断根措施对杨树和冬枣生长的调控作用

采用树木行间两侧不同距离断根的方法,研究了断根措施对I107杨和沾化冬枣的生长调控作用。杨树断根以促进生长为研究目的,而冬枣断根以抑制过旺营养生长,提高果实产量为目标。试验结果表明,两侧8倍胸径距离断根显著提高了杨树的胸径和树高生长量,在处理后短期内(35 d),杨树叶片N、P、K和生长素质量分数显著减少,降低了叶片光合速率;但是随着根系生长的恢复,在161 d时上述各项指标得到显著提高。对冬枣断根的研究结果表明,两侧3倍胸径距离断根能够显著降低枣头二次枝的长度和数量,没有明显影响到当年冬枣产量,次年则使产量显著提高了8.73%,同时果实Vc和可溶糖质量分数也得到显著增加。3倍和5倍胸径断根虽然降低了冬枣叶片的N、P和K质量分数,但显著提高了叶片光合速率。断根在短期内促进了枣头二次枝IAA质量分数的增加,在161d时IAA质量分数显著降低。

Regulation Effects of Root Pruning on the Growth of Poplar and Winter Jujube

Experiments were conducted to study the regulation effects of root pruning on the growth of poplar(Populus euramericana cv.Neva) and winter jujube(Zizyphus jujuba Mill.cv.Zhanhua) by partly removing root system at different distances from trunk on both inter-row sides of the trees.The objectives of root pruning were to improve the growth of poplar and decrease the excessive vigor of winter jujube.Results showed that the root pruning of 8 times DBH(diameter at breast height) distance significantly increased the DBH and height increments of poplar.The contents of N,P,K,and IAA in poplar leaves as well as photosynthetic rate were significantly reduced on the 35th day after root pruning,while they increased significantly on the 161st day in comparison with the control,due to the recovery of root system.However,for winter jujube,the root pruning of 3 times DBH distance significantly decreased the length and number of secondary branches.The fruit yield of winter jujube was not influenced in the current year after root pruning,but significantly enhanced by 8.73% in the following year.Also,the contents of vitamin C and total sugar increased.The root pruning of both 3 and 5 times DBH distances reduced the N,P,K contents in winter jujube leaves,but significantly increased the photosynthetic rate.The IAA content in the top of secondary branches increased on the 35st day after root pruning,but significantly decreased on the 161st day.