Growth and Development of First-year Nursery-grown White Oak Seedlings of Individual Mother Trees

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. INTRODUCTION There have been two Quercus regenera t ion prac t ices used to ma in ta in a s ign i f i can t oak component in new s tands following a harvest. One practice depends on obtaining advanced oak regenera t ion by she l te rwood or se lec t ion harvesting the current stands. Although this may be success fu l on lower qua l i t y up land s i tes (Sanders 1971, Lortis 1983), it may not be successful on high quality mesic sites due to the presence of fast growing, competing woody species that will generally occupy the site once the final canopy is removed (Loftis 1990, Hodges and Gardiner 1993, Lorimer 1993). The other practice, artificial oak regeneration, involves planting high quality 1-O nursery stocks on clearcut sites as advocated by Kormanik and others (1997,1998,2000). This practice takes only the top 50 percent of 1-O oak seedlings grown under a specific hardwood nursery pro toco l deve loped by Kormanik and others (1995). Seedlings are graded by their height, root collar diameter @CD), and number of first-order lateral roots (FOLR) that are greater than 1 mm in diameter. It has been proven with loblolly pine (Kormanik and others 1990) and var ious oak spec ies inc lud ing wh i te oak (Korman ik and others 1997, 2000) that FOLR number is highly heritable and a good indicator of seedling quality in nursery and outp lanted per formance in f ie ld . Here we investigated the growth and development of 1-O white oak seedlings from different mother trees from different states. The primary interest was to identify and quantify any early indicator of seedling quality that might be used with progeny from future mother tree selections. MATERIALS AND METHODS Open pollinated white oak (Quercus a/be L.) acorns from indiv idua l mother t rees in Ar rowhead Seed Orchard (ASO, Mi l ledgev i l le , GA) , Beech Creek Seed Orchard (BSO, Murphy, NC) and Savannah River Site forest stands (SRS, Aiken, SC) were sown at a density of 54 to 57 per meter in December 1999 a t Wh i teha l l Exper iment Fores t Nursery (Athens, GA). Seedlings were grown using the oak nursery protocol of Kormanik and others (1994). There were 25, 6, and 15 half-sib families from ASO, BSO, and SRS, respectively. All 6 mother trees from BSO were grafted. Four ASO, six BSO, and 14 SRS families were planted in a randomized block design with two blocks each consisting of 130 acorns per family. The other families were planted in an identical manner but with only 65 acorns per family per block. Germination percent was assessed as shoot emergence on March 23 and April 5, 2000. Numbers of seedlings with swelling first flush bud that was at least 3 millimeter long or elongating first flush were recorded for ‘Research Plant Physiologist; Principal Silviculturist, Institute of Tree Root Biology, Southern Research Station, USDA-Forest Service, Athens, GA 30602; Mathematical Statistician, Southern Research Station, USDA-Forest Service, Asheville, NC 28802, respectively. Citation for proceedings: Outcalt, Kenneth W., ed. 2002. Proceedings of the eleventh biennial southern silvicultural research conference Gen. Tech. Rep. SRS-48. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 622 p.