APPLICATION OF A CROP GROWTH-MODEL (SUCROS-87) TO ASSESS THE EFFECT OF MOISTURE STRESS ON YIELD POTENTIAL OF DURUM-WHEAT IN ETHIOPIA

A spring wheat growth model (SUCROS-87) was used to identify moisture stress periods during the growing seasons and simulate yield potential s of durum wheat (Triticum turgidum var. durum) in six durum wheat gro wing regions of Ethiopia. The start of the rainy season and distributi on of rainfall were erratic, particularly in the low-altitude regions. As a result, simulated dates of emergence varied from June to August. Moisture stresses of various intensities, at different growth stages of the plant, were limiting to durum wheat production in all the regio ns except Debre Markos. Terminal moisture stress was simulated in 7 ou t of 10 years in all locations except Debre Markos, whereas intermitte nt stress was simulated in three locations in 2 out of 10 years. In Me tahara rain-fed durum wheat production is not feasible without irrigat ion. Water use efficiency decreased with decreasing rainfall but the t ranspiration coefficient increased. The aver age simulated potential g rain yields at all the locations were high (6600 kg ha(-1)) compared w ith the actual national average. Development of versatile and region-s pecific improvement strategies are emphasized to improve durum wheat p roduction in the country.