Description and Symptoms
This stalk rot is not common in Iowa. It can occur any time during the season, particularly if conditions are very wet. It causes decay of the first internode above the soil. The rind and the pith become soft, brown, and water-soaked. Decayed tissue sometimes has a strong odor. The stalk typically twists and falls over, but the plant may remain green for several weeks because the vascular tissue is not destroyed. Plants affected by bacterial stalk rot have a foul odor. Some hybrids are more susceptible than others.
Bacterial stalk rot may occur after extended periods of flooding or high temperatures and and high humidity, or when corn is sprinkler irrigated with surface waters.
• Target fields that have had significant foliar disease.
• Target hybrids with low stalk rot and/or standability scores.
• Evaluate at least 100 plants per field (20 plants in 5 locations).
• Use the "push test" or the "pinch test" to determine standability. If 10 to 15 percent of plants lodge or are rotted, schedule an early harvest.
Photo by Darren Mueller