As regulation tightens its grip on the agrichemical industry, arable farmers have the opportunity to help prevent the loss of key pesticide products through voluntary, best practice measures. Adam Clarke reports.
Growers will need to go beyond the statutory codes of practice for the safe use of pesticides if they are to stem the flow of active ingredients being lost.
As the speed of the “disappearance conveyor” increases, the discovery pipeline has slowed to a drip, highlighting the urgent need to look after what we have.
See also: Read more from this year’s Cereals
Some elements of regulation are out of the industry’s hands, such as the European Commission’s definition of endocrine disruptors, which could potentially see swathes of chemistry lost.
However, the other drivers for product loss are environmental and consumer protection and operator and bystander exposure. These drivers can be countered with best application practice.
The Voluntary Initiative’s manager Patrick Goldsworthy says that protecting water from pesticides is one of the most important, but difficult tasks.
“Operator and bystander exposure is best addressed with training and efficient equipment, which has been demonstrated by the sprayer testing scheme and the National Register of Sprayer Operators.”
Similarly, residues in food can be managed by adhering to harvest intervals.
“But as farmers know, dealing with unpredictable weather is more challenging, as heavy rain and wind can increase the risk of products getting into watercourses or harming aquatic life,” explains Mr Goldsworthy.
The EU’s Water Framework Directive provides guidelines member states must follow to protect water bodies and aquatic environments.
The Environment Agency’s senior pesticide adviser Jo Kennedy says voluntary measures such as those described in the Metaldehyde Stewardship Group campaign “Get Pelletwise” have a vital role to play.
“Nobody wants more regulation if it can be avoided and the MSG campaign has shown these initiatives can make a difference.
“With the active ingredients under scrutiny, some areas or catchments pose a greater risk for water pollution, so growers should understand whether their land is high risk and what can be done to mitigate that,” says Ms Kennedy.
Here we look at some key active ingredients that are under threat and get some tips on how best to reduce the risk of them harming the environment or getting into water.
There is an increasing focus on the majority of pre- and post-emergence oilseed rape herbicides that are showing up in water depending on the season.
Experts warn without the pre- and early post-emergence herbicide actives metazachlor and quinmerac, and post-emergence actives propyzamide and carbetamide, rape could become uneconomic to grow.
There are things farmers can do to try to prevent these actives getting into water and guidance to equip growers to make informed decisions on their use ahead of the season and not in the heat of the battle in the autumn includes:
- Identify high risk fields – drained, cracked heavy soils and slopes
- Establish 5m “no spray zone” or 6m grass buffer strips around watercourses
- Soils – good structure and well consolidated seed-beds vital
- Drill high-risk fields first so metazachlor-based herbicides are applied before end of September
- Don’t apply when soils are saturated and drains running
- Follow Voluntary Initiative best practice for application.
Currently going through re-registration, chlorpyrifos is a vital insecticide, as it’s the only means of controlling frit fly, leatherjackets and orange wheat blossom midge and the most effective product against wheat bulb fly.
Dow’s “Say No To Drift” campaign, which is being run in conjunction with other manufacturers, has given the product a fighting chance of re-approval and demonstrated that the industry can reduce risks, says the company’s James Knight.
“Uptake of the guidelines has been superb and even encouraged the Chemicals Regulation Directorate to change its guidelines too,” says Mr Knight.
- When applying chlorpyrifos use LERAP three-star rated low drift nozzles
- Adopt 20m buffer zone around watercourses (1m for dry water bodies).
Slugs are the UK arable growers’ number one pest. Left uncontrolled it is estimated they would cost the industry about £50m/year.
Metaldehyde – marketed by several companies – is under threat as it finds its way into raw water supplies and is extremely costly for water companies to remove.
The prospect of a ban hangs over metaldehyde and with only ferric phosphate pellets as an alternative after methiocarb’s imminent removal, metaldehyde must be protected.
A new MSG pilot scheme is targeting specific “high-risk” drinking water catchments.
In the two high-risk catchments in the pilot scheme growers are urged to use ferric phosphate-based pellets in fields that are prone to run-off via a slope or under-drainage or are close to watercourses.
- Cultural practices help – bury/incorporate trash, produce fine seed-beds and drill at appropriate depth
- Use bait traps to assess risk and only treat if justified
- Establish crop and tramlines across slopes to minimise run-off
- Use minimum product for effective control
- Quality, wet processed pellets best
- Maximum application rate 210g active/ha
- Maximum total dose 1 August to 31 December 210g active/ha
- Maximum dose 700g active/ha a calendar year (statutory)
- Do not apply pellets within 6m of watercourse
- Do not apply metaldehyde when heavy rain forecast or drains flowing.
Seed treatments are a targeted and environmentally sensitive way of delivering relatively low concentrations of pesticide, says Bayer’s application and stewardship manager Paul Goddard. But the two-year suspension of neonicotinoid seed treatments in oilseed rape has been a blow to the industry. Cereal diseases such as bunt in wheat and leaf stripe in barley are only controlled by fungicide seed treatments.
“It will be vital to ensure seed treatments are available and further losses could be avoided by following stewardship guidelines,” says Mr Goddard.
- Minimise dust during handling, filling and drilling
- Avoid spills, don’t fill over vegetation and carry a spill kit
- Ensure seed is covered and not exposed for wildlife to eat
- Dispose of unwanted treated seed and bags safely.
Syngenta’s application expert Tom Robinson says 40-70% of pesticide pollution in water comes from sprayer filling areas. It’s crucial to improve those.
Many farms have made vast improvements to the areas where sprayers are loaded with water and chemical, or washed down, by creating hard standing with a sump to contain any spillages.
Pollution can then be further cut by using biobeds, biofilters, phytobacs (processing spray waste using microbes) or heliosecs (reducing spray waste by evaporation) to break down, reduce and dispose of spillages.
“Overfilling or foaming, resulting in spray mix spilling out of the overflow, is a big problem and can be addressed relatively easily,” says Mr Robinson
Herbicides also on the radar:
Although drift in the field only contributes to a small proportion of water contamination, it is an area where growers can help protect aquatic environments.
“I believe that the days of the 110deg flat-fan nozzle should be over as they create unnecessary drift and, where possible, Syngenta recommends using reduced drift nozzles, including the air induction Amistar nozzle,” says Mr Robinson.
- Install filling/washing-down areas on bunded hardstanding, capable of containing contaminated water and spills
- Process waste in biobeds, biofilters, phytobacs or heliosecs
- Everything from the container should end up in the sprayer
- Avoid foaming during filling – the sprayer should be at least a quarter full before adding chemical. Keep induction hopper closed when not in use and ensure air does not leak on the suction side of the pump
- Use drip trays under the induction hopper and tank overflow to contain spillages
- If possible use low-drift nozzles
- Get application right first time.