"Over 60% of our team saw increased weed problems invariably or generally associated with either ineffective stale seedbeds or minimum tillage," explained study co-ordinator, Clare Bend. "And just under half reported a clear association with herbicide-resistant weeds. "Brome has traditionally been a weed of headlands confined to specific areas, but in recent years it has become very much more widely distributed across both fields and farms," Clare Bend pointed out. "And while barren or sterile brome was invariably the primary problem in the past, we are now encountering growing challenges from great, meadow, soft and rye brome species.

"The bromes are better adapted to high intensity cereal growing than most grass weeds," she explained. "More wheat in the rotation, more winter drilling, earlier sowing, lower seed rates and autumn weed control regimes that remove competition from other grass weeds all play into their hands.

"Perhaps the greatest reason behind increasing brome problems, though, appears to be the inexorable trend to reducing tillage; especially where time or conditions prevent good pre-planting Roundup control. Indeed, well over 80% of the agronomists in our 2004 study reported their increased weed problems invariably or generally associated with either minimum tillage or ineffective stale seedbeds."

Independent studies show that, under competitive conditions, wheat yield losses of 0.80 t/ha from infestations of just 5 brome plants/m2 can rise to well over 2 t/ha with 20 plants/m2. In addition to compromising yields, of course, brome infestations are known to increase cereal lodging problems and interfere with harvesting efficiency.

Good control, therefore, clearly needs to be a priority wherever the weed is found. All the more so for the fact that individual plants are perfectly capable of producing 50 tillers and 350 seeds or more apiece, and can spread rapidly from a single focus courtesy of both cultivators and combines. This means an apparently insignificant incidence one year can easily turn into a serious infestation the next.

"Above all, the secret of tackling the brome menace is a carefully integrated programme of chemical and cultural control," stressed Clare Bend.

"We now have three useful spring herbicide options for wheat. The specialist brome-killer, Monitor (sulfosulfuron) also has excellent activity on cleavers, good tank mixing compatibility and a wide application window. This makes it particularly flexible to use and valuable for later spring treatment.

"Ethos and Attribut (propoxycarbazone-sodium) have narrower application windows, and are best used earlier in the season because they need good soil moisture levels. They have useful activity against low levels of black-grass.

"Finally, there's Atlantis (mesosulfuron + iodosulfuron) - or its new, higher dose spring-only formulation (05H) if approved in time. With the broadest grass weed control spectrum of all, this is best used early in the season if brome is accompanied by either black-grass and/or ryegrass.

"Because all three products are sulfonylureas, though, we have to be particularly careful to avoid sequence problems," Clare Bend warned. "And with SU-resistant black-grass already identified in the UK, we need to integrate applications carefully with other chemical and cultural controls if we are not to compromise their future value."

Clare Bend advises a careful programme of year-round management based on accurate identification and mapping of brome problems for maximum effectiveness.

This programme includes achieving the greatest pre-planting control with Roundup Max; using a good pre-em like Crystal or Avadex followed by an IPU-based post-em programme in place of autumn SUs; avoiding very early autumn drilling of fields with a history of infestations; making the greatest possible use of residuals in the OSR break; and maintaining good combine and field equipment hygiene to minimise seed spread.

"Where a brome problem is particularly acute it may be possible to introduce beans or even spring cropping into the rotation," she added. "Alternatively, 6m grass margins under the new Entry Level Scheme could also be a very effective control measure."

Brome is certainly a growing challenge for many cereal growers, but with the chemical and cultural weapons in our armoury used in a well-planned way it really need not be a problem for most."