Resistance status of some maize lines and varieties to the maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae)

2011

English

This study was conducted to determine the resistance status of maize lines and varieties to Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) attack. Ten maize lines; EVDTW99STRQPMCo, FU2090DYFP, TZEEY-PopSTRC4, DMLSRYQPM, GH90DYFP, FU2080DWF/DPop, TZE-Y-PopDTSTRC4, 2000SYNEEWQPM, GH90DWOP and Fu2090DWDPop, and three varieties; Dorke SR, Dodzi and Mamaba (flint maize) were subjected to Sitophilus zeamais attack in a completely randomized design set up. Ten females of S. zeamais were introduced into 50 grammes of shelled whole maize of each of the ten lines and three varieties to oviposit for three days. Based on knowledge of the life cycle of the pest, the set ups were checked for new emergences after 21 days. Emerged weevils were removed and counted daily without replacement, with the first batch of emergence occurring at 27 days after treatment from Fu2090DYFP and Fu2090DWDPop and the longest period of emergence observed in EVDTW99STRQPMCo, Dodzi, Dorke and GH90DWDP. The mean numbers of emerged weevils from the maize lines and varieties were significantly different (at P< 0.05). lines and varieties exhibited varying degrees of susceptibility and weight loss to the weevil attack, with line 2000S8NEEWQPMCo producing the least mean number of weevils, while line FU2090DYFP recorded the highest number. Based on their susceptibility indices, two lines and one variety are categorized as resistant and eight lines and two varieties as moderately resistant. The two lines (EVDTW99STRQPMCo and GH90DYFP) are therefore recommended to be included into the maize release programme. Maize lines FU2090DYFP, DMLSRYQPM, FU2080DWF/DPop, TZE-Y-PopDTSTRC4, GH90DWOP, Fu2090DWDPop, TZEEY-PopSTRC4, 20008YNEEWQPMCo and the varieties Mamaba and Dorke SR are also recommended to be included in breeding programmes to improve their resistance to S. zeamais for future release.

Issa, U. S.; Afun, J. V. K.; Mochiah, M. B.; Owusu-Akyaw, M.; Braimah, H.