The wetter than usual conditions experienced in the late spring, which disrupted farm schedules all over the country, proved inconducive to spraying docks in first-cut silage crops.

As the weather became more suitable for spraying, many silage crops were too advanced for a pre-harvesting application.

Therefore, farmers had no option but to take the hit on yield and potential quality due to heavy dock infestations.

Where docks weren’t controlled before silage was cut, every effort should be made to get rid of such weeds to ensure clean, productive swards for a second cut of silage or for subsequent grazing.

Docks compete with grass for light, nutrients and moisture, thus reducing grass yields. They have only 65% of the feed value of good grass and are generally unpalatable to livestock. As a long-term problem, docks require a long-term solution.

As well as cutting yield, docks can lead to a decline in silage quality through poorer fermentation. Dock stems inflict serious damage to the quality of baled silage through puncturing of the film.

In addition to triggering higher dry matter yield and better quality, eliminating docks will also ensure a clean, productive sward for subsequent grazing or a second silage cut.

Timing is everything

The timing of the spray is the key to effective control of docks and other weeds in grazing and silage swards, according to technical manager with Whelehan Crop Protection Chris Maughan.

“For best control, docks should be sprayed when they are actively growing and are 15cm to 25cm high or across and before a seed head begins to appear,” he said.

“Therefore, dock-infected silage fields that were cut around the end of May and early June should now be at the ideal stage for spraying with an effective herbicide about two to three weeks after cutting.”

When it comes to delivering the optimum dock-eliminating results, Doxstar Pro represents the specialised systemic herbicide of choice.

Manufactured by Corteva Agriscience and distributed on the Irish market by Whelehan Crop Protection, Doxstar Pro contains two powerful chemicals - triclopyr and fluroxypyr - ensuring the most effective kill of the dock root system, which can be up to a metre deep.

Highly effective on chickweed and dandelions, the use of Doxstar Pro doesn’t lead to any check to grass growth.

Chris Maughan had the following advice to offer about spraying with Doxstar Pro.

Wait for two to three weeks after cutting before spraying with Doxstar Pro. Docks should then be at the right growth stage for an effective kill.

If a second cut of silage has been taken, leave an interval of at least three weeks between spraying and harvesting the crop. This ensures that the chemicals get fully translocated down to the dock roots, a vital factor in achieving an effective kill.

If the sward is being grazed, keep animals off the sward for seven days after grazing.

Doxstar Pro Factfile

Forefront T: the ideal broad-spectrum spray

Forefront T has become a widely used herbicide among a growing number of farmers seeking to clean pastures of a wide spectrum of weeds.

With the most advanced chemistry in weed control technology, Forefront T contains two chemicals - aminopyralid and triclopyr.

This powerful combination makes it the perfect choice for docks, thistles and nettles, as well as a range of other weeds such as buttercups, chickweed and dandelions. It is also the product of choice for ragwort.

As with Doxstar Pro, the best results achieved by spraying with Forefront T occur when weeds are actively growing and before they flower.

Weeds ought to be gone beyond these stages at this time of the year.

Therefore, it’s best to graze out the pasture and top it. After two to three weeks of regrowth, the weeds should be at the ideal stage for spraying with Forefront T.

Forefront T should be used in a single application at two litres/ha in a minimum 200 litres water/ha, with stock kept off the pasture for seven days after spraying.

Proclova XL: a dock controlling solution

ProClova XL, another market-leading Corteva Agriscience product, is a clover-safe herbicide which kills key weeds in established grassland enabling farmers to build and preserve clover populations for lengthier periods. Where clover needs to be retained, Proclova XL offers a solution to controlling docks.

Use at 125gr/ha plus 250ml/ha (1 pack = 2 hectares). Again the ideal timing is when docks are 15cm to 25cm high or across and in the rosette stage and ensure there is active growth.

Proclova XL also controls buttercups, dandelions, plantains and hogweeds in grassland. A transitory effect (leaf deformation/growth inhibition) may be seen following application, but full recovery will follow.

For more information on best practice guidelines, click here.