Cereal growers need to control winter-germinating wild oats as early as possible in order to minimise spray costs and potential yield loss, Syngenta has advised.
Good conditions last autumn mean well-tillered winter oats are being reported in some early-drilled wheat and barley crops, said the firm’s Rod Burke.
“Growers should aim to spray off winter wild oats in cereals as early as possible once they’re confident that germination is complete. Not only does this remove weed competition early, but also saves costs by reducing the dose rate required.”
In Syngenta trials, yield fell by 1.2 t/ha where control was left until growth stage 37-39 rather than the earlier timing of before growth stage 30 – despite almost complete control.
But if spring-germinating wild oats are expected, spraying may need delaying, he added.
ADAS’s Tony Wade agreed. “Be sure germination is complete. Because of the patchy nature of wild oats you don’t notice them but they can become very noticeable later on.”
Trials using Axial (pinoxaden) at two timings against mixed winter and spring germinating wild oat populations in Herefordshire, Cambridgeshire and Yorkshire, found that a dose of 0.3litres/ha applied in mid-May gave better control than an earlier application.
This was due to later spring germinators not being hit by the earlier spray, he said.