Effects of Plant Density on Agronomic Traits and Yield in Spring Maize Zhongdan 909 and Their Regional Differences in Northeast China

Abstract

It is well evidenced that higher plant density will give higher grain yields, and the ecological situations of precipitation, air temperature and soil conditions are the key factors of plant density decision. Given the great regional variations of precipitation and temperature, to learn the integrated responses of crop growth to plant density and regional ecological situation will play an important role in designing optimal density with higher yield in Northeast China. Field experiments were conducted in Shenyang, Gongzhuling, Harbin, Huadian, and Taonan using spring maize cultivar Zhongdan 909 to determine the comprehensive effects of plant densities and regional ecological conditions on crop agronomic traits and grain yield. The results showed that, higher plant density significantly increased the plant height and ear height, and decreased the stem diameter. Regional ecological conditions had significant effect on plant height but less effect on ear height and stem diameter. With the increase of plant density, the population leaf area index (LAI) increased significantly. Meanwhile, the increment of heat and precipitation increased the LAI. The increase of population dry matter accumulation under higher plant density offset the decrease of dry matter accumulation per plant which ensured the higher grain yield. Under the plant density of 9.00 × 104 plant ha–1, the potential productivity for cultivar Zhongdan 909 was fully developed in the experiments. But regional differences of precipitation, air temperature and soil characters influenced the appropriate plant density. The optimum plant density should be from 8.6 to 9.6×104 plant ha-1 under different ecological conditions in Northeast China.