WEED CONTROL in potato crops should be given more importance and growers must make the most of existing product chemistry, according to United Agri Products.

Unlike sugar beet, weed control in potatoes is sometimes not given the same priority, but it is “hugely important”, said UAP’s Barrie Florendine.

He highlights volunteer oilseed rape, cleavers, bindweed, fat-hen and fumitory as the key weeds to target. The biggest problem with poor weed control is timing herbicides accurately, he said.

“Too many leave it too late and panic. Ideally, you should be aiming to hit the late flush almost at the point of the application window closing. After flowering, the crop will look after itself.

“It’s difficult to quantify with any accuracy the extent of yield loss resulting from failure to control weeds, but the crop competition element is as significant as maintaining maximum harvestability.”

With no new chemistry coming forward, growers should use mixes of existing products to maximise weed control – particularly against fumitory, he noted.

He suggests using rimsulfuron-methyl plus metribuzin, which also has activity against volunteer oilseed rape and cleavers – although cannot be used in seed crops, he said.