The use of a short wave near infrared spectroscopic instrument for estimation of mango fruit DM on tree, as a support in the decision to harvest, was confirmed. The technique was robust in face of change in ambient temperature and light. Agronomic treatments of water stress and fruit removal are recommended for fruit DM increase. The DA meter reading was not a useful measure of mango fruit maturity. Sampling of areas of the fruit with less chlorophyll is recommended, to allow change in chlorophyll levels to be monitored.