ABSTRACT
Drought hardening is the process whereby a plant is subjected to partial drying so that when it is exposed to a subsequent drought event, the plant is able to withstand a greater severity of drought. During drought hardening, morphological, physiological, and chemical changes are induced within the plant as a result of phytohormone activity that enable the cells to withstand greater dehydration. Drought hardening also confers greater cold tolerance to the plant. Drought hardening is widely used in seedlings to increase their survival rate when transplanted. The wetting and drying of seed, known as presowing seed hardening, is also used to increase the germination, emergence, and drought tolerance of seedlings.
