Crop inspections during spring 2017 have revealed relatively high levels of weed escapes in many paddocks. This is largely the result of the wet spring in 2016 which led to high seed set of weeds, plus the dry frosty conditions during 2017 which reduced herbicide efficacy. In some cases, lack of attention to detail has seen weeds spread from firebreaks and non-crop areas into cropping paddocks, while in others, weed issues can be traced back to seed set in the pasture phase.
Many of the weed issues are occurring on the perimeter of paddocks, although in some situations whole paddocks are affected. Regardless, these escapes are a reminder of the precariousness of the weed control situation.
Traditionally it has been said that mixed farmers had an advantage over full cropping operations, due to their ability to clean up weeds in the pasture phase. However in practice, it seems many mixed farmers are losing focus on weed control in the pasture phase, allowing the weed seed bank to build up. By contrast, the full croppers are generally more focused on complete weed control.
Looking forward, it is extremely important that all growers maintain focus on weed control in every part of the rotation. Successful weed control in the future will involve the following:
- Diversity in control method, and timing.
- A systems approach.
- Increased use of non-selective herbicide control measures.
- Increased use of non-chemical control measures.
- Removal of weed harbours such as fence lines.
- A willingness to make short term sacrifices for long term benefit.
- A high level of attention to detail and persistence.
The reality is that there is no room for complacency, growers need to be focused on weeds at every stage of the rotation. A blowout in weed numbers can have a relatively long term impact. Astute managers will be focused on weed control in every paddock, in every year. It is the adaptability of weeds that has made them so successful. Growers, managers and advisors will also need to adapt in order to gain the upper hand.