RNGR.net is sponsored by the USDA Forest Service and Southern Regional Extension Forestry and is a colloborative effort between these two agencies.

U.S. Department of Agriculture USDA Forest Service Southern Regional Extension Forestry Southern Regional Extension Forestry

Field and Greenhouse Fusiform Rust Symptoms Predict Mortality in Progeny Field Tests

Six annual field observations on 43 slash pine families in a progeny test at Jackson County, Florida, showed that gall type was closely related to rust-associated mortality. In the field, the number of galls per family that developed from infection of terminal shoots was the single best predictor variable (r 2 = .85) for rust-associated mortality at 8 years. The proportion of trees with normal stems at age 5 or 6 years ranged from 25 to 100% and appeared to be a good predictor of mortality. Greenhouse inoculations of 21 of the 43 pine families in the progeny test showed purple stem spots without swelling to be the best variable for predicting field infection and mortality. Increasing the number of variables to three gave an r 2 of .64 for predicting field incidence. Differences in virulence of Cronartium quercuum f. sp. fusiforme collections in this progeny test were not related to disease severity among the pine families.


Download this file:

PDF document Download this file — PDF document, 270Kb

Details

Author(s): Charles H. Walkinshaw, Jr.

Publication: Tree Improvement and Genetics - Southern Forest Tree Improvement Conference - 1987