Zambia Agribusiness Society

Introduction The transplanting process can be a shock to rapidly growing seedlings especially when set out into the cold windy garden in the spring. This is especially true for transplants started in the greenhouse, cold frame, hotbed or home. These young seedlings can be made somewhat resistant to heat, cold temperatures, drying and whipping winds, certain types of insect injury, injury from blowing sand and soil particles and low soil moisture by a process termed “ hardening .” The term “ hardening ” refers to any treatment that results in a firming or hardening of plant tissue. Such a treatment reduces the growth rate, thickens the cuticle and waxy layers, reduces the percentage of freezable water in the plant and often results in a pink colour in stems, leaf veins and petioles. Such plants often have smaller and darker green leaves than non-hardened plants. Hardening results in an increased level of carbohydrates in the plant permitting a more rapid root development than occurs