WHEAT growers may be better off seizing any spray opportunities they can to tackle serious black-grass problems

Picture: Earlier black-grass removal may be preferable to risking spraying being delayed until spring, says Alison Bosher of Syngenta Don't wait too late into New Year to hit black-grass

WHEAT growers may be better off seizing any spray opportunities they can to tackle serious black-grass problems still plaguing many crops, a weed control expert is warning.

Otherwise, there's a risk that delaying too late into the New Year could allow deteriorating weather to thwart attempts at control until spring.

"Even where some pre-emergence herbicides have been applied, there are some phenomenal black-grass problems this year," says Syngenta herbicide brand manager Alison Bosher.

Although, Ms Bosher admits that spraying slow-growing black-grass in cold weather may not give optimum control, she says provided its growth stage is suitable for spraying and it is possible to get a sprayer on the land, this may be the lesser of two evils - rather than waiting until growth resumes, only to find spraying is rained off and weed size gets out of control.

"Hawk (clodinafop + trifluralin) works even below 5 deg C. That could just give growers the edge they need to tackle black-grass while still at its most susceptible 1 to 2 leaf stage.

"Where you need to mix it with another herbicide, you may have to accept slightly lower control from the partner product if it requires active growth and higher temperatures to work. That's not ideal, but you have to weigh it against the serious difficulty of control if conditions mean you can't spray until black-grass is tillering.

"Correct nozzle choice will also maximise the effectiveness of Hawk," Ms Bosher points out. "Variable pressure nozzles allow you to spray in 100 l/ha water volumes and at 12 km/hr forward sprayer speeds - allowing you to treat more hectares during each spray window and hopefully control more of your black-grass on time."