Docks have continued growing throughout the winter and are now ready to grow rapidly as soon as the weather warms up. They could start growing earlier than usual, but need to be controlled in order to maintain silage quality, grassland yield and palatability. Docks are generally unpalatable to animals so the more docks you have, the less palatable stock will find your pasture.
“Docks are very competitive, with large tap roots that help them survive the winter period. They compete with grass for light, nutrients and water, so reducing yield. This year we are seeing more docks than ever, as fewer farmers were able to spray due to the cold weather conditions last spring,” says Stuart Sutherland, Business Development Manager for Interfarm UK.
“Based on amidosulfuron, Squire Ultra is one of the few herbicides recommended in grassland, particularly in grass with a clover component. Using it correctly can prolong the productive life of both permanent and rotational grassland, but its timing needs to be just right in order to get the most benefit – you don’t want to go in too early. Nor do you want to be too late,” says Stuart.
“Optimum timing for dock control is linked to the direction of weed’s translocation flow. Squire Ultra will ‘go with the flow’ and needs to be moved downwards in the translocation stream towards the roots. At the start of spring, when docks are starting to grow, nutrients are moved from the tap root reserves upwards to develop new shoots and leaves. This is not the right time, so application will be too early. However, when docks are “dinner plate size”, the flow reverses and nutrients are then going downwards from the leaves to the roots. Squire Ultra needs to be moved downwards and so it is best applied at this time,” he explains.
“But you can be too late. When docks have seed heads and overlapping leaves, the nutrient flow changes upwards again, as root reserves are transported to help with seed head development. At this time it is best to cut the docks and treat regrowth when appropriate.”
“Squire Ultra controls broad and curled-leaf docks and other annual broad-leaved weeds, including cleavers, charlock, shepherd’s purse and field forget-me-not, in both rotational and permanent grassland. It is fully systemic and, although slower acting than many dock herbicides, it is moved effectively into weed roots where it will act. Spraying is likely to be economic when docks cover at least 10% of the field area.”
Stuart Sutherland points out that an important benefit of this herbicide is that it is safe on white clover. “It can be applied to clover seedlings from the one or two trifoliate leaf stage onwards, with complete crop safety. Other products control docks but they also take out the clover,” he points out.
“Squire Ultra knocks back large established docks, but you may need a programmed approach over a few years for a more complete kill. One application is not enough; unsurprisingly when you see how large the root systems are. When used over a period of time, it will give good results, with no crop safety issues or following crop problems, which is a real advantage in grassland,” he says.
Squire Ultra contains 75% amidosulfuron formulated as a Water Dispersible Granule and is packed in a 240 grams pack. It is recommended on grassland for the control of docks, cleavers, charlock, shepherd’s purse and field forget-me-not at a dose rate of 60 g/ha. It should be used when docks are at a suitable growth stage between the 1st of February and the 30th June in rotational grass and between the 1st February and the 15th October on permanent grass.
It has no LERAP and is safe to white clover. Livestock should be kept out of treated areas for at least 7 days after treatment and until foliage of any poisonous weed such as ragwort has died and become unpalatable. Do not cut for hay or silage for at least 21 days following treatment.