The effects of hydro-priming and osmo-priming using nitrate salts on germination indices of soybean seedling (Glycine max L.)

In order to investigate the effects of pre-treatment of seed by hydro-priming and nitrate salts on germination and growth characteristics of soybean (Glycine max L.; cv. Williams 82), an experiment was conducted based on completely randomized design with four replications in Research Laboratory of Department of Plant Production and Genetics, University of Maragheh, Iran in 2017. Treatments included control (non-priming), hydro-priming and priming with osmotic solutions: 0.5, 1 and 2% of potassium nitrate, ammonium nitrate, calcium nitrate and sodium nitrate. The results of analysis of variance showed that the effect of seed priming treatments was significant on seedling dry weight, mean germination time, germination percentage and seed vigor index of soybean (P < 0.01). Increasing dose of potassium nitrate and sodium nitrate from 0.5 to 2% of priming led to reducing dry weight of seedling and seed vigor index. However, increasing of calcium nitrate dose of priming led to increasing dry weight of seedling and seed vigor index. Also, there was no significant difference between 0.5, 1 and 2% of ammonium nitrate for dry weight of seedling and seed vigor index. On the other hand, hydropriming had no positive effect on seedling dry weight and seed vigor index of soybean compared to control (non-priming). Ammonium nitrate 2% had the lowest seed germination percentage (57.5%) and the highest time for germination (5.1 days), and there was no significant difference between the other pre-treatments of saline nitrate and hydro-priming with control (non-priming). In general, ammonium nitrate 2% as the most ineffective pre-treatment and calcium nitrate 2% as the highest pre-treatment was considered among nitrate salts. Calcium nitrate 2% had a significant effect on germination and growth characteristics of soybean seedlings, therefore, it is recommended to seed pre-treatment of the crop.