|Table: Diagnosis and Control of Dothistroma Needle Blight|
|Pest Identification||Host Plants||Damage Symptoms|
|Dothistroma Needle Blight
|In the Midwest:
Austrian, ponderosa and mugo pines
|Yellow to reddish-brown spots and bands on needles.
Dead needle tips: spots and bands girdle needles, causing them to dieback from the tips.
Branch defoliation and dieback, starting on lower branches and spreading upward within the tree.
|Inspect nursery stock carefully, and plant only healthy trees.
Look for symptoms any time during the growing season.
Plant disease resistant varieties of Austrian pine (seed source: Yugoslavia). Avoid planting Austrian pines in open, exposed areas, prone to winter injury. Do not plant susceptible species next to infected trees. Promote good air circulation by adequate tree spacing and weed control. Do not prune or shear trees when foliage is wet.
|Bordeaux Mixture |
|Description and Life History|
Description: This disease can cause significant damage to pines planted
outside their natural ranges. Young trees are likely to be damaged more than
older trees, and seedlings may be killed within 1 year. |
Life history: The fungus overwinters mainly on infected needles on the tree. Infected needles release spores during wet weather during spring and summer. Needles of all ages can become infected, however, current-year needles are immune to infection until they have emerged from the needle sheath.
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