The research was realized to quantify the need for accumulation hours under low temperatures to the acid lime 'Tahiti' flowering, without water application and beyond evaluating gas exchange and chlorophyll a fluorescence under low temperature and light. The experiment was conducted in Vicosa-MG, Brazil, with plants from acid lime 'Tahiti' grafted on Rangpur lime grown in pots of 12 liters. The design was completely randomized with seven treatments and four replicates with one plant per plot. From 02/01/2008 until 04/30/2008, four plants were taken from each growth chamber (CC) (temperatures: 16/12 degrees C (day/night); air humidity: 70%; photoperiod: 10 hours; photosynthetic photon flux density: 100 mu mol m(-2)s(-1)) to 15 days and taken to a greenhouse (CV) without environmental control, totaling seven dates of transfer. Exposure of plants to low temperatures, under controlled conditions, does not cause significant changes in the characteristics of chlorophyll a fluorescence, but caused 80% of reduction in gas exchange. This reduction does not hurt the flowering plants. Plants exposed to no-induced conditions only issued vegetative shoots, while those submitted to lower temperatures, the greater was the exposure time, the greater was the number of flowers sent.