Agronomist and farmers have reported notably higher brome populations in cereal fields across some UK regions in recent seasons
There are many bromes , but for the purposes of control of the weed -which some suggest has beome more prevalent since the advent of managed field margins and wider adoption of mintill -they are not all alike .Knowing which of the two distinct species groups is present in a problem area is the key to effective control.
This is the emphasis from researchers , weed scientists and agronomists when questioned on what can be done to tackle a brome problem , after a succession of recent years during which field reports of issues with the weed increased markedly .
NIABTAG weed expert John Cussans points out bromes have not been alone among weeds in benefiting from the lack of decent frosts in recent winters .But their disctinctive appearance , when concentrated in patches , has made them particulary more noticeable , he suggests .The weather has aided their growth , but other practices have helped their spread .
“Bromes sit between black-grass and wild oats in terms of their effect on cereal yields , with barren /sterile brome having the most significant impact , at 2,4 % winter wheat yield loss where there are three plants /sq.m. But , of course , there are also the other problems they can cause , such as logding and combining difficulties .”
Field margin schemes
“Bromes aren´t classic weeds of arable situations , being typically more commonly found in field margins and uncropped areas such as beneath pylons. But the introduction of field margin schems has aided brome establishment in some cases , particulary where the margin seed mix hasn´t establishment well.Manage margin areas with the same attention to detail as the crop in body of the field , ensuring good seed mix establishmement and growth , and this weed seed source will be minimised .”
The other key aid to propagation of bromes has been the move to minimum tillage , says Mr. Cussans.
“Ploughing obviously buries shed seed deep , from where it cannot emerge – although barren brome , for example ,does have a seed of longevity of one to five years .No-till , on the other hand ,leaves it on the field surface , where it is exposed and ripens .But min-till of the top few centimentres of soil buries it just deep enough to invoke dormancy and create problems later “.
Preventing spread is a matter of managing field boundaries to ensure they are distinct and clean ,ensuring cultivation close to field boundaries does not drag out and disperse weed material , and preperly establishing any margins with their intended species .
“Brome species indentification , though , is critical to pre-drilling control of a problem that´s already become established in the body of a field , ” says Mr.Cussans .