Corn Diseases Caused by Bacteria

Diseases caused by bacteria in corn play a significant role in terms of crop loss to both the farmer, and to the novice gardener. Given the right environmental conditions, bacterial infections can flourish and destroy large portions of crops. Early detection and prevention are the best method of control for these common, but devastating diseases.

Goss's Wilt and Leaf Blight

Goss's wilt and leaf blight, caused by the bacterium Clavibacter michiganensis, are serious bacterial diseases that affect corn crops nationwide. According to the University of Nebraska, symptoms of infection consist of dark green water spots, legions on the edges of the leaves and bacterial ooze on the surface of the leaf. The disease initially affects the leaves of the corn plant, but can spread throughout the entire plant. Failure to prevent and treat this disease can lead to plant wilt, which causes substantial loss of crop yield, stalk rot and plant death. The University of Nebraska recommends the use of hybrid genetic resistant corn plants for best control against the infection. However, if infection occurred in the previous season, all infected crops should be removed from the planting area. The infection can winterize which means it survives from season to season; therefore, infection may occur annually.

Bacterial Stalk Rot

Bacterial stalk rot, caused by the bacterium Erwinia chrysanthemi, is a common infection in corn crops. According to the North Carolina State University, the bacteria infects crops when overhead irrigation methods are used, with infection generally taking place on the upper portion of the plant. Symptoms consist of crop collapsing, odor from infected crops and discoloration on the stalk and leaves. The disease is not spread from crop to crop; therefore, bactericides are not a viable solution for control. Typically, crop loss is not substantial and farmers use genetic resistant corn strains to combat the disease.

Stewart's Bacterial Wilt

Caused by the bacterium Xanthomonas stewartii, Stewart's bacterial wilt is a common and devastating infection of young corn plants. According to the Penn State University, symptoms consist of light green to yellow streaks on the margins of the leaf, brown streaks on the margin of the leaf (late symptom) and eventual plant death. Flea beetles carry the disease over the winter months, with infection occurring during the early to late summer months. Warmer temperatures during the winter months have a strong correlation to the amount of flea beetles that will hatch during the spring. Control for this disease consists of insecticide use throughout the season.

Sources:

http://ipm.ncsu.edu/corn/diseases/corn_diseases.html

http://pdc.unl.edu/agriculturecrops/corn/gosswilthttp://vegdis.cas.psu.edu/VegDisases/Identification_files/sweetcorndis.htm