Direct rooting and hardening of tea microshoots in the field

Micropropagation of tea (Camellia sinensis (L.) O. Kuntze) has been widely attempted but commercial exploitation of this method is limited by heavy losses during the hardening procedures. In the present study, optimization of time of harvesting (spring and early summer) of microshoots, shoot size, soil pH (4.0-6.4), plant growth regulator treatment (IBA; 500 mg l(-1), 30 min) CO2 (9.09/10x10(-5) mol l(-1) to 10.22/10x10(-5) mol l(-1) and 20/11x10(-5) mol l(-1) to 80/13x10(-7) mol l(-1)) enrichment and light (15 mu mol m(-2) s(-1)) conditions in specially designed hardening chambers, made a significant impact on the percent of success for hardening. Following the standardized procedure, up to 71.6% root induction and 73% survival could be achieved. Successful field transfer was also accomplished.