New challenges for sunflower ideotyping in changing environments and more ecological cropping systems

As a rainfed spring-sown crop, sunflower (Helianthus annuus L.) is increasingly exposed to negative impacts of climate change, especially to high temperatures and drought stress. Incremental, systemic and transformative adaptations have been suggested for reducing the crop vulnerability to these stressful conditions. In addition, innovative cropping systems based on low-input management, organic farming, soil and water conservation practices, intercropping, double-cropping, and/or agroforestry are undergoing marked in agriculture. Because of its plasticity and low-input requirements (nitrogen, water, pesticides), sunflower crop is likely to take part to these new agroecological systems. Aside from current production outputs (yield, oil and cake), ecosystem services (e.g. bee feeding, soil phytoremediation…), and non-food industrial uses are now expected externalities for the crop. The combination of climatic and societal contexts could deeply modify the characteristics of genotypes to be cultivated in the main production areas (either traditional or adoptive). After reviewing these changes, we identify how innovative cropping systems and new environments could modify the traits classically considered up to now, especially in relation to expected ecosystem services. Finally, we consider how research could provide methods to help identifying traits of interest and design ideotypes.