Friday, 30 March 2012

Controlling docks in grassland with clover

Controlling docks in grassland which contains a white clover component is important to maintain forage quality and livestock output and Jock Logan of Frontier Agriculture who advises farmers in the Lothians has cracked the job through the careful and considered use of the herbicide Squire Ultra.

“Although it is not the easiest of products to get right, when you do get it right, it does a great job. I would normally be going for mid-April applications to small docks that are growing well in grass mainly grown for silage. I think Squire Ultra works better when the weather is warm and sunny but there needs to be sufficient moisture. I have found that the addition of an Approved wetter adds to its performance by affecting the docks’ leaf wax and allowing the herbicide into the weed more effectively. One key benefit of Squire Ultra is that it does not affect white clover and can be applied to seedlings from the one or two trifoliate leaf stage onwards, with absolute crop safety. Other products control docks OK, but then wipe out the white clover,” Jock points out.

 Stuart Sutherland, Business Development Manager for Interfarm UK, points out that docks are the most economically damaging weeds in grassland.  “They compete directly with grass, reducing yield and reducing effective pasture life as well as affecting forage quality. Docks are competitive weeds with large tap roots that survive over the winter period and well into the early spring.  They are a real challenge to control.”
“Based on amidosulfuron, 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 rotational and permanent grassland. It is fully systemic and, although slower acting than many other traditional dock herbicides, it moves throughout the weed, even into the roots.  But, as Jock Logan points out, correct timing is key - not too early and not too late.”
The best time to apply Squire Ultra is when the weed itself is moving sugars from the leaves down to the roots, so that the herbicide is taken down to where it needs to be. Dock leaves should be expanded and horizontal and the plant should be the size of a large dinner plate.

Stuart explains that in the spring when docks are using up stored tap root reserves to grow, there is an upward movement of nutrients from roots to shoots.  “At this point, root uptake of Squire Ultra will be poor and so herbicide application will be too early. But when the weed is “dinner plate size” this flow reverses to transport sugars back to the root system – ideal for Squire Ultra applications. When docks start to grow upwards, forming stalks and developing seed heads, the systemic flow reverses once again in an upward direction. Squire Ultra should be applied when docks are horizontal and “dinner-plate” size and when nutrients are moving downwards from leaves to roots. Soil moisture is also important,” explains Stuart.

“Squire Ultra knocks back docks well, but may not wipe them out completely in one application, unsurprisingly when you consider how large the root system can be. But used in a planned way over time, it will give good results with no crop safety issues or following crop problems, which is a definite advantage in grassland,” he says.

Squire Ultra contains 75% amidosulfuron formulated as Water Dispersible Granule and is packed in a 120 grams pack to treat 2 hectares. 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 gms/ha. Squire Ultra 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. Keep livestock 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.

For further comment and information, please contact Stuart Sutherland, Business Development Manager for Interfarm UK Ltd., on 07887 755 576 (mobile) or via e-mail stuart.sutherland@interfarm.co.uk