Crop simulation models are part of the modern tools used for improving agricultural production performance. An application exercise of the DSSAT CROPGRO-cowpea model was carried out at two locations in Burkina Faso with the aim of contributing in enhancing agricultural practices for better yield of cowpea, through a seasonal analysis of the grain yield over 33-year period. The objectives were to (i) determining the optimum sowing window of cowpea varieties through a seasonal analysis of the grain yield at Kamboinsin and at Kouare, (ii) analysing the performance of Plant Production Department, Institute of the Environment and Agricultural Research of the DSSAT model in yield simulation in various environment. Simulations of the grain yield were performed using ten (10) sowing windows during the 33-years of experiment. The results showed that sowing period and the location affect the grain yield. For all the varieties (Gorom local, KVx396-4-5-2D, Moussa local and Tiligre), the highest grain yield was registered when sowing was done in early May. Mid-May to early June sowings lead to acceptable yields. Irrespective to the variety, late sowing (late June to late July) result in the lowest yields ranging between 980-327 kg
ha-1 at Kamboinsin and 554-443 kg ha-1 at Kouare. The best optimum recommendable sowing window in cowpea production is early May, followed by mid-May to mid-June. Producing cowpea at Kamboinsin results in higher average grain yields than at Kouare. The DSSAT model can be considered as an efficient tool for simulating cowpea
grain yield in various environments at different planting periods.

DSSAT model; Cowpea,; Sowing window,; Grain yield