Vanishing Molecules and the Amenity Sector
By Simon Barnaby
The omission of the important amenity sector from the discussions at the June seminar (reported in the October issue of the Horticulturist) caused the IoH to arrange a round table meeting for 15 October, which was both successful and stimulating.
The meeting fully agreed that the amenity sector, with the best will in the world, would continue to require pesticides, would need to use them economically and safely and would have to be guided by integrated pest management (IPM) principles. At the same time it was felt that 'green' PR overawed the sector and that public sector users were expected to work to inadequate budgets.
The meeting concluded by recommending that the IoH should:
- · Actively encourage better publicity about the use of pesticides in this sector and aim at the taxpayer, who, when convinced, exerts enormous influence on legislators;
- · Set up a working party to investigate which pesticides will continue to be needed but are at risk of withdrawal and identify gaps where either new molecules should be sought or old ones, withdrawn usually for commercial reasons, be re-introduced.
Simon Barnabyfrom the Scotts Company chaired the meeting, which his company had kindly sponsored. There were five speakers and about 20 invited participants, covering a wide range of amenity horticulture activities.
Robert Masonfrom the Pesticides safety Directorate (PSD) spoke about registration procedures. He explained that while PSD looked after the full range of pesticides, biocides such as substances used to control moss on hard surfaces, were the responsibility of the Health and Safety Executive (HSE). He made it clear that additional data required for off-label approvals need not be too daunting and could be made less so by co-operation within the industry. He believes that mutual recognition between European Union (EU) member states with similar environmental conditions could help niche markets for pesticides, but this has yet to be tested.
In discussion, it was agreed that there was a need for a research organisation to take on necessary investigations required by the amenity sector as a whole, but this would need funding. The Sports Turf Research Institute (STRI) carries out such work for sports turf management. It was also agreed that co-operation should extend throughout the EU. It was suggested that an approach be made through CEETAR (the European contractors' association). There was a strong feeling that the current rules and regulations were not being adequately enforced. Those present were aware of the use of products approved only for agriculture in amenity areas and allowing operators to spray without Certificates of Competence. The sector was not being encouraged to adhere to best practice.
Richard Mintonof Complete Weed Control Ltd, putting a weed control contractor's viewpoint, explained why weed control in public areas was needed, under the headings of safety, health and aesthetics. The legal requirement to prevent the spread of certain weeds was raised and the economics of various weed control methods was demonstrated. Herbicide spraying was significantly the cheapest.
Reduced availability of active ingredients (ai's) had caused problems, as customers still expect a single spray to give season-long weed control. This is no longer possible. There are severe restrictions on where the more persistent herbicides may be used within the environment. Restricting the products available for use in aquatic weed control means that certain weeds may become dominant. Withdrawal of effective products to control casting worms and root pests of turf will also cause problems.
On the positive side, improved technology has made spraying safer for the public as well as to the environment. Legislation should ensure that all sprayer operators are properly trained, and such legislation must be fully enforced. Industry codes of practice are setting standards higher than the minimum.
In discussion it was agreed that weed-free public spaces were more likely to remain litter- and graffiti- free. It was pointed out that maintenance of open areas had an impact on tourism and sport. Tourism and sport make a far greater contribution to the nation's GDP than does agriculture.
The withdrawal of diquat for aquatic use originated in the European Community (EC), as Robert Mason explained. It would need much effort to persuade the Technical Commission to change its views. In the meantime, fishing and water sports were likely to suffer, and weed-covered ponds would become a hazard to people - especially children, and animals - especially dogs.
David Walden, a golf course supervisor, commented on the range of materials that had vanished, and regretted how few were left. He highlighted turf problems for which there were no longer adequate controls, such as casting worms, cockchafers etc.
He emphasised particularly that if pesticides were not available, and that bio-stimulants work only under specific conditions, greenkeepers would have to return to first principles: to get the soil conditions right; to improve poor air circulation to use the correct cultural conditions at the right time and to use fertilisers with moderation and accuracy.
It would become increasingly important to keep accurate records, and to use these to improve management techniques. This would require better education for all concerned; younger people seemed to be receiving this now, the problem of adapting to change might lie with staff in the 30-50 age range.
As a practical Greenkeeper, David Walden put in a plea for more information on modes of action on pesticides labelling. For example, where a product needs to penetrate the soil, it should be made clear that there is no point in spraying it on to dry 'thatch'.
Nick Morganspoke about the experience of the Royal Horticultural Society (RHS) in managing a highly diverse set of plantings at its gardens, especially at Wisley. The RHS membership expects a neat, tidy and weed-free garden. The vast range of species grown complicates the situation, though the species range encourages a wide variety of wildlife, which act as predators.
The greatest part of the RHS's pesticides' budget is spent on biocides, for cleaning glasshouses and as soil sterilants. Phase 1 to 3 of the EU programme have had little effect on the ai's that the RHS uses, but Phase 4, which covers micro-organisms, pheromones and biocides, is causing concern. The RHS pursues a policy of horticultural best practice, which majors on an organic approach, management modifications and IPM. Compost from green waste and wood chippings are much used; mowing regimes are varied according to the requirements and use of the sward.
One of the RHS's greatest problems is that there are now so few products for the amateur gardener. The advisory staff answers over 30,000 queries a year, and are often unable to provide a satisfactory answer.
Guy Gibsonof Monsanto plc spoke about glyphosate and crop / weed tolerances. The enzyme system affected by glyphosate is known. It exists only in green plants - hence its safety to mammals, etc.
Weed tolerance has been reported on three species in four countries. Monsanto plc is uncertain as to the reasons, but the tolerances are not the source of the gene that renders crops tolerant to glyphosate; this is derived from a soil bacterium. Weed tolerances may have arisen from repeated low dose spraying in vineyards, aimed at suppressing inter-row grasses without eliminating them, as they provide a protective mulch against soil erosion. It is believed that the chances of weed tolerance to glyphosate occurring in the UK are minuscule, as long as full dose rates are used.
In the final discussion, it was suggested that the farm survey of pesticide use should be extended to amenity facilities, as the data would help in the protection of pesticide products and perhaps enforcement of regulations.