Kansas, the top US wheat producing state, could face hefty yield losses next year from a virus that cost it nearly 6 percent of production in 2017, according to a preliminary estimate, as low wheat prices may have deterred farmers from spending money on herbicides. This year's outbreak of wheat streak mosaic virus in Kansas was the worst since 2006, according to plant pathologists at Kansas State University. The disease also struck parts of Oklahoma, Nebraska and Colorado.
Amid a global glut of crops that is depressing prices of corn and soyabeans, milling-quality wheat has stood out as more vulnerable to shortages through adverse weather or disease. Earlier this year, high-protein wheat premiums surged as supplies were hit by drought in Australia and the United States. US wheat plantings for 2017 fell to the lowest in a century, amplifying the impact of crop diseases like wheat streak mosaic that can cause localized shortfalls, forcing grain buyers to widen their search for supplies.
The Kansas Wheat Commission, a trade group, estimated losses this year from the virus at about 19 million bushels, valued at $76.8 million. Total Kansas wheat production will be 324.3 million bushels, according to estimates by the US Department of Agriculture. The wheat streak virus is spread by tiny mites that thrive on "volunteer wheat" - plants that sprout from any kernels left on the soil after harvest in June and July.
To curb the mite population, crop exports say, farmers need to kill those plants with herbicide two weeks before they start to plant the 2018 crop, typically in late September. Not enough farmers did so last year. Some fields may have been infected by mites blown on the wind from volunteer wheat on other farms. A late first frost allowed virus-bearing mites ample time to thrive.
"A lot of people got a serious bloody nose because of negligent neighbors and deadbeat farmers," said Vance Ehmke, who grows seed wheat in Healy, Kansas. He lost crops valued at as much as $250,000 due to the disease. "The wheat streak mosaic virus turned a great crop into an average crop," Ehmke said.
Low cash prices may have discouraged growers from spending money to eradicate volunteer wheat. "The biggest thing is the cost of herbicide and time to send the sprayer, and the fuel to send the sprayer to the field," said Kirk Broders, Colorado State University plant pathologist. "With the wheat commodity prices at such a low point, they are pinching every single penny. And some of them are deciding it's not worth the investment to do it," he added.
Cash prices for wheat are not much better now than a year ago, hovering around $3.30 a bushel Friday in western Kansas. Broders said some farms are so big that growers may not know there are rogue plants, especially in fields left fallow. "They sort of stop paying attention, and sometimes that volunteer comes in," he said.
The Kansas Wheat Commission, Kansas State University and the Kansas Department of Agriculture launched a campaign this summer called "Stop the Streak" to educate farmers about eradicating volunteer wheat. Rick Horton, who grows wheat in Leoti, Kansas, said his family seeded about 3,300 acres of wheat in 2017 and nearly a third were infected by varying degrees of wheat streak mosaic. "If it happens again, there has got to be a monetary penalty attached," Horton said.