EFFECT OF PAWPAW PLANT EXTRACTS AGAINST Sitophilus zeamais (Mots) (Coleoptera: Curculionidae) ON MAIZE SEEDS
Adenekan, M. O1, Olubode, T2, Ikuejawa, I.I 3and Akinboboye, O.A1
1Department of Biological Sciences, Southwestern University, Ijebu-Ode, Ogun State. Nigeria,
2Department of Home and Rural Economics, Fed. Coll. of Agriculture, Moor Plantation, Ibadan.
3Department of Agric. Extension and Management, Fed. Coll. of Agriculture, Moor Plantation, Ibadan.
Email: mopadenekan@yahoo.com
ABSTRACT
The effect of Pawpaw plant partextracts (leaf, stem bark, root and flower) at different dosages (0.5, 1.0, 1.5, 2.0 and 2.5g) against Sitophilus zeamais infesting stored maize grains were assessed at the Biology Laboratory of the Southwestern University, Okun-Owa. Treatments were admixed with 30g of maize grains, infested with ten adults of S. zeamais and stored in 3.0 mm petri dishes. The experiment was laid out in completely randomized design (CRD) and replicated four times each. Data were collected on adult mortality, oviposition and percentage weight loss of the grain in each of the replicate. Data collected were analyzed using analysis of variance, while sample means were separated with the aid of least significant difference (LSD) at 5%. There were significant differences in adult mortality of S. zeamais treated with different dosages of the plant parts powder. The flower powder of the plant recorded the highest means adult mortality (10) compared to the lowest adult mortality of 0.1 obtained at the control experiment. The flower part powder also revealed the lowest mean eggs laid (oviposition) (7.1) and the lowest grain damage loss (1.4 %) when compared with the values of 18.7 and 40.0 obtained for mean eggs laid and percentage weight loss obtained when stem bark and control treatments respectively. This clearly showed that the powder of the flower of C. papaya showed good potential as bio-insecticide for protecting stored maize grains.
Keywords: Mortality, Sitophilus zeamais, toxicity, storage, oviposition, eclosion,