Genetic diversity for resistance to larger grain borer in maize hybrids and open pollinated varieties in Kenya

Abstract

Modern maize varieties and hybrids possess improved agronomic performance and tolerance to abiotic and biotic stresses. However, breeding for the traits that contribute to resistance to post harvest pests have not been given due attention. In Africa, lack of resistant varieties and appropriate grain storage technologies lead up to 20-30% losses, particularly due to post harvest pests. The larger grain borer (LGB) is currently the most damaging post-harvest pests of maize, causing substantial losses, and aggravating hunger and poverty. A total of 100 genotypes comprising of hybrids and open pollinated varieties were evaluated in Kiboko from October 2009. A 20x5 alpha lattice design with three replications was used. Morphological and bio-physical traits were measured. Harvested maize genotypes were sun dried for a week after which samples of 100g were taken for evaluation for larger grain borer resistance. The samples were incubated under ambient conditions for three months after which the contents of each jar were sieved to separate grains, insects, and powder (flour produced). There were significant (P<0.05) differences among the maize genotypes on the amount of flour produced due to larger grain borer damage, the number of damaged and undamaged grains and the number of live and dead insects. The study is on-going and will be repeated.