Effects of Fertilization on the Susceptibility of Scots pine Seedlings to the Large Pine Weevil, Hylobius abietis (Coleoptera, Curculionidae)

1991

21 S.

8 Abb., 3 Tab., 2 Anh.

Bandaufführung

2628

37285

The effect of nursery fertilization on the susceptibility of transplanted seedlings to pine weevil damages was studied in a two-year field trial with paired test plants. The study was based on two experiments: differently fertilized planted seedlings versus naturally regenerated seedlings, or between two differently fertilized types of planted seedlings. No insecticide was used. The seedlings fertilized with NPK were more frequently wounded than those fertilized with PK, or those without any fertilization. In a comparison between NPK fertilized and non-fertilized seedlings, the latter were less susceptible to attack and survived more frequently than the fertilized ones. PK-fertilized seedlings and N-fertilized seedlings performed better, and NPK-fertilized and non-fertilized were equally attacked and survived with the natural plants. When the area of stem bark wounds was related to the size of the plant, the natural plants were less affected than their planted counterparts. The results suggest that seedlings fertilized with less nitrogen, or PK fertilizer, were less attractive and more resistant against weevil attack. PK fertilization or raising seedlings without fertilization could reduce the susceptibility to attack by the pine weevil. However, such seedlings were smaller than their vigorous-looking counterpars. Their overall performance would require more long-term study.