Wheat virus threatens crop in US Plains as farmers save money
Kansas, the top US wheat producing state, could face hefty yield losses next year from a virus that cost it nearly 6pc 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 soybeans, 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 US.
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 19m bushels, valued at $76.8mi. Total Kansas wheat production will be 324.3m 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.