Whether or not mice populations reach economically damaging numbers across SA this year could depend on weather conditions, industry experts say.
But, GRDC Southern manager grower services Craig Ruchs believes growers’ interest in mice management indicates the threat posed by a mice outbreak could be matched with careful planning.
Mr Ruchs said it was clear mice would be an issue for seeding this year.
He said the potential risk was dependent on a region’s weather conditions and food source, but growers’ on-farm management coming into the season would hopefully limit the scale of the outbreak.
“I would say high-risk regions would be frosted areas, paddocks with small grains left over and suitable weather conditions,” he said.
“The Yorke Peninsula, Lower North and Mallee regions are where higher than normal mouse abundance is being recorded.”
He said the increase in continuous cropping meant mice were considered a consistent problem. Their present breeding pattern had the capacity to be more difficult to manage rather than if there was a “boom- type plague”.
“It leans towards the change in farming systems and the environmental conditions. We are providing all the things mice need to survive and thrive – high stubble retention, reduced soil disturbance with a consistent food source as well,” Mr Ruchs said.
“Last year we had wet weather at harvest, grain on the ground and, in some cases, we had screenings coming out the back of the harvester – a perfect combination for mice growth.”
A recent GRDC mice control webinar had more than 200 people join, showing growers were eager to learn the latest information, Mr Ruch says.
“Industry have recognised the problem and how farming systems have changed, so the challenge is we need to find innovative solutions for growers,” he said.
Cox Rural Keith’s senior agronomist Scott Hutchings monitors the Upper South East region from Padthaway to Coonalpyn and said with the consistent summer heat passed, mice burrows and population numbers had increased.
“It has been dry for a while so, since it is cooler and stock are starting to graze down stubble, any paddocks that have not been grazed are experiencing a lot of mice activity,” he said.
“In dryland lucerne crops, although harvested, there are a lot of mice holes under it that are active.
“After it was desiccated for harvest last year, reports are that mice were eating the pods off, which is something we have never seen before.”
Mr Hutchings said growers in the region had begun baiting high-risk paddocks.
The YP has recorded a higher level of mice than that seen at the same time last year, according to YP Ag agronomist Chris Davey.
“It is definitely worrying – activity is rated at medium to high, particularly in paddocks where lentils were affected by wind in October last year and provided a food source for mice,” Mr Davey said.
“Last year mice caught growers by surprise in late April-May, whereas this year we are seeing a lot of early mice activity in paddocks.”
But this season, he said YP farmers were prepared and had bait on-hand for assurity of supply.
“The small amount of bait across SA last year was absorbed very quickly and there was a delay in making more bait, which delayed seeding for some growers,” he said.