Yellowing and brown necrosis spreading from margins between veins of older leaves (J.
older leaves turn yellow and then necrotic in interveinal
and marginal zones.
symptoms usually develop some time after establishment, during
the storage root development phase.
young leaves remain of normal size and colour (but purple tips
may be less purple than normal).
mature leaves may show a pale green interveinal mottle.
storage roots are small and thin.
with other symptoms
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