Abstract
Only in Sweden 360 million conifer seedlings are planted each year but a substantial proportion of these are killed by pine weevils and black spruce beetles. A high survival rate is essential for a high primary production of forest raw materials and biomass. There is currently no suitable non-insecticide plant protection option for a large part of these seedlings. In the proposed project we will investigate a non-insecticide protection method for those seedlings. The method is to trigger the induced defense of the seedlings with the plant activator methyl jasmonate. Methyl jasmonate (MeJA) is a signaling hormone that is produced when a plant is attacked. A treatment with MeJA triggers the production of traumatic resin channels and different types of chemical defense substances. The growth rate is temporarily reduced but this is later compensated by that the treatment decreases the pine weevil damage. Recent experiments have shown that the method have great potential. In one study for example we found that that a MeJA-treatment decreased the mortality of Scots pine seedlings from 40 % to 8 %. The research questions that we will investigate are: 1. Does the effect of a plant activator differ between different spruce genotypes? 2. How effective is a plant activator at different pine weevil pressures? 3. Can the plant elicitor caused reduction in growth rate be exploited? 4. Will the use of a plant activator also reduce the damage by the black spruce beetle?
Sweden