Drought Injury
From Bugwoodwiki
Hagle, S.K; S. Tunnock; K.E. Gibson; and C.J. Gilligan. 1987. Field Guide to Diseases and Insect Pests of Idaho and Montana Forests. U.S. Department of Agriculture, Forest Service. State and Private Forestry, Northern Region. Missoula, Montana. Reprint 1990. Publication Number R1-89-54.
Contents |
Hosts
All conifers, especially young trees.
Distribution
Dry aspects, shallow soils, and areas experiencing unusually low rainfall.
Damage
Mild drought may be expressed only in reduced growth or early dormancy. More severe drought may result in foliage damage or even tree death.
Identification
Growth cessation may be followed by witting or discoloration (chlorosis or reddening) of new foliage. If drought continues new foliage is shed and shoots die back to lateral buds (fig. 148). With continued drought, tree mortality may occur, usually following bark beetle attack in larger trees. Drought in seedlings can be diagnosed in part from examination of roots; few if any active root tips will be found.
Similar damages
Conditions which cause general decline in trees often resemble drought damage. Root disease, bark beetle attack, some mechanical damages, and chronic needle cast or insect defoliation are all similar in general tree symptoms to drought.
References
- Bega, R. V. 1978. Diseases of Pacific Coast conifers. USDA For. Serv. Ag. Hndbk. No. 521, 206 p.
- Boyce, J. S. 1961. Forest Pathology. McGraw-Hill Book Co., New York, NY. 572 p.
