A Simplified Method of Measuring the Tree Vigor of ‘Fuji’ Apple Tree Grafted on JM7 Rootstock

Abstract

A simplified method of measuring the tree vigor of 'Fuji' apple tree grafted on JM7 dwarfing rootstock was investigated. The number of leaves of the terminal shoot (NL) at the beginning of July positively correlated with length of the terminal shoot, which is commonly used for estimating tree vigor. Therefore, since NL can be easily counted without special equipment, it is considered available in the field as a new index representing tree vigor. Moreover, NL showed a positive correlation with fruit weight per fruit at harvest time. By counting NL at the beginning of July, it is possible to estimate the final fruit weight at harvest. Key Words：fruit