Romaine lettuce

New outbreaks of the devastating disease Fusarium wilt in lettuce crops have been reported in Lancashire, Cambridge and Ireland.

The AHDB confirmed the new cases, warning that the disease was now spreading. All the cases found were in protected lettuce crops, grown in greenhouses.

They called on growers to help prevent spread of the disease by implementing good crop hygiene and seek early diagnosis if they suspect its presence.

Kim Parker, crop protection scientist for the AHDB, said: “The effective use of techniques to detect the strain of the disease identified in the UK – lettuce Fusarium wilt race 4 – in samples has provided the opportunity for prompt disease diagnosis. This has enabled affected growers to implement measures to minimise disease spread.”

The University of Warwick has used conventional and molecular techniques as part of work to detect presence of the disease.

Dr John Clarkson, who leads the AHDB-funded research on the disease, said: “Lettuce Fusarium wilt is a soil-borne disease that can survive in soil for several years, so rigorous hygiene is essential to prevent disease spread between crops, glasshouses, nurseries and plant propagators.”

AHDB said trials are currently underway with University of Warwick as part of their SCEPTREplus project to test the impact of plant protection products on the disease. New AHDB-funded work will start this autumn to find out more about the biology of lettuce Fusarium wilt.

Lettuce and baby leaf salad production was valued at £171 million in the UK in 2017.