Susceptibility of Some Maize Cultivars in Nigeria to Infestation and Damage by Maize Weevil, Sitophilus zeamais(Motsch.) (Coleoptera: Curculionidae).



ABSTRACT: The susceptibility of eleven maize cultivars to Sitophilus zeamais Motschulsky was investigated in the laboratory at 28 ± 2°C and 75 ± 5% relative humidity. The cultivars namely: T2BRCOMP.F2, T2BRELD.3C4, IWDSTRC1, TPB-SRPOOLC3W, BR928-DMRSRF2, EVIWFSTRC1, T2BRCOMP.2F2, LNTP-YCsF2, BR9943-DMRSF2, BR92-DMRSRF2, and LNP-WXLNTPC1F2, were obtained from the Maize Programme Unit, International Institute for Tropical Agriculture (UTA) Ibadan. Grain damage by the maize weevil and the growth performance of the weevils on the different cultivars were investigated using percentage weight loss, number of damaged seeds, percentage grain damage, and number of eggs laid as indices. Results showed that cultivars T2BRELD.3C4 and BR928-DMRSRF2, with percentage grain damage of 2.84% and 3.15%, respectively, were the least susceptible. Cultivars LNTP-YCsF2 and BR9943-DMRSF2• with percentage grain damage of 40.38% and 38.43%, respectively, were significantly (P<0.05) the most susceptible. Generally, the cultivars had significant (FIO•22= 7.514, P = 0.001) effect on the number of eggs laid by S. zeamais. Results also showed that more eggs were laid on cultivars LNTP-YCsF2 (8.33) and BR9943-DMRSF2 (8.00) than on other cultivars. No egg was laid on cultivar T2BRELD .3C4. The findings from this study suggest that planting the resistant maize cultivars such as T2BRELD.3C4 may reduce infestation and damage to grain by S. zeamais and enhance the shelflife of maize.
Keywords: Grain damage, maize cultivars, Sitophilus zeamais, susceptibility, viability

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