'RIM' joins fight against ryegrass by Brendon Cant

A new software package for managing herbicide-resistant ryegrass could put millions of dollars into farmers' pockets.

According to University of Western Australia researcher David Pannell, the Ryegrass Integrated Management (RIM) package could help growers to increase their returns on each hectare affected by herbicide-resistant weeds.

Associate Professor Pannell said the package, developed with support from growers and the Federal Government through the GRDC, assessed the likely performance of a wide range of weed-control strategies when herbicide resistance entered the farming equation. It was also useful for farmers who did not yet have a resistance, problem but who wished to explore delaying tactics.

The model has been adopted by the Western Australian Herbicide Resistance Initiative and will form a key plank of the program.

Pasture phase costs and benefits

An example of what RIM can do for the grower is its ability to look at the costs and benefits of introducing a pasture phase into a continuous cropping program.

"Many crop producers are understandably reluctant to include a pasture phase, but resistance is forcing them to consider it seriously," Professor Pannell said. "It is very difficult to properly consider all the pros and cons, since they are hard to predict and occur over a number of years, but RIM is an excellent tool to help in weighing up the decision.

"If a pasture phase is needed, its optimal timing and length depend on a whole complex of factors, such as how well weeds are being controlled within crops, prices of grain and wool, and which herbicides are still effective," Professor Pannell said.

Because some of these factors vary from farm to farm, decisions about pasture phases may also vary. RIM will help growers make informed decisions for their own situations.

Program 3.3.3 Contact: Associate Professor David Pannell 08 9892 8495

To order RIM, contact Robert Barrett-Lennard, WAHRI, Faculty of Agriculture, University of Western Australia, Nedlands, WA 6907, ph: 08 9380 7870. Price: $50 (including postage)

More information about RIM and a printable order form are available at the RIM web page: http://www.generd.uwa.edu.aU/u/dpanneU/rim.htm