Performance of Organically Grown Mango Cultivars in a Rainy Tropical Region

Research was conducted in 2014 to determine the performance of adult mango trees of ‘Osteen’, ‘Keitt’, ‘Edward’, and ‘Palmer’ with organic management in Mayaguez, a rainy region in Puerto Rico (averaging 1750 mm of annual rainfall, with 19.8 °C minimum and 31.5 °C maximum temperatures). Data was collected on flowering and harvesting dates, marketable fruit yield and quality, as well as pest and disease occurrence. Keitt, the cultivar of reference, was the latest in flowering (late March) and in harvesting (33 weeks after flowering), while ‘Osteen’, ‘Palmer’, and ‘Edward’ flowered in mid-March, early-March and early-February, respectively, taking 31, 25, and 27 weeks, in that order, from flowering to last marketable harvesting. As compared to ‘Keitt’, total marketable fruit weight was 14% lower in ‘Edward’, 23% higher in ‘Palmer’ and 86% larger in ‘Osteen’. Individual ‘Keitt’ and ‘Osteen’ marketable fruits were about 30% heavier than those of ‘Palmer’, and about 44% heavier than those of ‘Edward’. Soluble solid content in the juice of ripe fruit was greater in ‘Edward’ than in the other cultivars, while titratable acidity values were larger in fruits of ‘Keitt’ than in fruits of the other cultivars. Fruit anthracnose was more prevalent in ‘Edward’ than in ‘Osteen’, but was not detected in ‘Keitt’ and ‘Palmer’. The main pest found in the orchard was the fruit fly Anastrepha obliqua, affecting about 3 times as many fruits in the late-harvest cultivars ‘Palmer’, ‘Osteen’, and ‘Keitt’ than in the early cultivar ‘Edward’. These results indicate that while anthracnose may be an important concern with some cultivars in a rainy location, in the conditions of this study the fruit fly was a more important challenge to marketable fruit yield, and it should be addressed in future experiments in this location. Economic analyses must be conducted to determine if commercial production of these cultivars is profitable under the conditions of this research.