WeedSOFT®: a weed management decision support system

Abstract

WeedSOFT® is a decision support system that was developed to help farmers and consultants in Nebraska with the selection of optimal weed management strategies. WeedSOFT® evolved from HERB, a bioeconomic model for soybean that was developed in North Carolina. The program is composed of four independent modules, namely, ADVISOR, EnviroFX, MapVIEW, and WeedVIEW. ADVISOR helps the user select a treatment based on maximum yield or maximum net gain. EnviroFX and MapVIEW provide environmentally relevant herbicide information and county soil maps that indicate vulnerability to groundwater contamination. WeedVIEW is a visual library of color images and line drawings of 46 common weed species. Over 500 farmers and consultants in Nebraska and adjacent states use WeedSOFT®. As a result of the current regionalization effort, the user base is expected to increase rapidly during the next 2 or 3 yr. This article explains the algorithms implemented in the current version of WeedSOFT®.

Soybean row spacing and weed emergence time influence weed competitiveness and competitive indices

“…Coble and Mortensen (1992) proposed the CI indexing system and suggested that it measured relative weed competitiveness, with larger CI values indicating more competitive weeds. Such a ranking system of weed competitiveness is used in Weed-SOFT, a DSS developed in Nebraska (Neeser et al 2004). WeedSOFT calculates crop yield loss using several input variables and a set of yield loss functions.…”

Performance of WeedSOFT for Predicting Soybean Yield Loss

“…WeedSOFT is one such DSS, which was not specifically developed to model weed-crop interference process, but to assist producers and consultants with weed management decisions, and as an educational tool. It is currently being adopted for use in the north-central United States including Illinois, Indiana, Kansas, Michigan, Missouri, Nebraska, and Wisconsin (Neeser et al 2004). …”

“…The final module, ADVISOR, provides yield loss estimates and weed management recommendations, including a list of herbicide programs based on weed control efficacy (Neeser et al 2004). The main purpose of WeedSOFT is to provide a list of management recommendations based on input variables such as crop species, crop growth stage, densities of weed species, and weed growth stage (Neeser et al 2004). Yield loss is calculated using a competitive index (CI) value for each weed species.…”

“…Expert opinions differ, and results of crop-weed interference studies can vary among years and locations (Bauer et al 1991;Chikoye and Swanton 1995;Cousens et al 1988;Knezevic et al 1994Knezevic et al , 1995Lindquist and Mortensen 1999;Lindquist et al 1996;Lotz et al 1996), whereas CI values also can vary with environmental, edaphic, and agronomic variables (White and Coble 1997). Yield loss calculations in WeedSOFT are modified using an adjusted competitive index (ACI) value to account for relative time of weed emergence and crop row spacing (Neeser et al 2004). WeedSOFT uses a standard ACI modifier across all weed species (Table 1) and is calculated utilizing:…”

“…where CI i is the CI for a weed species (i) in a given crop and CIM i is a modifier that is determined by the weed (i) and crop growth stages (Neeser et al 2004). …”