Yield and Water Use Efficiency of Durum Wheat Cultivars under Different Sowing Dates and Water Regimes

This study aims at understanding the best management practices to improve water use efficiency of durum wheat, a strategic crop for the Mediterranean region. A field work was carried out at the experimental fields of Mediterranean Agronomic Institute of Bari (IAMB) in Valenzano (Southern Italy), to investigate the performances of two cultivars (Vendetta and Pietrafitta) of durum wheat when grown under the combined effects of two sowing dates (December and February, reported respectively as winter and spring cultivation) and three different water regimes (full irrigation, deficit irrigation with 50% of full irrigation supply, and rainfed). The responses in terms of growth, yield and yield quality and water use efficiency have been studied. The results demonstrated that both sowing practices gave very good yield, in terms of quantity and quality, especially when full irrigation was applied. The winter wheat cultivation resulted in greater yield water use efficiency (WUEy) than the spring wheat cultivation. 'Vendetta' was more productive than 'Pietrafitta', the latter was less adapted to spring cultivation and water stress. Full irrigated wheat provided the highest yield, but lower WUEy in respect to defici irrigated wheat. Favorable climatic conditions during the winter season supported a reasonable level of yield and high WUEy for rainfed crops sown in winter. Spring cultivation of wheat requires irrigation. Deficit irrigated wheat had the highest WUEy, showing that the use of non-optimal (supplemental) irrigation is a good strategy to improve yields of durum wheat in semi-arid areas and save water.