剪顶处理对红松苗木品质的影响

Effect of Top Pruning Treatment on Quality of Pinus koraiensis Seedlings

为研究剪顶时间和留干高度对红松苗木品质的影响,以4年生红松裸根苗为材料,进行剪顶试验,设置3个留干高度(20、25、30 cm)和5个剪顶时间(4月、5月、6月、7月、8月),测定不同剪顶处理苗木的地径、生物量、茎根比、根系长度、根系表面积和根系体积。结果表明,生长季中期(6月)剪顶处理可显著提高红松苗木地径生长量,较对照提高23.68%,其他时间剪顶处理提高作用不明显;剪顶处理对红松苗木生物量的提高、茎根比的降低和粗根的生长基本没有促进作用,但对细根的生长促进作用明显,其细根长度、细根表面积和细根体积较对照分别提高18.27%~84.95%,9.38%~75.01%和1.28%~64.68%。生长季中期(6月)剪顶提高了红松苗木地径生长量,促进细根的生长,在一定程度上促进红松苗木品质的提高。

In order to study the effects of top pruning time and retained stem height on the quality of Pinus koraiensis seedlings,a top pruning test was carried out with 4-year bare root seedlings of Pinus koraiensis as materials,and 3 retained stem heights(20,25,30 cm)and 5 top pruning times(April,May,June,July,August)were set.The root collar diameter,biomass,shoot to root ratio,root length,root surface area and root volume of seedlings under different top pruning treatments were measured.The results showed that top pruning treatment in the middle of the growing season(June)could significantly increase the root collar diameter growth of Pinus koraiensis seedlings by 23.68%compared with the control,but the effect of top pruning treatment at other times was not obvious.The top pruning treatment had no effect on the increase of biomass,the decrease of shoot to root ratio and the growth of thick roots,but had a significant effect on the growth of fine roots of Pinus koraiensis seedlings.The length of fine roots,surface area of fine roots and volume of fine roots were increased by 18.27%-84.95%,9.38%-75.01%and 1.28%-64.68%,respectively,compared with the control.The top pruning in the middle of the growing season(June)increased the root collar diameter growth of Pinus koraien⁃sis seedlings,promoted the growth of fine roots and promoted the quality of Pinus koraiensis seedlings to a certain extent.