Size and survival of 2-0 Douglas-fir seedlings

Results reported here are from a large study designed to evaluate the effects of certain nursery procedures on subsequent survival of Douglas-fir seedlings. The effects of storage conditions and lifting dates were reported elsewhere (9). The determination of the optimum size of seedling for planting on different sites has been the concern of foresters for many years (3, 6, 7, 8). Recently, Christmas-tree growers in the Pacific Northwest have planted Douglas-fir seedlings extensively and, like foresters, have shown interest in obtaining high survival at minimum cost. They often demand large seedlings. Nurserymen strive to produce adequate numbers of seedlings that meet desired size requirements and that can still be easily lifted, packed, stored, and shipped. A compromise is often made between the size of seedling wanted by foresters and other users and the size of seedling that is easy or even possible for the nurseryman to produce. Seedling size is of considerable interest to nurserymen, foresters, and other users. Foresters offer various reasons for poor survival of outplanted nursery stock, one being that seedlings supplied by nurseries are too small. Christmas-tree growers likewise complain that small seedlings do poorly. Published information both supports and refutes these claims because conditions vary on the plantation sites, and site is an important consideration in determining seedling survival. Although on some sites small seedlings may not survive well, on other sites they may prove satisfactory (1). Nursery conditions, date of lifting, and storage conditions for seedlings further confound the situation