Characteristics of Water Use and Dry Matter Accumulation and Distribution inDifferent High-yielding Wheat Cultivars under Supplemental Irrigation Basedon Soil Moisture

Abstract

Water shortage is a serious problem threatening sustainable agricultural development in the North China Plain, where winter wheat(Triticum aestivum L.) is the largest water-consuming crop. The objective of this study was to guide wheat production in this area by selecting high water efficient cultivar and improving irrigation regime. In a two-year field experiment from autumn of 2007 to summer of 2009, irrigation quantum was controlled based on testing soil moisture(SM) in 0–140 cm depth,which was designed in low(SM of 65% at jointing and 55%–60% at anthesis stage), medium(SM of 75% at jointing and65%–70% at anthesis stage), and high(SM of 75% at jointing and 75% at anthesis stage) levels. Water use efficiency(WUE), dry matter accumulation and distribution in wheat plant, and grain yield were tested and compared among 14 commercial cultivars.Based on grain yield and WUE, the 14 cultivars were clustered into three groups, namely, super-high yield and high WUE group(I), super-high yield and medium WUE group(II), and high yield and low WUE group(III). One representative cultivar was selected from each group to compare the amount and proportion of water consumption during sowing–jointing, jointing–anthesis,and anthesis–maturity periods. Shannong 15 from group I had significantly lower water consumption from sowing to jointing than Jimai 22 from group II and Yannong 21 from group III, and significantly higher water consumption from jointing to anthesis.However, water consumption amount and proportion had no significant differences among the three cultivars from anthesis to maturity. Under medium SM condition, soil water consumption in Shannong 15 was significantly higher than that in Jimai 22 and Yannong 21, but such advantage in Shannong 15 disappeared under high SM condition. Under medium and high SM conditions,translocation amount and ratio of dry matter accumulated before anthesis and its contribution to grain were significantly higher in Shannong 15 than in Jimai 22 and Yannong 21. Among the three cultivars, harvest index was the highest in Shannong 15, the medium in Jimai 22, and the lowest in Yannong 21.