Summary
Various aspects of the phenology, ecology and productivity of Umari (Poraqueiba sericea Tulasne) were studied. The phenological data indicated that in the vicinity of Manaus the species flowers in the dry season (June to October) with the crop reaching maturity at the height of the rainy season (January to March). Twenty one species of insects were found visiting the species, of which ten, all of them Apidae, presented significant quantities of pollen, a fact which suggests that there is no specific pollinator. The number of flowers was very high for all of ten trees studied, varying between 13000 and 82000 pen tree, with a relatively low percentage of set (between 4 and 9%). Even though this low percentage of fruit set may be due to inefficient pollination, the surprisingly high correlation between number of flowers and other production parameters such as number of immature fruit (r=0,987**), number of mature fruit (r=0,989**) and weight of the crop, suggests that other factors may be playing significant roles in determining productivity (Crop). It seems that the number of flowers is intimately correlated with the energetic potential of the tree to produce a certain weight of fruit, suggesting endogenous control of number of fruits formed and aborted in such a way as to maintain a certain number and weight of fruit reaching maturity.