Evaluation of Yield and Quality of Sorghum and Millet as Alternative Forage Crops to Corn under Normal and Deficit Irrigation Regimes = تقييم إنتاجية و نوعية الذرة البيضاء و الدخن كبديل عن علف الذرة الصفراء تحت احتياجات نظامي الري العادي و المتناقص

Abstract

Two field experiments were conducted to evaluate the possibility of increasing diversity of winter cereals- based double cropping systems and their responses to deficit irrigation. In experiment 1, forage yield and quality of three corn hybrids, three sorghum cultivars and three species of millet (foxtail, common and pearl millet) were evaluated. Based on the results obtained from experiment 1, corn hybrid S.C. 704, sorghum cultivar Jumbo, and pearl millet were selected for further investigations. In experiment 2, the effects of irrigation treatments of I100, I75 and I50 (providing 100%, 75%, and 50% of the corn estimated water requirement, respectively) were investigated on selected crops. Sorghum showed higher drought tolerance, but produced lower yield than pearl millet and corn, except at I50. The highest dry forage yield in I100 was produced by corn followed by pearl millet. A reduction of 25% in the amount of irrigation water reduced the yield of corn, sorghum and millet by 28, 13 and 24%, respectively. Corn had the highest value of digestibility and relative feed value (RFV). Deficit irrigation led to a rise in crude protein (CP) and acid detergent fiber (ADF) content, and caused significant reductions in digestibility and RFV values in the three crop species. Results indicated that pearl millet and sorghum could be considered as reasonable alternatives to corn in a double cropping system under moderate and severe deficit irrigation conditions, respectively.