Growth And Development Of First-Year Nursery-Grown White Oak Seedlings Of Individual Mother Trees
Abstract - White oak (Quercus alba L.) acorns from individual mother trees at Arrowhead Seed Orchard (ASO, Milledgeville, GA), Beech Creek Seed Orchard (BSO, Murphy, NC), and Savannah River Site (SRS, Aiken, SC) were sown in December 1999 at Whitehall Experiment Forest Nursery (Athens, GA). All 6 mother trees from BSO were grafted. By early April, germination exceeded 80percent for all but six families. Five of these six families were from BSO. Seedlings that emerged after mid-April generally were much smaller in size than those emerging earlier. More than 60 percent of seedlings from each seed source group had fewer than mean first-order lateral root (FOLR) number. Buds for the first flushes started swelling near the end of April for most seedlings. Time span from current bud swelling to next bud swelling in most seedlings was approximately 33 days for all flushes. Regardless of seed sources, elongation of the third, fourth, and fifth flushes occurred mainly between 4 and 12 days post bud break (dpbb) with most active elongation occurring approximately 10 dpbb. About 89, 55, and 9 percent of AS0 and SRS seedlings had three, four, and five flushes, respectively. Only 60, 15, and 2 percent of BSO seedlings had three, four, and five flushes. Seedlings with first flush length shorter than 5 centimeter generally had lower values in growth parameters including height, root collar diameter, flush number, and FOLR number. Based on germination rate and first flush length, it may be possible to assess progeny quality of given mother trees as early as mid-May. Progeny from grafted mother trees performed poorly in nursery as compared to progeny from other groups based on all parameters except for diameter.