An emergency authorisation (EAMU) for Cuprokylt (copper oxychloride) provides the only fungicide available to organic potato growers for the control of late blight, at a key time of the season.
The EAMU was driven by stakeholders, including Certis, Agrii, AHDB, NFU and organic growers’ associations. The active ingredient is available to organic potato growers until September 28, 2018.
Nick Winmill, Agrii potato development manager says: “Being able to utilise copper oxychloride will support organic growers and help them to capitalise on market demand.
“Without copper, only cultural control methods are available for the control of late blight in organic potatoes, and as a result it’s been difficult to keep varieties with preferential qualities blight free,” he says.
“When wet weather hits and if temperatures remain high, blight pressure is likely to increase, so this news comes at a crucial time.”
Mr Winmill adds that if another EAMU is not secured for copper oxychloride, or if an alternative is not found for use in organic potatoes, then production will become more difficult in future.
“Although blight resistant varieties are available, these do not necessarily meet consumer demand for cooking and taste qualities.
“This emergency authorisiation is an important milestone for organic potato production, but there is still work to do to support organic production going forward.”
Selchuk Kurtev, Certis’ IPM manager, says that strict guidelines must be followed when applying Cuprokylt under this EAMU.
“Growers must ensure they have a hard copy of the EAMU and written recommendation from a BASIS registered agronomist prior to application.
“Application timings must be based on a recognised disease forecast model, such as the widely used Hutton Criteria,” he says.
“Also, buffer zones of 18m from static water and 5m from the top of dry ditches should be left for water protection.”
Cuprokylt should be applied at a maximum individual dose of 0.85kg/ha combined with 1,100 to 1,300l of water. Growers can implement six applications per crop with a 10 to 14-day interval between each one., according to Certis.
The emergency authorisation lasts for 120 days and will expire on September 28, 2018.