Control thistles to combat orf and grow more grass

UK - May 26, 2009

Getting rid of thistles in sheep pasture with a herbicide such as Thistlex from Dow AgroSciences significantly reduces the spread of orf while increasing grassland productivity, according to David Cairns of MS and P Agriculture based in Berwick-on-Tweed.

“Orf costs the Scottish sheep industry dearly in vets’ bills, poor animal performance and lost days’ work for staff who unfortunately pick up this highly contagious virus,” says Mr Cairns. “Sheep become infected when they brush past sharp objects such as thistles, which act like dirty hypodermic needles, injecting and spreading orf within the flock.”

With no effective treatment once sheep develop the disease, and preventative vaccination failing to offer long term control, removing the thistle population is the best way of reducing the risk of infection, and has proved successful on many farms.

But curbing the spread of orf is not the only reason to control thistles. Mr Cairns suggests the yield advantages of using Thistlex to clean up pasture should not be ignored.

“A 10% infestation of thistles in a sward could reduce grass production by 1.1tonnes of dry matter per hectare, equivalent to a loss in lamb production of £312/ha. This is a waste of valuable home-grown feed,” he says.

“With many sheep farmers cutting back on fertiliser because of the price, grass yields will be down this year. So it will be very important to make the most of the fertiliser that is applied by ensuring the maximum cover of grass in each field.

“Controlling thistles with a long-lasting, grass-safe herbicide like Thistlex will not only increase yields for grazing, but also improve the quality of any forage that is made from the grass.

“For good control – treat actively growing thistles at the rosette stage; with little stem and four to ten leaves showing. If they have developed beyond this stage, it is better to top them and spray the regrowth six to eight weeks later.”

For more information on thistle control contact the Dow Hotline on tel: 0800 689 8899.