Search results for "Douglas fir"
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Nutrient disturbance through manganese accumulation in Douglas fir
1998
Abstract The disturbance of the nutrient balance induced by a surplus of manganese is discussed as the main cause of the disease striking Douglas fir. In this context a close examination of the iron balance is of great interest. Despite high total iron content, damaged Douglas fir show symptoms similar to that of an iron deficiency chlorosis in which the redox state of iron seems to be affected (physiological iron-deficiency). The first results of the project strengthen this assumption. During this research project iron dependent systems (e.g. activities of iron dependent enzymes, structure of chloroplasts etc.) are being scrutinised by the use of various microtechnical and chemical methods…
Qualité et performance de plants de Douglas soumis à différentes contraintes hydriques
1999
An experiment was carried out on 12 Douglas fir seedlings lots that were 3 years old and had all originated from the same seed lot. Treatments consisted in combining stock type with three different height to diameter ratios, storage duration and method (long at 2°C or short in various conditions), and protection from desiccation (by bagging or not). Seedling lots were assessed at planting by root electrolyte leakage (REL), root moisture content (RMC) and predawn shoot water potential (Ywp). They were planted simultaneously in well-watered or water-stressed conditions. Performance level was based on survival and height growth at the end of the growing season. Slender seedlings not bagged had…