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To contact one of our “Forage for Profit” team, call the Seed Office on 01769 576232
or Graham Ragg on 07798 583667
or email info@molevalleyfarmers.com.

Weed and pest problems and solutions

When establishing a new grass ley, which may be down for 5 to 8 years or longer, weed and pest control is vital to give the new pasture a good start and ensure the best results. Cereal farmers regard the use of weedkillers and pesticides essential tools to ensure the success of their crops which are renewed annually. How much more important is it that plants, which are expected to last for years, should be given every opportunity to flourish, by controlling weeds and pests in a new ley. Weeds and pests, can reduce seed establishment by up to 50%. This is obviously an unacceptable waste and an area where a timely, well designed spray programme is both cost effective and desirable, resulting in better establishment and greater yield. Achieving a well established ley can extend the crops expected life for years. It is important to use the correct product, particularly if there is clover in the ley. The table below shows weed control options for new leys with or without clover.

On heavy land or in wet sowing periods slugs can also play havoc with grass seed establishment and slug pellets will need to be used. A firm seedbed will help in slowing the progress of slug damage.

Leatherjackets and Frit Fly problems

Depending on the time of year, leatherjackets and Fritfly can also cause reseed damage or failure. Both can be controlled by the use of the insecticide Dursban WG. Frit Fly larvae destroy the central shoots of ryegrasses and can affect both establishment and development of a young ley after an arable crop or after grass. Application should be made at emergence where damage is anticipated or at first signs of attack.

Leatherjackets usually build up in old swards. Studies have shown up to 0.5 tonnes an acre of them can attack the sward from below ground.  After ploughing, bird activity can be a tell-tale sign of leatherjacket presence. Weed control in new leys will require a choice of herbicide based on the presence of clover, or not, in the mixture (see table).

Weed and pest control products

In established grassland, docks, thistles and nettles are the most common weeds. In some cases as a result of docks being allowed to seed in the fields and spreading them in slurry.  Docks can reach up to 30% of a pasture and choke the grass. At 5% infestation in a ley, docks will lead to a 5% reduction in grass yield. Control is cost effective at levels above 5%. There are several dock killers on the market and the choice will again depend on the presence or not of clover. For 2010 the product Pharoah, with a mixture of Aminopyralid and Triclopyr, probably the best all round weed controller in grass, is available for cattle and sheep grazing only.

NOTE: Due to residue problems in livestock FYM and slurries, Pharoah cannot be used on grass intended for silage.


By the judicial use of herbicides and pesticides on grassland, the sward can be kept in a more productive state for a longer number of years, ensuring livestock enterprises can make the most of what is the lowest cost feed on the farm so long as it is managed correctly.

For more information on the pests and weeds on your specific farm contact Graham Ragg on 07798 583667.
 



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