This seasons late drilled crops may be harbouring a nasty surprise for those who delay their herbicide programmes and wait too long.
Many farmers drilled late last autumn, making the most of the dry weather to get on top of their weed populations. However, for those who missed autumn residual treatments, there is still a risk of large numbers of annual meadow grass causing problems in spring.
Annual meadow grass can be simple to control if you apply herbicides in good time but any delay into late spring can cause problems. The weed has a long germination period and then tillers and flowers quickly when conditions are right.
Gareth Bubb, Bayer Commercial Technical Manager in the West Midlands / Welsh Borders explains. “If annual meadow-grass is present in the crop, look to control it soon before it gets too large and starts to take space, light and nutrients away from your wheat. Othello (mesosulfuron + iodosulfuron + diflufenican) provides good control and flexibility with applications.
“The added DFF gives you residual control on the small weeds, but Othello is also highly effective on the larger plants that have begun to tiller. Don’t leave your applications too late though, spray as soon as spring growth starts because meadow grass can go from tillering to flowering in just a couple of weeks.”
It may be tempting to delay so that you can control broad-leaved weeds at the same time but it is a false economy according to Mr Bubb. “Leaving your annual meadow grass until every broad-leaved weed comes through means it will already be competing with your crop. Large weeds can stress crops depriving them of nutrients and effecting their growth and your yield.”
Timing applications can be difficult especially with the unpredictable British weather so taking every opportunity to spray is important. “It’s critical to pay attention to your applications as it’s a sulfonylurea it needs to be timed correctly. The weeds should be actively growing with minimal fluctuations in diurnal temperatures avoiding frosts.
“Don’t over complicate your tank mixes either, the more complicated the mix the more likely you are to encounter problems. If mixing or sequencing with other ALS-inhibitors particular care should be taken as these need approval and should be stated on at least one of the product labels.”
Othello should be applied at a rate of Othello at 1.0l/ha with the adjuvant biopower to increase uptake by the plant.
