

Author: Berisford C. W. Kulman H. M.
Publisher: Society of American Foresters
ISSN: 0015-749X
Source: Forest Science, Vol.13, Iss.4, 1967-12, pp. : 428-438
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Abstract
The infestation rate of the Nantucket pine tip moth, Rhyacionia frustrana (Comstock), was studied on 6-foot Pinus taeda L. trees in Virginia. The rate of infestation was determined for the top, middle, and bottom of 1,250 trees in 1963 and 450 in 1964. Infestations were heaviest on trees in open stands and parts of trees exposed to full sunlight. Natural stands in old fields had a lower rate of tip moth infestation than plantations in old fields. Trees in dense stands had the poorest tree form, one of the lowest rates of growth, and were infested at rates only slightly below natural stands in old fields. Natural stands 6 feet tall growing in association with 15-foot trees was the only stand category with a relatively low rate of tip moth infestation in which the trees maintained a desirable form and rate of growth. Plantation trees with heavy competition from hardwood sprouts had better form and less severe tip moth infestation than plantation trees in abandoned fields. Shoots in the tops of trees were infested at rates about 10 percent higher than shoots in the next lower 2-foot segment and about 35 percent higher than shoots in the remaining bottom section of the tree. The average number of shoots per cluster of new shoots was positively correlated with the rate of tip moth infestation.
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