There are significant resources available to cotton growers and their consultants about management options for specific weeds, efficient ways to utilise alternative control tactics such as cultivation or double knocks and impacts herbicides can have on cotton. The aim of this project was to develop a framework which ranked the various weed control tactics and their effect on glyphosate resistance development so growers have a tool to identify which are of greatest value for their individual situations.

The framework is presented as a herbicide resistance management strategy (HRMS) which incorporates individual or combinations of weed control tactics in cotton farming systems. The objective of the HRMS was that it was based on the principles underpinning sustainable integrated weed management. The draft HRMS was developed based on the 2 + 2 + 0 (2 non-glyphosate tactics in crop plus 2 non glyphosate tactics in fallow + survivor control) current best practice weed control tactics promoted in cotton.

The strategy addresses weed management in both the in crop and in summer fallow phases of the cropping system. The initial HRMS is developed on glyphosate resistance in barnyard grass in herbicide (glyphosate) tolerant cotton which was identified as the highest priority issue currently facing growers. The scenarios modelled include both irrigated and dryland cotton farming systems. The major differences between these systems are the regularity of the summer fallow phase and the extra crop competition effect provided by cotton grown in an irrigated system.

The HRMS was drafted initially by the TIMS technical panel (herbicides) and then opened for a period of consultation to industry stakeholders. Feedback from the stakeholders was addressed and incorporated into the strategy which was then ratified by TIMS. The strategy was presented at the 2014 Australian Cotton Conference.

The strategy will be communicated to industry via inclusion in the Cotton Pest Management Guide 2014, the cotton information team through the various cotton grower organisations and articles in publications including Spotlight and the Australian Cottongrower Magazine.

Resources that would aid adoption of the HRMS include articles in regional media, in field demonstration trials incorporating various weed control tactic combinations and promoting the HRMS as an Integrated Weed Management Tool

The HRMS will be reviewed by TIMS on an annual basis in a similar fashion to the insecticide resistance management strategy which has been in place for many years. It is intended that the strategy will be expanded to include more weed control tactics, modes of action and herbicide tolerant cotton varieties as they become commercially available. The HRMS is a voluntary weed management tool that provides a framework for managing the increasing problem of herbicide resistant weeds.