种植密度和截干高度对辣木生物量的影响

Effects of difference planting densities and cutting heights on the biological yield of Moringa oleifera

为提高辣木的生物量,以辣木“PM2”品种为试材,设置种植密度和截干高度2个影响因素。其中种植密度设1.0 m×1.0 m、1.0 m×1.5 m、1.5 m×1.5 m共3个水平,截干高度设不截干(对照)、0.5 m处截干、1.0 m处截干、1.5 m处截干共4个水平。共设19种处理,其中单因素处理7种,双因素叠加处理12种。定植5年后测量辣木的树高、胸径、冠幅、全株生物量和根系生物量等指标,分析种植密度和截干高度对辣木生物量的影响。结果显示:在3种种植密度和4种截干高度的单因素试验中,种植密度对辣木的树高有显著影响(P<0.05),其中1.0 m×1.0 m处理的树高最大;种植密度对胸径和冠幅没有显著影响。截干高度对辣木树高和冠幅无显著影响,但对胸径有显著影响,截干高度为0.5 m处理的胸径均值显著(P<0.05)低于不截干、截干高度为1.0 m、截干高度为1.5 m等3种处理的。种植密度和截干高度的双因素试验中,交互作用对辣木的全株生物量和根系生物量均有极显著影响(P<0.01);其中种植密度为1.0 m×1.5 m、截干高度为1.5 m处理的总生物量最大。全株生物量与截干高度呈极显著正相关,相关系数为0.708;与种植密度呈极显著的负相关,相关系数为-0.562。

In order to improve the biological yield and planting area of Moringa oleifera,two influencing factors including densities and cutting heights were discussed,and M.oleifera"PM2"variety was used as material.The experimental treatments were set in which including three planting densities(1.0 m×1.0 m,1.0 m×1.5 m and 1.5 m×1.5 m)and four cutting heights(0 m,0.5 m,1.0 m and 1.5 m).There were total 19 treatments including 7 single factor treatments and 12 double factor treatments.The indexes of height,DBH,crown width,whole plant weight and root weight of M.oleifera have been measured to analyze the effects on the biological yield after 5 years of planting.In the single factor experiment with three planting densities and four cutting heights,different planting densities had significant effects on the tree height growths of M.oleifera,while the treatment of 1.0 m×1.0 m had the most significant effect(P<0.05).However,in this study,the four planting densities had no significant effect on DBH growth and crown width.Different cutting heights had no significant effect on M.oleica tree heights and crown widths,but had significant effect on DBH growth.The mean DBH of cutting height of 0.5m was significantly lower than that of no cutting,cutting height of 1.0 m and 1.5 m(P<0.05).Among the two-factor treatments interaction which including planting density and cutting height had significant effects on the whole plant weight and root weight of M.oleifera(P<0.01).Among them,the total biological yield of the treatment with a planting density of 1.0 m×1.5 m and cutting height of 1.5 m was the largest.There is a significant positive correlation between the whole plant weight and the cutting height.The correlation coefficient was 0.708.There is a significant negative correlation between the whole plant weight and the planting density.The correlation coefficient was-0.562.