Row Spacing Pattern Effects on Plant Growth, Canopy Radiation Interception, and Grain Yield of Winter Wheat under the Water-Saving Conditions

Planting pattern affects the spatial distribution characteristic of individual plants in population and modifies the plant productivity of cereal crops.This study reported the effects of row spacing distance on growth traits, photosynthesis behaviors, and agronomic traits of winter wheat plants cultivated under water-saving conditions.Compared with control (row width of 15 cm), the narrowed row treatment (NRT, row width of 7.5 cm) led to improved plant growth traits, such as population tiller numbers, leaf area index (LAI), and biomass of the tested cultivars at various growth stages.The uptake capacity of plants for nitrogen (N), phosphorus (P), and potassium (K) was elevated under NRT with respect to control, which was in consistent with the positive effects of NRT in affecting chlorophyll contents (Chl) and photosynthetic rate (Pn).During late growth stage, the upper position of canopy under NRT intercepted more solar radiation (SR) than control, suggesting that NRT benefits the population for interception of SR that contributes to plant biomass production during the late growth phase.Compared with control, NRT increased population spike amounts while maintained comparable kernel numbers per spike and grain weights, resulting in increased yields and water use efficiency (WUE) for tested cultivars.Additionally, the cultivars showed drastic cultivar variation in row spacing pattern responses; the drought-sensitive cultivar Jimai 585 exhibited more promotive effects on growth and agronomic traits upon NRT with respect to Shimai 22, a drought-tolerant one.Together, narrowed row mode promotes the productivity of winter wheat cultivated under deficit irrigation, which associates with its modulation on plant growth, nutrient acquisition, photosynthesis, and canopy solar radiation interception during late stage.