WAMITT – the Weed Action Management Integrated Threshold Tool – is an Excel model that reproduces, in an accessible and dynamic form, two decades of work on weed management decision-making in cotton. The critical period for weed control work conducted by Dr Graham Charles (NSW Department of Primary Industries and Rural Development, Australian Cotton Research Institute, Narrabri) involved painstaking data collection on the planting and removal of mimic weeds in cotton crops over 20 years. This resulted in a huge dataset on crop-weed competition and yield penalties, and an almost-as-large set of statistical models that describe the relationships between crop age since planting, weed emergence time, size and density, and the cost of proposed weed controls. Such a multi-dimensional problem space is very hard to capture in diagrams, so we devised a decision support tool that would allow the user to choose a model, set parameters, and see the outcome. In this way, students can play with the problem and learn about solutions, and growers can be supported to make real-world decisions about weed management with potentially very large economic ramifications.

The work of building WAMITT was supported by the NSW Department of Primary Industries and Rural Development and the Australian Cotton Research and Development Corporation.

WAMITT is a simple Microsoft Excel file with no macros, and is free to download here.