Salicylic Acid Concentrations and Its Effects on the Physiological Quality of Soybean Seeds

The objective of this study was to evaluate the physiological quality of commercial soybean seeds submitted to different concentrations of salicylic acid (SA), directly on germination paper and gerboxes for 24 hours. Seeds of cultivars NA 5909 RG and Tec Irga 6070 RR were soaked in salicylic acid solutions with concentrations of zero, 250, 500, 750, 1000, 1500, 2000, 3000, 4000 and 5000 μM. Seed imbibition occurred in two ways: (1) germination paper moistened with salicylic acid solutions; (2) imbibition of the seeds in salicylic acid solutions in gerbox boxes for 24 hours and subsequent sowing on germinated paper moistened with distilled water. On the fifth day after sowing, the number of normal seedlings (first count), length, fresh and dry mass of root and shoot were determined. It was concluded that the concentrations of SA between 250 and 750 μM can be used in soybean seeds, however, above 1000 μM may impair the parameters of physiological quality. The gerbox method for 24 hours provided the best results without the drastic reduction of the parameters in the lowest concentrations of SA.