13 August 1999

Brome and cleavers in just one hit…

A GRASSWEED herbicide with good cleaver activity sounds too good to be true. But that is how UAPs senior trials officer Derek Lewis describes MON375 (sulfosulfuron).

The spring applied herbicides prime strength is brome species, giving complete control of rye brome in UAP work last spring. "But it has the added advantage of broad-leaved weed control which could be quite useful, cleavers being one of them," he says.

On the label cleavers control is claimed up to 2-3 whorls and in UAP trials this year it achieved over 90% control from a Feb 12 full-rate application on cleavers 10cm across.

However, as a sulfonyl-urea, its use would rule out other sulfonyl-ureas in the same growing season, and a one year following crop restriction for sugar beet is expected. "It will require a lot of planning," notes UAP technical director Chris Bean.

Soft, rye, and meadow brome are all rated as susceptible, but sterile brome is only moderately susceptible, adds eastern region technical manager Brin Hughes. Avadex (tri-allate) pre-emergence to sensitise the weed, followed by a split spring application of MON375 should be growers best bet, he suggests.

"It is the first post-emergence option for getting on top of brome problems, and a significant advance on ipu."

Couch is stunted by the herbicide, protecting crop yield in the year of application. Bulbils of onion couch are significantly reduced, but for rhizomatus couch glyphosate pre- or post-harvest would still be required, says Monsanto product manager Jonathan Tann.

Wild-oat and blackgrass control is limited. But the only tank-mix restriction expected is for hormonal herbicides, so mixtures with reduced-rate Topik (clodinafop-propargyl) or Cheetah (fenoxaprop-ethyl) are possible, he says.

Already available in Ireland as Monitor, a UK launch is expected in time for use next spring, subject to registration approval.

MON375

&#8226 Brome, couch and cleavers control.

&#8226 Sulfonyl-urea: restrictions on multiple use/following crop.

&#8226 Launch in time for next spring?

&#8226 Following Avadex for sterile brome.