Pest control in maize: Search for source of resistance to stem borers

The relative response of 48 maize cultivars to infestation by stem borers, predominantly Sesamia calamistis Hmps., was determined in replicated small plot tests spanning 3 years (1975 to 1977) at Amakama. Cultivars showed ·no significant differences (P = 0.05) for average number of eggs/plant and mean % stand loss. The year effect was highly significant (P <0.01) for average number of eggs/plant and mean % stand loss. Cultivar x year interaction was not significant for both characters. Gravid moths deposited from 0.3 to 5.1 eggs/plant, apparently preferring Poey B 15, Poey T 84, Bulk-3, Inia VS 450, FARZ 23, and Onitsha to Ikom, UCA, Okoma, ICA H302, and H-101. Larval feeding injury caused the loss of 38.1 to 87.7% of the population of maize stands established, showing that none of the test cultivars has the potential to serve as a source of genes conferring resistance against borers. Ikom and Inia VS 450 were the least susceptible to borer feeding injury.