Fall Planting Preview

        In general, the cereal crops in Idaho have matured earlier then usual this year because of the hot, dry season. According to the suction trap collections, and the fact that we have had little rain to germinate volunteer grain and cause wild grasses to begin fall growth, it is safe to plant fall grain all locations. We expect that there may be fewer aphid problems than predicted during fall planting this year. 

        We do not recommend the use of at-planting systemic insecticides for winter wheat unless 1) you are planting very early, 2) the suction trap in your area is regularly collecting several Russian wheat aphids or more than 40 greenbugs and bird cherry oat aphids during planting season, and 3) your field is near a heavy infestation of aphids (such as an infested cover crop, late barley  or hay,etc.)

Hay Aphids

        We have collected spotted alfalfa aphids in Parma this last week. There are three species that regularly infest alfalfa, including spotted alfalfa aphids, pea aphids, and blue alfalfa aphids. Pea aphids are by far the most common. These can cause damage at levels of about 100 per sweep. Blue alfalfa aphids are more damaging but much less common. We recommend treatment if the apical leaves are wilted or small and you have several weeks before cutting. Spotted alfalfa aphids are damaging to new plantings. The threshold is one per plant for treatment.

Funded by the University of Idaho Agricultural Experiment Stations and the Barley Commission.

Samples collected August 15 & 22, 2003

*Not running-broke