Document Type : Original Research Article
1 Department of Crop Protection, Federal University of Agriculture, Abeokuta, Nigeria
2 Department of Applied Science, Rivers State University, Port Harcourt, Nigeria
The maize weevil, Sitophilus zeamais (Motschulsky), is a field-to-store primary pest in tropical and subtropical regions which causes up to 20-30% damage to stored maize grains.Twenty plant powders were screened for potency against Sitophilus zeamais arranged in Completely Randomized Design with four replicates and control without the treatment.The result recorded that the plant powders produced no significant effect (p > 0.05) on mortality at the second day post treatment against Sitophilus zeamais. However, significant effect (p < 0.05) was recorded on the 7th, 14th, 21st and 28thdays post treatment. The lowest value for adult emergence was found in Annona squamosa (0.18), Piper guinensis (1.33) and Vernonia amygdaliana (1.67). It was found that Annona squamosa (10.31%), Vernonia amygdaliana (23.73%) and Piper guinensis (24.18%) recorded the lowest value for percent grain damage. The percent weight loss was found to be significantly lower in Annona squamosa (4.85%), Piper guinensis (5.43%) and Vernonia amygdalina (10.83%) relative to others. The percent WPI was also found to be low in Annona squamosa (12.86%), Vernonia amygdalina (28.08%) and Piper guinensis (32.94%). Mortality of Sitophilus zeamais significantly varied with the plant powders and period of exposure. The result obtained indicated that the plant powders Annona squamosa, Vernonia amygdalina and Piper guineense may provide effective control of Sitophilus zeamais.