Resistance to the larger grain borer (Prostephanus truncatus) and yield performance in selected local maize landraces in Kenya

Abstract The larger grain borer (LGB) has continued to devastate maize grains especially in the dry and hot ecologies of Kenya. Resistance is a low cost environmentally sound avenue of pest management. Most of the improved cultivars are susceptible to the pest, and succumb to drought much faster. Local maize landraces are an important livelihood resource and form an alternative source of potential resistance for the LGB in these areas. The objective of this study was to evaluate selected local maize landraces for LGB resistance and yield performance. Laboratory screening was carried out for 25 germplasm at KARI-Kiboko field laboratory where the insects were also sourced. One hundred (100) grams of maize grains were infested with 50 unsexed LGB adults. Resistance was evaluated 90 days after infestation. Field data were recorded on grain yield, 100seed weight, shelling percentage, plant height and number of ears per plant. Percentage loss in grain weight and dust weight collected after three months of storage were used as measures of LGB resistance. Data were analyzed using SAS package and means separated by Fisher's protected LSD. CML492 was the most resistant followed by GBK- 044593, GBK-032419, GBK-032423, GBK-044611, GBK-34659 and GBK-032357. Over half the landraces gave higher yields than the local check. GBK-043731 was the highest yielding (6 t/ha). Appreciable levels of resistance against LGB were identified in the local landraces. These landraces are recommended for both production, and use in the development of LGB resistant maize in Kenya.