Rotations vary depending upon which nematode is causing problems. Root-lesion nematodes are well-managed by planting winter wheat the first year and spring barley the second year and then letting the field go fallow the third year. Cereal cyst nematodes are best-managed by rotating wheat or barley with broadleaf crops.

Crop damage can also be alleviated to a limited extent by applying extra fertilizer and water. There are no chemicals legally available for wheat and barley growers to kill the two types of nematodes.

OSU researchers have also tested more than 20 wheat, barley and oat cultivars to determine how badly yields are reduced. Most Pacific Northwest wheat varieties don't resist harmful nematodes.

In OSU's tests, nearly every variety suffered severe root injury. Only the hard red spring wheat WB-Rockland prevented cereal cyst nematodes from reproducing while also maintaining consistent yields. UI Stone, a soft white spring wheat, and Buck Pronto, a hard red spring wheat, allowed nematode populations to thrive but still produced a steady crop.

Additionally, University of Idaho, Washington State University, U.S. Department of Agriculture, and commercial wheat breeders are crossing sources of resistance with a number of wheat varieties to create new cultivars that can potentially stand up to the cereal cyst and root-lesion nematodes.

OSU researchers recommend growers have their soil tested for nematodes. Addresses for testing labs, as well as information about management strategies for farmers, are available in two OSU Extension factsheets at http://bit.ly/OSU_ExtBulletin3 and http://bit.ly/OSU_ExtBulletin2.

The U.S. Department of Agriculture, Washington State University and the University of Idaho are collaborators with OSU on its cereal cyst nematode research.

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