ONGOING spray drift complaints throughout South Australia have led to farmers being urged to use very coarse and extremely coarse droplets in summer spraying of translocated herbicides.
Mid North consultant Mick Faulkner said that while there appeared to be some improvement in broadacre spraying practices over the past summer, damage had again occurred in the Clare and Barossa Valleys and the Riverland.
"This occurred despite the threat of losing valuable chemicals and increased spraying buffer zones," he said.
"Farmers were also largely unaware that herbicides could travel for up to 100 kilometres when inversion layers are present and small droplets are produced by spray nozzles."
As a result of the problems, the Mid North High Rainfall Zone Group and Hart Fieldsite Group undertook a GRDC-funded project in February in collaboration with the Mid North Spray Drift Committee, the Clare Wine Grape Growers Association and Peter Cousins Consulting.
The project investigated the control of summer weeds using larger spray droplets under more adverse daytime summer weather conditions.
Trials manager Roy Rogers said the trials were in response to farmers depositing pesticides, causing damage to other agricultural industries, homes and gardens and environmentally sensitive areas.
"As farmers we have been causing damage to others and if we don't get it right we leave governments with little choice but to tighten-up regulations, " he said.
"The drift issue is continuing, particularly in the Mid North where we have vineyards within 100 kilometres of where there is a lot of summer spraying. Not having a vineyard within close proximity is not a reliable guide to the risk of damage from summer spraying.
"We've got these pressures and responsibilities and it's getting to the point where unless growers use these chemicals more safely, they might lose them."
* More in the Stock Journal's April 19 edition