LIVESTOCK farmers have been told they could improve grass dry matter per hectare by more than ten per cent through planned weed control.

However Nufarm, the Yorkshire-based crop protection company, said herbicide timing was critical, along with choice of product.

The company’s Simon Bishop said: “Dairy, beef and sheep farmers already believe they can get more from their grass – the cheapest form of feed – however they are not sure how to.

“The yield benefits of weed management are not yet widely understood by growers, but we know having clover safe options are important.

“Controlling common weeds such as docks and thistles from a ten per cent infestation level will deliver an extra ten per cent of grass dry matter.”

An independent survey recently commissioned by Nufarm found weed control was not at the top of livestock farmer’s minds as being essential to producing good quality grass cover, compared to fertiliser and seed.

“While only half of all grassland farmers had done some form of weed control in the last year, 80 per cent of those had a general feeling it was about ‘tidying up weeds’,” said Mr Bishop. “Just 20 per cent considered crop protection as improving grass production.

“Consequently, little more than five per cent of UK grassland has a herbicide application in any given year, and few grassland farmers treat more than ten per cent of their pasture in any season.”

Nufarm has now launched a Grassmanship programme to help farmers manage their grassland better and benefit from increased production and yield.

Dr George Fisher, independent grassland consultant, said weed control was a key element of productive grassland farming.

He said: “Every one per cent increase in weed ground cover will result in a one per cent decrease in grass growth.

“Controlling common weeds in a grazing sward with ten per cent infestation levels could improve yield from 10t DM/ha to 11t DM/ha enabling improved grazing availability and subsequent stocking rates to deliver a 14:1 return on investment (ROI). Similar results can be achieved from grassland for silage.”

But he said the correct timing of herbicide was everything. “Herbicides applied too early or too late will not work as effectively, if at all,” said Dr Fisher.

“Generally, herbicides should be applied when weeds are healthy and the leaves actively growing. Once stem extension starts, leaf growth is insufficient for the herbicide to work effectively.”

He said weeds in reseeds are best controlled when the grass is at the two to three leaf stage.

“Docks and chickweed are the two most critical weeds to control in reseeds and must be controlled at the seedling stage. Herbicide application is essential before the first grazing.

“Clover-safe options are available such as CloverMaster and Squire Ultra, but again, timing of application is crucial.

“In established and permanent grassland, it is important that farmers assess weed pressure as soon as grass starts to grow in spring.

“Early assessment allows time to prepare, choose the right product and plan for timely application, either using on-farm resources or getting in a contractor to do the job.”