Docks pose a regular challenge for farmers throughout Ireland. One mature dock alone can produce over 60,000 seeds and those seeds in turn have the capability to survive in the soil for between 50 and 80 years.

Its lengthy tap root, which can run a full metre deep, occupies a sizeable surface area and can take in significant levels of water and nutrients.

“Docks can devastate silage and grass swards,” said Chris Maughan, technical manager with Whelehan Crop Protection.

“Even a moderate infestation will cut silage dry matter yield by at least 1t/ac and severe infestations can cut yields by up to half. So, if you eliminate docks, more grass will grow in its place.”

For those who observed docks in their first-cut silage and didn’t have an opportunity to spray before the cut, all is not lost, according to Maughan.

“Spraying this difficult weed in the aftergrass will lead to a big increase, both in grass growth and animal performance for the rest of the season – and beyond.”

Doxstar Pro contains two ingredients: Fluroxypr and triclopyr – and the combination of both helps to kill out the root system.

Docks should be sprayed at the rosette stage Maughan said, when they're approximately 8-10in-high and across “when they’re green and leafy and have a healthy leaf”.

Doxstar Pro should be applied at a rate of 2L/ha as a single application or two applications at 1l/ha in autumn time, followed by another 1/ha application come the spring. This will help to eliminate the dock root and provide better long-term control.

“The key thing is getting the timing of the spraying right,” Maughan said.

“Spraying Doxstar Pro at the correct stage of growth is very important and will provide the best possible outcome for farmers this autumn.”

Whelehan Crop Protection is committed to showcasing the benefits of many of its herbicides when it comes to dock control.

A trial site in Carlow was recently infested with both curly leaf dock and broad leaf dock. On May 31, last, Doxstar Pro was applied on site and within five weeks, as pictured below, its benefits were readily evident.

Weed control is an essential element for an autumn reseeding programme, Maughan added.

“Reseeding gives a big boost to grass quality and output. However, the benefits are seriously eroded if weeds in the new reseed are not controlled early," he said.

“Teagasc research has shown that treating docks at the seedling stage with an effective systemic herbicide in a new reseed will result in a dock-free pasture for the following five years.

“Chickweed is another serious problem and can smother the new grass, resulting in a very patchy sward. The biggest risk is from common chickweed but mouse-eared chickweed can also be a problem,” said Maughan.

When it comes to choosing a herbicide for autumn-sown reseeds, Envy is an ideal choice.

Manufactured by Corteva Agriscience, Envy contains two powerful ingredients: Florasulam and fluroxypyr.

It is powerful on seedling docks and common and mouse-eared chickweed and is also highly effective on a range of other weeds including buttercups, dandelions, daisies, and plantains.

It can be applied from when the third-leaf visibility stage of the grass occurs. The application rate to new reseeds is 1.5L/ha in 200L of water.

Envy works well in cooler conditions and is licensed to be applied up to the 30th of November. 

Where it is not possible to apply a post-emergent autumn spray of Envy to a new reseed, it is vital that the weeds are controlled early in the spring. In this situation, Pastor Trio, is the herbicide of choice.

It contains three powerful ingredients, florasulam, fluroxypyr and clopyralid. In addition to controlling the same range of weeds as Envy, it is also powerful on thistles which can be a serious problem in new reseeds.

As with Envy, Pastor Trio, should be applied to new reseeds at 1L/ha in 200L of water.

For further information on any of the products discussed above, click here.