Pesticide risks from fruit and vegetable pest management by small farmers in sub-Saharan Africa. A review

Abstract

Chemical control has highly expanded over the last 30 years in sub-Saharan Africa to reduce bio-aggressors on all crops. Pest management of fruits and vegetables by small farmers in sub-Saharan Africa have developed anarchically in a fuzzy regulation framework. Pesticide toxicity and excessive application are often criticized both by farmers and consumers. Here, we review pesticide management in sub-Saharan Africa over the past 30 years. We then propose options to improve and reduce pesticide application, in order to decrease environmental and human hazards. The major points are as follows: (1) global changes in sub-Saharan Africa such as urbanization modify farmer practices and crop losses. (2) Pesticides are more and more used by small farmers in an unsustainable way. (3) The risk of pesticide application for human health and environment is poorly known. (4) We propose options to reduce pesticide application based upon integrated pest management (IPM) and agroecology. Moreover, IPM increases farmer economy, thus decreasing poverty. (Résumé d'auteur

High environmental risk and low yield of urban tomato gardens in Benin

“…Some data were not available in reviewed papers (na) of the persistence period, e.g., 20 days for pyrethroids. This result agrees with records on a weekly frequency of insecticide applications and validates the assumption of preventive practices (de Bon et al 2014). The highest TFI shown by early cropping systems with manual irrigation and water from drilling (TFI=25) resulted from frequent applications at excessive rates per application, i.e., one treatment every week at 2.3-fold the official rate.…”

“…In practice, we divided the amount of active substance applied by its official rate (E-phy 2013). European approved rates were used because of their availability for a large range of active substances and can be considered valid for our case study as pesticide recommendations in Africa were based on developing countries regulations (de Bon et al 2014). This indicator allowed us to compare pesticide uses regardless of the nature of the product or the number of actual applications.…”

“…In addition, our results suggested that the most intensive crop protection practices were not associated to better yields. Among many causes identified for poor pesticides practices (de Bon et al 2014), the unsuitability of the product to the problem source is of particular importance for tomato urban gardens in Benin. We also noticed that high TFI were often associated to active substances with low official rates, i.e., pyrethroids, thiophanate methyl, maneb, mancozeb, terbufos, and carbofuran.…”

“…According to a recent review, most vegetable growers in sub-Saharan Africa and the totality of Beninese ones apply pesticides. Moreover, pesticide use is expected to increase due to urbanization, the prevalence of the informal sector and climate change (de Bon et al 2014). The few studies analyzing pesticide use in such contexts suggested poor pesticide practices, i.e., frequent treatments with large rates of unsuitable active substances with respect to the target pest (Rosendahl et al 2009;Ahouangninou et al 2012).…”

“…The few studies analyzing pesticide use in such contexts suggested poor pesticide practices, i.e., frequent treatments with large rates of unsuitable active substances with respect to the target pest (Rosendahl et al 2009;Ahouangninou et al 2012). In Benin for example, a clear identification of the pests is not part of the key factors influencing the use of pesticides by the farmers (de Bon et al 2014). Regarding fertilizers, large quantities of nutrients in the form of chemical fertilizers and livestock manure are applied to urban gardens Sangare et al 2012).…”