Mycosphaerella leaf spot diseases Sigatoka disease (SD) and Black leaf streak disease (BLSD) are considered as the most severe diseases of bananas for the export market. Serious infestations can lead to a substantial reduction in the leaf area and thus to fruit yield losses. In addition, these diseases were found to have an impact on fruit quality, especially on ripening earliness, which causes some production losses for exported bananas. To assess the effects of these 2 diseases on the bananas quality (especially its physiological stage), plantation surveys and experiments were conducted in Guadeloupe (F WI) for SD and in Cameroon for BLSD. Bananas quality was characterised, on bananas harvested at a constant physiological stage evaluated in thermal time (temperature sums at 900 degrees day) from flowering to harvest, by its greenlife (duration of preclimacteric period) and by few physico-chemical (grade, weight). Diseases severity was measured either at flowering (for SD) or at harvest (for BLSD). Results of surveys revealed that bananas harvested on plants severely affected with SD or BLSD had similar diameter growth, but a shorter greenlife (GL) than bananas harvested from uninfected or lightly infected plants. A strong correlation was obtained between disease severity and fruit greenlife. All these results indicate clearly the direct effect of MLSD of banana greenlife rather than a trophic effect. The putative physiological mechanisms involved are also discussed.