The maize weevil (Sitophilus zeamais Mostch.) is one of the most damaging storage pests causing significant reductions in grain weight and quality in tropical and subtropical regions. The current study determined the effectiveness of two cycles of modified S 1 recurrent selection towards the improvement of weevil resistance in the maize variety ''Longe5''. Grain yield and resistance to Turcicum leaf blight, grey leaf spot and rust diseases, which occurred naturally at the time of experimentation, were also evaluated to enhance the overall worth of the maize variety. Selections were made by identifying and self-pollinating the foliar disease resistant and vigorous plants, with potentially big well-placed ears from the base population of the Longe5 (the original cycle i.e., C 0 ), grown at the National Crops Resources Research Institute, Namulonge, in Uganda. Over 540 selfed ears were obtained from the C 0 and were screened for maize weevil resistance under controlled conditions in the laboratory, after which 162 weevil resistant genotypes were selected and recombined in an isolated field to generate the C 1 . The second cycle (C 2 ) was generated from the C 1 in a similar procedure, by recombining 190 weevil resistant genotypes. The C 0 , C 1 , and C 2 were evaluated for grain yield and reaction to foliar diseases at three locations, and the ensuing seed was screened for maize weevil resistance in the laboratory. Significant gains were obtained for maize weevil resistance. There was a reduction in grain weight loss due to maize weevil damage of 65 % in C 2 and 15 % in C 1 . There was a 33 % reduction in the number of weevil progenies emerging in C 2 and 19 % in C 1 grain. Similar positive trends were realized for grain yield and resistance to foliar diseases in C 1 and C 2 compared to C 0 . The results indicate that the modified S 1 recurrent selection was effective in improving Longe5 for maize weevil resistance.

The maize weevil (Sitophilus zeamais Motschulsky) is the most destructive storage insect pest of maize (Zea mays L.) worldwide, especially among susceptible varieties. Breeding for grain resistance against the weevil is a major component of an integrated pest management strategy in maize production. The objective of this study was to identify diverse sources of weevil resistance for introgression in breeding programmes. A total of 180 inbred lines from three geographical areas were screened for maize weevil resistance. Screening was executed by infesting 50 g of maize grain with 32 newly emerged adult weevils, placed in 250 cm 3 glass jars in a "no-choice" laboratory test. The grain susceptibility parameters used were F 1 weevil progeny emergence, percent grain damage, median development period, Dobie's index of susceptibility, and parental weevil mortality. New sources of weevil resistance for maize breeding were identified. Eight inbred lines were consistently resistant and, therefore, selected as potential donors for weevil resistance in the maize improvement programmes. There was significant genetic variation, and high levels of heritability (89 -96%) for weevil resistance that suggested high potential for germplasm improvement through selection. No significant association was observed between maize weevil resistance and grain yield, suggesting that breeding for maize weevil resistance can be achieved without compromising grain yield.

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