Look to should spray dock infestations in silage leys in April, three to four weeks before the mower goes in. Reasons for controlling docks early:

  •             Grass is better able to recolonise bare patches at the start of the growing season
  •             Extra grass yield for the whole growing season
  •             Grass silage without weeds present = better quality silage
  •             Docks are healthy and showing rapid growth so translocation of herbicides is optimised

 

If a spray contractor is used, a date should be booked in now.

Docks have only 60-65% of the feed value of grass and can restrict silage fermentation, leading to lower dry matter intakes. Dock seeds can also survive in silage and pass out through cattle, infesting fields that previously had no problem or re-infesting fields that have already been treated.

The ideal time to spray docks with an effective translocated product such as Doxstar® Pro, is when the plants are young and actively growing and are 20cm high or across. Spraying three weeks before cutting allows the sprays to reach down to the roots to kill the plant and for the leaves to decay. Early season sprays also mean docks are all at the same stage of growth, making it easier to treat them all.

Apply Doxstar Pro at 2 litres/ha in at least 300 litres of water, or up to 400 litres of water if dock numbers are high or the grass sward is particularly dense. If low drift nozzles are being used, water volumes can be dropped to 200 litres/ha.