FAR FROM simply being the bane of middle-aged flower gardeners, snails are now a serious nuisance to Australia’s cropping industry.
Along with the damage they do to growing crops, snail contamination in export consignments is a sensitive topic with several buyers of grain from South Australia, where the problem is most pronounced.
The habitat of snails is growing across the low and medium rainfall zones in southern Australia and the leader of an alliance set up to control snail numbers said a concerted effort was required to keep them in check.
Michael Richards, Ag Excellence Alliance, Stansbury, South Australia, said farmers battling snails faced a delicate balancing act.
“The best time to bait is before they mate and lay eggs, but on the other side of that equation, the baits break down in temperatures above 35o Celsius,” Mr Richards said.
Speaking at a Grains Research and Development Corporation (GRDC) forum in Nhill in Victoria’s Wimmera, Mr Richards said snails were breeding much earlier than previously thought.
“We’ve done the research and they are certainly getting active earlier than we’d thought, which means earlier baiting is best, but then you run into problems with hot autumn weather reducing the efficacy of the bait,” he said.
“We found them active as of March 24, which is only really the start of autumn, we just are working out whether they can survive when they start breeding this early, hopefully not because baiting in March is risky.”
Mr Richards said farmers with serious snail problems might need to make two bait applications.
“At best, a single bait application can achieve 70 per cent snail control, but its estimated that a level of 98pc in needed to significantly reduce snail numbers the following year,” he said.
Mr Richards said snail numbers tended to increase the most in broadleaf crops such as canola and pulses.
For those who have not managed to control snails leading into harvest, he said the most efficient way to reduce snail contamination was to use crusher grain rollers.
“The technology has evolved and you can use them in all major crops,” Mr Richards said.
“It generally goes about as fast as a header can take the grain off, so it is not too bad to clean the grain immediately off the header.”
In terms of harvest management, Mr Richards said using stripper fronts on the header was the best way to reduce the number of snails getting into the bin.