Treated seed a key need for wheat growers

Monday, August 24, 2015

Oklahoma wheat producers should be treating their seed now to guard against a potential trespasser making its way through fields in northwestern and central Kansas: wheat flag smut.

The fungal disease poses no threat to people or animals but it can reduce yields. In addition, some countries that buy U.S. wheat have import restrictions on grain produced in areas where flag smut is known to occur.

Bob Hunger, Oklahoma State University Cooperative Extension small grains pathologist, said wheat growers who treat their seed with a fungicide seed treatment labeled to control smuts and bunts can significantly reduce the incidence of not only flag smut but also common bunt and loose smut.

“We haven’t historically seen flag smut in Oklahoma while common bunt and loose smut have pretty much been done away with, thanks to the consistent use of seed treatments,” he said. “Generally, the compounds approved for control of common bunt and loose smut work well against all three diseases, meaning producers shouldn’t have to do anything special provided they are already using treated seed.”

Common bunt, loose smut and flag smut all affect the grain of wheat, but whereas loose smut carries over in the seed, common bunt and flag smut spores can carry over via the seed and in the soil.

“If common bunt or flag smut was observed in a field and that field is to be planted again with wheat, then planting certified wheat seed treated with a fungicide effective against those diseases is strongly recommended,” Hunger said.

Also, if common bunt, loose smut or flag smut was observed in a field, grain harvested from that field should not be used as seed the next year.

“Should a producer have no other viable option but to use grain harvested from such a field as seed wheat, he or she should treat the seed at a high rate with an approved systemic or systemic plus contact treatment,” Hunger said.

Hunger recommends that any wheat grower who is uncertain about proper management practices relative to effective control of common bunt, loose smut and flag smut to contact his or her OSU Cooperative Extension county agricultural educator.

“Our Extension educators have the knowledge and experience to assist wheat growers, as well as access to a variety of helpful educational materials detailing disease verification and treatment options,” he said.

For example, in the case of flag smut, the disease – while relatively easy to manage – usually can’t be observed from the road or above the plant because infected wheat has tillers that are stunted and below the canopy.

“It sounds simple but it’s one of a number of facts wheat growers need to know,” Hunger said.

Oklahoma is the nation’s third-leading producer of winter wheat and fifth-leading producer in terms of total wheat bushels, according to U.S. Department of Agriculture statistics.