ABSTRACT

The study lasted for a period of three months (August to October, 2011). The insecticidal property of Agave americana leaf powder and leaf granules and seed powder and seed granules of Piper guinense (uziza) against bruchid Callosobruchus macu/atus (beans weevil) was investigated in the laboratory. Mortality rate of beans weevil was tested on leaf and seed powder and granules of Agave americana and Piper guinense using different grams ranging from lg, 1.5g and 2g for the powder and 2g for the granules against 20 adult. beans weevil. The experiment was carried out in different replicates. From the experiment it was observed that the powder and granules of the Agave americana and Piper guinense plant had insecticidal properties. 100% mortality rate was observed after five days of subjecting the adult beans weevil to P.guinense while 100% mortality was observed in Agave americana plant at 10 days of treatment. The granules had 100% mortality rate from both plants after six days from both plants. The efficacy of the plant powders on the emergence rate was investigated in two separate sets, A and B within a period of four weeks; the values obtained within these four weeks were analyzed in means, standard deviation and ANOVA. Agave americana mean and standard deviation values were (9.500) (±11.737) and (7.8333) (±10.0880) while Piper guinense values were (11.3333) (±11.1888) and (8.5000) (±11.7374) respectively. The values for the control of both plant powder were (111.8000) (±7.6289) and (112.2000) (±7.2250) respectively, the values shows significant difference at (P<0.05). It was observed that the both plants materials reduce the emergence rate of weevil. Therefore both plant materials should be used to protect stored beans from pest infestation although Piper guinense shows higher insecticidal properties but it is more expensive and hard to obtain than Agave americana which is cheaper and easier to access both plants are efficacious on beans weevil (Callosobruchus maculatus}.