Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
1970
Authors
Sverre SkoklefaldAbstract
No abstract has been registered
Authors
Øystein Austarå T. JonesAbstract
No abstract has been registered
Authors
A.L. FallasAbstract
No abstract has been registered
Authors
Øystein AustaråAbstract
In a further study to assist in estimating the profitability of insect control measures [cf. F.A. 30 No. 6021], 2-year-old Pinus patula plants were artificially defoliated in the rainy and the dry seasons at localities in Kenya, Uganda and Tanzania. Complete defoliation caused a reduction in height and diameter growth of ca. 50% for the year in question. With a few exceptions, ca. 50% defoliation, removing either (a) the youngest, or (b) the oldest foliage, did not significantly reduce growth, nor were there significant differences between (a) and (b). Trees defoliated at the start of the dry season recovered more slowly and showed a greater loss of growth than those defoliated at the end of the dry, or during the rainy season. Growth reduction by short-term 50% defoliation would seem to be economically tolerable, in that measures to prevent it would be uneconomic.
Authors
Øystein AustaråAbstract
Includes, inter alia: a list of the recorded hosts (conifers and broadleaved species) and localities of G. podocarpi in E. Africa; data on the relation of late-instar larval density to degree of defoliation; and natural control, especially by a virus disease and laboratory tests of three insecticides against late-instar larvae.
Authors
Øystein AustaråAbstract
No abstract has been registered
1969
Authors
Finn Roll-Hansen Helga Roll-HansenAbstract
No abstract has been registered
Authors
Bjørn TveiteAbstract
No abstract has been registered
Authors
Jon DietrichsonAbstract
No abstract has been registered
Authors
Øystein AustaråAbstract
No abstract has been registered