This is the warning to growers by Syngenta specialist crops manager Bruce McKenzie, who said the herbicide Skirmish works on both preand post-emergence stages of the plants' development to the second node stage.
He said: "It enables growers and agronomists to see the weed spectrum emerging and treat accordingly."
The Processors & Growers Research Organisation advocates that, where broad-leaved weeds such as polygnums, mayweed or volunteer oilseed rape are present, a tank-mix of Skirmish with a reduced rate of bentazone for added contact activity, along with residual weed control while the crop establishes.
McKenzie said: "Dry soil will slow crop establishment, so avoiding any further check from weeds will be even more important this season. When applying post-emergence, growers should ensure leaves have sufficient wax layer."
For further details on pea agronomy and application advice, see www.syngenta-crop.co.uk
Herbicide application Spraying advice
McKenzie said peas had, for the most part, been drilled into good seedbed conditions this season. But he advised that where dry conditions have left clods, the use of angled spray nozzles will provide a significant benefit in achieving good soil coverage with Skirmish, to enhance residual weed control.
"Syngenta trials have shown that when using conventional nozzles, clods cast a 'shadow' to about 75 per cent of their diameter that receives little or no spray," he added.
"Fitting Syngenta Defy Nozzles and alternating spray patterns forwards and back along the boom coats around the clods and across the surface for the best herbicide performance."