Todd Vagts,
crops field specialist
Situation
The soybean aphid (Aphis glycines) is a new pest to soybeans in Iowa and the
United States. First observed in Wisconsin in the fall of 2000, the soybean
aphid has spread to most north-central U.S. Soybean fields over the last three
years. Following two years of isolated infestations across the upper Midwest,
the aphid spread rapidly, in August of 2003, and heavily colonized soybean fields
in the upper two-thirds of Iowa counties, causing widespread confusion over
management strategies and ultimately resulting in yield and economic losses.
Response
In order to develop a consistent message on management strategies and to discuss
control options, several ISU Extension Crop Field Specialists, along with Campus
faculty met, at the ISU FEEL laboratory in early August. Following this meeting,
I developed a Web page to act as a clearing-house for information on the latest
recommendations to manage the aphid outbreak. On this Web page I included management
recommendations agreed upon from our meeting at the FEEL laboratory, recommendations
from neighboring states, as well as photos of leaves with aphids (counted) to
help crop scouts and producers estimate the number of aphids per leaf. I also
posted several crop simulation model estimates on the amount of yield that was
yet to be determined (needed protecting) depending on field location and planting
date.
Impact
After the early August meeting at the FEEL lab, I believe we were able to provide
a more uniform and concise message to growers and consultants on how to best
manage the soybean aphid problem in IA. The soybean aphid web page was heavily
utilized statewide and possibly into other areas of the upper mid-west region,
particularly in August. The soybean aphid home web page was viewed 2,323 times
from August to December of 2003 for a total viewing time of 9,575 minutes (160
hours). Other associated web pages with aphid pictures, aphid leaf counts and
estimated yield set were viewed 3,320 times during the same time period for
a total viewing time of 14,903 minutes (248 hours). Sixty percent of the traffic
on the aphid web page was recorded during the month of August. The use of the
web page allowed rapid information dissemination to those who needed it.
A survey presented to west-central Iowa farmers indicated that 80 percent of the farmers scouted for aphids and 34 percent of those farmers applied a control treatment. Eighty percent (n = 20) of the farmers that directly received notice and a Web link (via e-mail) to the soybean aphid Web page indicated that they are adequately informed about the soybean aphid, vs. only 45 percent (n = 273) of the general farming community.
Page maintained by Linda Schultz, lschultz@iastate.edu
