REPRODUCTIVE CHARACTERISTICS OF PITAYO (STENOCEREUS-QUERETAROENSIS) AND THEIR RELATIONSHIPS WITH SOLUBLE SUGARS AND IRRIGATION

Flower and fruit production by the columnar cactus, Stenocereus queret aroensis (Weber) Buxbaum, occurred during the dry season in the late w inter and spring, and the relatively small annual stem extension occur red primarily during the fall, Thus, reproductive growth does not dire ctly compete with vegetative growth for resources such as reducing sug ars, which increased during the wet summer season, a period when total sugars were decreasing, Stem extension, reproductive demography, frui t quality, seed size, and seed quality were not influenced by irrigati on, Final fruit size and seed germination, however, were enhanced by a pplying water. The times from flower bud differentiation to flower ope ning and from anthesis to fruit ripening were relatively short and una ffected by irrigation.