The plague threatening our farmers’ summer crop

Mice normally stop breeding in spring but thanks to 2021’s mild weather and the increase in no till cropping systems, they’ve continued to breed throughout summer and may not stop until after autumn.

No till cropping mean farmers retain the standing stubble from a previous crop by planting seeds into untilled soil. The aim is to move as little soil as possible so weed seeds do not come to the surface and germinate. While it’s a great system for subduing wind erosion and improving soils, it creates a perfect environment for mice.

“While no till farming is great for the soil itself, the lack of soil disturbance allows mice to build burrow networks out in the paddocks,” Mr Harvey said.

Quirindi agronomist Pete McKenzie estimates the damage caused by mice to this season’s crop revenue to be up to 5 per cent in some of the most affected areas. He emphasised the need for “control measures” such as baiting to limit grain loss to less than 100kg per hectare. He says ongoing control is required particularly in northern NSW to avoid a devastating impact to their upcoming crops of sorghum and corn.

“Even though the plague isn’t state wide, all NSW farmers need to be really vigilant because if the mice continue to breed throughout the rest of summer and into autumn when the winter crop is sown, they will get absolutely clobbered”, Mr Harvey said.

“If you’re on a property with a plague but don’t have sheep who can help by eating the leftover grain, you end up relying on the mice to overpopulate, turn on each other or become infected by disease,” he said.

Despite relatively few numbers in the Forbes shire, local agronomist Max Ridley is preparing his clients to brace themselves for a potential plague in April. “I remember sowing a paddock in 2011 and coming back four days later to see mice holes everywhere,” he said. “They’d burrowed down and eaten all our grain. That’s before they infest your house. We hope it won’t get to that this year but we’re seeing the early warning signs now and farmers may have to consider preventions like burning their stubbles.”

Quirindi crop trader Joe Hallman says the reason it’s so hard to curb a mouse plague is because it demands a huge amount of expensive resources and the incentive recedes as soon as the crop season is over.

“Many farmers expecting summer crops have to use crop-duster planes to lay bait, that is an incredibly costly exercise…continuing to try to get rid of them after harvest is often unjustifiable,” he said.

“People in the bush are resilient, mice smell and they’re horrible for morale but you get on with it… When you go to the shops, it’s not toilet paper everyone’s hoarding, it’s Mouse Off and Rat Sack,” he said.