Mice populations have reached plague proportions across SA and the change in farming systems to reduce cultivation could be the cause.
Biosecurity SA research officer Greg Mutze said SA plagues had occurred in the state in intervals of about five to 10 years since the 1880s, but in the past 15 years growers had switched to no-till and livestock-free farming and increased frequency.
“Little soil disruption and not using livestock to graze after harvest has meant there is more cover for mice in paddocks and easy access to grain,” he said.
National Mouse Management Working Group member Simon Humphrys said a team of growers and state government agencies had collected data from across Australia to help equip farmers with tools and information to lessen the plague effect.
“In the past in a mouse plague an ad-hoc group of people would be thrown together at the last minute, but at the end of the plague the group would disintegrate and what had been learnt, would be lost,” he said.
GRDC has funded two mouse-related programs – one to trap mice and measure activity in paddocks and begin a search for a new chemical to be used in addition to zinc phosphide.
“We are in uncharted territory in that we do not know how much of an influence new and emerging farm practices are having on other areas of farming and how much extra risk that poses to properties from mice,” he said.
“Maybe we are providing a system that is skewed towards mice.”
Mice strategy under pressure
MORE than 25 tonnes of mice bait was applied in Ben Wundersitz’s cropping program this season, after mice populations peaked and caused the most significant damage he had ever recorded.
Increased mice activity across his 6500-hectare business from Price through to Port Victoria caused a 5 per cent drop in Mr Wundersitz’s wheat, barley and lentil crops.
About 10pc of crops were baited with zinc phosphide five weeks prior and immediately after seeding but the strategy caused minimal impact on mice numbers.
Mr Wundersitz said he had since applied bait on five occasions and was monitoring paddocks to see if further action would be required.
“We baited straight off the back of the seeder but unfortunately this year it was not as effective as we had hoped,” he said.
“Mice are at the second highest level we have had in 10 years and unfortunately the damage was worse because we had such a dry start.
“The mice had six to 10 weeks to eat the seed while we waited for rain and again, once it germinated.”
The absence of livestock in his no-till farming had potentially increased the problem, Mr Wunderstiz believed.
“No cultivation to break up their holes and stubble for ground cover has also created a sustainable environment for mice to thrive and survive,” he said.
“The late harvest meant mice stored a lot grain underneath the ground and this was their food source instead of taking the bait.”
Concerns about wheat suffering early moisture stress have been replaced with early-maturing problems.
“The wheat is running up to head which is very early and quite concerning,” Mr Wundersitz said.
“Our coastal Scepter wheat crops suffered severe moisture stress through until the end of June,” he said.
“Lentils have suffered a significant set back and will produce an average yield.”
(Source – http://www.stockjournal.com.au/story/4816105/pest-rise-a-problem-in-no-till/)