Margin between the affected tissue, usually reddish brown, and healthy tissue is distinct. Damage by living organisms such as fungi and insects to needles usually occurs in a random, scattered pattern and rarely kills all needles of a particular growth period. Needles are usually affected over varying lengths and often appear straw yellow or light tan in color. Black fruiting bodies of causal fungus may be present on diseased needles. Foliar Chemical Spray Injury Pattern on Leaf Spots are usually uniformly and evenly distributed over the leaf surface, and generally will be of uniform size.
Color is usually uniform across the spot.
The margin between affected and healthy tissue is usually sharp. Injury pattern does not spread with time or move to previously undamaged plants. This site was developed for the Arizona Cooperative Extension , College of Agriculture , The University of Arizona . The University of Arizona. All contents copyrighted.