Sugar beet is very sensitive to weed competition early on and a planned approach to weed removal is the best and the most common approach. More recently black-grass has become more of an issue in sugar beet, generally due to the difficulties of effective control in other parts of the arable crop rotation. Growers who are struggling to control this particular damaging weed on their farm should integrate the new graminicide Centurion MAX (clethodim) into their weed control programme this spring and so reduce weed competition in sugar beet and minimise seed weed return in following crops.
“Centurion MAX was introduced to the UK market last autumn in winter oilseed rape and many growers and agronomists have been delighted with the results they have seen on farm. Many have noted the superior performance of clethodim on black-grass, even strains that have been more difficult to control in the past. We are expecting that growers who use this graminicide in sugar beet this spring will be equally delighted,” says Stewart Woodhead, Technical Manager for Interfarm UK.
“Centurion MAX controls black-grass, annual meadow-grass, wheat and barley volunteers in sugar beet. One of its special attributes is that, although it is an ACCase inhibitor product, it is active on strains of black-grass that are resistant to other ACCase products. It has been shown to outperform all graminicides, even tepraloxydim which, until clethodim’s launch, was considered to one of the best grass-weed herbicides and was the leading graminicide in sugar beet. Centurion MAX could now take the top position in terms of performance. But despite its activity, it is important that it is used wisely in an integrated way,” says Stewart.
“This integrated approach in sugar beet should involve both cultural and chemical control. Winter ploughing and use of glyphosate can be implemented before drilling beet. When it comes to herbicides, growers should aim to use products with different modes of action such as ethofumesate and clethodim. Just as in cereals, stacking pre-emergence herbicides should be planned and then post-emergence herbicides including the best graminicide, which in my view is clethodim. Recent Pesticide Usage Surveys indicate that between 35% to 40% of sugar beet crops receive a post-em graminicide. It makes sense to use the most active.”
Stewart advises that Centurion MAX is applied at a dose rate of 1 l/ha from when the sugar beet has fully expanded cotyledons or first leaves visible up until before row closure. It will control black-grass and cereal volunteers from the 3 leaf stage to 5 tillers, with annual meadow-grass from 3 leaves to tillering. “In practical terms it is the black-grass stage which governs application timing, with 3 leaves being the best timing.”
He advises that the dose rate of 1 L/ha should not be reduced. “This is the effective dose rate and one that delivers the high level of weed control we would expect. In trials Centurion MAX gave 98% control of black-grass and 96% control of annual meadow-grass, a weed that few other ACCase graminicides can control.”
In UK and EU trials Centurion MAX gave good activity on rough-meadow-grass, wild-oats, rye-grass species, brome species, canary grass and fescue. In trials in sugar beet to control wild-oats, clethodim gave 90% control, tepraloxydim gave 80% and cycloxydim and propaquizafop 85% control. “Removing weed competition early and effectively will help the sugar beet grower achieve his ultimate aim of high yields,” he says.
Centurion MAX should not be applied in situations where the target weeds are under stress e.g. waterlogging, frost, natural dieback drought or other environmental conditions that could interfere with its activity.
Centurion MAX contains 120g/L clethodim and is formulated as an emulsifiable concentrate with its own in- built adjuvant and packed in a 5L container. It is recommended for use post-emergence in sugar beet and winter oilseed rape to control black-grass, annual meadow-grass and cereal volunteers. It is applied at a dose rate of 1 litre/ha in 200-400 litres of water
as a fine or medium spray quality. In sugar beet it can be applied from cotyledon stage up to before row closure and 56 days before harvest. One application can be applied per crop. Centurion MAX has no LERAP.