Effects of Irrigation and Precision Planting Patterns on Photosynthetic Product of Wheat

Winter wheat (Triticum aestivum L.) is characterized by a high tillering capacity and disadvantageous spatial structures, which may result in intraspecific competition. This study aimed to determine whether tiller productivity, radiation use efficiency (RUE), and grain yield of winter wheat could be manipulated through irrigation and precision planting patterns in North China. The experiment was conducted during winter seasons of 2011/2012, 2012/2013, and 2013/2014 at Tai'an, Shandong Province, China. The field experiment was based on a two-factor split-plot design with three replications under the same plant density (200 x 104 ha(-1)). Three irrigation levels (0, 90, and 180 mm) were allocated to main plots, and three planting patterns namely single-single (SS), single-double (SD), and double-double (DD) were kept in subplots. Irrigation amount 0, 30, 60 mm of water were applied at GS34, GS48, and GS70, respectively. Results showed that photosynthetically active radiation (PAR) capture ratio of 0 mm was higher than that of the 90-mm irrigation at 0 to 40 cm, but irrigation increased the total PAR capture ratio, leaf area index (LAI), RUE, and grain yield. The interaction of irrigation x planting pattern indicated that the grain yield of SD was high under 180-mm irrigation and that of DD was high under 0-and 90-mm irrigations. Leaf area index, PAR capture ratio, and RUE of DD were higher than those of SD under 90-mm irrigation. The application of DD planting pattern combined with 90-mm irrigation resulted in positive response to yield.