Effects of spacing interval of wide bed planting on canopy characteristics and yield in winter wheat

Aims Spacing interval is a cultivation technique to obtain high yield. Our objective was to investigate the effects of spacing interval on canopy characteristics and yield in winter wheat (Triticum aestivum) under different planting patterns of wide bed planting methods with 8 cm drilling width and conventional drilling planting methods with 2 cm drilling width.
Methods A field experiment was conducted in growing seasons of 2010-2011 and 2011-2012, growing multi-spike winter wheat cultivar ‘Aikang 58’ under different planting methods with three spacing intervals of 7, 12 and 17 cm for wide bed planting methods and 20 cm of row spacing for conventional drilling planting methods. Time-course measurements were taken on canopy leaf area index, mean leaf angle, canopy openness, light interception, canopy temperature, relative humidity and yield during the experimental periods.
Important findings Compared with conventional drilling planting methods, the leaf area index, mean leaf angle, light interception, relative humidity, spikes numbers, biomass and grain yield for wide bed planting methods are higher, while canopy openness and temperature are lower. Subsequently, spike numbers per unit area increased by 4.8%-16.4% (in 2010-2011) and 8.9%-21.0% (in 2011-2012) and yield increased by 2.96%-15.94% (in 2010-2011) and 4.09%-14.23% (in 2011-2012). Leaf area index, mean leaf angle, light interception, relative humidity and spike numbers decreased, and canopy openness and temperature increased with increased spacing interval under wide bed planting methods. Grain number per spike, grain weight, grain yield, biomass and harvest index are the highest in the 12 cm treatment and lowest in the 7 cm treatment. It can be concluded that 12 cm spacing interval under wide bed planting methods can be used as a feasible, promising planting pattern with reasonable canopy architecture and sufficient light distribution and interception and favorable microclimate.