In view of the recently increased interest in developing botanical pesticides as an alternative to synthetic pesticides, this investigation was carried out to examine the insecticidal potentials of the Zanthoxylum Zanthoxyloides (Lam.) Waterm. (Rutaceae) Root Bark Powder against Seed Beetle, Callosobruchus 0 maculatus (F.). The experiment was carried out at ambient temperature of 28±3 C and relative humidity of 68±3% in the laboratory. Population suppression activities of Z. zanthoxyloides Root Bark Powder against Seed Beetle was recorded at 5, 7 and 10 g/150 g cowpea grains laid out in completely randomized design replicated four times including the untreated control. Plant products applied at rates greater than 20% of the grain weight would not be economically viable in suppressing the population of insect pests. The root bark powder was applied to assess contact adult mortality, adult emergence, percentage weight loss and percentage grains damaged. Application rates of Z. zanthoxyloides were found to possess insecticidal activity against adult seed beetle. Topical application of the root bark powder caused significant (P<0.05) increase in adult mortality, reduced adult emergence, reduced weight loss of the grains and offered protection of cowpea grains against damage in small scale storage. Highest rate of treatment significantly increased adult mortality of C. maculatus compared to lower rates at 2 DAT. From the results, it could be concluded that the adults of C. maculatus were susceptible to Z. zanthoxyloides root bark powder. On the whole application of the plant material was better than no treatment at all. Such findings would be helpful in promoting research aimed at the development of new agents for C. maculatus control. The plant powder could also, be incorporated in Integrated Pest Management approach against C. maculatus in storage.

No abstract

This study was conducted to evaluate the impact of the population dynamics of species of flea beetle on Okra (Abelmoschus esculentus (L) Moench) production in FCT Abuja. The experiment was conducted at the Teaching and Research Farm, University of Abuja, Abuja. The treatments comprised of four different plant spacing of 50cm x 30cm, 50cm x 35cm, 50cm x 40cm and 50cm x 45cm. The two species of flea beetle encountered in the study (Monolepta goldingi and M. nigeriae) were recorded from 3 Weeks after Planting (WAP). The population of M. goldingi recorded was higher than M. nigeriae in the entire plot and throughout the duration of the experiment although the population of both remained high throughout the vegetative stage than the reproductive phase of growth of okra. Also, it was observed that the closely spaced plants had more pest infestation than wider spaced plants. The difference in the plant spacing has significance on the insect count and its population has significant reduction (P < 0.05) in fruit production, branching and Days to Flowering. The best fruit yield was obtained on the plot with plant spacing's of 50cm x 40cm, which yielded 11.84 fruits.

No abstract

Aqueous leaf extracts of two naturally growing plants inNigeria viz: Vernonia amygdalina and Ocimum gratissimum were admixed with maize grains infested with maize weevil, Sitophilus zeamais Motsch. in the laboratory at 30±3 0 C and 75±2% relative humidity. The plant extracts showed efficiency against the test insect with respect to adult mortality, larval and progeny emergence and percentage grain damage. Adult mortality was highest (88.9%) in maize grains treated with 3% (v/w) of the leaf extracts 3 days post treatment. It was observed that leaf extracts of V. amygdalina and O. gratissimum applied at 3% per 30 g maize grains caused significantly higher (P<0.05) adult mortality than the 1% rate of treatment during storage. There was significant difference in the rates of treatment of V. amygdalina causing grain damage compared to the control. The results suggest the ability of using these plant extracts for maize protection against maize weevils with V. amygdalina showing greater potential.

No abstract

To combat the problem of food scarcity and insecurity in areas affected by salinity, crop varieties that are tolerant to the stressful conditions should be selected and used. Therefore, this study was carried out to investigate and know the effects of salinity stress on growth and yield of three cowpea cultivars to select the best salinity tolerant cultivar for optimum yield production. To achieve this, three separate experiments were concurrently carried out using ITIOK-298-15, IFE BROWN and SAMPEA 11 cowpea cultivars in the glass house of the Faculty of Agriculture, University of Ilorin, Nigeria. The salinity levels tested in each of the cultivars were 0mM (the control), 50mM, 100mM and 200mM sodium chloride (NaCl). The imposition of salinity stress was for a period of two weeks at maturity because this stage is the most sensitive stage for any crop grown under any environmental stress. The experiments were laid out in randomized complete block design (RCBD) with four replications. Data collection was centred on root length, plant height, number of leaves, leaf area, dry mass, final yield, chlorophyll content of leaves, crude protein and crude fat contents. From this work, it was found that 200mM NaCl decreased the final yield by 51% in ITIOK-298-15, 73% in IFE BROWN and 100% in SAMPEA-11 compared to the control. Furthermore, 100mM NaCl reduced crude protein contents of the leaves by 6% in ITIOK-298-15, 10% in IFE BROWN and 17% in SAMPEA-11 compared to the control. From the above results, it was found that ITIOK-298-15 was the most tolerant cultivar while SAMPEA-11 was the most susceptible cultivar to salinity stress. It is, therefore, recommended (subject to further confirmation) that ITIOK-298-15 cultivar, which is the most promising cultivar of the three cultivars experimented, be used in cowpea production in saline environments of the Southern Guinea savannah ecological areas of Nigeria.