“V”字形苹果幼树二维图像的分形特征

果树的树体结构对树木的生长和生产力具有极为重要的影响。然而目前对幼树树形特征的研究和评价较少。2009-2011年,采用计盒维数和Photoshop图像处理技术,调查不同方位及不同品种两年生"V"字形苹果幼树二维图像的分形维数与分形特征。从"V"字树形整体水平上看,果树侧视图的分形维数按品种排序为富红早嘎>红盖露>玉华早富>长富2号>丽嘎啦>烟富6号,变化范围为1.650～1.700;正视图的分形维数按品种排序为红盖露>玉华早富>丽嘎啦>烟富6号>富红早嘎>长富2号,变化范围为1.583～1.631;正视和侧视图总体分形维数按品种排序为红盖露>玉华早富>丽嘎啦>富红早嘎>长富2号>烟富6号,变化范围为1.620～1.660。从"V"字形树的局部特征看,树体由东边和西边树组成。6个品种东边和西边苹果树侧视图的分形维数分别为1.593～1.683和1.645～1.720;正视图的分形维数分别为1.548～1.627和1.568～1.657。"V"字形苹果树东边树的二维图像正视和侧视分形维数都比西边树小。因此,果树二维图像的分形维数随着方位和品种而变化,可以表征不同品种及不同方位树体结构特征,并可用来指导幼树的整形修剪。

Fractal Characteristics of Two dimensional Images of Young Apple Trees Trained to V shaped Configuration

The architectures of fruit trees are very important to their growth and productivity. However, there have been few reports on the research and assessment of the architectures of V shaped configured young apple trees. The fractal dimension of two dimensional images of 2 year old apple trees with this configuration with different cultivars at different orientations were investigated employing box counting and Photoshop image processing technology during 2009-2011. On the whole level, the fractal dimensions of trees ranged from 1.650-1.700 for side views and from 1.583-1.631 for front views and the ranking order was Honggailu>Yuhua Early maturing Fuji>Li Gala>Yanfu No.6> Fuhong Early maturing Gala>Nagafu No.2 and Fuhong Early maturing Gala>Honggailu>Yuhua Early maturing Fuji>Nagafu No.2>Li Gala>Yanfu No.6 respectively. The total fractal dimensions of front views and side views ranged from 1.620-1.660 and the ranking order was Honggailu>Yuhua Early maturing Fuji>Li Gala>Fuhong Early maturing Gala>Nagafu No.2>Yanfu No.6. On the partial level, the tree configuration was composed of eastern and western trees. The fractal dimensions of side views ranged from 1.593-1.683 for eastern trees and from 1.645-1.720 for western trees. The values of front views ranged from 1.548-1.627 and from 1.568-1.657 respectively. The values of front and side views of eastern trees were both smaller than western trees. Hence, the fractal dimensions of two dimensional images of apple trees trained to V shaped configuration differed and varied with their cultivars and picture taking directions, and could be employed to evaluate the structural characteristics of young trees with different cultivars at different orientations, and to guide training and pruning.