Aspectos fisiológicos de variedades de citros submetidas à deficiência hídrica progressiva

Abstract

The work aimed to evaluate the effects of water deficit on citrus varieties for the identification of the ones with the best answer for the water stress situation. The experiments were carried out on the Experimental Station II of the Federal University of the Reconcavo of Bahia (UFRB). When the plants were nine months old their relative water content (RWC), gas exchange rates (photosynthesis, transpiration, and stomatal conductance), and photosynthesizing pigments (chlorophyll a, b and total) were evaluated for irrigation and water deficit conditions. The reading followed the course of the day (6, 8, 10, 12, 14, and 16 hours) using six repetitions for each varieties, for three plants. It was evaluated the following varieties: ‘Jacaranda’ sour orange, ‘Santa Cruz’ rangpur lime, ‘Volkamer’ lemon, and the mandarins ‘Cleopatra’, ‘Sunki of Florida’ and ‘Sunki Tropical’. In a general manner, all the genotypes had their RWC and exchange gas rates influenced by the water stress conditions, showing a slow recovery after the relief of that situation. The photosynthesizing pigments did not show any change, in any genotypes, for any soil water condition. We suggest that the ‘Santa Cruz’ rangpur lime and the ‘Cleopatra’ mandarin are the less sensitive to the water deficit condition with a power of recover after the relief of the water stress condition.