The paper “Optimal choice of cotton cultivar for rainfed conditions in Sahelo-Sudanian climate with late planting: a case study in Senegal“, published in The Journal of Agricultural Science, has been chosen as the latest Editorial Highlight and is freely available to download for one month. 

In Senegal, cotton is a major cash crop which is exclusively grown under rainfed conditions, mainly by smallholders and on small plots. Early planting is essential for good yields but unpredictable early rains and labor constraints make it difficult for farmers to plant at the right time, before July 10. Consequently, late planting is frequent and has a negative impact on yield. The cultivar widely used is not performing well under late planting. Therefore, the identification of alternative cultivars adapted to late planting date (from July 10) is crucial.

This study analyzed the interaction between cotton cultivars and planting dates on yield in order to provide a model that eases the choice of the best cultivar for early, late or any proportion of late planting at the country level.

Field experiments were conducted in 2018 and 2019 using a split-plot design with two planting dates and eight cultivars at three experimental stations. Robust analysis of yield was used to moderate the effect of potential outliers.

The average yield of the eight cultivars was 1404 kg/ha under early planting, and 714 kg/ha only under late planting. The loss due to late planting was significantly affected by cultivar choice. None of the cultivars outperformed the others under both early and late planting conditions. Therefore, the extension of two cultivars, CS 50 for early planting and IRMA Q302 for late planting is recommended. For cost and logistics reasons, if only one cultivar can be used in Senegal, a tool to support the choice of the best cultivar for any chosen proportion of early planting was provided.

The monetary income improvement to farmers that could be generated by the choice of new cultivars depends on the possibility of promoting either two cultivars, or only one cultivar (as is currently the case). In the case of two cultivars, when compared with the current cultivar, the cultivar CS 50 would be a suitable choice for early planting and IRMA Q302 for late planting. These could generate an expected gain of 14.6 €/ha for early planting farmers, and 68.8 €/ha for late planting farmers. In the case of only one cultivar, the optimal choice is cultivar CS 50, where the expected income drops to 21.5 €/ha for late planting farmers, but remains unchanged for early planting farmers. At the country scale, cultivar replacement would allow an additional production of 906 metric tons of cotton with two cultivars, and 560 metric tons with only one cultivar.

The Journal of Agricultural Science Editorial Highlights are selected by the Editor-in-Chief and are freely available for one month. View the recent selections here.