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

OGUNWOLU, E.O. and NWOSU, K.

ABSTRACT: 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.

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