
LEADING into the critical autumn sowing period, grain growers are being urged to keep an eye out for potential mouse activity.
CSIRO experts have warned, given the large volumes of grain on the ground following a big harvest last year, there was ample food to allow mice to breed up to problematic numbers.
At the National Mouse Group meeting, experts warned while mouse numbers vary, if present in high numbers they can have devastating impacts on crops being sown.
Growers are already reporting mouse activity in Queensland and NSW summer crops, while there are concerns about mouse numbers in parts of western Victoria and South Australia.
CSIRO researcher Steve Henry said farmers needed to take extra time to assess the mouse situation.
"Even if you don't think you have a problem, you may in fact have a localised population about to explode."
He said regular monitoring and early identification of infestations was essential.
"If left unchecked, a mouse population can quickly escalate and result in crop losses, reduced yields and increased costs associated with pest control measures," Mr Henry said. "Mice are everywhere but numbers are patchy, so farmers should focus on paddocks that have sustained pre or post-harvest grain loss."
If mouse numbers are high enough to warrant baiting, Mr Henry said the best idea was to target a period of time when there was less alternative feed around.
Both CSIRO and the Grains Research and Development Corporation advised growers the best baiting strategy involved using 50g/kg zinc phosphide baits to ensure each bait grain is a lethal dose. There has been some dissent among the bait manufacturing sector, which has said the 25g/kg bait is effective as well.
GRDC pests manager Leigh Nelson said growers should talk to resellers and manufacturers if they had any issues with baits and efficacy.
"We encourage growers to monitor mouse numbers pre and post-baiting, to determine bait take-up and evaluate the outcomes of their baiting program," he said.