Insect & Disease ID And Diagnosis Guide: Blotches
January 19, 2009 
Seeing blotches on your crops? Take a look at these pictures to see common diseases that can lead to blotches.
When scouting for pests, look closely at individual plants, noting which leaves or other parts exhibit symptoms.
Cloudy black blotches on New Guinea impatiens leaves indicate INSV.
Brown patches on this ranunculus foliage are indicative of infection with INSV.
Water-soaked patches at the base of these ivy leaves are a symptom of Phytophthora palmivora attack, moving up into petioles from the root crown.
Verbenas with powdery mildew sometimes show purple patches on the leaves.
These dead white patches on celosia leaves resulted from sulfur dioxide pollution injury when a poor quality fuel was used for the greenhouse.
Vein-bounded patches signify downy mildew on agastache.
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