Take advantage of autumn conditions to reseed pastures

Farmers who missed out reseeding fields in this year’s dry spring can still upgrade their pastures now by carrying out an autumn reseed.

“New swards that mainly consist of perennial ryegrass can produce more than 3t DM/ha more grass than old permanent pasture and are 25 per cent more responsive to soil nutrients,” says Dr Nicola Perry, weed biologist for Corteva Agriscience.

“Reseeding in September makes the most of high soil temperatures which allows the grasses to establish rapidly. However, weeds will also germinate quickly too.”

Broad-leaved weeds such as chickweed and buttercups, along with seedling docks compete strongly with the young grass for space, light, nutrients and water. Newly sown fields need to be monitored closely to check which weeds are emerging and to assess when to treat with herbicide.

“With the cost of a full reseed reaching up to £600/ha, reseeding is an investment in the future that will pay for itself in savings on bought feed within two years,” says Dr Perry. “But to achieve their full potential, the fields need to be clear of weeds.

“Envy, which is based on a combination of fluroxypyr and florasulam, controls a wide range of broad-leaved weeds and does not harm young grass. It is also much more cost effective to spray young docks in the autumn, than waiting until the spring when they have established a much deeper root system.”

Envy can be applied as soon as the grass has three true leaves, at a rate of 1-1.5 litres/ha in 200 litres/ha of water and can be sprayed until the end of November. Envy also copes well with fluctuating diurnal temperatures typically found in late autumn but should be applied within two weeks of forecasted first frosts.

Livestock grazing the new sward to encourage the grass plants to tiller, must be removed for just seven days after spraying. If the ley has been excessively grazed, it is advisable to give the grass a chance to recover before spraying.