Management alternatives for improved durum wheat production under supplemental irrigation in Syria

摘要

In a field trial between 1992/93 and 1995/96 on a deep clay soil at Tel Hadya, N. Syria, durum wheat cv. Cham 1, Cham 3, Lahn and Omrabi 5 were sown in mid-November (early), mid-December (normal) or mid-January (late), were not irrigated, or given one or two thirds or total supplemental irrigation (SI, irrigation to avoid water stress), and were given 0, 50, 100 or 150 kg N/ha. Delaying sowing from November to January reduced yields and response to both SI and N. With irrigation, crop responses were generally significant up to 100 kg N, whereas the optimum response for rainfed conditions occurred with 50 kg N. Yields increased with increasing irrigation, but almost maximum yields were obtained with two thirds of full SI. Water and N use efficiencies were greatly increased by SI, with little variation among cultivars. However, irrigation and delayed sowing decreased grain protein levels, which were partially compensated for by added N. A similar effect was observed for kernel vitreousness. It wasconcluded that, in most growing seasons, minimum irrigation during the winter growing season, combined with appropriate fertilizer application, can enhance wheat output and yet maintain grain quality.