Crowded or shaded situations should be avoided since they are conducive to development of soft rot. Sanitation is also very important. Cleaning up all plant debris on which the borer eggs overwinter in the fall or very early spring will cut down materially on borers. Leaves with early symptoms of disease can be cut well below the water-soaked areas and must be done before the bacteria reach the rhizome. Leaf spot, Xanthomonas .
Symptoms appear as translucent, irregular spots on the leaves.
These are dark green and water-soaked during wet weather. When many spots develop, they coalesce and the entire leaf appears to be involved. This symptom is often confused with Didymellina leaf spot. The bacterium does not invade the rhizomes as is the case for soft rot. Sanitation is very important to minimize the impact of this disease.