Tar spot (Myrothecium roridum Tode Ex fr.)
Period of occurrence:
The disease generally occurs during the rainy season (June – October). Severe incidence is found in west Bengal and northeastern parts.
Identification of the disease:
- The spots are circular at first enlarging progressively and become irregular in the later stages especially under extensive moist condition.
- The vein tissues are also included in the necrosis.
- The circular spots vary in size up to 2 cm dia., occasionally centre of the lesion cracks irregularly and rupture.
- On minute observation, dark sporodochia with shiny black and wet spore mat can be seen on the lower surface of the dead leaf tissues.
Leaves in the highly infected garden Tar spot infected leaf Sporodochia with shiny black spore mat