BROAD-LEAVED weeds may be best left until spring in late-drilled crops, says Morley Research Centre director, Jim Orson. More options with modern herbicides should ease the decision, he suggests.
"I am constantly annoyed by claims of timing versus yield response for autumn applications. The claims dont fit the data. In most cases the classic theory of removal of weeds before GS31 in spring results in no yield loss," he says.
The exception is when the winter survival, or establishment of the crop is threatened. That is more likely with early drilling, but in crops drilled after mid-Oct autumn herbicides should target difficult grassweeds, and leave broad-leaved weeds to spring sprays.
"Growers drilling now should ask themselves if it is worth autumn broad-leaved weed control. Why hit the weeds twice when one spring application would be sufficient?" *