Overview
PG Suspension is the only approved biological control agent for stump treatment in UK forestry and is available for purchase directly from Forest Research. It is used as a biological alternative to urea.
Both PG Suspension and urea are used to control Heterobasidion species in the UK. These root and butt rot fungi primarily affect conifer species, increasing risk of windthrow and reducing growth, carbon sequestration, timber quality and strength. The pathogen can persist for decades in infected stumps and root systems following thinning & clear-felling, resulting in infection and mortality in newly established crops during subsequent rotations.
PG Suspension is currently approved for use on pine species only. If stump treatment is required for non-pine conifer species, please refer to our page on urea.
Background
PG Suspension is comprised of Phlebiopsis gigantea, a wood colonising non-pathogenic ‘crust’ fungus which colonises freshly cut stumps preventing the ingress of the pathogenic Heterobasidion. The fungus grows as thin grey wax-like coating on the treated stumps and effectively out competes Heterobasidion when applied during tree felling or immediately afterwards.
The strain of P. gigantea used to produce PG Suspension is native to the United Kingdom and has low environmental impact compared to chemical treatments. The fungus has proved harmless to living trees, making it sustainable and suitable for forest use.
Application
PG Suspension is supplied in 10 ml sachets, usually in a booklet containing 5 sachets, with boxes containing 10 booklets (50 sachets) available for commercial use.
One 10 ml sachet is diluted into 25 litres of water before use and can be spread onto stumps in a variety of ways:
- For small scale use, PG Suspension can be applied to stumps using a brush to effectively coat the surface after felling.
- For medium scale, a backpack sprayer can be used to treat multiple stumps quickly and effectively.
- In commercial forestry situations, PG Suspension is pumped through the head of the harvesting machine and sprayed directly onto the stump during cutting.
Production
All PG Suspension is produced in a clean laboratory by staff at Forest Research. Small volumes are always kept in stock and are available for delivery with little to no lead time.
Larger batches of PG Suspension, such as those ordered for commercial use, require a two-month lead time due the biological nature of the product.
Batches of PG Suspension undergo rigorous testing to ensure consistent quality and effectiveness of the product.
Storage information
PG Suspension is a ‘live’ product containing both live spores and fungal mycelium, and the product is supplied in and requires refrigerated storage to ensure quality and effectiveness.
PG Suspension has a shelf life of six months from the time of manufacture.
All PG Suspension is supplied with a usage guide and safety pamphlet, if you have further questions please use the contact form.
Purchasing and queries
For all purchases and queries please use the contact form. If you are unsure if PG Suspension is the right product for you, we will be happy to assist you in finding the suitable treatment.