Weeds face a new foe this year, thanks to the development of a computer software program called WeedSoft 2002. The program allows users to determine the severity of weed pressure within a field, recommended herbicide options for control, and the ramifications of treating or not treating, both in bushels and dollars gained or lost.

“That’s what strikes me most about the software,” says Chris Boerboom, University of Wisconsin weed scientist. “It’s the only program I know of that layers in the economics, so you can see what kind of return you’re getting for the $30 or $40 you’re investing per acre for weed control.”

Designed for the Midwest. University weed scientists, led by Alex Martin at the University of Nebraska, designed WeedSoft 2002. In this introductory year, the software is available for use in Illinois, Kansas, Missouri, Nebraska and Wisconsin. It has been customized to fit the weed profiles, competition ratings and herbicide programs for corn and soybean crops in each of these states. It also includes information for additional crops such as wheat in Kansas and sugar beets, wheat and grain sorghum in Nebraska. University researchers anticipate the software program will become available in other states as the software is further customized. Michigan and Indiana will introduce their versions in 2003.

Economic benefits. Weed scientists say WeedSoft offers significant economic benefits when a crop grower is trying to determine whether a second herbicide application, or respray, is needed. Bill Johnson, University of Missouri weed scientist, offers this common Missouri scenario. “Perhaps you used a soil-applied herbicide in the field early on, but now you have 20-in. corn with three or four giant foxtail showing up about every 100 sq. ft. You plug in the weed counts, and the software in turn tells you the potential yield reduction from not treating, as well as your possible treatment options and the net gain in dollars per acre from treating.”

That type of detailed economic information, say both Johnson and Boerboom, can quickly cover the $195 price of the software. Boerboom adds that row-crop growers also benefit from the various crop rotation scenarios the software helps address. “For Wisconsin, the software gives a heads-up on what herbicides could pose a carryover problem the following year if you were to rotate to alfalfa or small grains,” he explains. “The software filters out those products, so they aren’t even options for use.”

Primary modules. The software runs off a Windows-based system and includes up to four modules, depending upon the state. The two primary modules are Advisor and WeedView, which are included in all versions of the software. The Advisor module allows a user to insert information about the crop, soil and weeds present. It then sifts through herbicide control ratings for those weeds, based on trial results in that state, and then lists treatment scenarios, expected costs and expected return on investment. “You can enter the data and have the recommendations within about three minutes,” Boerboom says. “It’s a pretty quick process.”

The WeedView module is a photographic database to help farmers confirm weed identity. Approxi-mately 64 grass and broadleaf weeds are included, with some variations from state to state, depending upon the economic significance of the weed, Johnson says. Photos of each weed at various growth stages, including photos of a seedling and seed head, are provided in the module along with a line drawing of the weed.

Leaching patterns. Two additional modules, EnviroFX and MapView, are currently available only for the Nebraska-based version of WeedSoft. EnviroFX calculates a herbicide’s mobility and vulnerability for leaching to help users avoid groundwater contamination.

MapView allows producers to use digitized field maps and soil maps to assess a field’s potential for groundwater contamination.

Johnson emphasizes that WeedSoft works best as a supplement to weed biology guides and not as a replacement. To purchase the software, call 402/472-1544. Updated versions should be available each year for about $40. In some of the states, copies of WeedSoft 2002 have been made available for demonstration at county extension offices. See your local extension specialist for more details.