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Spring Barley Russian Wheat Aphid Resistance
Study
Near Stoneham, Colorado - Don Mais Farm
M.D. Koch
PROBLEM: Russian wheat aphid Diuraphis noxia (Mordvilko)
resistant spring barley varieties developed by USDA-ARS in Stillwater, Oklahoma
are being tested throughout the region. Don Mais of Stoneham, Colorado has been
influential in helping ensure dryland farmers will have a barley variety with
resistance suitable for this area.
APPROACH: The plots were located approximately five miles
northeast of Stoneham. It is a harsh environment with less normal precipitation
than Akron, Colorado. There is not a weather station near the plot location.
However, precipitation through the past year has been significantly less than
that of Akron. Barley is drought tolerant but this year was hard on the toughest
of plants. There were no aphids artificially introduced to the plots. The
information gathered was to aid in reducing the varieties being examined. Once
it is determined which are suitable for the climatic conditions, aphid
resistance will be evaluated.
The plots were planted 18 March 2002 using a six foot cone
planter. Each plot was six foot by six foot with a border around each
replication. There were four replicates of twenty varieties in a complete
randomized block configuration. Otis barley was used as the check variety. In
the event of an economic natural aphid infestation, Otis treated with 8.3 ounces
per hundred pounds of imidacloprid (Gaucho) was added to compare with the
resistant varieties. There were a few Russian wheat aphids in the plots. No
damage was noted and populations remained very low.
RESULTS: Dolores Mornhinweg with the USDA-ARS in
Stillwater, Oklahoma has been analyzing data taken on the plots at all
locations. For further information on this study contact her at 1301 N. Western
Road in Stillwater, OK 74075-2714 or by phone (405)624-4141 extension 237 or
Mike Koch at the Central Great Plains Research Station, Akron, Colorado 80720 or
phone (970) 345-2259 feel free to leave a message.
FUTURE PLANS: It was a goal of the researchers to reduce
the number of varieties being studied by more than half this past year. This
spring the experiment will be repeated in the Stoneham area. Resistance to the
aphid will be determined on the top yielding five to ten varieties.
The author may be reached via e-mail at:
M.D. Koch
or phone: 970-345-2259. |