The first sulfonylurea herbicide for use in oilseed rape could be available by autumn this year, according to Adam Espir, regional agronomist for manufacturer DuPont.
Ethametsulfuron is a new active ingredient based on sulfonylurea chemistry that promised to boost broad-leaved weed control programmes, he told delegates at the 2011 AICC conference last Monday (10 January)
“It’s the first new active ingredient we’ve had for oilseed rape for a number of years.”
The active’s main use will be as tank mix partner for metazachlor products to boost broad-leaved weed activity, but it can be applied on its own with an adjuvant.
Charlock, chickweed, cranesbill, mayweed, shepherd’s purse and hedge mustard control are its main strengths, but it also offers some activity against other broad-leaved weeds including fumitory, groundsel and thistle.
In trials carried out by the firm, the new active was tank mixed with Novall (metazachlor + quinmerac), Springbok (dimethenamid + metazachlor) and Shadow (dimethenamid + metazachlor + quinmerac), and in all cases it improved activity.
Crop safety was good and the product could be applied before plants were “waxed up”, said Mr Espir. “This means it can be used from the cotyledon stage right up to eight leaves.”
Because ethametsulfuron is a contact material it is best applied early post-emergence when weeds are small. “The key with ethametsulfuron, as with other sulfonylureas, is to get on early when the weeds are actively growing.”
There was also potential for statutory off label approvals (SOLA) in some salad and vegetable crops, he added.