SUGAR BEET herbicide applications on later sown crops are being significantly disrupted by cooler weather and growers must be careful to avoid crop damage, warn experts.

Applications to crops still requiring weed control should be delayed if frost is forecast, advised Mike May from the British Beet Research Organisation (BBRO).

“Damage we’ve seen has been mostly associated with weather after spraying, which is quite unusual. Heavy rain or hail two days after herbicide application has caused significant crop check.”

Cooler, wetter conditions also mean that any damaged crops are not recovering quickly, he added. “If in doubt, hold back on sprays,” he said.

Nufarm’s Jon Staton acknowledged that this season has been worse for problems with spray damage to the crop, pointing to late frosts, varied crop growth stages and heavy rainfall as key factors.

“We have seen slightly more crop damage this year, across a range of different herbicide products,” he commented.

Where weed control has been delayed, later dose rates should be increased to compensate, or ‘back-to-back’ treatments around five days apart should be used, said Mr May.

Increased acidity of soils this season is also something growers should be aware of, he noted.

“Low pH could be linked to wet weather, or it could also be a sign of the times as growers haven’t got around to testing fields and treating them.”