Effects of winter storage temperature and age of Pinus sylvestris seedlings on the occurrence of disease induced by Gremmeniella abietina

Three winter storage temperatures, -7 degrees C, -3 degrees C and 0 degrees C, were studied to determine their effects on the infection of Scots pine (Pinus sylvestris L.) seedlings by Gremmeniella abietina (Lagerb.) Morelet. Pine seedlings in the first and second growing seasons were inoculated wit h conidia on two different occasions during the season. After the following winter, seedlings were examined for symptoms of the disease. The seedlings overwintering at -7 degrees C and - 3 degrees C were more diseased than th ose kept at 0 degrees C. Seedling bud break was slower the lower the winter storage temperature, suggesting that growth initiating activity has a like ly effect on the outbreak of disease.