These treatment options are listed in the pest management handbooks mentioned earlier. There are more chemical options for preventing brown spot than for Dothistroma. A different fungus is the pathogen and Scotch pine is the major host, but otherwise spores must be compared to distinguish these two diseases. In the home landscape, some control may be attained by removing fallen needles and helping tree vitality through fertilization and watering practices.īrown spot needle blight is nearly identical to Dothistroma blight. Two sprays are required-one when needles are just emerging in mid-May and another when new needles are fully expanded. The copper fungicides, including fixed or neutral copper compounds and bordeaux mixtures, are registered for use on pine to control Dothistroma needle blight. Prune surrounding plants, control weeds in the area, and space plants properly. Early drop of entire needles is not uncommon, with the period of greatest needle loss from Dothistroma in spring and summer.Ĭultural controls to promote more rapid drying of foliage may help. As the disease progresses, needle tips turn brown and fall from the affected needles, leaving green needle bases. The fruiting bodies are black, pinhead-sized specks in the needle lesions. Laboratory confirmation relies on finding the diagnostic fruiting bodies and spores within the spots.

Look closely at the needles for yellow to brown bands or individual spots. Symptoms of Dothistroma first occur in the fall but may go unnoticed. The problem is more intense in a monoculture, such as a nursery or plantation, than in a landscaped area, but we have seen a fair amount of this needle blight the past year or two in landscaped areas. The disease causes spots and bands on needles, especially in the lower part of the tree. This fungal disease of pine occurs most often on Austrian and Ponderosa pine. Dothistroma Needle Blight and Brown Spot of Pineĭothistroma needle blight has been diagnosed several times in the past week at the Plant Clinic.

Brown spot needle blight treatment