Abstract

During July 1986, one-month-old seedlings of Mimusops elengi raised in nurseries at the Kerala Forest Research Institute at Peechi were found affected with a collar rot diseasethe disease caused about 20 mortality. Development of a discolored areaat the collar region of the seedlings was the first symptom of the disease. Later, the collar region decayed leading to wilting and death of seedlings within a week of the appearance of the initial symptoms. Two species of Cylindrocladium (C. quinqueseptatum [Calonectria quinqueseptata] and Cylindrocladium camelliae) were consistently isolated from affected parts of the seedlings. Pathogenicity of these was tested on one-month-old seedlings. Symptoms of collar rot appeared after 7 days in seedlings planted in soil infested with both the fungal species. However, no disease developed in seedlings planted in soil infested with either species alone. The affected seedlings died 10 days after inoculation, and both fungal species were