Fruit set in the mango (Mangifera indica L.) cultivar ‘Haden’ is exceptionally low. In an effort to determine the reason for this phenomenon, the influences of temperature and application of boron on pollen germination and the effectiveness of cross- versus self-pollination were investigated. It was found that the highest percentage of successfully pollinated stigmas (stigmas with germinating pollen grains) was obtained when: (i) pollination occurred at 25°C and 30CC, (ii) stigmas and pollen were treated with boron and (iii) ‘Haden’ stigmas were pollinated with ‘Zill’ pollen rather than being self-pollinated.