Sugar beet growers warned on herbicide limits

Sugar beet growers are being warned to stay within label restrictions when tailoring herbicide programmes to difficult field conditions.

"There are a range of restrictions, which growers need to be aware of, including a limit on the use of ethofumesate of 1000g/ha of active ingredient within a three year period,” advises Pamela Chambers, knowledge transfer manager for Broom's Barn Research Centre in Suffolk.

Products containing ethofumesate include Betanal maxxPro, Betasana Trio, Magnum, Power Twin, Torero, Twin, Ethosat 500 and Ethofol 500SC.
 
Phenmedipham restrictions are a particularly grey area. In last year’s difficult conditions a lot was used, prompting some growers to ask if they could exceed the 960g/ha of active permitted per year by switching to a different branded product for their final spray.

Relevant brands include Betanal Maxxim, Betanal maxxPro, Betasan Trio, Betasana SC, Powertwin and Twin.

Advice from the Chemicals Regulation Directorate is clear: “Changing products containing the same active substance so that more active is applied than the maximum dose specified for any one product is strongly discouraged.

"It could be seen as going against the legal requirement to take all reasonable precautions when using pesticides to protect people, animals and the environment.”
 
But restrictions on phenmedipham do not apply to desmedipham. Using a co-formulation can cut phenmedipham use and give better weed control, Ms Chambers notes.

Care is also needed with the number of applications permitted, particularly in FAR programmes. Amongst phenmedipham/desmedipham mix products Beetup Compact has a maximum of three applications per season, whereas Betanal Maxxim has no such restriction.
   
Mistakes can also arise if tank mix recommendations are updated following a last minute field check or if a different brand of an otherwise familiar active ingredient is supplied. The latter may apply to chloridazon products unused pre-emergence and now planned for post-emergence use. Some labels stipulate pre-emergence use only (Pyramin DF), whereas others (Takron) allow pre- and post-emergence use.
 
Other restrictions include a 2.6kg/ha maximum total dose every third year for chloridazon (as in Magnum, Takron, Fiesta T and Volcan Combi) and for triflusulfuron-methyl (as in Debut and Safari Lite WSB) a maximum dose of 60g every third year, with no application to foliage destined for feeding to livestock.

Finally, for resistance management purposes, use only one ACCase herbicide (such as Aramo, Falcon, Fusilade Max, Laser or Panarex) at a time. Only use a second, different, ACCase inhibitor to control different weeds at different timings.