sealPurdue News

February 27, 2003

Software lends computing power to weed management

WEST LAFAYETTE, Ind. – A software program new to Indiana shows farmers which weed control measures compute and which don't.

WeedSOFT 2003 provides producers customized treatment options for dozens of common weeds, and calculates what those applications will cost and the anticipated yield benefit. Farmers can purchase the computer program for $195. Annual updates are about $40.

WeedSOFT is a joint project of land-grant schools, including Purdue University, the universities of Nebraska, Illinois, Missouri and Wisconsin, Kansas State University and Michigan State University.

The software, available on CD for Windows-based computers, takes weed management to an advanced level, said Bill Johnson, Purdue Cooperative Extension Service weed specialist.

"WeedSOFT is a computerized weed management decision aid that allows you to enter specific weeds and their densities in a crop growth stage," Johnson said.

"The program provides a herbicide recommendation, what your weed control will be with specific herbicide treatments and the potential yield loss associated with not controlling the weeds. WeedSOFT will help you manage or control approximately 80 different weeds. Most of the common summer annual weeds that are present in Midwestern corn and soybean production are addressed by this software."

Johnson recently adapted WeedSOFT for Indiana's unique weed and crop growing conditions. Six other states have, or are developing, versions of WeedSOFT. The original software program that became WeedSOFT was introduced in Nebraska in 1992.

WeedSOFT consists of two modules: WeedVIEW, a photo database for weed identification, and ADVISOR, a diagnostic and treatment calculator. The latter module can analyze herbicide applications ranging from soil applied to postemergence followed by cultivation.

The software is easy to use and requires some basic information, Johnson said.

"There's a series of windows that you fill out when you're using WeedSOFT," he said. "You need to know your soil type, soil pH, the weeds you have and an approximate estimate of weed density. If you're spraying postemergence herbicides, you need to know the crop growth stage.

"What a lot of that information does is allow you to filter out treatments that can't be used under certain circumstances. WeedSOFT helps prevent you from picking the wrong herbicide that could cause crop injury. It takes the information you've entered and generates a list of treatments, ranking them either by the percent of maximum yield or net economic return. WeedSOFT allows you to choose not only the treatments that control weeds the best, but also the ones that cost the least."

In addition, WeedSOFT lists application rates per acre for recommended herbicides and a crop safety rating for each.

Johnson said WeedSOFT is unlike any other weed management software he's come across.

"Most previous weed management decision support systems like this were really a herbicide selector – you put in a couple of weeds and it gave you a herbicide recommendation, but never tried to tie in any economics or yield loss potential," he said. "The thing that makes this software a little unique is that it is a bioeconomic model. We try to factor in how much yield loss is going to occur, even if you control 95 percent of the weeds.

"In addition to being a valuable tool for making decisions, you can learn a lot about weeds by running through test scenarios to see how competitive different weeds are compared to crop growth stages."

Farmers interested in taking WeedSOFT for a test drive can contact their county Purdue Extension office. Many county offices have demo programs. A demo CD also can be purchased for $5, plus shipping and handling, through the WeedSOFT Web site. Click on "What's New" and then the demo link.

Another Web page link takes users to a WeedSOFT order form. Hoosier farmers should make sure to check the Indiana box under "Select a state version."

An order form and additional information also appears in the Feb. 21 issue of Purdue's Pest & Crop Newsletter. The newsletter can be downloaded online.

Writer: Steve Leer, (765) 494-8415,

Source: Bill Johnson, (765) 494-4656,

Ag Communications: (765) 494-2722; Beth Forbes,;

Related Web site:
Purdue University Department of Botany and Plant Pathology

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