Combining wide seedling strip planting with a higher plant density results in greater yield gains in winter wheat

Abstract

Both increased plant density and wide seedling strip planting (WSP) can improve wheat grain yield. However, whether and how greater gains in grain yield can be achieved by combining WSP with an increased plant density is unclear. In this study, two winter wheat cultivars were subjected to three plant densities (lower, normal, and higher) and two planting patterns (conventional planting [CP] and WSP). The effects of plant density, planting pattern, and their combination on the solar radiation interception and conversion, biomass accumulation, harvest index, and grain yield were investigated. In response to an increase in plant density from lower to higher and a shift from CP to WSP and their combination, grain yield increased by 15.43 %, 10.85 % and 27.62 % for cultivar Taimai198, and by 13.13 %, 8.31 % and 22.41 % for Shannong30, respectively. The larger increases in grain yield were mainly ascribed to enhanced dry matter production, in particular after anthesis with no variation or a slight decline in the harvest index. The higher plant density was the dominant driver of the enhanced radiation interception, whereas WSP was mainly responsible for ameliorating the reduction in radiation use efficiency (RUE) caused by the higher plant density. The combined effects of these two management practices in increasing grain yield were much greater than the independent effects of a shift from CP to WSP or an increase in plant density. Optimizing the planting method may thus be a promising option for further improving grain yield of a densely planted wheat population by increasing the RUE.