Tips for using herbicide Centurion MAX

A leading distributor technical manager is impressed with the new graminicide for oilseed rape, Centurion MAX, but warns growers and advisors not to misuse it or they will lose it. Dr. David Ellerton, Technical Development Director for Hutchinsons considers Centurion MAX, based on the active ingredient clethodim, to be the most broad spectrum of all the graminicides, even on difficult to control black-grass, but he says not to take it for granted or it will go the way of all graminicides in terms of weed resistance.

“I know the active ingredient clethodim well and know that it is extremely good on a range of grass-weeds. It controls black-grass, wild-oats, annual meadow-grass, rye-grass, brome and cereal volunteers. But its strength is that it is extremely good on black-grass, whatever the strain. Because of this strong activity it is crucial to look after it and protect it from resistance. If we misuse it, it will succumb to weed resistance just like every other grass-weed herbicides has and so lose its unique benefits.”

Dr. Ellerton advises growers and advisors to stick to a number of key guidelines that will protect Centurion MAX in the longer term.  “Firstly don’t cut the dose rate. Always use the label rate of 1 l/ha which is the effective dose. Secondly don’t use Centurion MAX as the only method of controlling grass-weeds, particularly black-grass. Use cultural control where you can in the rotation – such as stale seedbeds - and always use other active ingredients with different modes of action such as metazachlor, carbetamide and propyzamide in the programme.”

“Thirdly don’t waste it purely to control volunteer cereals. Use it where you get the most value from it. In fact CRD have effectively stopped its early use on volunteers by imposing the earliest application date of the 4 leaf stage of the rape crop. This means that, abiding by the label, it really shouldn’t be used on early flushes of volunteers. Centurion MAX is very good on volunteers and it will take them out later but it is best to use another graminicide early on. Fourthly use Centurion MAX later on in the autumn when the grass-weeds are there at the right stage and always either mix it or sequence it with a residual.”

David Ellerton considers Centurion MAX will be the last of the fop and dims to get to market in the UK.  “CRD have registered it and so must believe in its ability to work, even under the testing conditions in the UK. They see clethodim as an important active; all the more reason to make sure that Centurion MAX is used carefully and strategically in a planned programme to make sure it’s working life is prolonged. It is simple, if we over use it or misuse it, we will lose it.”

Stewart Woodhead, newly appointed Technical Manager for Interfarm UK Ltd. also urges growers and advisors to use Centurion MAX wisely in a black-grass control strategy.  “In oilseed rape it is extremely important to use it in a programme with herbicides with different modes of action such as propyzamide or carbetamide. Such products should be used either in mix or after Centurion MAX. Clethodim should not be the last herbicide treatment in the programme. This way any survivors from a clethodim treatment are removed by the other herbicide or herbicides, thus preventing or reducing any weed seed return. This could help minimise or prevent the selection and development of resistant weed strains.”

He points out that it should be the black-grass stage which governs the application timing, with 3 leaves being the best timing for Centurion MAX.  “This is normally when oilseed rape has 4 leaves. Only one application per crop is permitted.”

Stewart concludes that it is important that Centurion MAX is used in a way that does not put any risk on its performance, especially in its first year of commercial use.

Centurion MAX contains 120g/L clethodim formulated as an emulsifiable concentrate and packed in a 5L container. It recommended for use post-emergence in winter oilseed rape and sugar beet 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 and at a fine or medium spray quality. In winter oilseed rape it can be applied from the 4 true leaf stage of the crop and in sugar beet from cotyledon stage. One application can be applied per crop and the latest time of application in oilseed rape is before stem elongation and in sugar beet before row closure. Centurion MAX has no LERAP.