It's called Butt Rot, Stump Rot, Fomes, or H. annosum Root Rot. No matter what you call it, when your forest gets infested, it becomes a major problem.
There are two major problems with H. annosum. First, it attacks the butt log, drastically reducing the most valuable part of the tree, and then spreads from recently cut stumps to live trees via the root system. Secondly, it infests the seedlings and saplings, killing new growth.
Cellu-Treat is a Disodium Octaborate Tetrahydrate (DOT) wood preservative that is available in a 98% water soluble powder and a 50% liquid concentrate.
CELLU-TREAT kills and prevents Fommes. It is soluble borate powder that can be sprayed on using a simple backpack sprayer or applied during harvest with a stump spray bar.
The active ingredient in Cellu-Treat is boron. Boron is a natural mineral salt that is mined from the earth. Boron is an essential plant micronutrient. Cellu-Treat is specifically designed to kill H. annosum root rot and then, over time, be diluted to natural background levels in the soil and allow natural succession of non-pathogenic fungi.
One pound of Cellu-Treat makes 2 gallons of solution and covers 2,000 six-inch stumps or 500 twelve-inch stumps.
H. Annosum (“butt rot”) spreads over time via infected root contact.
Spores settle on the stumps of freshly cut trees and germinate. Once stumps have become infected, they act as long-term inoculum sources, producing basidiospores over many years that travel hundreds of miles to infect newly cut stump surfaces. As the spores grow, the rot reaches down into the roots and begins infecting adjoining trees and saplings. Stump colonization, germination and mycelium formation takes place. Decay advances in stump roots and spreads to adjacent tree roots. Root contact promotes the transfer of decay between root systems of both mature and young trees.
Once an area is infected, two control options include stump removal or planting the area with a non-conifer species. However, the leading treatment is applying Cellu-Treat DOT borate wood preservative. Cellu-Treat can be sprayed on the stump directly or by using a through-the-bar application on the harvester.