Spraying docks with an effective translocated herbicide two to three weeks after taking a silage cut will give good control, as dock plants will all be the same size and have fresh healthy leaves when treated.
That’s the advice from Corteva Agriscience’s Nicola Perry, who adds that spraying with a herbicide a few weeks after cutting means that docks will have reached ‘dinner-plate’ size, which ensures optimal spray coverage.
“There will also be less grass growth around the weeds, so it will be much easier to hit the target plants when spraying,” she says. “An appropriate herbicide, such as DoxstarPro, should be applied at a rate of two litres per hectare in 300 to 400 litres of water, unless low drift nozzles are used and then water rates can be reduced to 200 litres per hectare.
Dr Perry adds that fields should be treated at least three weeks before the next silage cut so that the herbicide has time to get down right into the roots to give thorough, long-term control. “The dock plant will also have decayed sufficiently, so it is not picked up by the forage harvester and put into the clamp.
“If the interval between spraying and cutting is reduced, for example to around 14 days, control of the weeds is unlikely to be affected, but the amount of weed going into the clamp will increase.”
Producers using contractors to spray grassland need to work out when to book them to meet these timings. They should think about when they will be taking their next silage cut and then work back three to four weeks, to when the contractor needs to spray.
The benefits of using a grassland spray contractor includes them having appropriate, modern and well-calibrated machinery, being experienced at spraying grassland, and they may take away and dispose of empty containers as part of their service.