Development of the Banana Fruit and Occurrence of the Maturity Bronzing Disorder

Maturity bronzing is a preharvest disorder of cultivar Williamsbananas (Musa, AAA group, Cavendish sub-group) involving necrosisof the peel surface Lesion development is described and is distinguishedfrom damage caused by banana rust thrips Chaetanaphothripssignipennis (Bagnall)] Anatomical studies on the peel of thedeveloping fruit showed that (I) the area of epidermal cellschanges little during fruit expansion, and (II) epidermal cellsbecome flattened in the radial direction and tangentially-elongatedto accommodate the more rapid growth of the underlying tissuesFruit produced in the wet season in North Queensland, Australia(lat 17° 36' S, 146° 00' E) has an exceptionally highgrowth rate and is highly susceptible to maturity bronzing Underthese conditions stretching of the epidermis exceeds its elasticlimit and leads to cracks and cell disruption in the peel surface,and subsequently to formation of the lesions characteristicof maturity bronzing Musa, banana fruit, peel, disorder, lesion, banana rust thrips