Silviculture of Weymouth Pine

The advantages of being able to grow Weymouth pine ( Pinus strobus L.) on a commercial scale are indicated. The growth of this species in Thetford Forest is described, and the point is made that serious infection from White Pine Blister Rust ( Cronartium ribicola J. C. Fischer) has occurred in dense unthinned plantations only. Maintenance of vigour by early heavy thinning, and early brashing and high pruning to remove moribund branches, are suggested as means of minimizing deaths from the disease. Whilst individual Weymouth pines in pure plantations treated in this way are no more susceptible to Blister Rust than individuals in mixture with other species, mixed plantations have the advantage of providing alternative species for the final crop if the Weymouth pine fails.