Agronomists are reporting a late-season disease surge in cereal crops after warmer weather after another wet May.
Brown rust in particular is thriving in the warmer weather, says Mike Thornton, head of crop production for agronomy firm ProCam. It is also encouraging the spread of Septoria through crop canopies.
“Growers need to be on their guard,” says Mr Thornton. “There are some good grain prices, so cereals are worth looking after, and we’ve seen the effects on disease development of wet weather followed by warmer conditions before.
“There’s no single fungicide prescription. Each field needs judging individually to head off infection before it gets too established. But more robust fungicide doses may be needed to cope with heightened infection pressures.”
An increased need for effective control is likely where the interval between earlier T1 and T2 fungicide sprays was stretched beyond the optimum three weeks – or if T1 fungicides were trimmed back for any reason, says Mr Thornton.
With an exceptionally cold spring, many crops are developing later than normal, with T3 T3 spray timings delayed. Rapid crop development brought on by the warm weather will also make regular crop monitoring more important.
“It’s not just wheat that we need to be vigilant with – it’s a similar situation with barley. As well as the usual wet weather diseases of Rhynchosporium and net blotch, barley crops have been under a lot of stress.
“Stress is a trigger for any latent Ramularia infection to manifest,” says Mr Thornton. “So there’s an equal need for attention to detail to keep barley healthy to protect the important grain-filling period.”