Dormancybreaking

Dormancy breaking is the set of practices used to end natural dormancy in seeds, buds, or other plant organs so growth can resume. Dormancy is a temporary suppression of growth that helps plants survive adverse conditions and synchronize germination or flowering with favorable environmental conditions. Breaking dormancy involves environmental cues, physical or chemical treatments, and is often specific to the organism and the type of dormancy involved (physiological, physical, or morphophysiological).

In seeds, dormancy is commonly physiological or physical. Physiological dormancy can be overcome by stratification, which is exposure to cold and moisture for a period to mimic winter conditions; scarification, which weakens the seed coat by mechanical or chemical means to permit water uptake; and after-ripening or dry storage under controlled conditions to reduce dormancy. Seed priming, a controlled hydration followed by drying before sowing, can also hasten germination and improve emergence. Light and temperature requirements may influence the success of these treatments.

In buds of woody plants, endodormancy is typically released after a sufficient period of chilling, often expressed as chill hours or units. Once chilling requirements are met, buds may break dormancy and resume growth when temperatures become favorable. Chemical dormancy breakers have been used in some agricultural systems to synchronize bud break, with agents such as certain plant growth regulators; their use is subject to safety, regulatory, and environmental considerations.

Vernalization and related storage conditions affect bulbs, tubers, and perennials by promoting or accelerating dormancy release and subsequent growth or flowering. The appropriate method depends on species, local climate, and production goals, and improper application can reduce germination, vigor, or yield.