RIM (Resistance Integrated Management program) is a computer based decision support tool designed specifically for evaluating various ryegrass management options. RIM includes the biology and economics of the ryegrass plant in a complex and dynamic framework. In so doing, it tracks the changes through the season in regards to the weed seed germination, weed seed production and weed competition on the crop. The effect of annual ryegrass on the crop manifests itself over several seasons due to carryover of weed seeds into the next step of the rotation.

RIM simulates the effect of many different possible management strategies on ryegrass seed numbers and economic return over a ten or twenty year period. Within RIM there are several enterprises, such as wheat, barley and sub-clover pasture that you can choose from. Through the selection of chemical and non-chemical control strategies, you can evaluate the effectiveness of various scenarios. The economics encountered with each strategy is accounted for and contributes to the financial picture.

Key Features of RIM

• 10 and 20 year options are available for evaluating various control strategies.
• RIM is flexible enough to simulate various cropping environments. Default values are given for all parameters, but spending time localizing the model is very beneficial.
• RIM is based on a single paddock basis and shows most results on a per hectare basis, except plant and seed densities which are shown per square metre.
• Herbicide resistance is simulated by limiting the number of applications for each selective herbicide after which the ryegrass populations is assumed to be fully resistant.
• There is a range of selections for enterprises. They include wheat, barley, canola, lupins or peas for a pulse option, sub-clover pasture, cadiz pasture and volunteer pasture.
• There are many options for integrated weed management control methods.
• Weeds other than ryegrass are assumed to be well controlled. The economics of controlling other weeds have been included in the model.
• RIM allows you to evaluate many cropping/pasture management strategies by analyzing economic data and ryegrass weed pressure.

The developers of RIM include David Pannell, Anne Bennett, Vanessa Stewart, Carmel Schmidt, Marta Monjardino and Stephen Powles. The model was developed with funding from the GRDC.

Another good on-line source of information about RIM is David Pannell's RIM website

The RIM workshop package was developed by Rick Llewellyn, Alister Draper, and Marc Cartwright of the Australian Herbicide Resistance Initiative (AHRI), and the School of Agricultural and Resource Economics (UWA), in conjunction with the Department of Agriculture, Western Australia.

It is based on the original Ryegrass RIM model.

To obtain a copy of RIM please contact Lisa Mayer (08) 6488 7870.