低氮条件下密度对红壤旱地秋芝麻产量和叶面积指数的影响

为了探索低氮条件下红壤旱地秋芝麻高产栽培的适宜种植密度,2016年-2017年在进贤县和南昌县开展试验,研究6个密度（D1-15.0、D2-22.5、D3-30.0、D4-37.5、D5-45.0和D6-52.5 株/m2）对秋芝麻产量构成因素、产量和叶面积指数的影响。结果表明：2017年南昌县试验点D1和D2的单株蒴果数较D4显著增加18.32%和20.27%,其它处理的每蒴粒数较D3显著增加15.92%~25.04%;随着密度的增加秋芝麻产量呈现先增后减再增的趋势,2016年进贤点密度为D6时产量较D1显著增加40.78%,2017年进贤点为D2和D6时产量较D3显著增加18.00%和16.74%,2017年南昌点为D2、D5 和D6 的产量较D3 显著增加32.86%~44.15%。D2、D5、D6 的产量平均值较D1 显著增加20.66%~26.82%。叶面积指数随着种植密度的增加而增加,同时随着芝麻生长发育都表现为先增后减的趋势。因此,秋芝麻适宜密度应控制在22.5株/m2或45.0~52.5株/m2,才能够构建合理冠层,达到高产效果。

Effects of density on yield and leaf area index of autumn sesame in red soil dryland under low nitrogen

In order to explore the suitable planting density for high-yield cultivation of autumn sesame in red soil dryland under low nitrogen, experiments were conducted in Jinxian and Nanchang from 2016 to 2017 in Jiangxi Province,China. 6 planting densities(D₁:15.0;D₂:22.5;D₃:30.0;D₄:37.5;D₅:45.0;D6:52.5 plants per square meter)were set on yield and leaf area index of autumn sesame. Results indicated that number of plant capsules from D₁ and D₂ in Nanchang was significantly increased by 18.32% and 20.27% respectively as compared to D₄ in2017. The numbers of plant capsules of other treatments were significantly increased by 15.92% to 25.04% respectively as compared to D3. Sesame yield increased first and then waved with the increasing density. At D₆ in 2016 in Jinxian, the yield was significantly 40.78% higher than that of D₁. In 2017, the yield of D₂ and D₆ at Jinxian were18.00% and 16.74% respectively, which were significantly higher than that of D₃. The yields of D₂, D₅ and D₆ at Nanchang site were 32.86% to 44.15% higher than that of D₃ in 2017. The average yields of D₂, D₅ and D₆ treatments were significantly increased by 20.66%-26.82% as compared to D₁. Sesame growth waved with the increasing density, and leaf area index increased with the density. Thus the suitable density of autumn sesame should be controlled at 22.5 plants or 45.0-52.5 plants per square meter to construct a reasonable canopy and achieve high yield.