A STUDY OF THE CAUSE OF THE MANGO BLACK TIP DISORDER

Causative factors of the fruit black tip disorder (BT) in mango (Mangi fera indica L.) have been studied in Guangdong Province, China. Dippin g fruits in 150 and 600 mg kg(-1) fluoride solutions induced symptoms similar to that of the black tip disorder. The F content of the fruits with artificially induced symptoms was about 25% higher than that of control (healthy) fruits. The F content of BT fruits from an affected orchard was twice as much as that of the normal (healthy) fruits from an unaffected orchard. The leaf F content of affected trees was about six times as much as that of the control. This study has provided evid ence that fluorine in fumes emitted from adjacent brick kilns was the direct causative factor of the mango black tip disorder.