Foliar application of biostimulant doses in two phenological stages in common bean culture

Abstract

Salinity is one of the environmental stresses that most affects plants' vital processes, especially germination. Brassinosteroids, including 24-epibrassinolide (EBL), have multiple actions in essential processes in plants. Thus, this research's objective was to evaluate the effects of EBL on tomato seeds' physiological conditioning on germination, growth, and production of dry seedling mass under salinity conditions. The experiment was carried out in a 2x5 factorial scheme, as follows: two concentrations of EBL (0 and 10-6 M) and five levels of salinity (0.5 control; 1.5; 3.0; 4.5 and 6.0 dS m-1), consisting of ten treatments, with four replications of 50 seeds. In isolation, the salt stress reduced the percentage of germination and germination speed index from four to 14 days, besides all the plants' growth traits. In turn, the EBL increased the percentage of germination, germination speed index, seedling length, and radicle dry matter. The application of 10-6 M of EBL in seed immersion no effect on the seed germination of IPA 6 tomato cultivar under salt stress but increases the root length and the dry matter of the seedlings.