A study was conducted to determine the effects of different dormant pruning treatments on subsequent plant development and water use of crape myrtle (Lagerstroemia × Fauriei Koehne ‘Tuscarora’) transplanted into containers. Dormant, bare-root plants were pruned to the normal practice of a 30% reduction of existing shoot length by heading back and thinning of weak branches. Plants were randomly assigned to 3 pruning treatments including: 1) control—no further pruning, 2) shoot pruned—an additional 50% reduction of remaining shoot length for a total of 65% reduction in shoot length, or 3) a 50% reduction of root area in addition to the 30% reduction in shoot length. Fifty percent (50%) root pruning severely reduced earliness of bud-break and plant survival when compared to either the control or the 65% shoot pruning treatments. Earliest bud-break and highest plant survival were rated for plants in the 65% shoot pruned treatment. Plants in the 50% root pruned treatment had a significantly higher number of terminal shoots, but average shoot lengths were significantly shorter when compared to plants in the 65% shoot pruned treatment. At final harvest there were no significant differences in mean dry weights and leaf area, total shoot length, or average water use between treatments. However, a large plant to plant variation in growth and water use due to the pruning treatments was observed. Plants in the 50% root pruned treatment were less uniform in size and water use as compared to control plants or 65% shoot pruned plants which exhibited the greatest uniformity.
Texas Agricultural Experiment Station Publication No. 25311.
1Assistant Professor, Department of Horticultural Sciences.
2Post Doctoral Research Associate and Professor, resp., Department of Agricultural Engineering.