Fusarium infections in potatoes are common, but more strains are showing resistance to fungicides, according to Mike Harding, a plant pathologist at Alberta Agriculture’s Crop Development Centre.
“Resistance management is an important piece to consider when making plans about how we are going to manage fusarium,” Harding told producers who gathered for the Potato Growers of Alberta’s annual potato conference held in Red Deer, Alta. Nov. 18-19.
“Fusarium is well adapted to survive in Alberta. It is not going away and it has been here longer than we have,” Harding said. He added there is no single way to control the disease, so growers need to use as many best management practices as they can to keep it from destroying an entire crop.
“Fusarium diseases can sneak up or sometimes cause losses that go seemingly unnoticed,” he said.
“They are especially problematic when we try to store potatoes for a long time because people like to eat potatoes all year long.”
Fusarium can cause dry rot, foliar wilt and decay. It is common in potato fields and can attack a plants’ roots and crown, colonize vascular areas and cause tuber rot.
“We don’t have dry rot every year, but when we do it is a big hit,” Harding said. He noted that a national fusarium survey started in 2010 has found different types across the country, including fusarium sambucinum, fusarium coeruleum and oxysporum.
“It is important to understand the biology so that we can make the correct decisions,” he said. “We need to think carefully about resistance management so we don’t lose the products we have available to us.”
Growers who look for potato varieties that carry resistance need to match the disease to the variety, he said.
Other management controls include:
- Avoid planting in fields infested with fusarium
- Use clean seed
- Store in a disinfected facility
- Remove diseased tubers before cutting
- Promote rapid wound healing. The potato skin is an effective protector against fusarium, so try and reduce tuber injury during harvest and handling operations
- Monitor storage conditions
- Use a registered fungicide seed treatment
- Don’t use fungicides with the same active ingredients multiple times. Check products’ mode of action so they can be rotated
- Plant when soil and temperature conditions promote rapid sprout growth and emergence
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