A weed management software program, RIM (Ryegrass Integrated Management), allows users to evaluate the impact of today’s weed management choices across a 10-year horizon. First developed in the 1990s, RIM has been upgraded to include more than 40 updated management options and a user friendly interface. Originally designed for cereal crops in Australian dry environments, RIM is now easily adaptable to other broadacre farming situations and other annual weeds, such as encountered in the US. A key feature of RIM is to explore issues such as the economic impact of herbicide resistance, before practices are implemented in the field.

An article in the new issue of Weed Technology discusses the new features of the upgraded software. Eleven experts with extensive field experience helped update the program contents. Current farming practices and new technologies to combat herbicide resistance are now included in the software. These include harvest weed seed control techniques which are herbicide-free option gaining momentum in both Australia and the US.

RIM was originally developed for the Australian southern grain belt, where ryegrass is a common and widespread weed, competing with crops and threatening the profitability of farming enterprises. Herbicide-resistant ryegrass is challenging the region’s no-till farming methods that heavily rely on herbicides.

By using RIM simulations, more diversified farming methods can be explored, including rotating herbicides, cultivating, burning, burying, high seeding rates, and competing crops. Ryegrass seed germination patterns, plant and seed survival and proliferation, and crop yield losses due to ryegrass can be estimated for various field operations and control options. Because the program simulates the influences of these actions over a 10-year period, long-term effects on crop yields and production costs can be estimated.

The upgraded system allows adaptation to other weed species and cropping regions, which will broaden its usefulness. The programming codes and supporting documents are now available online, and the copyright terms have been redefined to make RIM an open-source software. This wider access and usability may help RIM to play a role in combating herbicide resistance and adopting best management practices.

The authors stress that while RIM is an excellent resource, its true value can be realized by applying it in workshop settings. As a research and extension tool primarily aiming at raising awareness, it can be used to teach those making weed control decisions in the field. RIM can help inform people about herbicide resistance and how to delay its onset as well as promote Integrated Weed Management, a diverse range of weed control methods.

Full text of the article, “Upgrading the RIM Model for Improved Support of Integrated Weed Management Extension Efforts in Cropping Systems,” Weed Technology, Vol. 28, No. 4, October–December 2014, is now available.