Background:
Bacterial leaf streak (BLS) is a plant disease caused by bacterial pathogens that affect various grass species, particularly in agricultural settings. It can be found in field corn, seed corn, popcorn and even sweet corn.
Causes:
BLS is caused by the bacterium Xanthomonas vasicola.
Hosts:
BLS commonly affects grasses, with corn being a notable host.
Scouting:
Bacterial leaf streak begins as narrow leaf lesions with wavy edges that occur between the veins of corn leaves. These 1-inch or longer lesions can found anywhere on the leaf blade, sometimes close to the midrib. They can be yellow, tan, brown, or orange and will look greasy or water-soaked. When backlit, they can appear translucent with bright yellow halos extending from the affected area.
BLS symptoms in corn have been observed as early as the V7 growth stage, first appearing on the lower leaves. It’s more common to see symptoms in the upper canopy after tasseling.
Transmission:
Because BLS is relatively new to the U.S., not much is known about its disease cycle. Agronomists have some educated assumptions about how it spreads: through irrigation, splashing rain and wind-driven rain. However, it’s unknown how far it can travel. Agronomists also believe that a plant must be wounded for infection to occur.
Similar diseases:
Symptoms of BLS can be mistaken for other common diseases like grey leaf spot and common rust.
Management:
– There is little information available for managing bacterial leaf streak.
– Field observations suggest that corn hybrids differ in susceptibility.
Impact:
Researchers have only limited information about how bacterial leaf streak impacts yield percentages but expect BLS-related losses will be minimal if symptoms develop late in the season.
