No abstract

Objective: The in vitro and in vivo effects of seed extracts of Thevetia peruviana (Apocynaceae) on the growth and the germination of spores of Phytophthora megakarya causal agent of black pod of cocoa was evaluated. Methodology and results: Five extracts obtained by soxhlet apparatus (extracts of hexane, ethyl acetate, acetone, methanol and aqueous extract) were used. One fungicide (Ridomil ® gold plus) served as control reference. Five strains of P. megakarya (Mbal 121, Ngoke 111, Nom121, Mbal 212, njo111) were tested. Three concentrations of extracts (6.25, 12.5 and 25 l/ml) and one concentration of fungicide were used in V8 medium. Detached fruit bioassay was performed. Spores of five strains of P. megakarya were inhibited by methanolic and acetonic extracts of T. peruviana with an inhibition percentage ranging from 99-100 %. Thus, the smallest concentration of extract is capable of acting on the germination of spores of the fungi. Only hexane extract did not inhibit the growth of strains. Methanol extract reduced the growth from 60 to 100% at 25 l/ml. The detached fruits bioassays demonstrated the effectiveness of extracts on plant tissue when inoculated with P. megakarya zoospores. Conclusion and application of findings: Statistical analysis shows that methanol and acetone extracts are as effective as the tested fungicide on the growth and germination of zoospores, aqueous extract are effective as Ridomil ® on growth on the black pod disease of cocoa. These extracts could be used in the integrated pest management strategy of the plant pathogens tested.

Some insects cause high losses of the common bean during storage, namely, <i>Acanthoscelides obtectus</i> Say. Chemical insecticides are commonly used to control insects, but their overuse adversely affects the environment and consumers' health. There is, therefore, the need for an alternative control method. This study was aimed to evaluate the chemical characterization and insecticidal property of <i>Moringa oleifera</i> seed extract on the developmental stages of <i>A. obtectus</i> in stored beans. Three types of <i>M. oleifera</i> seed extracts, namely methanol, ethanol and acetone extracts, were used at doses of 12.5, 25 and 50 µl/ml each. HPLC-MS was used to characterize these extracts. The toxicity of extracts against the adults, the number of eggs and the viability rate of laid or emerged eggs of <i>A. obtectus</i> were evaluated. The results show that <i>M. oleifera</i> seed extract is rich in Hesperidin, Quinic acid, gallic acid, protocatechuic acid, 4-OH benzoic acid, cynaroside, isoquercitrin, cosmosiin, quercitrin, luteolin, naringenin, salicylic acid, Apigenin and Fumaric acid. The acetone extract, from day 2, showed a 100% mortality rate in all doses compared to about only 14% in the control treatment. The number of eggs laid in control (236.67) was higher than the null (0) in acetone treatment at 50 µl/ml. M. oleifera seed extracts contain chemical molecules. They significantly reduced the damage caused by <i>A. obtectus</i> on stored <i>P. vulgaris</i> grains. Therefore, they can be used as an alternative to chemicals for the protection of stored foodstuffs.

No abstract

Maize is a major crop grown and consumed in the world and it requires a high fertilizer input. Although chemical fertilizers are an important input to get higher crop productivity, they have an impact on soil fertility, environment and human health. A field study was carried out to find alternatives to the mineral fertilization of maize. The aim of this study was to determine the influence of fertilizers on maize growth and yield while evaluating economic profitability. Four treatments (control, compost, poultry manure and mineral fertilizer NPK 20-10-10) and two maize varieties (local variety and improved variety CMS 8704) were used in a split-plot design with four replicates. Physicochemical analyses of soil and organic fertilizer were determined. Growth parameters, yield and acceptability index were evaluated. As results, poultry manure and compost are rich in nitrogen and phosphorus. At 9 weeks after sowing (WAS) the best stem diameter was obtained by the local variety in the plots fertilized with mineral fertilizer (2.83&plusmn;0.31 cm). The yield of the CMS 8704 variety was significantly higher in the plots fertilized with poultry manure (2.23 t ha-1) than the yield of the local variety in the control plots (1.16 t ha-1). Principal component analysis (PCA) shows that compost and poultry manure were characterized by an increase in growth parameters as well as mineral fertilizer NPK. Poultry manure had the highest acceptability index of 1.25. In view of these results, it is clear that organic fertilizers; especially poultry manure, would have a positive impact on increasing maize production.