More About RIM A Decision Support ToolRIM is a decision support tool designed specifically for evaluating various ryegrass management options. RIM is an acronym for Ryegrass & Integrated Management. You can use it to assess the likely biological and economic consequences of a wide range of ryegrass control strategies. Its design helps you take into account the development and impact of herbicide resistance. 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. Multi-species RIM; a version of RIM incorporating both annual ryegrass & wild radish weed species has been developed. Copies of Multi-species RIM can be obtained by contacting WAHRI. 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. Notes on Multi-species Resistance and Integrated Management (RIM) This information on the Multi-species RIM model is intended to be used in conjunction with the RIM manual. Multi-species RIM (Resistance and Integrated Management) is a bio-economic model that simulates the population dynamics of annual ryegrass (Lolium rigidum) and wild radish (Raphanus raphanistrum) over a 10 or 20-year period within a farming system. The Multi-species model is a decision support tool designed for the evaluation of various management strategies to control co-existing annual ryegrass and wild radish weed populations in dryland southern Australian Mediterranean-type agriculture. The model includes over 50 different crop/weed management options to influence weed densities and gross margins. How is it different to Ryegrass RIM?
The Multi-species RIM model is based on the Ryegrass RIM model but with the addition of the second weed species (wild radish). The Multi-species model therefore considers plant competition between the two weed species as well as competition between weeds and crop. Groups F, G and I herbicide categories have been added to the Multi-species RIM model for further control options of wild radish. Both wild radish and ryegrass populations are influenced by Group B, C, L and M herbicides. As with Ryegrass RIM, there is the potential to manage herbicide resistance by limiting the availability of herbicide options. Within Multi-species RIM, a canola crop production can either be managed under a “Triazine Tolerant” crop variety or an ‘IMI’ crop variety scenario. However, a temporary program ‘Error!’ will appear if Atrazine and/or Simazine (triazine herbicides) are used in conjunction with “On Duty” (imidazoline herbicide) in the same year of canola production. The 2004 updated version of Ryegrass RIM includes the options of ‘Seed with full-cut cultivation’ and ‘Swathe and apply glyphosate’. These management practices have not been included into the Multi-species RIM model. Multi-species RIM assumes a no-till crop production system. Consistent with modelling data for the potential risk of glyphosate resistance in regards to the double knockdown (glyphosate followed by Spray.Seed), implementing the ‘2 knocks: glyphosate + Spray.Seed’ option within the RIM model does not deplete the number of glyphosate ‘shots’ available. Important note Due to less biological and field research data being available; the wild radish component of the Multi-species RIM model has not undergone the same level of field validation as the ryegrass component. Therefore the Multi-species RIM model should be considered a beta version. Through wider use, feedback from users and the increasing availability of trial data it is intended that the model will continue to be developed. Acknowledgements The Multi-species RIM model was developed at WAHRI and the School of Agricultural & Resource Economics at the University of Western Australia by Dr. Marta Monjardino, with further development at WAHRI by Alister Draper. It is based on the original Ryegrass RIM model. To obtain an edition of Multi-species RIM or for more information on the RIM models, please contact Sueli (e-mail) or phone (08) 6488 7870. | 
