Identification Symptoms
- The disease is common in the
orchards where mealy bug, scale insect and hopper are not controlled
efficiently.
- The disease in the field is
recognized by the presence of a black velvety coating, i.e., sooty mould
on the leaf surface. In severe cases the trees turn completely black due
to the presence of mould over the entire surface of twigs and leaves.
- The severity of infection
depends on the honey dew secretion by the above said insects. Honey dew
secretions from insects sticks to the leaf surface and provide necessary
medium for fungal growth.