Still time to tackle blackgrass this season

UK - December 17, 2012

Farmers shouldn’t be putting sprayers away just yet as there is still time to treat both winter oilseed rape and winter wheat to gain control of blackgrass and other grassweeds.

That’s the advice from leading herbicide manufacturer Dow AgroSciences for farmers looking for help with grassweed control at a difficult time.

According to the latest Grassweed Emergence Monitor, if conditions turn mild and active growth occurs as a result, then there is a good opportunity for grassweed control with pyroxsulam-based products like UNITE or Broadway Star.

Dow AgroSciences’ cereal herbicide specialist Stuart Jackson says: “It’s still not too late for crops that need a residual herbicide – but they should be applied as soon as you’re able to travel. This will help to hold back size of grassweeds for follow up treatments when active growth resumes.

“Where blackgrass is the driver weed in winter wheat, farmers should look to use UNITE and where ryegrass, wild oats and bromes are the driver weeds, Broadway Star is the answer.”

If growers can travel they should apply a residual herbicide appropriate to the target weed:

• 240 g ai/ha flufenacet up to the end of December for blackgrass control
• 120 g ai/ha flufenacet + additional residual e.g. PDM or prosulfocarb from 1st January for blackgrass control
• Minimum 1,000 g ai/ha PDM for blackgrass and brome control
• Minimum 1,500 g ai/ha CTU combinations for ryegrass control.

Mr Jackson says: “Follow-up treatments should be made once active growth resumes and approximately four weeks after the residual spray.”

For oilseed rape growers, there is still time to apply Kerb Flo 500 which continues to offer first rate control of blackgrass, even populations resistant to cereal herbicides. Attention needs to be paid to stewardship guidelines to protect water courses where heavy rain is forecast or ground is frozen.