Application of low level of growth regulators may break the seed dormancy. Most widely used growth regulators are gibberellins and kinetics.
Among other chemicals potassium nitrate (0.2%) and thio – urea (0.5 to 3%) are widely used for breaking seed dormancy in oat (Avena Sativa), barley (Hordeum vulgare), tomato (Lycopersicon spp).