stable fly BUSINESS
VEGETABLE GROWERS
come together to problem-solve the stable fly scourge
Managing stable fly in the Shire of Gingin
In the Summer edition of WA Grower magazine, I mentioned in my article, ‘Shire of Gingin, Tackling the Biting Fly Scourge’, “we still have some way to go”. This statement is a reference to the on-going commitment by vegetable growers to make necessary changes to tackle the problem.
Words Mick Emmanuel, Stable Fly Officer, Shire of Gingin
PHOTOGRAPHY DPIRD
GROWERS have pledged their support for sharing ideas and adapting their practices to realise better outcomes regarding stable fly breeding. In my role as the Shire-appointed Stable Fly Officer, I act as a communications resource, sharing ideas and fresh approaches with all growers. This approach is well-received with farm managers and owners, alike.
One of our more important approaches is our annual Vegetable Growers Workshop focused on mitigating stable fly breeding.
On the 2nd April, 2025, we held our second annual workshop at the Guilderton Country Club. The workshop is an opportunity for vegetable growers to work together on problems and issues impacting us all. It is a very effective problem-solving and decision-making forum.
Farms represented included: Brookrise Farm, Loose Leaf Lettuce, Trandos Farms, Greenacres, T & C Do and Son Farm, Monte Farms, Bogdanich Farms, Sumich Farms. Also present were, vegetablesWA, Ms Katrina Hill and Mr Chi Nguyen.
Summarising the session
The session commenced with a brief outline of the season so far. The winter was unusually warm with regular rainfall, resulting in stable fly breeding extensively through the winter period (in non-irrigated farming properties). Unfortunately, in turn, this led to a huge outbreak of stable fly through spring and summer.
Videos
A few short videos were shown to the attendees to focus the group’s attention on the serious impact the fly has on grazing and other animals.
Selective harvesting
This was discussed because of the serious risk it poses and will often lead to stable fly breeding. The group acknowledged that brassicas ripen at different rates, making it difficult to have the water turned off before the fly-breeding cycle becomes a risk. When this occurs, chemicals with 24 and 48-hour holding periods are applied. Unfortunately, this is often unsuccessful in mitigating the fly breeding.
Fixed irrigation
Mr Al-Boraich (Ali, T&C Do and Son Farm) spoke to his approach (fixed irrigation), stating that he has reduced stable fly breeding by approximately 95 per cent. To achieve that, they ensure the water is turned off and tractor wheel ruts are lifted within several days of harvesting the vegetables. He also uses a flail mower to mulch the harvested material. This speeds up the drying process. He reports a significant reduction in water usage and power consumption (up to 29% less water).
Pivots
This irrigation type presents the most significant challenges. Unfortunately, it is almost impossible to discontinue the water before the stable fly completes its breeding cycle. A lengthy discussion ensued in which fresh approaches were discussed. One farm manager stated they have been planting two different brassicas in one quarter. This practice helps to speed up the harvest process and mitigates the fly breeding risks. Another participant suggested netting to cover partially harvested crops. This was discussed. Some thought that this approach might be very difficult in windy conditions. Another very different approach was introduced with celery (under pivot irrigation). The farm manager spoke of rotary hoeing immediately after harvest and then applying chemical. This process is repeated weekly (once per week) for 3–4 weeks. Whilst this is a very new approach, the early results are promising.
Chicken manure
The use of chicken manure was discussed. Two farm managers spoke to this issue. What we do know is that chicken manure is very low risk if it is spread immediately it arrives on the property (at no more than 20 cubic metres per hectare). It must never be stockpiled.
Communication strategy
By consensus, the attendees agreed to continue to communicate with each other when problems arise, and solutions are sought. They also agreed that the stable fly officer could play an important role in communicating between growers any new ideas/ approaches which realise better outcomes.
Not all problems were solved at this workshop. It was, however, reassuring to be part of the discussions and problem-solving efforts. It is very evident that all attendees are committed to continuous improvement and, to that end, will work with the stable fly officer to hone their practices to mitigate stable fly breeding.
Brassicas ripen at different rates, making it difficult to have the water turned off before the fly-breeding cycle becomes a risk.
Where to from here
As stated above, not all problems were resolved at this workshop. However, success is not always realised in the short term. Most will agree, success is often achieved over time, through commitment, trial and error and a determination to achieve desired outcomes. My strong view is that effective communication plays a very important role in this process.
The willingness of our vegetable growers to collaborate and communicate on this issue is commendable. We may, indeed, have some way to go but progress is being made. With every success, animal suffering diminishes. This outcome is worth every effort and is a great motivator for us to continue this journey.
Growers have agreed to continue this communication process as well as the trial-and-error approach to mitigate stable fly breeding. For its part, the Shire of Gingin will continue efforts to raise awareness in the community. Every member of the community has a shared responsibility to play their part.
Furthermore, research money is desperately needed. The Shire of Gingin will pursue avenues to secure funding to re-commence scientific research and in-field experimentation. Unfortunately, State funding in this area was discontinued several years ago, resulting in lost opportunities. Vegetable growers are demonstrating a willingness to reform. With that in mind, they deserve all the help they can get.
2025 has been a terrible season for stable fly. Many animals, businesses and community folk have suffered significantly.
Research funding will assist us to apply scientific rigour to our work and to collate evidence in support of our ‘better practices’ when these new approaches are discovered.
There are 14 Shires/Local Government Areas (LGA) within which the stable fly is a declared pest (under the Biosecurity and Agriculture Management Act 2007).
All 14 LGA’s will benefit from the lessons learned in Gingin. In this knowledge, our work here is important well beyond our Shire borders.
MORE INFORMATION
Contact Mick at mick.emmanuel@gingin.wa.gov.au or (08) 9575 5100.