Genotype MBR C5 Bc F8-1-1-1- B-2-2-B -B-B was the most stem borer resistant line.