FOR effective snail control, farmers need to 'know their enemy' in terms of identifying the types of snails on their property, their densities, sizes and behaviour.
This was a key message presented at the Snot The Snails workshops, at Tumby Bay, Elliston, Streaky Bay and Charra last month. More than 150 Eyre Peninsula farmers attended, emphasising the severity of the issue and the need to be proactive.
Organiser Linden Masters, Minnipa Agricultural Centre, said the workshops were held because many farmers had seen snail numbers building and spreading to previously unaffected paddocks and they need to be better equipped to "stop the invasion".
The key speaker was Michael Richards, who has a wealth of experience on snail control through involvement in South Australia farm groups and his Stansbury property.
"Farmers need to start building a picture of what is happening on their farms so they can tailor control measures to suit their own conditions and requirements," he said. "You need to know the types of snails you are dealing with, their numbers, locations and behaviour in order to get the best results from control methods."
Snails love free lime, organic matter and opportunities to avoid dehydration - unfortunately all common in coastal areas. And given the scale of farming area to cover on EP, the economics of control are a key factor.
Stubble management and burning are the first steps to reducing snail numbers. Baiting is the next.
Consecutive days with temperatures above 36C degrees can provide a prime opportunity to significantly lower snail numbers. Tools such as cabling or burning can deplete a snails' moisture reserves sufficiently to cause death.
"Farmers need to keep in mind that it isn't just the mode of heat which will kill a snail, it is exhaustion," Mr Richards said. "So operations such as cabling may need to be repeated and scheduled to allow enough time for snails to re-climb the stubble, but not so long as to allow them to rehydrate. Controlling summer weeds is also important as this provides a snail food and moisture source and will reduce the effectiveness of summer treatments. Intensive grazing with high numbers of stock over several hot days can assist with reducing snail numbers."
Fence posts and roadside vegetation are popular spots for aestivating snails, so baiting in these locations and control of grasses and weeds in these areas can prevent invasion of snails into paddocks.
"The objective of baiting is to time it so that egg-laying is prevented. This will eliminate the next generation - however, you still need to monitor snails' activity," Mr Richards said. "Many of the problems last year arose from cool moist conditions which brought forward mating."
Mr Richards said that baiting should start as day length shortens and snails become active and stay on the ground for six to seven days.
*Full report in Stock Journal, February 9 issue, 2012.
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