fusarium proliferatum induces gum in xylem vessels as the cause of date bunch fading in iran

date bunch fading (dbf) is a serious disease of date palm (phoenix dactelifera l.) in iran. fusarium proliferatum was isolated from the xylem of fruit bunch samples sent from kerman and fars provinces groves to the laboratory. koch’s postulates were completed in the greenhouse by crown injection and root inoculations. shriveling of the fruits was induced by peduncle inoculations. symptoms on the seedlings indicated the effects of ethylene. the possible involvement of f. prolifertum phytotoxin(s) in the induction of dbf through elicitation of ethylene is discussed. the gas is suggested to be responsible for the gums deposits and, in turn, water stress resulted in shriveling and fading of the fruits.