Black leaf streak of bananas in Fiji

SUMMARY Black leaf streak of bananas, caused by Mycosphaerella sp., prevented fruit of export quality forming and bunches maturing. Some infected leaves lived less than 50 days and were seldom retained until harvest. Maneb or benomyl applied in oil/water emulsions gave good control and benomyl was so effective that plants had ten leaves at harvest and some leaves survived for 245 days. Plants sprayed with maneb or benomyl flowered I month early. No benomyl residues were detected in the fruit exported to New Zealand. The control of black leaf streak by sprays containing oil has caused other leaf diseases to become more prevalent and the ensuing complex disease situation is discussed.