Hard to control weeds are nothing new to Wimmera Mallee farming systems. Occasionally weeds that are present have a more local context but investment into their management is somewhat limited, because the issue is more isolated. Rosinweed and Star of Bethlehem are two such weeds affecting areas of the Wimmera Mallee.
Rosinweed
Rosinweed (Cressa cretica var. australis) is a summer growing small perennial shrub commonly located on salt affected swampy land. Some regard it as having great feed value for sheep but its perennial nature and ability to produce extensive root systems, that when broken lead to the establishment of new plants, see its impact on crop production in affected areas significant. It extracts large amounts of water from depth, limiting any value of summer rain, and is difficult to control with many commonly used herbicides without having implications on rotations or costing a small fortune. Practices of cultivation and even sowing are nothing more than a spreading mechanism for this weed and can see the increase in location and numbers of this weed, although it still stays concentrated to those salt affected swampy soils.
Star of Bethlehem
Star of Bethlehem (Ornithogalum umbellatum) is a garden escapee, likely being a popular species in farmyard gardens before it spread to neighbouring cropping land. A bulbous species emerging in winter, Star of Bethlehem successfully shelters in the crop with limited visually effective options in crop and then sets many new bulbs leading to small patches growing quickly. It, like any weed, competes for resources with the crop and has seen growers sacrifice areas of crop by spraying it out to try and keep this species in check.
Localised research
BCG has been engaged by the GRDC to conduct localised research into these two species to look at the spread and impact of the problem, current practices undertaken and their level of success or failure, and screening of options in a controlled environment before taking the best performing treatments to the field to determine the best practices growers can use to manage these weeds in their systems. In addition to this, rosinweed will also be studied to better understand its lifecycle and biology that may inform strategies best engaged to manage problem areas.
Surveys
To understand the scale of the issue and impact these weeds are having on cropping systems, we have a two-part survey to undertake (We know – another survey!). Firstly, a short snap shot of the impact these weeds are having to gain a better understanding of where the areas of impact are, and how much impact they are having. Secondly, for a smaller number of participants (advisors and/or growers), an interview will be conducted to further unpack the impact, strategies employed and areas of potential further research to manage this problematic weeds. While we all get survey fatigue, the best way to try and secure more research into a particular area, is to have good metrics on the impact it is having so please take time to be involved.
The short surveys (via survey monkey) can be found below, they should only take five minutes to complete and if you are keen to let us know more about how you have tackled these weeds and what levels of success you have/have not had please leave your details in the final question and a BCG staff member will be in touch.
Rosinweed Survey
https://www.surveymonkey.com/r/6HM7QGF
Star of Bethlehem Survey
