截干对叶用银杏生长及树形的影响

对叶用银杏大指品种１年生、２年生和３年生实生苗分别以不同留桩高度截干（或抹顶芽）处理，并对截干后当年的生长及树形指标进行调查。结果表明：（１）截干能矮化树体，扩大冠幅，减少光秃带距，加大部分处理树冠总体积；（２）截干能增加部分处理枝条数量及枝条总长；（３）对当年叶产量影响最大的指标分别为地径、长枝数、长枝长、高幅比及冠长比。因引截干能促进银杏形成优质叶用树形。

Effects of Coppice Management on Growth and Tree Shape in Gingko Leaf-producing Plantation in Jiangsu Province, China

In order to improve the yield and quality of Gingko leaf producing plantation, coppice management of 1,2,3 year old Dafuzhi (one of Gingko varieties) seedling at different stump heights (or top pruning) was taken in March, 1997. The following conclusions were drawn on investigation of growth and tree shape at the end of the first year: (1) Coppice management could lower Gingko tree height, reduce crown height, and enlarge crown diameters and crown volumes for some treatments.(2) Long branch number and length per plant of some treatments were increased by coppice management. (3) The main indexes which affected leaf yields were root diameters, long branch number, long branch length, the ratio of seedling height to crown diameter, and the ratios of crown diameter to leaf layer depth. So the good quality tree shape could be formed by coppice management.