Many conifer samples showing needle diseases have been arriving in the Plant Disease Clinic. Most of these diseases can be diagnosed by carefully examining needles. Rhizosphaera needle cast , is a needle disease of spruce, most commonly on blue spruce.
Symptoms usually begin on lower branches and spread to upper branches.
Diplodia tip blight affects primarily Austrian and Scots pine in Iowa. The most obvious symptom is stunted, brown shoots with short needles. Small black fungal fruiting bodies usually can be seen at the base of infected needles in the fall. Small black fungal fruiting bodies may also be seen on the scales of infected cones. The disease causes annual destruction of buds and shoots.