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Bacterial leaf streak of corn

Bacterial leaf streak (BLS), a relatively new disease, has been found in sweet corn in several locations in Minnesota this year.  
green leaf with orange and tan streaks
Bacterial leaf streak in sweet corn
Dr. Vince Frtiz, UMN Extension

What is BLS?

Bacterial leaf streak is caused by the bacteria Xanthomonas vasicola and has been found in sweet corn, popcorn, seed corn and field (dent) corn. This disease was first identified in Nebraska in 2016 and has since been found in 9 states in the Midwest including Minnesota.

How to identify BLS? 

Bacterial leaf streak causes long thin leaf streaks that may be yellow, tan, orange, or brown. The edges of the leaf streak appears wavy.  When back lit, a yellow halo can be seen around the streaks. Streaks first form between leaf veins and extend parallel to the leaf veins. In severe cases, leaf streaks may grow together resulting in large dead brown areas on the leaf.

Many other leaf problems can be confused with BLS. The best way to confirm BLS is through submitting a sample to the UMN Plant Disease Clinic.

close up of corn leaf with tan streaks
Bacterial leaf streak in sweet corn
Dr. Vince Frtiz, UMN Extension

What we know about BLS? 

As a relatively new disease, little is known about the infection cycle of this pathogen. Disease has been observed to increase with rain or irrigation during hot weather. Wounding is not necessary for infection as the bacteria infect the leaf through natural openings for air exchange, called stomata, on the leaf surface. It is believed that the bacterial pathogen can survive in crop residue from one season to the next and that it is spread through splashing rain or irrigation. Research is needed to better understand bacterial leaf streak.

How does BLS affect yield? 

At this time it is unclear how BLS will affect crop yield or quality.

What management options are available?

There are currently no recommended management practices for bacterial leaf streak of corn. Chemical controls are not effective. Different varieties have been observed to have varying levels of disease, indicating that disease resistance may be a viable option in the future. Further research needs to be conducted in this area. Growers with active BLS in sweet corn this year should rotate to a different crop next year. Bacterial leaf streak is commonly observed in areas where corn is grown without rotation.

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