Optimization of Mineral Fertilization of Cotton (Gossypium hirsutum L.) under Late Sowing Conditions in the Countries of the Regional Program for Integrated Cotton Production in Africa (PR-PICA)

Late sowing of cotton is an increasing constraint in West and Central African countries due to irregular rainfall, which reduces the length of the growing cycle and limits the effectiveness of mineral fertilization. This study aimed to determine the most efficient and cost-effective mineral fertilization strategy for cotton cultivation under late-sowing conditions in the countries of the Regional Integrated Cotton Production Program in Africa (PR-PICA). Trials were conducted during the 2023 and 2024 cropping seasons at ten experimental sites in Benin, Burkina Faso, Mali, and Senegal using a randomized complete block design with four replications. Four treatments were compared including a control with no fertilization (0% FMR), the recommended dose (100% FMR: 200 kg ha⁻¹ of NPKSB + 50 kg ha⁻¹ of urea), 75%, and 50% of this dose. Agro-morphological parameters, yield components, seed cotton yield, and the benefit/cost ratio were evaluated. The results show that application of mineral fertilization significantly improves plant growth, the number of bolls per hectare, and seed cotton yield compared to the unfertilized control. However, no significant difference was observed between doses of 100%, 75%, and 50% of the recommended mineral fertilizer for seed cotton yield. Country and year effects were significant for most of the variables studied, reflecting the influence of soil and climate conditions on crop performance. The economic analysis indicates that 50% of the recommended mineral fertilizer dose offers the best economic efficiency by reducing the fertilization costs with no significant effect on seed cotton yield. These results show that under late sowing conditions, applying 50% of the recommended mineral fertilizer is an agronomically effective and economically advantageous strategy. This mineral fertilization dose represents a relevant option to improve the profitability of cotton cultivation while limiting input costs under late sowing conditions in PR-PICA member countries.