Aberdeen, Idaho, USA
September 17, 2013

This year’s harvest shows a fungal disease is a growing threat to wheat yields and prices for southeastern Idaho farmers in particular, a University of Idaho Extension plant pathologist says.

Juliet Marshall said headblight or scab, which is caused by Fusarium fungi, is costing farmers as much as $1.50 a bushel as they bring their wheat to grain elevators after harvest.

“I’m hearing lots of complaints from growers about being docked 45 cents to $1.50 a bushel because of headblight,” Marshall said.

Klasic, a hard white wheat grown mostly in southeastern Idaho, seemed to be one of the varieties hardest hit, she said. “It’s a 30-year-old variety, but it is highly prized for its taste and its baking qualities.”

The problem has been growing in severity for at least the last four years, Marshall said, and coincides with the increase in corn production.

The Fusarium fungus favors corn as a host and persists in debris left after harvest, Marshall said. In southeastern Idaho’s arid climate, corn debris can persist for several years and harbor the fungus.

Klasic wheat was hit hard this year, Marshall suspects, because it flowered as the fungus was releasing its spores. Unusual weatherconditions may have played a role in setting up the unfortunate overlap.

Although harvest is the moment of truth for growers, field monitoring and action during the growing season can lessen losses to the fungus, Marshall said.

Growers can apply fungicides to protect grain at flowering from infection, the most susceptible growth stage for infection. Fungicide treatments then can lessen but not completely control the damage.

Changing crop rotations to increase the time between corn and spring wheat plantings could also help. So could switching wheat varieties to lessen the threat because other wheats may flower at different times or have more resistance to infection.

Increasing the seeding rate, growing more plants in the field, can also shorten the length of time the plants are flowering. And that can make it easier to protect the plants from infection.

Marshall said she’s confident wheat growers will adapt to the growth of corn plantings and its fungal hitchhikers, adding, “It’s a problem they’re going to have to live with.”
 

Website: http://www.uidaho.edu

Published: September 17, 2013