Tolerância à salinidade de acessos de umbuzeiro na formação de mudas

Abstract

Water availability is fundamental to agriculture, particularly in semi-arid regions like the Brazilian Northeast, where poor rainfall distribution and high evapotranspiration restrict productivity. Irrigation appears as a fundamental measure to ensure production, especially of crops sensitive to water deficit, such as perennial fruit trees. In this context, the umbu tree (Spondias tuberosa), adapted and native to semi-arid environments, shows promise due to its adaptive form to dry environments with water scarcity and its socioeconomic importance. In this study carried out in the municipality of Nossa Senhora da Glória, at the Embrapa Semiárido experimental farm, the general objective was to evaluate the tolerance of Spondias accessions to water salinity during seedling production by cuttings. The morphological and physiological growth of the plants under two salinity levels (0.14 and 6.0 dS m−1) were compared in three genotypes, in a randomized block design totaling 24 plots. In the experiment, the variables evaluated in the plants were stem diameter, main stem length, and absolute and relative growth rates, as well as statistical analysis. Analysis of variance showed an effect between accessions, but no significant effect with water salinity, nor with the diameter of the shoot stem, nor with the length of the main stem. Conversely, a significant effect of the accession factor was observed for the diameter of the shoot stem and for radial growth rates, highlighting variability among the evaluated materials, with accessions G1 and G3 performing better than accession G2. The variables associated with length growth showed more conservative behavior and less discriminatory capacity between accessions. It is concluded that, under the experimental conditions and during the evaluated period, irrigation water salinity did not compromise the initial growth of Spondias seedlings, while radial stem growth stood out as the main indicator for early differentiation between accessions. The results provide initial support for the use of saline water in the seedling formation phase, highlighting the need for complementary studies with longer exposure times and the inclusion of physiological assessments to consolidate criteria for salinity selection and management.