POTENTIALS OF TUMERIC PLANT (Curcuma longa L.) POWDER FOR THE CONTROL OF BRUCHID BEETLES ON COWPEA SEEDS (Vigna unguiculata L) DURING STORAGE

¹Adenekan, m. O., ²Olubode, T., ¹Awogbade, A.l. and ¹Adesanya, O.A.

¹Department of Agriculture, Federal College of Agriculture, Ibadan

²Department of Home and Rural Economics, Federal College of Agriculture, Ibadan

Email: mopadenekan@yahoo.com

ABSTRACT

There has been growing interest in the use of natural plant products for protection of agricultural commodities due to their low mammalian toxicity and low persistence in the environment. It is against this background that this study was conducted to evaluate the potentials of Tumeric (Curcuma longa L.) plant powders for the control of bruchid beetles on cowpea (Vigna unguiculata) seeds. A synthetic insecticide, Cypermethrin and three Curcuma longa plant products (leaf, root and flower powders) were tested on cowpea seeds infested with ten teneral adults of male and female bruchid beetles in a Completely Randomized Design (CRD). The products were tested at 2.5g/50 g of cowpea seeds, while Cypermethrin was applied according to manufacturer’s recommendation to serve as the standard check.. Each treatment was replicated four times with the control and left for five days before data collection commenced. Data were collected on mean egg laid, hatched, mean number of adults that emerged from each replicate, mortality of insects, mean number of holes and weevil perforation index (WPI) as well as the total developmental period of the insects treated with different plant products of C. longa. The results obtained revealed significant differences (P ≤ 0.05) in the mean egg laid of 11.6 ± 1.8 when the root powder was applied, when compared with the value of 84.6 ±3.9 obtained at the control experiment. Similarly, the lowest mean mortality was obtained at the control experiment (1.4±0.2) and was significantly different from the highest value of 10.0 obtained when Cypermethrin was applied. The results of this experiment also revealed lowest seed perforation (4.1 %) and Weevil Perforation Index of 1.2 when the powder of root was applied indicating that the root powder showed good potential as bio-insecticide for the control of bruchid beetles on cowpea seeds during storage.

Keywords: Cowpea, Oviposition, Tumeric, Eclosion, Cypermethrin, Curcuma longa