幼龄直播密植枣园的拉枝效应研究

【目的】拉枝对直播密植枣园树体生长、光环境以及枣果产量和品质的影响。【方法】对参试株干径和基径进行调查,分析拉枝处理与对照的生长量差异;采用LAI-2000冠层仪和照度计进行行间叶面积指数、株间透光率及树冠中部光照强度日变化进行测定;果实成熟期用蒽酮法、氢氧化钠滴定法和钼蓝比色法分别测定其总糖、总酸和VC的含量。【结果】(1)拉枝处理的干径生长量小于对照,基径生长量则高于对照,差异达显著水平;(2)拉枝处理后行间叶面积指数较对照提高119.0%,株间透光率较对照提高1倍;(3)拉枝后树冠中部光照强度日均值为334.70 lx,对照仅为101.01 lx,光环境明显改善;(4)拉枝后单果重和单株产量与对照差异达极显著水平,品质差异不显著。【结论】在不减少密植枣园有效株数的前提下,株间拉枝方式改善树体光照环境和枣果品质,提高枣果产量和经济效益。

Study on the Effects of Branch Drawing for Young Direct-Seeding Close Planting Jujube Field

【Objective】Study the effects of branch drawing on the tree growth,light environment,fruit quality and yield of jujube in direct seeding close planting jujube field.【Method】The stem diameter and branch diameter of the test trees are investigated to analyse the difference between branch drawing treatment and CK.Interplanting leaf area index,the daily changes of light transmittance and light intensity in the middle part of the canopy are observed with the LAI-2000 type and photometer. The content of total sugar,total acids and Vc was detected by anthrone method, sodium hydroxide titration method and molybdenum blue colorimetric method.【Result】(1)The growth of stem diameter was smaller than the contrast, the growth of branch diameter was higher than contrast,and the difference between them was quite significant;(2)The interplanting leaf area index after branch drawing was increased 119.0% more than the contrast,interplanting light transmittance was twice more than the contrast;(3)After branch drawing,the light environment of the middle part of the canopy was obviously improved,the average daily light intensity was 334.70 lx,and the contrast was only 101.01 lx;(4)Single fruit weight and fruit yield of a branch of direct seeding jujube and the contrast achieved significant difference after branch drawing,but fruit quality was not obviously different.【Conclusion】Under the presupposition of not decreasing the effective number of trees in the jujube field,branch drawing helps to improve the light environment and fruit quality,increase fruit yield and economic benefit.