Articles by Jukka Selander
Category : Article
Two-year-old containerized Scots pine (Pinus sylvestris L.) seedlings, raised under different fertilization and watering regimes, were subjected to feeding preference tests with pine weevils (Hylobius abietis L.) in a bioassay. In the tests carried out with pairs of seedlings, the weevil preferred water-stressed seedlings to well-watered ones. In the case of well-watered seedlings, the weevil caused significantly more damage to NPK-fertilized seedlings than those given pure PK fertilization, or no fertilization at all. It is apparent that PK fertilization reduces, and water stress increases seedling susceptibility to weevil damage. The results support findings from field trials that water stress (planting shock) predisposes seedlings to weevil damage. Weevil resistance is discussed with respect to fertilization and water stress as determinants of seedling quality.
The PDF includes an abstract in Finnish.
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Selander,
E-mail:
js@mm.unknown
- Immonen, E-mail: ai@mm.unknown
The dying-off of more trees in an over-aged Norway spruce (Picea abies (L.) H. Karst.) stand caused by Ips-bark beetles was reduced by a pheromone preparation, ipslure. 20 preparations placed in trapping bolts captured more than 13,700 specimens of Ips typographus L. and Ips duplicatus Sahlb., which alone corresponded to a saving of five old trees in this valuable exhibition and seed collection stand. Attractance of ipslure to the following predators of bark beetles was also examined; Thanasimus formicarius, T. rufipes, Epuracea bickhardti, Rhizophagus ferrugineus, Pityophagus ferrugineus.
The PDF includes a summary in English.
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Selander,
E-mail:
js@mm.unknown
- Nuorteva, E-mail: mn@mm.unknown
The development of Scots pine (Pinus sylvestris L.) seedlings and damage caused by Hylobius abietis L. (Coleoptera, Curculionidae) were studied during a three-year period. Olfactory responses of H. abietis was studied in laboratory with several volatile oils isolated from different kinds of P. sylvestris seedlings. Resistance of seedlings against H. Abietis was evaluated in terms of their monoterpene composition. Three aspects of resistance (preference, antibiosis and tolerance) were evaluated separately. Seedling chemotype was found to be associated with these aspects of host resistance on only minor scale. Discussion was attached to a further search for host resistance arising from other properties and constituents of oleoresin. Height growth of the seedlings recovering from weevil damage was 86–91% compared to healthy seedlings.
The PDF includes a summary in English.
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Selander,
E-mail:
js@mm.unknown
- Kalo, E-mail: pk@mm.unknown
The purpose of the study was to find out whether Fomes annosus (now Heterobasidion annosum) growing in a Norway spruce (Picea abies (L.) H. Karst.) stump can, with its mycelium, take up the radioactive isotopes 3H, 33P and 125I in the heading, and whether it transfers them via the sporophores in situ to its basidiospores. Wood material in close proximity to active sporophores was injected with radioactive isotopes. All isotopes could be verified from the basidiospores. The production of viable basidiospores by sporophore was reduced by the isotope injections. This latter result may be of importance e.g. in meteorology for observation of the movements of air masses.
The PDF includes a summary in English.
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Kallio,
E-mail:
tk@mm.unknown
- Selander, E-mail: js@mm.unknown
- Uusi-Rauva, E-mail: au@mm.unknown
