AS AUSTRALIAN tolerances for snails in grain tighten, the need for better control within crops has been highlighted.
AgEx Alliance’s Michael Richards is working with Minlaton Agricultural Bureau, using Australian government funding through the Landcare Smart Farm grant, to assess if emerging practices are more successful in controlling snail numbers.
The two-year project, which will begin in the next fortnight, is evaluating some of the newer products on the market as well as comparing management practices such as baiting times, bait size and cultivation options.
Mr Richards said there had been some wins in snail management in recent years, as time lapse cameras helped understand snail behaviour.
But he said the present success rate of 85 per cent snail mortality was not going to be good enough to meet expected standards.
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For the 2018-19 season, snail tolerances in F1 and malt barley have changed to one snail per half a litre of grain, down from two last season, with growers concerned there will be a push for zero tolerance. Wheat standards are unchanged at one snail per half litre for better quality samples.
He said there was a concern these lower snail tolerances from markets, such as China, may have some farmers moving away from minimum tillage practices to reduce snail numbers.
The trials will target emerging liquid snail control products for efficacy at three key times to control snail populations – post harvest, prior to mating and egg laying; juvenile and adult snails during the early plant stage; and keeping snails down the plant below harvest height prior to harvest.
It will also compare new stubble and soil treatments, such as the speed tiller, and compare wax-based baits, rather than bran-based baits.
Mr Richards said there had also been a trend towards smaller bait sizes to try and make the most of the allowable rate for baits to be distributed.
But he said smaller baits might not be the best option, based on snails’ habits of “cluster feeding”.
“There is a lot of mystery about snails, about what works and what doesn’t,” he said. “We're aiming to get grain on the boat without any issues.”
Mr Richards said there was evidence some of the bait times used by growers might be missing opportunities.
He said previous research showed snails were beginning to mate in late March, relying on humidity, which can often be at 90 per cent at that time of year, with the first eggs laid about April 18-27, following rain that wets the soil to a depth of 30 millimetres to 50mm.
Mr Richards said estimates indicated farmers could spend $27 a hectare on bait while post-harvest cleaning was as much as $17 a tonne.
Pests prove costly at harvest
Minlaton cropper Adam Cook says snails have been a big problem during this harvest, despite trying multiple control methods, such as rolling in summer and baiting in autumn.
“But come harvest time, they’re still there, as thick as ever,” he said.
He said within one half litre grain sample they had stopped counting at 150 conical snails.
“They are a continuing pest and we have no real way of getting rid of them, only reducing numbers,” he said.
Mr Cook said they would be putting the grain through a snail crusher to make it deliverable.
“It is expensive and time-consuming,” he said.
Mr Cook will be taking part in a Yorke Peninsula-based study, trying to control exotic pest snails.
“We need a solution,” he said.