28th February 2007

Targeted weed control needed in sugar beet

Weed control should be prioritised early in sugar beet, with a view to keeping the crop weed-free until the 6 to 8 leaf stage, thereby preventing competition and loss of yield. But growers need only target those weeds that either grow above the crop or interfere with harvesting and can mix and match herbicides rather than spend on expensive coformulations, says Interfarm.

Now that growers are aiming for higher yields in order to help produce a profitable crop, weed control should be particularly prioritised early on in the crop’s life. But they need only focus on weeds that will cause the most damage or nuisance. This means tall weeds such as fat-hen and redshank that grow above the crop and compete with the crop early on and those weeds such as knotgrass and bindweed that interfere with harvest. One tall weed per square metre can reduce yield by 10% which in the context of lower price per tonne for the crop is very significant,” explains Dr. David Stormonth, Technical Manager, Interfarm (UK) Ltd.

“As well as aiming to increase yields, growers are also balancing out input costs and so are looking at less expensive but effective options. Interfarm has three sugar beet herbicides that can be incorporated into a cost-effective programme. Burex which contains chloridazon is a well known and kind soil-acting herbicide that controls germinating weeds via the roots during or shortly after weed emergence. It can be applied pre-drilling and incorporated or pre-emergence of the crop or post-emergence in tank-mix with a contact herbicide such as phenmedipham, with excellent crop safety. It controls key weeds such as black bindweed, black nightshade, charlock, chickweed, red deadnettle, fat-hen, knotgrass, mayweed, poppy, redshank and speedwell but is also well regarded for its crop safety particularly at the establishment phase when adverse conditions may lead to crop check from other compounds ” points out Dr. Stormonth.

“Lenacil is also a residual herbicide with an excellent weed spectrum including difficult weeds such as volunteer oilseed rape, charlock, bindweed, fat-hen, redshank and knotgrass. It can be mixed with metamitron, phenmedipham/desmedipham, ethofumesate and triflusulfuron to give improved control of certain weeds. For instance lenacil and phemedipham will give improved control of deadnettle, groundsel, nettle, volunteer oilseed rape and pansy. It offers good flexibility and gives growers the opportunity to target key weeds at a cost-effective price,” says David.

Sugar beet also offers an opportunity to get rid of difficult grass-weeds such as couch and black-grass on the farm and David points out that the graminicide Co-Pilot, based on quizalofop-p-ethyl, offers a flexible approach according to weed species and weed size. “Co-Pilot is active on rye-grass, brome and wild-oats, too. It has excellent rainfastness of less than one hour, a wide range of tank-mixes and has no LERAP, making it easy to use. This makes Co-Pilot an excellent choice for growers looking for effective weed control at an affordable price.”

Burex 430 SC contains 430 g/litre chloridazon formulated as a suspension concentrate. Lenacil contains 440 g/litre lenacil formulated as a suspension concentrate. They are approved for use in sugar beet, fodder beet and mangels, pre and post-emergence up until when plants meet between the rows. Both control a range of annual broad-leaved and grass weeds. They are packed in 5 litre packs.

Co-Pilot contains 100 g/litre quizalofop-p-ethyl formulated as an emulsifiable concentrate. It is a fully systemic post-emergence herbicide offering excellent control of a range of annual grasses, cereal volunteers and couch in a range of broad-leaf crops such as sugar beet, oilseed rape, peas, beans and linseed. In sugar beet it is used from when the crop has 2 fully expanded leaves, when weed are at the appropriate stage and actively growing and before the crop meets across the rows. Wheat and barley volunteers, wild-oats, rye-grass, sterile brome and susceptible black-grass are controlled. It is packed in 1 litre packs.

For further comment and information, please contact Dr. David Stormonth, Technical Manager, Interfarm (UK) Ltd. on 01354 741414 or 07818 036506 (mobile).