SCREENING OF SEEDS FROM SOME MAIZE LINES FOR STORAGE TOLERANCE AND RESISTANCE AGAINST Sitophilus zeamais MOTSCHULSKY (COLEOPTERA: CURCULIONIDAE).

ABSTRACT
Studies were conducted on fourteen maize lines to determine the relative susceptibility and storage tolerance/resistance of the seeds to Sitophilus zeamais (Mots) infestation. S. zeamais is one of a few most important pests of stored maize. The maize lines were replicated four times in plastic containers. Ten adult weevils were placed in each container which had 30 whole maize grains. The experiment was laid out in a complete randomized design under laboratory conditions of 26.80 + 1.14oC and relative humidity (r.h) 71.27 + 5.16%. Data derived were subjected to a two-way analysis of variance. The maize lines tested were S2 progenies and the parent seed (TZBRELD.3C2), which were grown in a field trial at Nigerian Institute for Oil Palm Research (NIFOR), near Benin City and Ozoro in Delta State. The results showed that there were no significant differences among the infested test seeds using measurements of mortality, developmental period (days) and adult emerged weevils with the maize lines (P > 0.05). There were however, significant differences within the maize lines in terms of punctured grains and weight loss with lines FS2-5, FS2-9 and FS2-18 offering tolerance to S.zeamais attack (P < 0.05). Generally significant differences were observed in all parameters used among the maize lines in the various locations (P < 0.05). The NIFOR maize line offered better tolerance to the weevil attack than Ozoro and ‘Original’ maize lines. The control maize variety conferred similar tolerance to the weevil infestation as in the 14 maize lines used. From the experiment, it would appear that genetic variability for resistance to S. zeamais existed in these maize lines.