Certis technical officer Alan Horgan advised that growers are able to continue using up stocks for a further year until March 2011. "Dacthal is an effective residual herbicide that provides a robust foundation to weed control programmes," he said.
He added that Dacthal, a registered trademark of Amvac Chemical Corporation, can be used across a range of crops including "Brassicas, leeks, bulb onions, ornamentals, runner beans, sage and soft fruit such as strawberries, making it a flexible option for weed control in a number of situations.
"The unique active ingredient chlorthal-dimethyl is extremely effective and kind to the crop as well as having no Local Environment Risk Assessment for Pesticides buffer zone restrictions."
"Applications are recommended either preor post-crop emergence, but growers must ensure that treatments are applied before the weeds emerge. Moist soil at application is vital, so a light irrigation if conditions are dry will increase efficacy and activate the chemical."
Horgan also noted that Dacthal has been granted a specific off-label approval for use on salad onions - replacing the role of Decimate (chlorthal-dimethyl and propachlor) following its revocation earlier this year.
The off-label notice gives salad onion growers 12 months of use up until the final revocation date in March 2011.