Order form
Background information
Required
hardware and software
Assumptions
of RIM: An overview
How
to use RIM: An overview
The
treatment options included in RIM, both chemical and
non-chemicalRIM - Resistance and Integrated Management
A decision tool for integrated weed management
Background Information
This page is based on Chapter 1 of the RIM User's Manual.
Over the past two decades there have been substantial increases in crop yields in Australia. This has been made possible in part through the use of herbicides as the main method of weed control. As herbicide use has increased, the dependence on tillage and grazing weed control methods has decreased. The area of pastures has been reduced as farmers have responded to price changes for crop and livestock products. The high selection pressure associated with the repeated use of herbicides has resulted in several weed species evolving resistance to the main chemical groups. Where this has occurred, it has led to a substantial loss in income for farmers and has required them to rethink their weed control and tillage systems (Powles et al. 1992).
Of the plant species that have developed herbicide resistance, annual ryegrass (Lolium rigidum) is by far the most serious problem.
So what are farmers to do once they have herbicide resistance on their property? RIM is a tool that can help farmers (and others) grapple with this question.
In a nutshell, what is RIM?
RIM is a decision support system – it is designed to provide information and insights to farmers to help them in their long-term decision making about management of ryegrass. It does this by allowing the user to try out many different combinations of weed control treatments and observe their predicted impacts on ryegrass populations, crop yields and economic outcomes.
RIM represents a paddock. You can specify whether or not the ryegrass population in the paddock is resistant to each herbicide group, or how many shots of each group are available before resistance will develop. A wide variety of non-chemical weed treatment options are included, so that as chemicals are lost, the next best substitute can be identified.
In the Select strategy sheet of RIM you can specify a sequence of crops and pastures, and any valid combination of 35 weed treatments, ranging from selective herbicides to ecological treatments, such as increasing crop competitiveness by increasing seeding rates.
There is a lot of biological and economic detail behind the calculations of RIM. You can adjust most parameters to better suit the region or farming system or specific paddock that you wish to analyse.
What types of questions can RIM address?
Here are some examples of the types of questions that RIM can provide helpful information about:
What regions is RIM designed for?
RIM was created specifically for farmers in the wheatbelt of Western Australia. The standard data values included in the model are selected to be suitable for farms in the eastern part of the central wheatbelt. Before basing any decisions on the results from RIM, it is important for farmers to review the data included in RIM to make sure it is suitable for their farm, making adjustments to the numbers where necessary. This obviously applies to farmers outside the eastern wheatbelt, but it also applies to farmers in the eastern wheatbelt, since every farm is unique. A bare minimum set of data values to review and adjust is included on the Start here sheet of RIM, but you really should also check the values presented on all the following sheets: (a) Control %, (b) Crops & weeds, (c) Pasture, (d) Prices & rates. Also ensure that the number of shots available for each herbicide group is suitable for your situation, given the number of shots used in the past. This is one of the items included for review in the Start here sheet, and it can also be adjusted at the bottom of the Select strategy sheet.
With sufficient effort, RIM could be adjusted to make it useful for non-irrigated crop producers across southern Australia. The Cooperative Research Centre for Sustainable Weed Management Systems is planning to provide this effort and make available adjusted versions of RIM.
When time allows, we also plan to release information about recommended adjustments to the RIM data for regions in Western Australia other than the eastern wheatbelt.
Intended users
We expect that RIM will be useful for a number of different types of users, including:
Background knowledge required
Use of RIM requires some specialised knowledge about agriculture, and a basic level of skill with the Microsoft Excel® spreadsheet package. We have provided in this manual information about the agricultural issues to help people without strong expertise in agricultural management. However, inevitably, there are hidden assumptions about the logic and practice of agriculture that will be unknown to many students and non-farmers. We can only advise that you obtain expert help and advice.
The necessary level of expertise with Excel is not great, but it is not zero. If you are running RIM without expert computer assistance and without experience with Excel, it is strongly recommended that you complete at least the basic tutorials provided with the Excel package.
Order form
Background information
Required
hardware and software
Assumptions
of RIM: An overview
How
to use RIM: An overview
The
treatment options included in RIM, both chemical and
non-chemical