May 17, 2019
Disease Pressure Across the Regions
As temperatures begin to rise in most parts of the country, so has disease pressure. We talked with WestBred wheat Southwest Regional Commercial Manager Grant Poole about what he is seeing in fields across his area.
“The main things we are seeing are leaf rust, stripe rust and septoria,” Grant said. “Septoria is the number one thing that has been popping up in our region and that’s really been expressed in the last couple of weeks. This year, there was a long, lengthy period where it was just so cool and wet for so long and it really delayed the expression of the diseases. We definitely saw it as soon as temperatures warmed up.”
Leaf rust isn’t typically a common disease in his region, but stripe rust is.
“We battle stripe rust every year and the best preventive method is resistant varieties,” Grant said.
The other treatments Grant recommended to control disease pressure include fungicides with azoxystrobin and propiconazole as active ingredients. “A lot of growers spray propiconazole at herbicide timing as a preventative. Fungicides are a preventative measure and some are systemic and some aren’t, so you just want to make sure you are spraying the right fungicide at the right time,” Grant said.
Powdery mildew has also made a subtle appearance within the region according to Grant. He doesn’t have too much concern for powdery mildew as they are headed toward the finish line in his area and out of powdery mildew’s preferred environmental conditions, and he thinks they are through the worst of it.
Montana and Southern Idaho
For WestBred wheat Technical Product Manager Trenton Stanger, disease pressure hasn’t become a concern for growers in his region. there hasn’t been a whole lot of talk about disease pressure in his region. “Right now, I’ve not heard much about any diseases. The one thing people talk about are some of the virus-borne diseases like wheat streak mosaic and barley yellow dwarf,” said Trenton.
“Barley yellow dwarf seems to be more an issue in southern Idaho when it happens,” Trenton said. “Wheat streak mosaic virus tends to be in Montana; some things are just environmental. Say we have a hail storm that runs through an area. Those areas are usually the ones that are going to have a higher pressure because the green bridge is going to be a little more present and a little more evident.”
Even without signs of disease pressure popping up, for now they are keeping an eye out in Washington and Oregon for stripe rust. “Generally, stripe rust will blow into southern Idaho and sometimes up into Montana,” said Trenton. “Montana is generally a hit or miss year to year. I’ve only seen it in a couple areas, and those varieties that are more susceptible is where it has shown up on.”
Trenton’s advice to growers is to just keep an eye out for any signs of disease pressure throughout the season. “If we know pressure is heavy in Washington and we know it’s moving this way, then let’s be proactive,” said Trenton. “If it doesn’t look to be heavy, if it doesn’t look to be moving this way, I would generally want to just make sure you’re spraying those varieties that are more susceptible versus the ones we know have tolerance genes in them.”