Bioinputs in seed treatment as an attenuator of salinity levels in the germination and seedling formation of soybeans

Abstract

Salinization occurs in agricultural areas in Brazil, compromising seed germination. The use of bioinputs in seed treatment can protect against damage caused by salt stress, favoring germination. This study aimed to evaluate the use of seed treatment with bioinputs to attenuate salt stress on seed germination and seedling formation of soybeans. The experiment was conducted in a completely randomized design with soybean seeds of the Olimpo and Guepardo cultivars, in a 5 x 5 factorial scheme. Treatments included a control (T1), T2 - Bacillus aryabhattai; T3 - Bacillus aryabhattai, B. haynesii, and B. circulans; T4 - Extract of Ascophyllum nodosum algae, P, and Mo; and T5 - Mineral fertilizer (N, Zn, Cu, and Mo). The salinity levels were 0 (zero), -0.3, -0.6, -0.9, and -1.2 MPa, with four replications of 25 seeds each. Germination, first count, germination speed index, relative frequency of germination, shoot and root length, and dry mass of seedlings were evaluated. After ANOVA, bioinputs were subjected to the Scott-Knott mean test, and salinity levels were subjected to regression analysis. The cultivars were compared using Principal Component Analysis. Seed treatments with bioinputs (T4 and T5) reduced the effects of salt stress on the germination and initial development of the soybean cultivars Guepardo and Olimpo. T4 was the most effective, minimizing the reduction in germination and seedling vigor, suggesting that bioinputs are a promising strategy for saline soils.