Acker-Funk Orchard Inoculation and Rating

November 17, 2008

Drs. Fred Hebard and Paul Sisco of the American Chestnut Foundation rated the reaction hybrid chestnut trees growing at the Acker-Funk Orchard had to chestnut bark fungus inoculated last spring. The orchard was inoculated in June of 2008 by Cody Luedtke and Steve Barilovits IV, Stanback Interns working for the American Chestnut Foundation. Click on any photo to enlarge it.

Each tree rated was inoculated twice near the base with a strong form of the fungus and twice higher on the trunk with a weaker strain. Trees were rated by Dr. Hebard using a scale of 1 to 5 with 1 standing for good resistance to both strains and 5, for poor reaction to both.

A number of inoculated trees displayed moderate resistance, as expected, and received a rating of between 3.0 and 3.75. Trees rated 4.0 or 5.0 will be removed from the orchard. Trees will be rated again in the spring of 2009 to determine which trees have recovered somewhat, shown no change, or deteriorated. A decision will be made as to which trees to keep in the orchard and which to remove. Trees kept will be candidates for further backcross and intercross pollination.

During the rating, Dr. Fred Hebard took time to peal off bark from an area of a tree inoculated with the blight fungus. The fungus grows under the outer layer of bark. If not halted by the hybrid tree’s defensive growth of cankerous tissue, the fungal growth will circle the tree and cut off nutrients that would sustain the tree.