Genetically Improved Ponderosa Pine Seedlings Outgrow Nursery-Run Seedlings with and without Competition—Early Findings
Abstract Three classes of ponderosa pine (Pinus ponderosa) seedlings (nursery-run, wind-pollinated, control-pollinated) were evaluated for stem height and diameter at the USDA Forest Service's Placerville Nursery and the Georgetown Ranger District in northern California. Pines in all three classes were grown with competing vegetation or maintained in a free-to-grow condition. Control-pollinated seedlings were statistically taller (P < 0.05) than nursery-run counterparts when outplanted, and after 1 and 2 growing seasons in the field with and without competition. They also had significantly larger diameters when outplanted and after 2 growing seasons in the field when free to grow. Wind-pollinated seedlings grew taller than nursery-run seedlings when free to grow. A large amount of competing vegetation [bearclover (Chamaebatia foliolosa)—29,490 plants per acre; herbaceous vegetation—11,500; hardwood sprouts—233; and whiteleaf manzanita (Arctostaphylos viscida) seedlings—100] ensure that future pine development will be tested rigorously. West. J. Appl. For. 9(2):00-00.