Stopping pine weevils with glue and sand?
Pine weevils are the biggest single cause of tree seedling destruction in southern and central Sweden, as in many other countries. Work to find solutions to this problem is a priority. The methods vary. At Elmia Wood exhibitors presented everything from sand and glue to chemical treatments.
At the Svenska Skogsplantor stand, Anders Elling showed Conniflex-protected seedlings.
“This is a non-chemical treatment that is done in the nursery,” he says. “First a water-based glue is applied to the seedling and then it is sprayed with sand. We have recently invested in a complete processing line for this kind of mechanical application.”
Larger seedlings
Another way to protect your seedlings against the pine weevil is to choose larger seedlings.
“We have our Svepot Air XL, which has a thick stem relative to its length,” Anders says.
To achieve this, the seeds are first planted close together. An automatic machine then gives each seedling more room.
“This gives the seedling room to grow and increase its diameter rather than its length, and it is thereby more resistant to the pine weevil,” Anders explains.
Air holes favour fine roots
The Svepot XL is grown in newly developed pots which are equipped with air holes.
“The advantages of these open systems is that they reduce the risk of root deformation,” says Anders. “They also create more fine roots nearby the air holes which are evenly distributed in every pot. The fine roots are important to how efficiently the seedling can absorb water and nutrients after it has been planted out.”
Flexcoat extends the protection
Interagro Skog specialises in products that protect the forest from damage by insects and game animals.
“We have a strong belief in Flexcoat as an effective protection against the pine weevil,” says Pontus Svinhufvud. “One treatment provides two years of protection.”
Fewer treatments mean lower costs and less environmental impact.
“This is a chemical method so of course it is a good thing to keep the number of treatments down,” he says.
Flexcoat combines an insecticide with a binding agent to create a covering around the bark.
“Compared with an ordinary chemical treatment, Flexcoat is never absorbed into the seedling, but instead it creates a protective surface thanks to the binding agent,” he says. “In this way, the pine weevil never gets to the bark. Flexcoat also helps prevent the insecticide from evaporating or being washed off by rain, so it provides longer protection.”