Temporary interruption of visible growth of any plant structure containing a meristem. Physiologists distinguish between different types of dormancy depending on the receptor organ of the environmental or endogenous signal. Lang et al. (1987) define: endodormancy if the specific perception occurs within the affected structure of the plant; paradormancy if it originates in a structure other than the affected structure; ecodormancy to include all causes of dormancy due to unsuitable environmental factors which are non-specific in their effect on plant metabolism (e.g. temperature extremes, nutrient deficiency, water deficit). Bud dormancy is considered released when 25 to 75% (more typically 50%) of the buds are capable of growth.