Improving pre-em weed control


07 April 2022
Farm manager shares his tips

FARM manager Adrian Howell from North Norfolk said he has been achieving season-long weed control across 60 hectares of Maris Piper grown mainly on sandy soils with a wide weed spectrum, by applying Emerger (aclonifen), since it was introduced in 2019.

“It has proven to be a reliable residual that has become the basis of our weed control programmes because it mixes well, has a broad spectrum of activity, is less constrained by soil moisture than some other residuals and is crop safe,” he said.

Over the years, he has learned how to best use it and what partners he needs to mix it with for effective weed control.

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“First, it is different to linuron, so growers need to think differently about how they use it.  I always apply Emerger in a mixture with prosulfocarb, which bolsters control of cleavers, and metribuzin, as this has the widest weed spectrum of any herbicide authorised for use in potatoes. As we grow Maris Piper, post-emergence applications of metribuzin are not an option available to us and I try to avoid rimsulfuron wherever possible as it can be hard on the potato crop. As such, I have to focus efforts at the pre-em stage.”

A typical tank-mix would be 1.5 L/ha of Emerger with 3 L/ha of prosulfocarb and 0.25 L/ha of metribuzin applied seven to 14 days ahead of expected emergence.

“Timing is always prioritised to promote efficacy and even coverage of the ridges. In practice this means spraying on a still day with no wind, and preferably, soon after a shower of rain so moisture is in the soil to activate the chemical and promote weed germination,” he said.

Source: Bayer Crop Science UK

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