In situ Observations on Plum Root Growth1

Abstract

Abstract In situ root growth of young plum trees (myrobalan rootstock on which ‘Shiro’ plum was budded) was studied for one season at the University of Guelph rhizotron. Root growth of this combination, at the field-transplant stage, began before leaf growth and extended past leaf fall. Relatively large roots of myrobalan stock made some winter growth in length, below frost penetration. The rate of growth during July to mid-September was twice that of the balance of the season, corresponding closely to shoot and trunk increments. Root diameter and elongation rate are positively correlated. Irregular and patchy suberization was the rule with the young plum roots.