Two potato blight fungicides have gained label extensions, giving growers more options for the protection of their potato crops against early blight (alternaria).

Bayer’s Neil Thompson says this confirms Consento and Prompto’s (fenamidone + propamocarb) unique role as dual-purpose products for use during the rapid canopy growth phase.

“Their fenamidone component provides good protection against primary alternaria infection – which can come in two to four weeks from emergence – and propamocarb brings the systemic activity needed to protect new growth against late blight.”

Although Markies is now acknowledged as the variety most susceptible to early blight, many others can become susceptible when stressed. Over the last two seasons, Agrovista technical manager Mark Palmer has seen it affect crops of Estima, Saturna, Maris Piper and Lady Rosetta. Worst cases have been where growers have held back on nitrogen.

“With early blight, timing is key as the fungicide options are protectant,” he advises. “This means growers of susceptible varieties need to build fungicide programmes that include the necessary protection, while still achieving the main objective of securing late blight control.