The effects of shade level and irrigation regime on conditioning container-grown Abies seedlings for fall planting

Graduation date: 1981First season container-grown noble fir (Abies procera) and Shasta red fir (Abies magnifica var. shastensis) seedlings were given six combinations of shade (0%, 30%, and 50% shade) and irrigation (moist and dry) treatments in the nursery beginning in late July, 1977. To evaluate frost hardiness\ud development, destructive freezing tests were conducted on September 22, October 31, and November 23, 1977 on sample seedlings from all treatments. These seedlings were then examined for survival, foliar browning, cambiuni condition, bud color, and bud condition. In addition, other sample seedings\ud were measured for the effects of the treatments on height growth, diameter growth, dry matter production, root regeneration and rate of bud-break after chilling. Results indicate that full sunlight (0% shade) hastened the development\ud of frost hardiness in the fall and that the effects of the applied irrigation regimes were not significantly different in inducing frost hardiness. Seedling height was not significantly different among the treatments; however, treatments of full sunlight at both moisture levels and moist irrigation at all three shading levels yielded seedlings significantly larger in diameter. No significant differences in seed1ing dry matter production, root growth, or rate of bud-break following chilling were apparent