Recommendations for Selection and Management of Seed Orchards of Western White Pine

摘要

Seed orchards of western white pine should be located on flat sites within the botanical range of western white pine. They should be planted at a 6 m by 6 m spacing, and they should be sprinkler irrigated, fertilized in August with 300 lb/acre ammonium nitrate, and sown with grass. Trees should be top pruned at 3 m and managed so that they develop three to four tops. All trees should be tagged and the amount of pollen, number of cones, ripening day, and seed-germination capacity recorded for each individual tree.