The use up period for chlorothalonil-containing products has been announced by the HSE as November 20, 2019 for sale and distribution and May 20, 2020, for the disposal and final use of existing stocks.

Professor Fiona Burnett, of the SRUC and commenting for the Farm Advisory Service, said: "There was a real risk that the withdrawal and use up period would be very rapid so the fact that we will have chlorothalonil (CTL) chemistry for the crucial early part of next season is better news than it might have been.

"Thinking beyond next May, though, we will have have issues and the loss of CTL will impact significantly on crop protection programmes, in terms of both efficacy and resistance management. Alternative multi-sites are less effective against key disease, such as septoria and any new chemistry coming onto the market is at greater risk of resistance development without effective multi-site partners to help steward."

In planning ahead for the 2020 crop, she said anything farmers could do to reduce the risk of disease at source would help reduce reliance on chemistry. "The inclusion of more disease resistant varieties in recommended lists has improved in in recent seasons, so consider selecting more robust varieties for drilling this autumn and plan rotations, sowing dates and other cultivations to minimise disease pressure and reduce reliance of fungicides," she said.

With a raft of open events and trials days coming along, checking out the more resistant varieties would be great place to start. "For drilling this autumn, have a look at wheat varieties like LG Sundance, which rates as 7.9 for septoria, or winter barleys like SY Baracooda, which rates as 8 for mildew and 7 for rhynchosporium.

"In spring barley, which will largely fall outside the ability to use chlorothalonil next season, a move away from susceptible varieties like Concerto to varieties like Fairing, Laureate, KWS Sassy and Sienna which all have ratings of 6 for rhyncho will help to reduce reliance on early fungicides," said Professor Burnett.