January 9, 2012
Encouraging results from southern field trials of a new biological agent to combat snails in grain crops have researchers on track for development of a commercial control.
Recent Grains Research and Development Corporation-funded field trials of the nematode-based control on South Australia’s Yorke Peninsula, where snails are a major pest, have been declared a success, enabling scientists to progress with more refined field trials to be conducted this year in SA and Victoria.
The Victorian trials will also target slugs which were a significant problem in that state’s cropping regions during the 2011 growing season.
Conducted by Charles Sturt University (CSU) with collaboration from the SA Research and Development Institute (SARDI), the field trials in September-October last year involved one combination of a native nematode and a symbiotic bacteria.
Professor Gavin Ash from the CSU’s EH Graham Centre said the biocontrol was applied in high and low rates against conical and round snails and was compared with application of metaldehyde-based baits. The trial involved 16 replicated plots each of 100 square metres.
Dr Ash said the biocontrol was just as effective as the metaldehyde bait when applied in high levels, and offered a reasonable level of control at the low rate.
Dr Ash and his team are now preparing for a series of field trials this coming autumn which will involve a different approach.
“We will be looking to exclude the snails from the paddocks being cropped by applying a barrier of nematodes around the perimeter of paddocks using a protein-based foam formulation similar to that used in fire fighting.
“We are working with an organisation in the United States to prepare the foam formulation that will offer protection for the nematodes.”
The development of an alternative control for snails is encouraging news for grain growers in the southern region where snails again presented as a major pest issue during the 2011 cropping season.
GRDC New Farm Products and Services program manager, Paul Meibusch, says snails in particular are a significant and costly in-crop pest issue and pose a risk to grain exports.
“Snails feed on emerging crops, clog up farm machinery and contaminate harvested grain,” Mr Meibusch said.
Mr Meibusch said the last economic study commissioned by the GRDC to assess the impact of snails on farming systems showed a direct cost to farm businesses on Yorke Peninsula and in the Lower North of SA was an average $59,180 per farm or $41 per cropped hectare.
He said the development and commercialisation of a biologically-based control agent had the potential to dramatically improve current control techniques and reduce farm costs.