Cotton HRMS
The Herbicide Resistance Management Strategy (HRMS) draws together available information, enabling growers and agronomists to understand and manage the risks of herbicide resistance in Australian cotton farming systems.
HRMS for irrigated and dryland cotton, fallow and rotational crops
The HRMS enables you to determine which other weed control tactics can be incorporated into your management system by providing guidance on how much extra time they will give you until resistance develops, and demonstrating the effect they will have on the weed seed bank, which is critical to effectively managing resistance.
Implementing the HRMS in cotton requires fitting a range weed control tactics into real situations with lots of variables. Finding room for 6 different tactics every two years is feasible but can be challenging.
A few of the important considerations are:
- What weed species are you actually dealing with?
- What’s your crop rotation?
- When, and how often, can you include soil disturbance for weed management?
Tables B and C include some example IWM strategies in-crop and during fallows, rated for resistance risk and seedbank control. The most diverse strategies (at the top of each table) maximise seedbank control and minimise resistance risk, but potentially have the highest input costs. In order to fit the HRMS requirements of 6 different tactics every 2 years, aim for a strategy similar to those in the green rows (low or low-moderate risk). Avoid high or very high risk strategies where possible, and remember that if high risk strategies are used in one part of your rotation (e.g. in-crop), you’ll need an even greater focus on reducing risk in the following year to reach the HRMS target.
Non-cropping areas and the HRMS
Areas adjacent to cotton fields such as irrigation channels, head ditches, tail drains, roadways, fence lines and areas next to stock routes can be a significant entry source for resistant weed seeds. Where possible, use a range of tactics to manage weeds in these areas, and do NOT rely on glyphosate to manage weeds in these areas. Prevent survivors of herbicide application from setting seed.
This section is extracted from the 2025-26 Cotton Pest Management Guide.
Access the whole publication on the CottonInfo website.
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