Sterile Brome is becoming more common due to the presence of more continuous winter cereals and the adoption of tillage systems that don't use a plough. I am noticing that it is now starting to work its way into ploughed fields over the past number of years and farmers need to be aware of how this can take hold as a real problem.
While sterile brome flowers from May to July, autumn is the main period for emergence, so farmers need to be acutely aware of it at this time of year; if they haven’t addressed the issue sooner. On average, more than 200 seeds are produced per plant following flowering and a high proportion of these become viable 3-7 days after flowering so an issue can quickly take hold. The seed matures rapidly on the plant once ripening begins, and most seed is shed from late June to early August. Because the bulk of seed spreads before harvest, the aim should be to get this seed germinated so it can be sprayed off before the next crop is sown.
Unfortunately there is no post emergence chemical control available for winter barley against sterile brome other than pre-emergence with the likes of Firebird, Flight, Tower or Vigon being the best options available. These can give up to 60 to 70% success rate, especially when used in conjunction with competitive varieties of hybrid winter barley.
Chemical control with a herbicide will be a necessity where brome is present in winter wheat land, with good options available like the pre-emerge sprays mentioned above, and the post emergence options like Broadway Star, Pacifica and Alister.
In a moist autumn, there may be an opportunity to kill sterile brome seedlings if the winter cereal is not sown too early. Therefore, delaying sowing, similar to the technique used to control all grass weeds, will reduce the population.
Damp weather is great for stale seedbed techniques as the moist conditions allow for excellent germination of the brome and a pre-sowing spray with Round-Up will kill a lot of seeds if these conditions are present. Sometimes a second run may be needed if a second flush comes before sowing.
Seedlings are unable to grow from below 130mm so good ploughing can be an effective method.
Rotational ploughing, such as one year in three, will normally keep moderate infestations in check. Ploughing the headlands worst affected to limit the spread outward into the field is also a useful practice.
Growing a spring crop is unlikely to reduce the weed unless a dry autumn has prevented germination, leaving the weed to emerge in the spring-sown crop.
Break crops like oilseed rape or beans are also a good option to aid control.
For more information or assistance on implementing an effective weed control programme, contact the RED MILLS agronomy team.
- Winter Crops
- Winter Wheat