Symptomatology of stem canker of cocoa in India

Stem canker of cocoa was observed in 2 to 18-year-old plants. Detailed studies of the symptoms of this disease revealed oval to round, brownish rusty discolouration on the external bark as the most characteristic and common symptom. The collar infection usually appeared as dark brown, irregular, water-soaked lesion with comparatively more bleeding. Greyish brown water soaked lesion with a dark brown to black margin and a rusty deposit due to drying up of the exudate from the lesion was also observed. In two to three-year-old cocoa plants the stem was slightly sunken at the infected area without any external symptom on the bark