Weed Management Planning

Published on 22 January 2019

Weed management program

As we come out of a fairly temperamental summer, with late December rainfall and variable January conditions, a lot of areas are carrying large populations of opportunistic weeds. No matter what the farming system, these weeds have the potential to impact on production and performance of pasture and crop as a green bridge host for pests and diseases, as well as competing with desirable plants for nutrients, water and light.

Throughout the year, the Surf Coast Agribusiness Digest includes articles to help identify and manage weeds of particular concern in the Surf Coast Shire.

It’s important to go into the season with a weed management plan as a part of your whole farm plan.

Having a well designed weed management plan, and keeping accurate records is critical to managing herbicide resistance. Planning for key weed emergence and control times, keeping track of application rates and herbicide types, and tracking knockdown rates after application all help to identify resistant plants and prevent seed set before emerging resistant populations can develop.

Key features of a good weed management plan include:

  • Identified weed species list – knowing what weeds you’ve got on the farm allows you to plan your management options and control timing. It can also help to spot new weed species incursion a lot sooner, giving you the chance to eradicate before they become a major infestation.
  • Identified weed population locations – know where you’ve had weeds in the past, track progress of control, identify any areas of new weed invasions.
  • Planned crop or pasture varieties and grazing rotation – with some herbicides having plant back periods and residual effect spanning 12 months or more, going in with the wrong management control can be a costly mistake. The same applies to withholding periods if the crop is going to be grazed.
  • Application record from previous seasons – keeping track of what’s been applied to manage weeds in previous years, as well as observed levels of control can help to avoid selecting for herbicide resistant populations, as well as avoiding costly mistakes of having to re-treat paddocks.
  • Accurate application records – as well being a compulsory requirement for application of any agricultural chemicals, maintaining accurate records of applied chemicals will reduce the risk of poor control of weeds or rejection of produce due to exceeding maximum residue limits (MRLs).

It should be noted that while keeping accurate records of non-chemical weed management practices such as stubble burning, slashing, solarisation or manual removal are not necessarily required under chemical use legislation, these records can help to track responses to all control techniques and relative effectiveness of all control options.

Please be aware that an Australian Chemical User Permit (ACUP) is required for receipt, transport and application of all agricultural chemical formulations, including those approved for use on organic certified farms. For Livestock producers, it is your obligation to keep accurate chemical application and brought in feed data under the Livestock Production Assurance (LPA) program.

There are a range of weed management planning resources and guides for reducing the impact of herbicide resistant weeds available online from: