Phlebiopsis gigantea (strains VRA 1985 and VRA 1986)

The active ingredient consists of spores of the fungus Phlebiopsis gigantea, a naturally occurring saprotroph. It acts as a biological control agent through the principle of competitive exclusion.

Upon application to fresh wood stumps, the spores germinate rapidly and colonize the surface. By covering the available wood tissue, the fungus physically prevents pathogenic fungi from establishing and accessing nutrients.

The fungus produces enzymes that facilitate rapid growth and dominance over the substrate. This ensures that the pathogen cannot infect the stump and subsequently spread through root grafts to neighboring healthy trees.

Strains VRA 1985 and VRA 1986 are selected for their high vitality and ability to thrive in various temperature conditions. Their persistence on stumps makes them an ideal choice for forest health management.

This biological method is an environmentally friendly alternative to chemical treatment. It integrates seamlessly into natural forest processes without causing harm to other non-target species.

The primary target is Heterobasidion annosum, the causal agent of root rot and butt rot in coniferous trees. This disease is one of the most destructive in boreal and temperate forests.

The treatment is specifically used for coniferous species, including pine, spruce, and fir. It is a critical component of silvicultural practices following thinning and harvesting operations.

By protecting stumps, the product prevents the fungus from entering the stand's root system. This helps maintain the long-term productivity and stability of forest stands.

The product is effective in preventing new infections in healthy areas. Once a stand is infected, the main goal is to protect the surrounding healthy trees from being colonized by the pathogen.

Additionally, Phlebiopsis gigantea contributes to the decomposition of woody debris. This natural process helps cycle nutrients back into the forest soil efficiently.

The biological fungicide is applied directly to the surface of fresh stumps immediately after felling. Any delay in application reduces the effectiveness as natural colonization by other fungi begins.

Application rates depend on the diameter of the stump and the equipment used. Manual or machine-integrated sprayers provide the most uniform coverage of the wood surface.

The working suspension is prepared by mixing the concentrate with clean, untreated water. It is essential to ensure that the water does not contain chlorine or other disinfectants.

In mechanized logging, the application can be automated via nozzles on the harvester head. This ensures that every stump is protected the moment it is cut.

Proper coverage of the entire surface, including the bark edges, is necessary for maximum protection. Uniformity is the key to preventing "gaps" where pathogens might enter.

Do not mix this biofungicide with chemical pesticides. Exposure to chemicals will kill the spores of Phlebiopsis gigantea and render the product ineffective.

Store the product in a cool, dark place to maintain spore viability. Exposure to high heat or direct sunlight will drastically reduce the shelf life and efficacy of the treatment.

Operators should use standard personal protective equipment (PPE) during application. While the fungus is not pathogenic to humans, breathing in spores in large quantities should be avoided.

The treatment is ineffective on stumps that have already been colonized by other fungi. Timing is crucial, and the product should only be applied to fresh cuts.

Ensure that all tools and equipment used for application are free from chemical residues. Clean water is the only acceptable diluent for preparing the suspension.