I’ve covered this topic before here, halopriming is basically soaking seeds overnight in a salty solution, whether that be calcium chloride, potassium nitrate or common sea salt sodium chloride. The reason for doing this is it greatly improves the seed germination of many species, particularly common garden vegetables and grains like rice and wheat.
Here is an abstract from a scientific paper:
Seed priming improves the seed performance and also helps the seedlings to alleviate the detrimental effects of various stresses. Seed priming is believed to bring about some biochemical changes in the metabolism within the seed, which ultimately favors germination and the further growth stages of the seedlings even under stressed conditions. The present investigation was carried out to study the effect of hydropriming and halopriming in three rice varieties, with varied abiotic stress tolerance potential under NaCl and PEG stress. In general, the application of both stresses, NaCl and PEG induced retardation of growth and metabolism of the seedlings. However, seed priming treatments could reduce the extent of decrease in these biological attributes. Both hydro- and halopriming resulted in the enhancement of protein, carbohydrate, and photosynthetic pigment content, modulated antioxidant enzyme activities, reduced the lipid peroxidation of biomembranes, and enhanced the photochemistry and mitochondrial activities in rice seedlings subjected to NaCl and PEG stress as compared to non-primed ones. According to the various morphological, physiological, and biochemical characteristics studied in the rice seedlings raised from primed and non-primed seeds, we confirmed that both hydropriming and halopriming had a positive influence on stimulating metabolism in rice seeds, which ultimately resulted in improved seedling vigor and tolerance under NaCl and PEG stress. Halopriming was found to be more efficient than hydropriming in enhancing the seedling vigor, overall growth, and stress tolerance potential of rice varieties.
Peganum harmala or Syrian Rue is native to Meditteranean region, Arabia and Western Asia. The seeds contain beta carboline alkaloids identical to those found in Banisteriopsis caapi and are used as monoamine oxidase inhibitors in the same way as the ayahuasca vine is. They also have many traditional uses. We have conducted many experiments on the seed germinaton of Syrian Rue and have found that halopriming is an excellent way to treat Peganum harmala seeds and it provides a method germinate strong and robust seedlings of this plant which is generally hard to grow in cultivation. Soak seeds for 24hrs+ in a salt water solution (about as salty as seawater; actual seawater may work really well) rinse in fresh water and then let them dry off, before sowing as normal.