Effect of plant diversification on pest abundance and tomato yields in two cropping systems in Burkina Faso: farmer practices and integrated pest management

Son, Diakalia [Université Nazi Boni (UNB), Institut du Développement Rural (IDR), Unité Santé des Plantes du Laboratoire] Somda, Irénée [Université Nazi Boni (UNB), Institut du Développement Rural (IDR), Unité Santé des Plantes du Laboratoire] Legrève, Anne [UCL] Schiffers, Bruno [Gembloux Agro-Bio Tech/ULIEGE, Laboratoire de Phytopharmacie Passage des Déportés 2, 5030 Gembloux, Belgium.]

In Burkina Faso, pests are the main constraint to tomato production because they can cause a complete loss of yields. To protect their crops, producers use extensively chemical pesticides. However, this method can be ineffective and creates collateral effects on public health and on environment. To mitigate this problem, Integrated Pest Management (IPM) trials based on tomato crop in association with basil, garlic or onion were compared with the usual practices of producers in field trials in 2017. The tomato-onion association provided both the best protection of the fruits and the highest yield (3 kg / m²) compared with peasant and other IPM practices. No pesticide residue was detected in samples (tomatoes and soils) from IPM practices. However, several active substances (profenofos, lambda-cyhalothrin and chlorpyrifos-ethyl) were detected in samples from farmers' practices. Only chlorpyrifos-ethyl showed a residue level above its Maximum Residue Limit (MRL) in tomatoes (360% of MRL), without acute intoxication risk for consumers according to the calculations of the Predictable Short Term Intake (PSTI). Awareness-raising and producer training on the better agricultural and phytosanitary practices are necessary to protect public health and environment against adverse effects of pesticides in Burkina Faso.