Biografi

Min forskning fokuserer på Phytophthora og soppsykdommer på skogstrær, juletrær og planter i planteskoler. Siden august 2018 har jeg jobbet på NIBIO ved Divisjon for bioteknologi og plantehelse, Avdelingen for Soppsjukdommer i skog-, jord- og hagebruk.

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Sammendrag

The fungus Neonectria fuckeliana has become an increasing problem on Norway spruce (Picea abies) in the Nordic countries during recent years. Canker wounds caused by the pathogen reduce timber quality and top-dieback is a problem for the Christmas tree industry. In this study, four inoculation trials were conducted to examine the ability of N. fuckeliana to cause disease on young Norway spruce plants and determine how different wound types would affect the occurrence and severity of the disease. Symptom development after 8–11 months was mainly mild and lesion lengths under bark were generally minor. However, N. fuckeliana could still be reisolated and/or molecularly detected. Slow disease development is in line with older studies describing N. fuckeliana as a weak pathogen. However, the results do not explain the serious increased damage by N. fuckeliana registered in Nordic forests and Christmas tree plantations. Potential management implications, such as shearing Christmas trees during periods of low inoculum pressure, cleaning secateurs between trees, and removal and burning of diseased branches and trees to avoid inoculum transfer and to keep disease pressure low, are based on experiments presented here and experiences with related pathogens.

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Sammendrag

Phytophthora cryptogea, P. gonapodyides, P. lacustris, P. megasperma, P. plurivora, P. taxon paludosa and an unknown Phytophthora species were isolated from waterways and soil samples in Christmas tree fields in southern Sweden. In addition, P. megasperma was isolated from a diseased Norway spruce (Picea abies) plant from one of the fields in Svalöv. Inoculation tests were sequentially carried out with one isolate from each of the three species P. cryptogea, P. megasperma, and P. plurivora, all known pathogens on conifers. The same three isolates were used to study a few morphological features to confirm the identification, and temperature-growth relationships were carried out to see how well the organisms fit into Swedish climatic conditions. Seedlings of Norway spruce and Nordmann fir (Abies nordmanniana) were inoculated in the roots and the stems. None of the isolates caused extensive root rot under the experimental conditions, but all three species could be re-isolated from both Norway spruce and Nordmann fir. Phytophthora root rot is currently of minor concern for Christmas tree growers in Sweden. However, the Phytophthora isolations from soil and water indicate the presence of this damaging agent, which may lead to future problems.