Manage Wheat Streak Mosaic Now

There's no insecticide solution; only breaking the green bridge two weeks before planting winter wheat works.

Published on: Aug 22, 2012

Controlling wheat streak mosaic virus disease before planting is getting winter wheat off to a good start.

If you want another good crop of winter wheat next year, take steps to control wheat streak mosasic disease now, advises Marcia McMullen, NDSU Extension plant pathologist.

Key to controlling the wheat streak mosaic virus disease is to break the green bridge through effective use of herbicides and appropriate planting date, she says.

Insecticides are not effective in managing this disease.

Jan Knodel, NDSU Extension entomologist, says she's gotten some questions about trying to control wheat curl mite, which transmits wheat streak mosaic virus.

Wheat streak mosaic life cycle.
Wheat streak mosaic life cycle.

 "The wheat curl mite, Aceria tosichella, belongs to the Acari: Eriophyidae family, and should not be confused with the two-spotted spider mite, Tetranychus urticae, in the Acari: Tetranychidae family. The drought of 2012 has been a bad year for two-spotted spider mite infestations in soybeans, dry beans and field corn. Producers know that the two-spotted spider mite can be effectively controlled with selected insecticides and/or acaricides. However, it is important to understand that these insecticides or acaricides have been tested and they will NOT control the wheat curl mite," she reports.

To prevent wheat streak mosaic virus from being infecting winter wheat, there are two steps:

1) Plant winter wheat during the recommended planting windows: ie. Sept. 1-15 for the northern half of North Dakota, and Sept.15-30 for the southern half of the state. Earlier planting will result in winter wheat emerging when mites are still very active and when grassy weeds, volunteers in the field or adjacent fields, and corn are still green, all of which may harbor the mites.

2) Control volunteer wheat and grassy weeds in a field two weeks prior to planting the next susceptible crop. A two-week window of not having a host present assures that the mite has gone through its life cycle and not found a subsequent host to feed on and transmit the virus.

Source: NDSU Crop Pest Report