Friday, October 28, 2011

Be a Good Neighbor! Destroy Volunteer Cereals

There are some fields of winter wheat in our area that were heavily infested with aphids, probably Bird Cherry Oat Aphid. They vary in color from orange green to olive green, and sometimes are greenish black. The aphid itself DOES damage the crop. “Heavy populations may cause a golden yellow streaking on the leaves; do not confuse this with the white streaks caused by Russian wheat aphid. Occasionally heavy populations cause the flag to curl up in a tight corkscrew fashion that may trap the awns, resulting in a fish-hook appearance to the head. Leaf curl caused by the bird cherry-oat aphid resembles a corkscrew, while that by the Russian wheat aphid resembles an upright soda straw.”

In addition, bird cherry oat aphid WILL vector barley yellow dwarf virus! These fields had symptoms that to me, indicated infection by BYDV, but molecular testing will need to confirm this before we can say for sure.

General recommendations – CONTROL VOLUNTEER wheat and barley! Delay planting winter grain to reduce the potential for a green bridge. Cold temperatures should kill most of these insects.

Bird cherry-oat aphid populations are usually kept under control by a combination of predators and parasites (see APHIDS – GENERAL CONSIDERATIONS  ). Before considering chemical controls, evaluate the activity and control potential of these natural enemies.

For additional information, contact your extension educator,
Juliet Marshall
Associate Professor, Cereals Pathology and Agronomy
Idaho Falls R&E Center
1776 Science Drive Suite 205
Idaho Falls, ID 83402

208-529-8376 office
208-390-4859 cell

http://www.cals.uidaho.edu/scseidaho/

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