A research project aims to help growers optimise their mouse-bait spreading to minimise crop losses. ANDREW MOLE reports on its impressive progress.
WHEN confronted by mice plagues of biblical proportions, the key to eradication is getting as much bait onto as much country as fast as possible.
And a research project is now underway to help Australian grain growers reduce crop losses due to mouse damage by optimising bait spreading operations.
Mouse populations across a large slice of grain-growing regions were higher than average across the 2021 and 2022 seasons, requiring an increased effort in mouse management from growers.
Now the “Guidance for spreading mouse bait to improve efficacy and maintain bait integrity” project is examining mouse bait application techniques to better understand the performance and likely success of various delivery methods.
Victorian-based Kondinin research team machinery specialist Mark Saunders – working with WA-based agricultural research engineer Ben White and mechanical engineer Josh Giumelli – tells North West Farmer that in regions where mice are a more frequent issue, grower awareness on bait spreading best practice is high.
However, he says in areas where mouse activity has not been as frequent, growers are not accustomed to spreading mouse bait.
“We are looking at things as common as three-point linkage spreaders, for example,” Mark says.
“We know they can deliver 100-200kg of urea per hectare but with mouse bait, we only want about 1-2kg in the same space, so we need to consider a little fine-tuning there,” he says.
“There is even the C-Dax 12 volt spreader, which you can use on a side-by-side, and I have seen them attached to the boom on a self-propelled sprayer.
“Aerial application, using conventional light aircraft, became the go-to option in 2022 with so much flooding across Victoria and southern NSW – the only real problem here is there simply were not enough aircraft available to meet demand.”
Mark says the other aerial option is the drone, with their payload capacity improving all the time.
However, he says it is not yet as simple as wandering into your local drone shop, slapping $40,000 on the counter and taking a drone home to spread 40kg of bait over 20-25ha.
“Could drones do the job? Almost certainly. But drones also involve a lot of very strict regulations from CASA – the Civil Aviation Safety Authority – from training and understanding the technology to strict requirements on using them,” Mark explains.
“But if you are in a flood situation or similar, aerial delivery is the only option,” he added.
In the past 10-15 years, major users of the technology, such as the US Geological Service, say “enormous improvements have been made in the capabilities, performance, and applications of unmanned autonomous vehicle (UAV) systems (airborne, marine, and terrestrial)”. The USGS says although unmanned underwater vehicle systems used extensively in the oil and gas industry have been around for decades, the advent of unmanned aircraft systems (UAS), popularly referred to as drones, is relatively new.
Despite that, in the US, they are being purchased by the millions every year and increasingly used in agriculture as well as other industries.
Mark says the Kondinin team is about to start test protocols over test trays with treated wheat, as well as testing other spreaders.
Team leader Ben White says during periods of high mouse numbers – and with the imminent threat of crop losses – growers might access and use spreaders built for other purposes, such as mollusc bait and fertiliser spreaders.
“As these spreaders are not set up correctly for applying mouse bait, growers have encountered issues such as scraping of active ingredients from the surface of the grain, blocking of apertures and difficulty spreading at label rates and achieving the required bait coverage,” Ben says.
“Poor control through ineffective baiting operations increases the risk of crop losses caused by mice and the likelihood that additional bait applications may be required throughout the season, significantly impacting grower profitability.
In consultation with researchers from CSIRO, including rodent expert Steve Henry, the project has developed a protocol to measure mouse bait spreading distribution uniformity of at least two from each of the four types of ground application spreaders, and two aerial application methods:
* 12v adjustable aperture metered spreaders
* 12v roller metered spreaders
* Conventional linkage spreaders (PTO and hydraulic drive)
* Modified metering door belt spreaders (trailing and linkage mounted)
* Fixed wing aircraft
* Unmanned Autonomous Vehicles (UAV).
Steve Henry is the guru of rodent research in Australia.
His list of awards is long and glittering and he has worked in everything from wolf fertility in Canada’s wild Yukon region to mice in Australian paddocks.
He is focused on understanding mice in zero and no-till cropping systems and applying this knowledge to develop effective control strategies to reduce the negative impacts of mice in the grain production industry.
The work comprises three parts: monitoring mouse populations to predict future mouse population outbreaks, improving baits to enhance bait effectiveness, and applying knowledge of the ecology of mice in current farming systems to develop more effective control strategies at the interface between science and the agricultural industry.
Funded by GRDC, Ben says the project will also seek further input from researchers from Analytics for the Australian Grains Industry (AAGI) to analyse and quantify the uniformity of mouse bait distribution from each spreader.
He says if deemed appropriate, an effective Coefficient of Variance (CoV) will be established, or alternative measures to assess the uniformity of bait distribution in the context of bait spreading will be explored.
“A CoV for bait spreading serves as a tool to gauge how uniformly the bait is distributed within a swath,” Ben added.
“It helps us understand how evenly or unevenly the product might be spread. In the case of ZnP (Zinc Phosphide), achieving an even distribution is essential to ensure optimal exposure for mice while also adhering to the legal requirement specified on the ZnP label with product rate.”
Additionally, the project has examined current grower practice through a consultative review, exploring grower, researcher and agronomist experiences with bait spreading options including spinner spreaders, small seed boxes, high velocity air and spreader plates; mounting options including air carts/seeding bars, 4WD vehicles, tractors, boomsprays and two-wheel motorbikes; and alterative spreading options including fixed wing, rotary wing (helicopters) and UAVs.
Mice pose a persistent challenge in broadacre cropping, with communities of grain growers across Australia highlighting their need for better insights into effective mouse management strategies, particularly when it comes to baiting efficiencies.
This project is geared towards equipping Australian grain growers with the necessary resources and knowledge to do this.
Research is continuing throughout 2023, with results expected to be available for Australian grain growers from mid-2024.
Growers are also urged to report and map regional mouse activity using the mouse alert website at www.feralscan.org.au/mousealert, which assists in identifying mouse population hot spots to facilitate timely management actions and help CSIRO’s rodent research team build a broader picture of mouse activity for the prediction of future outbreaks.
