Abstract
Banana and plaintain germplasm was assessed for reaction to black leaf streak disease caused by Mycosphaerella fijiensis in trials in the South Pacific as part of a crop improvement programme. Parameters used for measuring reaction were time from infection to first streak symptoms, mature lesion formation, and death of one third or more of the leaf lamina. An estimation of these parameters was obtained by counting the leaves from the first fully unfurled leaf to the leaf with the corresponding symptoms. The most useful parameter was considered to be the appearance of 10 or more mature lesions. Of the cultivars tested, Ducasse (Pisang awak) was the most resistant. Other resistant cultivars were Bluggoe, Sucrier, Pisang mas, Amas, Mysore, TS, and SH 3436. Improved diploid lines from the Honduran breeding programme, SH 3142 and SH 3362, were also resistant. Cultivars Pisang rajah, Pacific plantain, Horn plantain, Lady finger, Calypso, Red Dacca, Santa Catarina prata, and 2390 were rated as susceptible.
