September 25, 2009

Many factors can lead to the development of stalk rot diseases in corn.  In general, pathologists agree that plant stress from a number of sources can increase the incidence and severity of stalk rots.

A balance exists between the plant's priority to fill grain with carbohydrates and its ability to produce carbohydrates.  Loss of leaf area caused by extensive foliar disease(s) reduces the plant's photosynthetic machinery that produces carbohydrates.  Maintaining optimal soil fertility, particularly the balance between the macronutrients, nitrogen, and potassium, is important to this process.

Risk Factors

• Hybrid susceptibility
• Moisture stress, either excessively wet or dry weather
• Plant injury (such as that caused by weather events or insects)
• Foliar diseases can reduce photosynthetic leaf area predisposing the plant to stalk rot
• Unbalanced soil fertility, especially nitrogen (both in excess and deficient) and potassium deficiency
• High plant populations that lead to thinner stalks
• Cloudy weather may favor the pathogen and allow for reduced photosynthetic activity
• Extreme temperatures favor some stalk rot pathogens
• Infected residue in the field. Consider burying debris, crop rotation, and/or plant resistant varieties
• Continuous cropping. Crop rotation can reduce the incidence of stalk rots, but be aware that some stalk rot pathogens can affect other crops.
   

More Information

Learn more about the symptoms, scouting and treatment of stalk rot diseases common to Nebraska in Stalk Rots Already a Problem in Some Nebraska Fields and Common Stalk Rot Diseases of Corn.

Tamra Jackson
Extension Plant Pathologist