natural-products-in-plant-pest-management

Prospects of Large-scale Use of Natural Products 193very formidable success in their control attributes on both pests and diseasesin plants. The discovery of residues of synthetic pesticides in the food chainand their effect on the environment have led to agitation by environmentalists,ecologists and the Environmental Protection Agencies (EPA) worldwideto look inward for a better alternative in order to produce safe food foreverybody, and maintain a friendly environment. The natural productswhich can also be referred to as botanicals and their products have and willcontinue to play important roles in alleviating human suffering and alsocontrol the losses of farm products experienced in most developing countries(Edeoga and Eriata, 2001; Aworinde et al., 2008). Crop production andprotection are being supported by the use of botanicals in developing countriesin Africa and some third-world countries (Lale, 2007; Isman 2008).Researchers in Nigeria and some other African countries have investigatedseveral plant species for their efficacy as pesticides for protecting their cropsagainst pest degradation especially with the storage pests and diseases(Boeke et al., 2001; Ofuya et al., 2007; Olufolaji, 2008).Until recently, conventional pesticides had been used to curb these pestsand, in most cases, quite efficiently. However, the technicalities involved inthe formulation, standardization and distribution of the botanicals as pesticidesto reach the teeming population in the developing countries still remainproblems for their usage (Lale, 2007). There are the attendant problems ofresistance, environmental pollution, and adverse effect on health and climatechange traceable in part to the high levels of chloro-fluoro-carbon being usedas carriers in aerosol pesticides, which is affecting the ozone layer. This led tocaution in the continued use of persistent synthetic pesticides, especiallythose in the class of chlorinated hydrocarbons and the highly toxic organophosphoruspesticides (Olaifa, 2009).9.2 History of Natural Products in the Developing Countriesand their Use by Local Farming CommunitiesDeveloping countries have been endowed by nature with large quantitiesand diverse collections of many such natural products, which are more ofplant origin (botanicals). The population of inhabitants in developingcountries is fed by farm produce from the local peasant farmers. Thus themajor users of botanical pesticides are the local farmers who are less educated,very poor and most of them cannot afford the expensive syntheticpesticides.The tropical forests, characteristic of most developing countries, are theabode of naturally occurring genera and species of most of these botanicals.Over centuries, evolution of these botanicals has occurred to produce variousbiotypes that are in good use today as medicines and pesticides (Table9.2). A survey of the use of the botanicals in local farms revealed that around50% of about 500 peasant farmers in India and Pakistan who stored foodgrains for more than 6 months used neem (Azadirachta indica) leaves to get ridof storage pests, whereas the relatively affluent and better educated farmers