Author Description

During most of the nursery regime used to grow planting stock in containers, cultural factors are manipulated to ensure rapid shoot and root growth. Towards the end of the regime, however, the seedlings must be prepared or hardened to withstand either the 4-6 months cold storage preceding field planting or an overwintering outdoors in low temperatures. This hardening phase involves the forming of resting buds, lignification of stem tissue, and development of cold hardiness. This report describes the results of experiments undertaken to determine the relative effectiveness of long-night (16 hours for 4 weeks) and moisture stress treatments in modifying the physical and physiological quality of one-year-old container-grown Douglas-fir planting stock.