All are methods of overcoming seed dormancy except

Chemical inhibitors such as abscisic acids, phenolic acids, para-ascorbic acid promotes seed dormancy. Dormancy can be overcome through natural means and various man-made measures. For example, the seed coat barrier in some seeds can be broken by mechanical abrasions using knives, sandpaper, etc. or vigorous shaking. In nature, these abrasions are caused by microbial action, and passage through digestive tract of animals.