Growth and Carbohydrate Distribution of Young Apple Trees in Response to Root Pruning and Tree Density

Abstract

Root-pruning young greenhouse-grown MM.111 apple trees decreased leaves per tree, total leaf area, and dry weight of leaves, shoots, and roots. Root pruning had no influence on the carbohydrate fractions in the leaves or shoots, but caused an increase in soluble and insoluble fractions in the roots. No interaction occurred between root pruning and number of trees in the container. As number of trees per container increased, leaf, shoot, and total dry weight per plant decreased. Root pruning decreased shoot growth for 3 weeks after root pruning, with a return to the unpruned shoot growth rate in the 4th week. Photosynthesis and transpiration were reduced by root pruning, but not affected by tree density.