Abstract: In wheat (Triticum aestivum L.) high-yielding and high-quality production, a great attention has been gradually paid to the effects of environment and cultivation technique. Currently, many reports on the stability of yield and quality give different results and conclusions due to different cultivars and environments in different experiments. In this study, field experiments in 2005–2006 growing season were carried out in seven provinces with seven strong-gluten cultivars under four irrigation regimes to give further explanation on this topic. Grain yield and protein content in grains were evaluated at maturity. The results showed that the highest grain yields were obtained with no significant difference in the treatment of 3 irrigations (at emergence of the 2nd spring-leaf, emergence of the 5th spring-leaf, and anthesis, respectively, 600 m³ ha^-1 per irrigation) and 4 irrigations ( the above 3 irrigations plus 1 irrigation at grain-filling) with rainfall below the average. The grain yield in all the seven experimental sites showed an increasing trend with the increase of irrigation times and quantity, and the differences among eco-environments were also shortened. The effect of irrigation was larger in sites with lower “environmental index”, indicating that irrigation could strengthen the yield stability of strong-gluten wheat in different environments. Cultivars with higher environmental index had smaller variation coefficients(CV) of grain yield. The protein content was significantly different among irrigation treatments. The average protein content decreased with the increase of irrigation times, expect for Renqiu site in Hebei province where the rainfall was extremely scarce (43.9 mm in the growing season). The protein content in the same cultivar varied obviously in different sites, but showed better stability in cultivars with smaller CV values. It suggested that the ecological factors affect protein content greatly in wheat.

Key words: Strong-gluten wheat, Irrigation, Grain yield, Protein content, Stability