Cereal growers can simplify brome weed management post-harvest by responding to environmental conditions, regardless of the brome species present, says John Cussans, principle weed science consultant with Adas.

Instead of considering different cultivation strategies for various brome species, growers should focus on whether there’s moisture present or not, advises John.

“If it’s dry, leave the weed seed on the surface. If it’s wet, cultivate to try and get a chit,” he says. 

See also: How to identify different brome species

“Where conditions are suitable for getting weed seeds to germinate, then anything that helps with that should be done.”

That’s in contrast to previous advice which urged famers to leave rye and meadow brome seed on the soil surface for a month to ripen, but to bury sterile brome seed so that dormancy wasn’t induced by being exposed to light.

This “light and dark” message didn’t really work in practice, explains John, as only a small proportion of seed responded due to mixed populations.

“In an unusual move, we’re going away from the different cultivation strategies message now and concentrating on the conditions following harvest.

“What is important is to get a good chit so as much of the population can be removed as possible before drilling.”

Rye brome in a wheat crop © Blackthorn Arable

Identification struggles

There’s also evidence to show that growers are struggling to identify the different species properly.

“The mix of species present is often different to the understanding. There’s more great brome and rye brome out there than was thought,” notes John.

With a changing species mix and control becoming more difficult, John believes that simplifying post-harvest management will bring better results.

“It’s time to move away from the type of brome present determining the best approach to management.”

As with other grassweeds, brome control relies on good agronomic practice based on an integrated approach of cultural and chemical methods, says Ben Giles, commercial technical manager at Bayer.

Both great brome and sterile brome germinate in the autumn and winter, so having residual activity in the herbicide programme is important, he notes.

“The pre-emergence actives used in the autumn won’t just be for brome,” Ben acknowledges.

“Flufenacet-based products are a good starting point, with mix partners such as pendimethalin, diflufenican and prosulfocarb all adding to brome control.”

For meadow and rye brome, which germinate in the autumn and the spring, greater reliance on cultural control is required.

You then have the acetolactate synthase (ALS) contact herbicides such as Pacifica (amidosulfuron + iodosulfuron + mesosulfuron) and the Broadway products such as Broadway Star (florasulam + pyroxsulam).

However, you shouldn’t expect more than 50% control from these used alone, he says.