Above and Belowground Plasticity Traits Allow Safflower ( Carthamus tinctorius L.) Cultivation Under Low‐Input Water Management in Three Mediterranean Environments

Biofuels can play an important role to reduce fossil fuels consumption and decrease carbon dioxide emissions. However, current biofuels derived from food crops can exacerbate food security concerns due to their competition for cropland and resources. Second‐generation biofuels obtained from non‐food crops can represent a promising opportunity to overcome this conflict. Safflower ( Carthamus tinctorius L .), an under‐utilised crop (UUC), shows promise for biofuel production due to its oil properties and resilience in extreme/unsuitable environments. In this study, we evaluated the response of two safflower genotypes CWL990L (CWL) and Oscar (OS) under two different water treatments: well‐watered (100% of ETc) and half‐watered (HW) (50% of ETc) across three locations in Southern Italy. CWL maintained high shoot biomass, seed yield and oil yield under HW conditions in the two deepest soils, whereas OS showed reductions up to 75% and 62% in biomass and seed yield, respectively. CWL had a reduced relative water content by only 6% (vs. 20% in OS), increased leaf mass per area by 26%, and developed a root system with 70% steeper root angle. In contrast, OS showed a much more limited plasticity in these traits. However, we observed significant variations in productivity across locations due to the different pedoclimates. In conclusion, safflower holds great potential as a sustainable biofuel feedstock. These results also demonstrate that resilient genotypes that require moderate agronomic inputs can maintain good yields while adapting to diverse environmental conditions.