What is Heterobasidion Root Disease?
Heterobasidion (also known as Fomes) Root Disease (HRD) is a highly damaging disease of conifers caused by the fungal pathogen Heterobasidion irregulare (H. irregulare). This invasive fungal pathogen causes root rot, which leads to growth loss, and mortality. It decomposes both living and dead wood tissue and can survive in stumps for decades. HRD spreads via airborne spores landing on newly cut stump surfaces and also through root grafts or root-to-root contact. HRD affects red, white and jack pine trees; with red pine being the species currently most affected.
Economic Impacts of HRD
Pines from managed plantations and natural forests produce many valuable products throughout a rotation. Decline and mortality from HRD can result in premature harvesting or even clear cutting, yielding less valuable products and therefore smaller financial returns. Treatment is a cost-effective management option. Studies in Wisconsin indicated that the potential loss by not treating a stand is up to 25 times as high as the cost of treatment itself.
What is Rotstop C?
Rotstop C is a biological fungicide that is applied as a stump treatment after felling. It contains spores of the naturally occurring wood decay fungus Phlebiopsis gigantea (P.gigantea), which grows into the stump and prevents HRD from becoming established.
How Rotstop C Works
Rotstop C is applied on the stump surface, P. gigantea grows into the stump and penetrates deep into the infected root system, naturally out-competing H. irregulare and preventing it from becoming established or spreading. Rotstop C was developed for use with automated/mechanized harvesters or with manual spray systems and is applied as an aqueous mixture to the stump surface directly after felling.
Rotstop C should be applied evenly across the stump surface to the point of wetness. BioForest recommends using a blue dye to help better observe treatment coverage.