b"At 20/20 Seed Labs reports of the disease started as an increasing number of incidents of crop disease that werent responding to fungicide treatments. Kenward explains most diseases that growers expect in crops are associated with a fungus so to find a disease in field thats not able to be treated by a fungicide can be a surprise.The seed lab in recent years has started to offer a DNA test on seed to diagnosis BLS infections. During the 2023 growing season, 20/20 Seed Labs also started testing tissue samples also in order to do comparison tests and learn at what levels of infection the symptoms appear at. Our pathologist would have a really good hard look at suspect leaves to assess the amount of damage and check for evidence of bacteria under the microscope. We would then run the DNA test to measure how much Xanthomonas was present. There were a few instances when we detected bacteria but at low levels that werent sufficient to account for the level of damage seen on the tissue, Kenward says. While the disease is being studied, as of right now there isnt much growers can do to manage BLS during the growing season. As its a bacterial and not fungal disease, fungicides dont work to treat it. Turkington says research is showing the bacterium doesnt survive in fields long term, so a two-year break from growing cereal crops could help reduce incidence in fields.As we see more widespread development, more build up in individual fields, the residue aspect will become important especially in cereals especially under short rotations or continuous A barley crop at the screening nursery for barley at Agriculture and Agri-Foodproduction, Turkington adds. However, even if you rotate to Canada Lacombe, it has a moderate bacterial leaf streak infection.non-host (crops), volunteer cereals, if not managed effectively, can PHOTO: KELLY TURKINGTON support infection and development.Farmers are also recommended to make sure theyre using a clean seed source not infected with BLS. Seed tests for infection can be If you get really heavy infections or high up into the plant, itdone by 20/20 Seed Labs, SGS Biovision Canada and Discovery affects filling of the kernels causing reduced kernel size. So inSeed Labs. If growing a crop under irrigation or if there are wet addition to yield loss, you'll also get less healthy seed off of itconditions during the growing season, farmers should scout their because it just won't have as much nutritional value to it, Kenwardfields for any possible infections.explains. Scouting is a good measure to give the farmer an idea of if a It impacts cereal crops including wheat, barley, oats, triticaledisease is present. It's recommended to scout starting at the in-crop and rye. BLS is primarily a seed-borne disease. Infection happensherbicide timing and all the way into when the leaf tissues start to when its warm and humid out, theres a susceptible host and thenaturally senescence, Ruoxi Xia, agronomy extension specialist pathogen is present. It spreads through oozing masses of bacterialwith Alberta Grains, says during a phone interview. (Scout) cells splashing moisture droplets from infected plants onto non- especially after a major rain or thunderstorm events, because that's infected plants, and from the lower to upper canopy. It can also bewhen humidity is high, and the bacterium can be blown in by the spread through infected seeds.storm.It has to have a susceptible host that's alive. And then it has toHarding adds that theyre seeing BLS in more fields each year at have enough moisture that the bacterium can grow and divide,levels that can cause economic impacts on crops. During the 2023 and it has to be between about 15 degrees Celsius and 30 degreesgrowing season it was discovered in new fields which hadnt had Celsius. If all those conditions are met, it can get going, Hardinginfections in the past. explains. It's not like an epidemic that's widespread across the province, While bacteria leaf streak has been present in Alberta for a fewit's still relatively isolated. But we're not seeing the spread and the decades, as of late there has started to be increased incidence ofnumber of fields, and the number of producers affected, we're not it in fields under irrigation. Frequent and heavy rainfall can alsoseeing that really slow down, he adds. It's definitely something cause symptoms to pop up, but with drier conditions in Albertathat cereal producers across the Canadian Prairies should be aware during recent years BLS infections have mainly been discovered inof and be scouting for.irrigated cereal crops. Ashley Robinson16seed.ab.ca"