WITH OR WITHOUT MORINGA (Moringa oleifera) ON COWPEA, ALIEN Sitophilus oryzae SCARIFIES AND OVIPOSIT ON SEEDS

ABSTRACT

Cowpea (Vigna unguiculata) is an economic crop that is susceptible to stored product pests and recent observations reveals that apart from infestation from Callosobruchus maculatus, a population of Sitophilus oryzae is increasingly becoming a problem on cowpea in Nigeria. The bioassay was conducted at different concentrations in a completely randomized design. To achieve this, two objectives were tested namely effects of moringa plant parts on S. oryzae’s ability to scarify cowpea and their developmental time. Results showed that the Sitophilus oryzae that emerged from cowpeas treated with moringa leaf powder had a concentration dependent delay in development, which was only significantly longer than the those that emerged on the control when compared with the cowpeas that had the highest Moringa leaf treatment. For scarification test, the paired choices (marked/ unmarked and unmarked/ treated) treated with different concentrations (1g and 5g) and control (marked/ unmarked and unmarked/ treated) were tested to assess the ability of Moringa to prevent the Sitophilus oryzae from feeding on the cowpea. Results showed that for cowpea seeds treated with 1gram of seed powder obtained from Moringa (Student T-statistics= 3.16, p=0.03) significantly had fewer counts of scarified seeds which had an average of (3.2 ±0.8) than the untreated cowpea seeds which had an average of   4.2 ±1.2 scarified seeds. Those treated with 1gram for both paired choices were not significantly different different (Student T-statistics= 2.227, p=0.08) with those treated with 5g. Similarly, leaf powder treated compared with control were not significantly different.