Agronomic and Phytosanitary Determinants of Cotton Yield in C？te d’Ivoire: A Five-Year Multi-Site Analysis (2021-2025)

Cotton (Gossypium hirsutum L.) is a strategic cash crop in C？te d’Ivoire, yet substantial yield variability continues to constrain productivity under smallholder farming conditions. This study aimed to identify and quantify the principal agronomic and phytosanitary factors associated with cotton yield variation across the Ivorian cotton belt. We monitored 2693 farmer-managed cotton plots over five consecutive cropping seasons (2021-2025) in 59 localities distributed along a latitudinal gradient from 7.02？N to 10.49？N. Recorded variables included sowing date, variety, cultivation type, previous crop, and pest infestation levels. Descriptive summaries were established for the full monitored dataset, whereas non-parametric analyses (Kruskal-Wallis tests, Dunn’s post-hoc comparisons, and Spearman correlations), Principal Component Analysis, and multiple regression were applied to an analytical subset of 1514 plots with non-zero yield and complete information for the variables analyzed. Within the monitored dataset, mean seed cotton yield was 1146.25 ± 314.18 kg/ha, with a median of 1115.00 kg/ha. Year was the strongest determinant of yield (η² = 0.23), followed by cultivation type (η² = 0.13). Animal traction was associated with substantially higher yields than manual cultivation (1167 vs. 899 kg/ha; p < 0.0001). Early sowing (May 21 - June 20; D1 - D3) improved yield by 15% - 20% relative to late sowing (July 1 - 20; D5 - D6). Among phytosanitary variables, jassids exhibited the strongest negative association with yield (ρ = ？0.28; p < 0.0001), and PCA indicated that jassid pressure was the dominant axis structuring pest-related variation. Cotton yield in C？te d’Ivoire is shaped primarily by inter-annual environmental variability, cultivation practices, and jassid infestation. The results support the promotion of animal traction, timely sowing, and strengthened jassid management as practical levers for improving productivity in smallholder cotton systems.