High blight pressure – the highest for a number of years according to some experts – means growers should be looking for kickback activity in blight products, according to Masstock’s Malcolm Smith.

“Warm temperatures, humidity and rainfall are combining to present an extremely high risk of blight infection.”

Mr Smith recommends products such as Roxam/ Electis (mancozeb + zoxamid) or Ranman (cyazofamid) are alternated with a product offering kickback action such as Valbon (benthiavalicarb-isopropyl + mancozeb), Infinito (flupicolide + propamocarb), Merlin (chlorothalonil + propamocarb hydrochloride), Curzate (cymoxanil + mancozeb) or Invader (dimethomorph + mancozeb).

“Kickback action is particularly important where weather conditions have delayed applications and the seven-day interval has been stretched,” he says.