HOW TO use Local Environmental Risk Assessments for Pesticides to ease spraying near water

Watercourse size –  Category B products –  Nozzles

CONDUCTING A LERAP can help reduce spray buffer zones beside water for certain agrochemicals without jeopardising the environment.

The LERAP scheme was introduced in 1999 because some pesticides harm aquatic life, explains Voluntary Initiative manager Patrick Goldsworthy.

“Before the scheme, these products had mandatory 6m buffer or ‘no spray‘ zones when applied next to watercourses.”

Now with LERAPs, growers can cut the width of the buffer zone to 1m from the top of the watercourse bank, if certain criteria are met.

“These include the size of the watercourse, the dose and use of low drift application equipment.”

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Watercourse size

The principle behind the first is that as watercourse size increases, the impact of any drift is reduced by dilution, explains Mr Goldsworthy.

“Using lower doses reduces the concentration of pesticide in the spray,” he adds.

“Equipment with low drift status, or 3-star rating, also greatly reduces the amount of drift.”

Only pesticides with a buffer zone requirement are LERAP eligible.

The buffers for Category A products, those containing organophosphate or synthetic pyrethroid insecticides, must not be trimmed.

“Any reduction would be an unacceptable risk. As such, no LERAP is permitted and growers must apply the standard 5m buffer zone.

“It‘s also important to remember that some pesticides have a separate requirement not to spray within 6m of the field boundary.”

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Category B products

Category B products do qualify for LERAP.

“They all have a requirement for a 5m buffer zone and users can retain this if they wish. Or they can opt to reduce it.”

Many other products have no buffer requirements, so the LERAP scheme does not apply to them, he notes.

Growers choosing Category B pesticides should follow three steps for the full assessment, he advises.

“First, you need to determine the size of the watercourse. It should be measured at its narrowest point next to the spray site.

“You then record this measurement as part of the LERAP record.”

Next, dose information, whether quarter, half or full rate is required.

“If you are using a quarter rate of any category B product, you can simply apply a 1m buffer zone in all situations.”

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Nozzles

Knowing the LERAP status of the sprayer or nozzles is the third step.

“The most up-to-date list of recognised low-drift equipment can be found on the Pesticide Safety Directorate website.

“Equipment not formally recognised by PSD should be considered standard reference.”

Using 3-star equipment allows growers to apply a 1m buffer zone from the top of the bank for all category B products, he notes.

“Armed with this basic information, it is then possible to calculate what reduction you can make from the standard buffer zone tables.”

Look in the next issue of Farmers Weekly for the latest Baseline Advice.

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