S15 - Session P2 - Phytosanitary practices in the market gardening area of Niayes, Senegal

Authors: Mamadou Diatte*, Babacar Labou, Serigne Sylla, Etienne Tendeng, Issa Alé Ndiaye, Serigne Omar Sene, Amadou Balde, Omar Seydi, Pape Diop, Karamoko Diarra

In sub-Saharan Africa, vegetable crops are an essential component of sustainable development. However, pests and diseases, particularly insect pests, are a major constraint to improving the productivity and quality of horticultural production. To limit crop losses, producers resort to chemical control, with potential drifts in the use of insecticides. The objective of this study is to assess the phytosanitary practices of producers in the Niayes zone. Surveys were conducted among producers on a total of 116 cabbage plots and 98 tomato plots in a north-south transect of the Niayes, from transplanting to harvest. The results show a significant variability between producers in the conduct of phytosanitary protection of their plots, with the number of insecticide treatments per plot ranging from 0 to 12 for a crop cycle (4 treatments on average). No difference was observed between cabbage and tomato crops. The average number of treatments was higher in the southern (4.5) and northern (4.2) zones than in the central Niayes zone (3.4). In the northern zone, almost half of the treatments are carried out with organophosphates (OPs), while they represent only 22% in the southern zone, where pyrethroids are used more (30%). The central zone is dominated by avermectins (21%). In the southern and central zones, a little more than 20% of treatments use binary (or even ternary) formulations, combining pyrethroids and neonicotinoids. Nearly one treatment out of ten combines two different formulations. The environmental impact (EIQ) of these practices was moderate on average (32), but highly variable (0-169) between plots. This study highlighted the state of phytosanitary practices of producers in the Niayes zone.