Corn stunt disease confirmed in Missouri

By Blake Jackson

University of Missouri Extension specialists have identified the first case of corn stunt in the state, raising concerns about potential yield losses.

The disease, transmitted by corn leafhoppers, has already caused significant damage to corn crops in Argentina.

Early symptoms of corn stunt include yellowing or reddening of leaf tips, stunted growth, and the formation of multiple small ears with loose or missing kernels. Affected plants may experience substantial yield reductions.

MU Extension agronomist Tim Schnakenberg first received reports of corn stunt-like symptoms in southwest Missouri counties. Upon inspection, he observed corn leafhoppers in the affected fields, confirming the potential link to the disease.

Laboratory analysis conducted by MU Extension Plant Diagnostic Clinic director Peng Tian confirmed the presence of corn stunt using PCR and gene sequencing techniques.

Infected plants may grow only to half their normal height and exhibit shiny leaves due to honeydew excretion by the leafhoppers. This honeydew can lead to black sooty mold, further hindering plant health.

While fungicides are ineffective against the pathogens causing corn stunt, management efforts can focus on controlling the corn leafhopper population.

These insects are light tan or yellow in color and can be identified by two dark spots between their eyes. They reproduce exclusively in corn and its relatives and can overwinter in grasses.

Cultural control practices, such as early planting, crop rotation, and managing volunteer plants, can help reduce the population of corn leafhoppers. However, it's important to distinguish corn stunt from other factors that can cause yellowing and reddening of corn leaves.

MU Extension specialists are closely monitoring the situation and providing guidance to farmers affected by corn stunt. By understanding the disease and implementing appropriate management strategies, farmers can mitigate its impact and protect their corn crops.

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