Development of a Jack Pine Seed Orchard by Mass Selection

An experimental jack pine seed orchard was developed in eastern Manitoba by mass selection in a plantation established with seedlings of 220 open-pollinated progenies. Three thinnings to 11 years from planting resulted in selection of 208 of the best trees out of 5280 planted on 0.3 ha. Mean height was increased from 190 to 217 cm in the first thinning and from 512 to 552 cm in the second thinning. Seed orchard trees in progenies that were found to be superior in a concurrent family test were not retained more frequently than trees from other progenies.