This work aimed to investigate the influence of controlled water deficits on flowering and yield of Arabica coffee (Coffea arabica L. cv. Obatã grafted on C. canephora cv. Apoatã) in three different local conditions of São Paulo State, in the counties of Adamantina, Mococa and Campinas. Plants, with 2.5 years old, were cultivated at full sun, on spacing 2.5 m x 1.0 m, from July of 2001 to May of 2002, under the following water management: non irrigated (NI), irrigated continually (IC) and withholding irrigation by 30 days in the month of July (I30) and 60 days the months of July and August (I60). Irrespective of local cultivation, the irrigation provided larger yield of coffee per plant, with the largest significant differences observed in Mococa. The treatment I60 was able to impose a predawn leaf water potential (Ψwa) of -1.1 in Adamantina, -1.6 in Mococa and -1.2 in Campinas, which was more effective for flowering synchronization of coffee plants, allying yield uniformity with good production. A greater number of flowers and a low yield uniformity of continually irrigated plants (IC) to ratify the importance of a controlled drought period for flowering synchronization. The low Ywa values (-2.5 to -2.8 MPa) of the non irrigated plants (NI), reduced the number of flowers per plant when compared to the irrigated plants with reflexes in the final production indicating the need of irrigation in order to assure good floral initiation.
Flower synchronization; irrigation; water deficit; water potential
