The araçá-boi (Eugenia stipitata McVaugh ssp. sororia McVaugh, Myrtaceae) is a small fruit species native to western Amazonia with international potential as a juice and flavor. Although seldom planted in Brazilian Amazonia because of its acidity, the species is being cultivated in other countries. A knowledge of phenology can help plan plantation management and fruit commercialization. The phenology of ten plants growing in a degraded oxisol was observed during five years. The araçá-boi generally flowered and fruited three times during the year, with at least one strong flowering peak in the dry season (July-September) and a strong fruiting peak in the rainy season (January-March). Flower initiation is a complex event that appears to take two to three months, although the period from flower bud appearance to anthesis is short (~15 days) and the period from anthesis to fruit maturation takes between 50 and 60 days. The multiple regressions used to determine the effect of climatic variables on flowering and fruiting had low determination coefficients, although the models were significant, probably because the araçá-boi flowers several times during the year and the most important stimulous for flowering is still unknown. Fruit set varied from less than 5% to about 15%. Mean fruit weight in January 1988 was 135 g, with 77% of pulp. During the 5 years, the 10 plants yielded 1000 fruits/year, with a median number of 890 fruits/year. Most of the insect visitors were bees, especially Apis mellifera, Eulaema mocsaryi and Ptilotrigona lurida.
flowering; fruiting; leaf change; fruit set; climate