Dealing with docks: ‘If you can eliminate them more grass will grow in their place’

The amount of grass grown on farms would increase if farmers eliminated docks from their swards, according to TP Whelehan’s Chris Maughan.

Speaking at a Teagasc Better Beef Farm walk in Co. Meath, the Technical Director said as the amount of docks increase in a sward the amount of grass grown falls at the same rate.

“If you eliminate docks more grass will grow in its place,” he said.

Maughan also spoke about research trials carried out in Teagasc Kildalton, which showed that grass production falls as docks increase in both first and second cut silage.

Let’s say you have 10t of DM grass cut, he said, if 50% of the field is covered in docks and 50% is covered in grass, you’ll harvest 5t of grass and 5t of docks.

If 90% of the field is covered in grass and 10% is covered in docks, you’ll harvest 9t of grass and 1t of docks, he said.

The TP Whelehan representative also said that farmers can get very good levels of dock control if the manage the spraying protocol correctly.

The key thing is getting the timing of the spraying right. Spraying at the correct stage of growth is important.

“Docks can have a large taproot, up to 1m in length at times, and this can make the weed difficult to eliminate,” he said.

Because of this, he said, it is essential to spray the docks at correct growth stage.

Chris Maughan showing a dock in its reproductive stage.
Chris Maughan showing a dock in its reproductive stage.

Maughan also said that docks should be sprayed when they are green and leafy, as spraying when the seed head is formed (reproductive stage) will result in a lower kill.

When the dock is at its reproductive stage, more energy is supplied to the top of the plant and as a result the chemical will not be taken up as well by the root, he said.

“The weed killer will still work but you will get poor long term control.”

For swards including clover, Maughan said there were two clover-safe products available on the market, these are Eagle and Prospect.

However, he said there are no clover safe products currently available for nettle control and if spraying for nettles, clover can be easily reintroduced into the sward through over sowing into existing swards.

Clover can be spread using a fertiliser spreader, onto the surface of the field. It doesn’t need to be rolled or stitched in- clover will germinate on the surface.