What kind of cotton ideotype is adapted to agroecological cropping systems and climate change in Benin?

Abstract

Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton (Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertility. A study was conducted in Benin from 2020 to 2023 to compare six different cotton cultivars in three agroecological cotton based cropping systems in two cotton growing zones. Plough based Tillage plus Incorporation of cover crop biomass (PTI), Conservation Agriculture with Strip Tillage (CA_ST) and Conservation Agriculture with No Tillage (CA_NT) was compared with the reference Plough based Tillage (PT). The objective was to identify morpho-physiological traits that increase yields in agroecological cropping systems in an approach combining field experimentation and Crop Simulation Modelling (CSM) of CROPGRO-cotton to evaluate the effects of Genotype (G) x Environment (E) x Management (M) interactions on seed cotton yields. Results: Results showed that cultivars Tamcot_camde and Okp768 performed best in CA systems. Traits such as high seed mass, large and thick leaves, and longer maturity were identified as beneficial for yield enhancement in CA systems. Cultivars and ideotypes that combine these traits have better nitrogen and water use efficiencies in CA systems. Under different climate scenarios up to 2050, ideotypes were designed that could increase seed cotton yields by 3% to 172% in Benin. Conclusion: A set of morpho-physiological traits associated with vegetative vigour is required to ensure a good seed cotton yield in agroecological cropping systems. These results provide useful knowledge and scientific evidence for breeders and research programmes on cropping systems focused on the adaptation of cotton to climate change.