With recent significant rainfall to most cropping areas in the State speeding up summer spraying, PIRSA Biosecurity SA is urging growers to consider potential distance of impact before commencing their spraying.
Manager, Rural Chemical Operations at PIRSA Biosecurity SA Michael McManus said producers must be particularly alert to NOT spray during inversion conditions in order to avoid spray drift.
"We urge broad acre farmers to consider their neighbours, particularly those with vineyards, and to not underestimate the potential distance of impact before spraying summer weeds," he said.
"Actively growing grapevines are highly susceptible to off-target herbicides so as part of any planning process it is vitally important to be aware of sensitive crops in your surrounding area, even those many kilometres away, and check that the weather conditions are suitable.
"Inversion conditions are likely in the early morning, evening and at night. We believe undertaking planning before any spraying operation is a key to avoiding such issues. Please also make sure you use the largest droplet size possible, according to the label.
"Good planning will help make sure you don't drift into bad neighbour territory, and it will also help to avoid any potential impacts on local and export markets."
Mr McManus reminded growers that Biosecurity SA will investigate all reports of farmers spraying in less than ideal conditions.
"Being careless when spraying can not only result in unnecessary damage to someone else's crops but can also hit the hip pocket," he said.
"Biosecurity SA will pursue all reports of anyone who has either deliberately or negligently caused damage to others by not following regulatory requirements. If caught and prosecuted, offences can carry a maximum penalty of $35,000."
Growers in some parts of the State now have access to technology to help ensure spraying does not take place under inversion conditions with the implementation in September last year of the Mid North Mesonet system, managed by Ag Excellence Alliance.
Grains Producers SA Board member and Mid North Mesonet Committee member, Peter Cousins said the tool would be particularly useful for cereal and grain producers in the region.
"Cereal and grain producers in the Mid North now have a dedicated tool at their disposal this summer to assist with their summer weed control programs and help avoid spray drift," he said.
"The Mid North Mesonet system, allows producers - through their mobile phones and computers - to assess more applicable, up-to-date weather information, and in particular to identify weather inversions near their properties."
Farmers who use Delta T to assess when to spray should be aware that strong inversion conditions can occur when the Delta T is in the ideal range of between two and eight, so farmers should check local weather conditions as well.
The recent label instructions on 2,4-D products now include a legal requirement to NOT spray during inversion conditions. These latest label instructions, set by the Australian Pesticides and Veterinary Medicines Authority (APVMA), are a direct result of spray drift damage from 2,4-D products in the past and aim to address the risk to non-target crops.
In addition to the requirement to NOT spray during inversion conditions, the latest instructions include new mandatory label requirements to produce very coarse (VC) droplets for all 2,4-D products. There are also advisory instructions specifically for 2,4-D use in cereals, fallow and pasture between 1 October and 15 April for summer weed control aimed at producing extremely coarse(EC) to ultra-coarse (UC) droplet sizes. Growers must ensure their spraying is being applied at the correct spray quality.
They also include instructions for mandatory no spray zones, more clearly defined mandatory instructions for suitable weather conditions and application techniques, and detailed mandatory record keeping for all users.
- For information on avoiding spray drift and best practice chemical use visit www.pir.sa.gov.au/biosecurity/rural_chemicals/chemical_use_best_practice
- For information on the latest APVMA 2,4-D labels visit www.apvma.gov.au
- Grain Producers SA also offers resources about spray drift through their campaign, 'Hit your Target', for details visit https://grainproducerssa.com.au/policy/policy-points/hit-your-target/