Ten Years' Growth of Pruned and Unpruned Cottonwood Planted at 40- by 40-Foot Spacing

Four pruning treatments have been applied for 5 years on cottonwood (Populus deltoides Bartr.) select clone Stoneville 66, planted at 40by 40-ft spacing. As pruning severity increased, average diameter and maximum crown width decreased. Diameters ranged from 9.2 inches for trees pruned half of height yearly to 11.4 inches for unpruned trees; crown widths ranged from 16.5 to 24.6 ft. Addltional keywords: Populus deltoides. trees. And resulting diameter growth would serve as an upper limit for comparison to diameter growth at other spacings and would also tell us how fast sawtimber and veneer logs can develop. Widely planted cottonwood trees would need to be pruned for quality growth. A comparison of several pruning intensities would tell us how crown length influences diameter growth. This paper gives data on 5-year growth of .widely spaced cottonwoods whose crown length has been controlled by pruning (fig. 1).