-
initially small, brown to black
oval lesions with a typical bulls’
eye appearance of concentric rings on leaves, stems and petioles.
-
as disease progresses, lesions become necrotic, usually surrounded
by a wide yellow halo.
-
soon after, the whole leaf blade turns
chlorotic
and drops. Blackened veins are observed on the lower side or undersurface
of the leaf.
-
lesions on petioles and stems are initially grey then turn black
and sunken as they enlarge. Petioles and stems are girdled
and the plant dies.
-
lesions get a silvery tone during dry conditions.
-
bases and middle sections are more affected than the vine
terminals. The ground under affected vines is often carpeted with
blackened leaf debris.
