The recent rains that helped perk up heat-stressed wheat fields are creating a new problem for some farmers: a pesky fungus capable of cutting into yields — and profits.
Stripe rust, a disease caused by a fungus that thrives in cool, damp conditions, has shown up in winter wheat in central Montana and other isolated areas, and it's also been detected in spring wheat in northeast Montana, said Jack Riesselman, a plant pathologist at Montana State University in Bozeman.
Rust, which appears as orange or reddish stripes on a plant, won't kill the crop, but it can lead to lower yields and production for some farmers, he said. And it may become a bigger problem if rain falls frequently and temperatures hover below 80 degrees, he said.
Unfortunately, "the crops right now just yearn for a damp, cool July," said Carl Mattson, a farmer and official with the Montana Grain Growers Association. Drier conditions in May took a toll on some winter wheat, he said, and raised concerns about a less bountiful or fruitful harvest in parts of the state. While some farmers still likely will have a "shorter than normal" crop, he said, recent rains also have boosted some producers' optimism.
Montana's branch of the National Agricultural Statistics Service rated last week's topsoil moisture at 80 percent adequate to surplus and 20 percent short to very short — a slight improvement over the previous week. Subsoil moisture conditions also improved.
Riesselman said it's possible that 15,000 to 20,000 winter wheat acres already have been sprayed; an amount equal to that or greater also probably should have been treated but hasn't, he said, possibly because farmers must wait 45 days to harvest after applying the fungicide to a crop approaching maturity.
Spraying also costs farmers $20 to $22 an acre, he said.
Where spraying is an option, Riesselman suggests weighing the cost against what a crop is capable of producing in growing conditions far more favorable than what many farmers saw in the drought-affected, not-too-distant past.
"When conditions for production are favorable, the potential for stripe rust is up," he said.