Abstract

Dieback caused by Botryodiplodia theobromae is characterized by development of a stem canker, gradual dieback of shoots and, finally, death of trees due to girdling of stems by progressing cankers. In pathogenicity tests of the isolate, only wound inoculation resulted in cankers similar to those observed in the field. Of the five plantations surveyed, dieback was recorded in fourthe occurrence appeared to be closely associated with fire, debarking by animals, and cultivation of cassava (Manihot utilissima [M. esculenta]) amongst trees in plantations. During 2 yr observation, initial incidence of about 50 declined to 13-25disease severity was initially medium, then remained low throughout. Regular observations in a plot with moderately severe infection indicated that high incidence of dieback occurred during the dry-warm period, but during or just after the monsoon it declined as some of the affected trees partially or completely recoveredoverall incidence gradually