Keeping on top of blight

The Blightwatch alert system, hosted by AHDB and the Met Office, has displayed red warnings since June 11 – indicating the highest level of blight threat – just as many crops are reaching the crucial rapid canopy growth stage.

Red alerts have been issued in England for Lincolnshire, Yorkshire, Lancashire, East Anglia and across the West Midlands.

Potato agronomist John Sarup says crops are growing rapidly in most places. “It is sticky and humid, ideal conditions for blight to develop but I have not seen any as yet.”

He advises choosing products to protect new growth such as Infinito (propamocarb) or Revus (mandipropamid).

“Or you can use Ranman but it you use it now there will be less opportunity to use it for tuber blight.

“Spray at intervals of seven days unless you are using Zorvec where it is 10 days, which I am comfortable with.”

Corteva Agriscience field technical manager for potatoes, Craig Chisholm, also highlights latent blight present in volunteer potatoes from fields that were abandoned following a difficult harvesting campaign in 2019 as a threat.