Erratic hygiene good for brome
Erratic hygiene good for brome
TOO much hygiene in some areas and too little in others is playing into the hands of brome.
Nick Peters, of IACR-Long Ashton, says modern cereal systems give the weed the chance it needs to become more troublesome than it already is.
"Brome is a complicated problem in the UK because it involves five separate species – barren, great, rye, meadow and soft brome," says Dr Peters. "There is considerable variation in germination and survival patterns within each as well as between them."
As few as seven brome plants/sq m can reduce wheat yields by 0.5t/ha and each brome plant easily produces up to 50 tillers and 2800 seeds.
To tackle brome, growers must understand its biology and give sufficient priority to control. It must be hit hard wherever it is evident, says Dr Peters.
He advocates integrating cultural controls with a well-planned programme of autumn and spring herbicides, such as an Avadex (tri-allate)/isoproturon/ Monitor (sulphosulfuron) sequence.
Most growers could profit from far less attention to field margin spraying and far more to machinery hygiene, he says.
Field margins are the natural reservoir of all brome species and LA studies show spraying out edges and hedgerow bottoms merely encourages the weeds.
"As aggressive annuals, there is nothing brome loves more than plenty of open space with relatively high fertility and little if any competition from perennials. Spraying field margins is likely to do more harm than good.
"If you really want to suppress brome and cleavers at the edges of fields, mow them in spring. Alternatively, deliberately establish species-rich margins which will have an important environmental bonus.
"Hedgerows and gateways invariably have some brome plants. Their long-awned seeds are easily picked up and spread by cultivators and combines.
"Tackle this by cutting back gateways and field entrances before brome comes to head. And be more diligent in cleaning tractors and machinery regularly." *
The soft variety is one of several species which make controlling brome complicated, says Nick Peters.
• Several different species.
• Integrated control a must.
• Avoid spraying field margins.
• Clean gateways & machinery.