O cloreto de potássio afeta a germinação de sementes e o crescimento inicial de plântulas de Mimosa caesalpiniifolia Benth.

Abstract

Mimosa caesalpiniifolia Benth., popularly known as sabiá, is a tree species native to the Caatinga and belonging to the Fabaceae family. It has great economic and environmental potential, being used in the production of firewood, charcoal, and forage, as well as being recommended for the recovery of degraded areas. In soils of arid and semi-arid regions, as is the case with the species M. caesalpiniifolia, seed germination can be negatively affected by unsuitable conditions, such as saline soils. Thus, the objective of this study was to evaluate the germination and vigor of Mimosa caesalpiniifolia Benth. seeds subjected to salt stress by potassium chloride (KCl). The experiment was conducted in a completely randomized design with four replications of 32 seeds per treatment. Different osmotic potentials were tested, namely: 0.0 (control); -0.2, -0.4, -0.6, -0.8, -1.0 MPa. The variables evaluated were: germination percentage, germination speed index, shoot and root length, and shoot and root dry weight of seedlings. The species was found to be sensitive to salt stress, reducing germination and vigor significantly with increasing concentrations of KCl.