Seed World

Cutting Through the BLS: A Guide to Building Knowledge on This Disease

Bacterial leaf streak (BLS) is a plant disease in cereals caused by the bacteria Xanthomonas translucens. It manifests as streak-like lesions on the leaves of infected wheat and barley plants and can affect various crops depending on the specific strains of bacteria involved. To safeguard your crops and mitigate the impact of BLS, it is essential to understand the disease and implement responsive measures. Here’s what you need to know:

Know the Enemy: Understand BLS

Bacterial leaf streak is not a single disease, but a term commonly used to refer to different strains of Xanthomonas translucens. These strains can cause disease in different plant hosts, with two prevalent strains identified in Canada: one primarily affecting barley (pv. translucens) and another affecting both wheat and barley (pv. undulosa). Recognizing the specific pathogen is helpful for surveillance and research projects.

Grasp the Impact: Protecting Canadian Agriculture

The impact of bacterial leaf streak on Canadian seed and agriculture is significant. Infected crops experience reduced yield and grain quality, resulting in economic losses for farmers. Moreover, the disease spreads rapidly, posing challenges for disease management and potentially affecting neighboring fields. Taking proactive measures is vital to protect your seed and minimize the impact.

Use Technology: The Power of Real-Time PCR

Efforts are underway to detect and monitor the presence of bacterial leaf streak. Real-time polymerase chain reaction (RT-PCR) techniques are commonly employed to identify and differentiate specific strains of Xanthomonas translucens causing the disease. This DNA-based testing method enables quick and accurate detection, empowering farmers to gain insight into local crop pathogens.

Photo: Maria Costanza Fleitas

Continue to Learn: Take Notes

a. Beware of Host Weeds: The presence of host weeds significantly influences disease spread. Certain perennial grasses growing in ditches can host bacterial leaf streak and serve as a source of infection for different crops. Monitor and manage host weeds in and around your fields to reduce the risk of disease transmission.

b. Watch the Weather: Know the impact of weather and irrigation on the disease cycle. The combination of warm days, high moisture, and winds are dynamite for disease transmission and bacterial colony replication.

Test for Confirmation and Troubleshooting

In Field: Diagnosis of plant pathogens is complex and at times tricky. If you observe symptoms of what you believe is bacterial leaf streak during the growing season and wish to confirm its presence, a RT-PCR test can provide straightforward results indicating whether the pathogen was ‘Detected’ or ‘Not Detected’.

Seed: New 2023 published protocols have improved testing specificity, and therefore accuracy. Reach out to SGS at to understand how results will deliver knowledge to your business.

Protecting your crops from bacterial leaf streak necessitates a proactive approach: understand the disease cycle, utilize reliable detection methods, and keenly watch the impacts of weather and irrigation management. Stay vigilant and informed of new developments of BLS.