Varnish Spot

Varnish spot affects only the inner leaves of head lettuce varieties. To see the symptoms, remove the outer leaves of the head. Varnish spot appears as dark brown, shiny, firm, necrotic lesions on these inner leaves. Lesion size can range from small to very large. Lesion borders are not delimited by veins, but areas along veins are most often affected. In severe cases, an infected leaf may have 90% or more of its surface area diseased. A notable feature of these lesions is that affected leaf tis