From the Foundation for Research, Science and Technology For immediate release
SOFTWARE HELPS TO REDUCE SPRAYING
New software that helps grape growers decide when to spray against disease will be introduced to a wine industry
conference at Nelson on August 24-26.
The Bacchus program is a product of a Technology New Zealand-supported project conducted by the Marlborough Grape
Growers' Association and wine companies. The project aims to reduce fungicide and pesticide use and promote a "clean,
green" image.
"Bacchus helps farmers identify when Botrytis, a grape-rotting disease, infects the vines, and helps them decide when to
spray," association chairman Ivan Sutherland says. "The industry has relied extensively on fungicides to control
diseases, but we've become aware of the need to reduce fungicide use because of environmental concerns, fungicide
resistance and chemical residues in produce."
The new software displays the infection risk based on rainfall and temperature.
Research scientist Rengasamy Balasubramaniam says the research team took a new approach to tackle the disease problem.
"In the past the strategy has been to focus on the pathogen - the disease-causing organism - and fight it by spraying,"
says Dr Balasubramanium, who was working for HortResearch on the project. "We looked at the environmental factors that
helped cause the disease. That came down to the wetness and temperature. Under favourable conditions - 20 degrees
Celsius, wetness and high humidity - organisms can grow in 12 hours."
Part of the solution was to use sensors in the field to discover whether the conditions were conducive to disease
development. This has led to a fax service for subscribing growers.
Weather and temperature data from five stations in Marlborough is gathered by HortResearch technician Rob Agnew in
Blenheim. He faxes the data to 65 growers each week.
"They get weather summaries, rainfall and growing degree days, crop-growth stage and disease information," he says. "If
a Botrytis infection period is recorded, the growers get a supplementary fax telling that, too."
Mr Agnew says growers can also buy the Bacchus software to help them detect for themselves the conditions when Botrytis
is likely to occur, and then decide whether to spray.
Mr Sutherland says the four-year programme is already producing results.
"Many grape growers are now spraying only when disease is present or when Botrytis infection periods are recorded," he
says. "This is target-based spraying as opposed to traditional calendar-based spraying. Many growers have found they
have had to spray only once instead of up to six times.
"Most are saving money from reduced spraying costs." -ends-
Contact: * Ivan Sutherland, Marlborough Grape Growers' Association. Ph: (03) 572-8914, mobile 025 456 638. E-mail:
cloudybay@xtra.co.nz * Dr Rengasamy Balasubramaniam, Delegat's Wines Ltd, Blenheim. Ph: (03) 579-1290, (025) 244 6604.
E-mail: bala@delegats.co.nz * Tony Hadfield, Technology New Zealand at the Foundation for Research, Science and
Technology (Auckland Office), (04 917 7800 or 025 454 095. Website: www.technz.co.nz
Prepared on behalf of the Foundation for Research, Science and Technology by ID Communications. Contact: Ian Carson (04)
477-2525, ian@idcomm.co.nz