Evaluation des pratiques phytosanitaires en agriculture urbaine et périurbaine à Lubumbashi : Etat de lieu et perceptions des risques

Abstract

In Lubumbashi, urban and periurban agriculture is one of the means of survival for many households in a city where population growth and the unemployment rate are worrying. Chinese cabbage (Brassica Chinensis L.), which is usually grown in monocropping, attracts pests that cause enormous damage and important economic losses. In order to assess phytosanitary practices and their associated risks, a research based on an interview survey associated with observations and experimentation was carried out in five sites of the farming perimeter of Lubumbashi. Jointly to three approaches, a simulated treatment with fluorescein was carried out to assess the level of exposure of operators to pesticides. The UK POEM model was used to estimate operator exposure to two active substances used and found to be highly toxic (dichlorvos and lambda-cyhalothrin). The results of the survey showed that the proportion of women as well as older men decreased among vegetable gardeners in Lubumbashi. The majority of vegetable farmers (66%) surveyed consider black worms (Agrotis ipsilon) as the main pest and more damaging in Chinese cabbage crop. To protect the crop, 86% of producers use pesticides, which make up 5% of production costs. Even if the pesticides are applied at doses twice lower than those recommended, applicators do not wear PPE and 76% spray under risky conditions with buckets and brooms that promote waste and poor distribution of the spray mixture on the treated culture. These alarming conditions of work potentially expose operators to the risks associated with immediate symptoms such as eyes irritation (76%), skin (52%) and headaches accompanied by the common cold. The exposure values estimated by the UK-POEM model for operators are respectively 0, 345050133 mg / kg ˃ 0. 0005 mg / kg AOEL of dichlorvos and 0.022700667 mg / kg ˃ 0.00063 mg / AOEL of lambda-cyhalothrin. This creates an unacceptable level of risk for operators. Fluorescein deposits have shown that the hands, back, arms, thighs, tibia and feet are the most exposed parts of the operator's body but differently depending on the spraying equipment used. Environmental risks mainly concern poor management of packaging and destruction by pesticides of non-harmful living organisms (crop auxiliaries, earthworms, etc.). Production of Chinese cabbage allows earning € 1.04 per working day, which is less than the $ 1.25 corresponding to the poverty line in the DR Congo, and very low in terms of the risks incurred by farmers.