Help farmers get rid of docks in silage

UK - April 04, 2011

As grass growth really gets going and heads towards its spring time peak, many farmers will be hoping for good cuts of silage this month.

With the price of feed wheat double what it was last year, many will be looking to take at least three cuts this year, and making as much, high quality conserved forage as possible.

Another way to increase the amount and feed value of silage is to get rid of any perennial weeds.  

Research at IGER showed that a 20% infestation of docks can reduce silage yields by 20%. So for a crop that normally yields 11t DM/ha, as much as 2.2t DM/ha could be lost each season in a weedy field.

Docks are also less digestible than grass and will pull down the feed value of any resulting silage. This means extra supplementary feeds will have to be bought to feed livestock over winter.

Hit docks for good with Doxstar
Herbicides based on traditional phenoxy chemistry such as MCPA and 2, 4-D offer a short-term, above ground solution for docks, but rapid re-growth is very likely.

Newer products such as Doxstar containing triclopyr get right down into the roots of the target weeds and do a better job over a longer period.

Also they will not hold back grass growth – the last thing farmers want when trying to maximise output. This was confirmed in IGER trials which demonstrated that there was no reduction in yield from spraying grass with this type of product.

Spraying window
The period between first and second cut is an ideal time for tackling docks, when they are actively re-growing. This means they will all be at the same stage of growth when sprayed – giving uniform results across the treated area.

For best results spray at 3litres per hectare in 300litres of water, when the docks are at rosette stage and up to 25cm high or across.

Ideally allow two to three week’s re-growth after first cut so that the docks have big enough leaves to take the spray fully on board.

Advise your customers to wait at least four weeks before second cut, so that the weeds have chance to transport the spray right down to the deepest roots for the most effective, long-term kill.