Integrated Crop Management

Progress in soybean rust sentinel plots

Our cooperators have worked hard to establish sentinel plots across Iowa. As of May 1, we have 25 of the 30 plots sown and five plots have begun to emerge. Cool temperatures have temporarily halted plant development. We are thankful that, to date, we have lost no plots to frost.

Our objective with these plots is to have an early warning should soybean rust reach Iowa. Our strategy for detecting rust early is to have known areas where the host and environment will allow disease development and to closely monitor these areas.

So far, soybean rust has only been found in and adjacent to Florida and spores are predicted to move to eastern areas according to the United States Department of Agriculture (USDA) soybean rust site. Once plants in our plots have leaves on them and computer models predict possible spore movement to northern soybean production regions, trained scouts will closely monitor these plots for soybean rust. This great effort is worthwhile because it gives us confidence that we will detect soybean rust early if it reaches Iowa, and early detection will give producers time to apply fungicide when needed.

We are grateful to individuals and companies who provided land and planted these plots. Iowa State University Research Farms put out 10 plots and Croplan Genetics put out eight. Others who put out plots are the Andrew Jackson Demonstration Farm, UAP Midwest, and individual producers who represent the Iowa Soybean Promotion Board, Syngenta Seeds, Pioneer Hi-Bred International, Asgrow Seed, and Garst Seed.

In addition to providing an early warning system for Iowa farmers so that they need not waste resources on unnecessary and ineffective fungicide treatments before the pathogen is present, these plots also will help us learn about the spread and development of soybean rust if it reaches Iowa.

Sentinel plots are being put out in all soybean-producing states. The North Central Soybean Research Program and the United Soybean Board are funding the establishment of sentinel plots in 20 states. The USDA-APHIS is also establishing sentinel plots. This national effort is to help all soybean producers because producers can use information from other states for decision making. You can monitor the scouting and observations of these plots at

The locations of the plots in Iowa are as follows (see map):

County Location
Adair Greenfield
Appanoose Plano
Black Hawk Waterloo
Buena Vista Newell
Carroll Ralston
Des Moines Mediapolis
Fayette West Union
Floyd Nashua
Franklin Bradford
Fremont Sidney
Fremont Farragut
Hamilton Webster City
Hancock Kanawha
Hardin Eldora
Jackson Maquoketa
Johnson Iowa City
Keokuk Keota
Linn Marion
Lucas Chariton
Marion Pella
Marshall Marshalltown
Monona Castana
Muscatine Fruitland
O'Brien Sutherland
Polk West Des Moines
Pottawattamie Lewis
Poweshiek Grinnell
Shelby Harlan
Story Ames
Washington Crawfordsville
Woodbury Sioux City

Iowa 2005 Soybean Rust Sentinel Plots

This article originally appeared on pages 70-71 of the IC-494 (8) -- May 2, 2005 issue.

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