CEREAL VOLUNTEERS in oilseed rape need controlling early-on to reduce the risk of delayed flowering and ripening, according to one independent agronomist.

While moist seedbeds and warm weather is ideal for oilseed rape germination, conditions are also favouring volunteer cereals, warned Adrian Farley of Vale Agronomy.

“Growers’ attention has turned to preparing seedbeds and sowing wheat, but they can’t ignore oilseed rape if it is to have any chance of establishing strongly.”

Competition must be removed at the earliest opportunity, even if it means a follow up treatment will have to be applied with the first Phoma spray to catch later germinating weeds, he said.

The best timing for treatment is at the 1.5-2 true leaf stage, he advised.

Controlling volunteers can also reduce the risk of carrying over diseases such as Fusarium, Microdocium and eyespot through the oilseed rape crop into first wheats, added Syngenta’s Martin Frost.

He suggests using Fusilade Max (fluazifop-P-butyl) which, in ADAS trials, has given a 0.5t/ha yield increase over the untreated control when volunteers are removed at growth stage 12 to 13.

He also advises growers to look out for signs of Flea Beetle damage when controlling volunteers. Crops where no seed treatment was used – such as broadcast osr – will be most vulnerable to attack, he said.