Plants adopt physiological defense mechanisms to counteract droughts. In Colombia, there is no information for these mechanisms in pears ( Pyrus communis L.), cv. Triunfo de Viena. Therefore, the present study aimed to analyze the hydric conditions of this plant in order to determine if it has developed a mechanism to avoid, reduce, or tolerate water stresses as a defense. This experiment used a pear crop located in the municipality of Sesquile (Colombia), with 16-year-old trees that were subjected to three irrigation treatments: a control that received 100% of this crop's evapotranspiration (100%ETc), and 73%ETc and 53%ETc treatments were irrigated at 73% and 53% of crop's evapotranspiration, respectively, for the entire rapid fruit growth period of 2012 to 2013. The results indicated that the irrigation reduction in 53%ETc treatment present an adaptive mechanism in the trees, with a structural change in the cellular wall that allowed for 47% water savings in this fruit growth stage.