PRODUCTIVITY AND QUALITY INDICATORS OF ALOE GEL UNDER SALINE STRESS CONDITIONS

Abstract

Arid lands cover large regions of Mexico, with problems of water scarcity, shallow soils, poor organic matter content and high salt content. Aloe [Aloe vera (L.) Burm. f.] is a viable alternative for production under limiting environmental conditions. This study evaluated the effect of salinity on leaf growth and gel quality of aloe. The study consisted in testing six saline treatments: 0, 500, 1000, 2000, 4000 and 8000 mg L^-1 of NaCl, corresponding to electrical conductivities (EC) of 0.36 (irrigation water without adding NaCl), 1.39, 2.0, 3.6, 5.6 and 7.6 dS m^-1, respectively. The trial was conducted under a randomized complete blocks experimental design with four replications. The traits measured were leaf length, leaf width, leaf thickness, leaf biomass, gel biomass, fresh and dry biomass of the plant without root, gel pH, total soluble solids and solids precipitable in methanol. Leaf biomass and gel content were similar between 0.36 and 3.6 dS m^-1, which suggested some degree of tolerance to salt stress; however, from 5.6 dS m^-1, there was a negative effect on these and other traits. Total soluble solids concentration and precipitable solids in methanol increased as a function of EC, up to a certain limit. These parameters are considered an indicator of high added value from a commercial point of view. It is confirmed that under moderate stress conditions, in this case salinity, the quality of the gel is favored, but a negative effect accompanies growth and production of the aloe leaf.