An outbreak of lettuce wilt and root rot caused by F. oxysporum f. sp. lactucae was reported in the UK for the first time in early October at an unconfirmed location.
The pathogen was identified as Race 4 which is a particularly aggressive strain of the fungus with no known treatment or varietal resistance available to date.
UK propagators and growers are advised to review their production protocols, particularly regarding crop hygiene. Prompt diagnosis is recommended, so if wilt is suspected at any stage during production, most lettuce breeding companies will test samples for you. Independent diagnostic services are also available at several UK research organisations.