Influence of temperature on pine mortality caused by Bursaphelenchus xylophilus
In Illinois (US) experiments were carried out to investigate the influence of temperature on the development of pine wilt in Scots pine (Pinus sylvestris) caused by Bursaphelenchus xylophilus (EPPO A1 organism).
4-6 year old pines were inoculated with pine wood nematodes then incubated at constant temperatures in a growth chamber for 8 weeks and finally placed in a greenhouse with a temperature range of 15-30ø C for 10-12 weeks. At temperatures of 32ø and 30ø C pine wood nematode infection was greater, tree mortality higher and disease incubation shorter than at 25,23,18 and 11ø C. Foliar symptoms also developed faster and more uniformly at the higher temperatures. 95% of all the trees died within the first 8 weeks when incubated at 32 or 30ø C in contrast to trees incubated at 18,16, and 11ø C which died later in the greenhouse.
The authors conclude that high-temperature stress predisposes Scots pine to lethal infections by B. xylophilus.
Sikora, E.J.; Malek, R.B. (1991) Influence of temperature on development of pine wilt in Scots pine.
Journal of Nematology 23, 188-193.