19 November 1999

Couch and brome control for wheat

COUCH and brome control in winter wheat plus useful broad-leaved weed action from spring spraying is Monsantos claim for new herbicide Mon 37500 (sulfosulfuron)

"For the first time growers have a solution to brome and couch in the crop," herbicide product manager Jonathan Tann said at the British Crop Protection Council Conference in Brighton earlier this week.

Already available in Ireland as Monitor, UK approval is hoped for in time for next springs Feb 1 to GS 39 application window. Cost is expected to be similar to Irelands £30/ha (£12/acre).

Couch and brome are not killed, but suppressed. "It freezes weed growth, keeping the weed below the crop canopy at critical growing times," Mr Tann explains. Yield response is said to be up to 20% from brome control and 40% from couch control. Lodging is also reduced.

Viable brome seed return is reduced 80-90%, but stubble treatment is required to kill couch rhizomes. Blackgrass and wild oat control is claimed to be 50-60%, cleavers control 97% and mayweed and charlock 96%.

As a sulfonyl urea, MON37500 will come within the one sulfonyl urea application per crop rule. Sugar beet and possibly oilseed rape may have following crop restrictions. &#42