Female Strobili on 12-Month-Old Jack Pine

Forest geneticists and tree breeders are continuously searching for ways to reduce the age at which flowering begins. Jack pine (Pinus banksiana Lamb.) is among the youngest of the pines to flower (4).At wide spacing in the nursery, Wright (8) noted flowering at 3 years of age. However, in standard nursery beds in lower Michigan, only 0.3 percent of 3year-old seedlings produced female strobili and only a small percentage of these bore male strobili (5). When seedlings were grown under near optimum conditions in the greenhouse and nursery, two separate studies showed that from 16 to 23 percent of 17month-old seedlings produced female strobili, 62 percent flowered at 23 months, and 71 percent at four years (3,5). Practically no male strobili were produced on these plants in the first 3 years. In this paper I report the production of female strobili on jack pine seedlings about 12 months old.

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Author(s): Thomas D. Rudolph

Publication: Tree Planters' Notes - Volume 30, Number 2 (1979)

Section: general

Volume: 30

Number: 2