Five fungicides were evaluated to control Botrytis blight of containerized western larch seedlings at the Champion Timberlands Nursery, Plains, MT. Fungicides were applied at biweekly intervals before and after seedling inoculation with Botrytis. Vinclozolin (Ornalin®) caused severe phytotoxicity to seedlings, resulting in enhanced mortality and premature needle loss. Captan and...
Repeated thinning to five growing-stock levels resulted in widely differing tree sizes and volumes per acre after 30 years. Largest trees but the least cubic-volume yield per acre were produced in the heaviest thinning level, whereas highest board-foot yields were found in intermediate thinning levels. partial defoliation by larch casebearer...
Numerous stands of western larch, Larix occidentalis, on the St. Joe, Coeur d'Alene, and Kaniksu National Forests, Idaho, show signs of gradual deterioration following repeated defoliation by larch casebearer, Coleophora Zaricella Hbn. (Tunnock et al. 1969). Stand deterioration can occur after 4 years of continued heavy defoliation. The main symptom...
Upper-stem diameter measurements from a levels-of-growing-stock study on Larix occidentalis in the Blue Mountains of eastern Oregon were collected over a 25 year period with an optical dendrometer. The following hypotheses were tested with these data: 1) stand density regime has a significant effect on stem form; and 2) crown...
Causes of mortality of containerized western larch seedlings at the Champion Timberlands Nursery, Plains, Montana, were investigated. Seedlings were rated for disease severity based on extent of foliar decline symptoms and fungal isolations made from their roots. Isolations were also made from selected larch seed. Consistent associations between root colonization...
Needlecast caused by Meria laricis caused serious losses of 2-0 bareroot western larch during 1983 at the USDA Forest Service Nursery, Coeur d'Alene, Idaho. Cool, wet weather throughout the spring and summer of 1983 was ideal for disease buildup and spread. Control attempts with fungicides were largely unsuccessful because of...
Live western larch, Larix occidentalis Nutt., a tree species resistant to the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, produces the monoterpene 3-carene in higher concentrations compared to Douglas-fir, the preferred host of D. pseudotsugae (Reed et al. 1986). The inhibitory effects on attraction to aggregation pheromones and toxicity of 3-carene to...
Six fungicides were evaluated to control Botrytis blight of western 41 larch in seedbeds at the Coeur d'Alene Nursery. Fungicides were applied at biweekly intervals during the spring of 1982; test seedlings were inoculated with spores of B. cinerea twice during the evaluation period. Seedling mortality and height were recorded...
Douglas-fir (Psudotsuga menziesii (Mirb.) Franco) seedlings were outplanted on eight dates (every three weeks from mid-August 2005 through mid-January 2006). On each plant date, seedlings from a conventional dormancy (CONV) induction treatment, including moisture and nutrient stress, and a shortened daylength (SD) treatment were outplanted on three western Oregon sites...
An evaluation during the summer of 1985 showed that parasites were still exerting control on the larch casebearer on the Flathead NF. Parasitism ranged from 4 to 60 percent and averaged 25.2 percent in the 12 areas surveyed. Four species of parasites were involved. The most abundant was Agathis pumila...