The Impact of Drought Stress on Common Bean Landraces ( Phaseolus vulgaris L.) in Mediterranean Environment: Agronomic Performance and Tolerance to Stress Evaluation

ABSTRACT Drought events represent an ever‐growing concern in Mediterranean areas. The occurrence and intensity of this abiotic stress can variously affect the growth and productivity of common bean. In order to shed light on the impact of the drought stress on the growth and agronomic performance of the crop, forty‐four landraces and two testers were grown under stress and non‐stress conditions. The water deficiency started on the onset of the reproductive phase. The experiment was carried out as a split‐plot design over a period of 2 years. The effect of the drought stress on the common bean landraces was assessed by analysing the results of the grain yield and its components, which were significantly affected by the water availability ( p ≤ 0.001). Drought tolerance indices were then calculated based on the grain yield results to further investigate the effect of the water deficiency on the crop phenology and productivity, and to identify drought‐tolerant genotypes. Six landraces with climbing habitus were identified as the most drought tolerant; two dwarf landraces showed low yield depression and low susceptibility to drought. These drought‐resistant candidates could be used to maintain the traditional cultivation of common bean in areas exposed to limited water availability in Southern Italy and other territories with similar climate conditions.