An integrated approach to major disease and weed problems in an expanding Norwegian Christmas tree industry

The Christmas tree industry has evolved rapidly over the last two decades, from being an additional source of income for forest farms with young spruce plantings to currently being run as fir (Abies spp.) plantations on agricultural land, with sophisticat ed cultural measures. Norwegian Christmas tree farmers yearly increase the domestic market share, and exports has increased rapidly from 2006. However, when entering a strongly competitive domestic and not least export marked, high quality, disease free t rees are a prerequisite. Therefore, the overall aim of this project is improved control of fungal diseases in fir Christmas trees based on an integrated pest management (IPM) approach. IPM is a combination of biological, cultural, physical and chemical co ntrol methods. The main focus in the project will be on the serious diseases current season needle necrosis (CSNN), in close collaboration with Washington State University. Furthermore Phytophthora root rot, and Interior needle blight will be addressed. W eeds may influence tree health by restricting air movement, host damaging agents like the rust fungus Pucciniastrum epilobii, and compete with the trees for water and nutrients, thus, part of the project will focus on weed control in the ground cover. Due to high yearly precipitation and steep land in the main areas for Christmas production a satisfactory ground cover is necessary to avoid erosion and obtain high quality trees that do not get soil infested during harvest. The disease and weed problems are not unique for Norway; hence, the project will be anchored internationally.