For a fungus to be active in wood, there are four essential elements – air, temperature, moisture, and food. If you remove one of the four elements, you can eliminate the risk of fungal damage. Air is the hardest to control. The key here is to create an anerobic environment which can be done by saturating the wood with water. Some small operators will store logs in a pond and larger operators use a sprinkler system to achieve an anerobic environment. Fungi need temperatures of 50 – 110 F for active growth. If the temperature is outside of this range, it is dormant; temperature over 130 F is toxic to most fungi. Fungi typically need at least 25 percent moisture content to be active. Rapid drying will reduce the risk of fungi attack, especially blue stain fungi, due to moisture content.
The food (wood) can be poisoned with a wood preservative. Since air drying is not a good option during warm, humid summer months. Dipping or spraying the lumber with a fungicide can be used. This protects the outer 1/100 of an inch and creates an envelope of protection. Fungicides must be applied immediately after sawing. If the application is delayed, then the fungi can penetrate to the center of the board when the fungicide is applied. Always follow all label instructions when using a biocide. The label is the law.
The most immediate threat to green lumber is fungi. These are simple plants that do not contain chlorophyll. They cannot produce their own food, so fungi get their energy from other organic materials (e.g., wood). The cellulose and lignin in wood provide food for a wide range of fungi. The hyphae (mycelium) of the fungi secrete enzymes that break down the carbohydrate materials, and sometimes lignin, into simple sugar-like compounds that are used for energy (metabolized). Most fungi can only attack wood in wood moisture is already present. However, there are some water conducting species of fungi that have the ability to transport water to the wood material affected.