Chapters authored
Farmer’s Perception of Associates Non-Cocoa Tree’s Leaf Litterfall Fertilizing Potential in Cocoa-Based Agroforestry System
Investigations to assess farmer’s perceptions on the fertilizing potential of associated trees species in cocoa agroforest of degraded forest ecology were carried out in southern Cameroon. The perception of the farmers was based on the ability of the trees to maintain or improve soil fertility of their farms. The verification of these perceptions was done through an evaluation of litter fall biomass nutrient content (N, P, K, Ca and Mg) of selected trees. The top 5 associates trees ranked by farmers was: Milicia excelsa, Ceiba pentandra, Ficus mucuso, Asltonia boonei, Terminalia superba. The chemical analysis of the leaf litter from the different tree species revealed a significant different between their chemical components. N appeared to have the highest concentrations varying from 2.82 to 5.57% with a mean value of 4.25 ± 1.065%, P had the lowest concentrations typically around 0.001%. The top 5 tree species based on the chemical analysis ranking were: C. pentandra, M. excelsa, Eribroma oblungum, Alstonia boonei, Zanthoxylum heitzi. Farmer’s perceptions thou holistic, are not completely different from scientific finding. Therefore, they should be taken in consideration in management plans for cocoa- based systems in order to enhance their ecological and economic performance.
Part of the book: New Generation of Organic Fertilizers
Use of Biological and Chemical Pesticides in Agricultural Production: What Fate for Entomopathogenic Fungi?
In the context of integrated pest management, the compatibility between the products used and even with the natural enemies of crop pests should still be elucidated. In this study, interviews were done with about 60 coffee growers to assess the use of pesticides in the protection of coffee berries. Then, in vitro tests were used to evaluate the effects of extracts of the seed powders of Thevetia peruviana, Azadirachta indica, the chlorpyriphos-ethyl insecticide and the chlorothalonil + dimethomorph fungicide, on the development parameters of the entomopathogenic fungus Beauveria bassiana, the natural enemy of the coffee berry borer, Hypothenemus hampei. The said tests consisted of the method of poisoning the culture medium with pesticides, observation and counting of spores under the optical microscope. The analysis of the collected data showed that depending on the type and severity of the pest pressure, growers apply several types of mainly chemical pesticides. Among the pesticides tested, extracts of T. peruviana, A. indica and chlorpyriphos-ethyl considerably reduced the development of B. bassiana. These results show that in crop protection, the use of biological or chemical substances should be done in a judicious way, to ensure the conservation and the valorization of natural enemies of phytosanitary pressures.
Part of the book: Insecticides