between veins on a mature leaf (J. O'Sullivan).
Browning (necrosis) spreading from the margins to areas between
dark grey necrosis on old leaves spreading from margins into
dark necrotic spots on mature leaves, aligned midway between
the main veins.
necrosis is not preceded by yellowing, but affected leaves
eventually yellow and fall off.
crop wilts readily in dry weather.
with other symptoms
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