Use of hydrogel in the irrigation management of white pitaya (Hylocereus undatus) seedlings: Biometrics and accumulation of organic and inorganic solutes

Abstract

The initial development of pitayas may be limited by a few factors, among them, water deficit. Agricultural hydrogels can be used as an alternative to enhance the retention and availability of water and nutrients in the soil. Therefore, this study aimed to evaluate the influence of irrigation frequency and hydrogel doses on the development of white pitaya (Hylocereus undatus) seedlings to establish a time interval in days between irrigations that provides better seedling development and determine the hydrogel dose that provides a reduction of water consumption without damaging seedling development. The experimental design consisted of randomized blocks in a 4 x 4 factorial arrangement, in which the treatments corresponded to 4 hydrogel doses (0, 2, 4, and 6 g/plant of Biogel Hidro Plus) incorporated into the substrate and four irrigation frequencies (1, 3, 5, and 7 days of interval). The biometric characteristics, photosynthetic pigments, and organic and inorganic solutes of the plants were evaluated after 120 days. The use of daily irrigation negatively influenced the growth and biomass accumulation of the aerial part of the seedlings and, consequently, provided the lowest values of cladodes of the pitaya seedlings. Pitaya seedlings had greater development when using an irrigation frequency of around 3 days. The application of 6 g/plant of hydrogel provided the highest averages for accumulation of dry biomass, photosynthetic pigments, and organic and inorganic solutes at irrigation levels of 3.6, 4, and about 3.8 days of intervals, respectively. Hydrogel incorporation allowed increasing the interval between irrigations by 1 day without damages to the seedling development.