Reduction of the Bark Splitting Injury to Young Tea Plants by Ridging

The ridging to the basal stems of young tea plants, which was applied to 15-16cm above the ground before or iust after the occurrence of the injury, was examined for the effectiveness in reducing the bark splitting injury which was a kind of cold injury by autumn frost and occured mainly on stems.1. The previous ridging did not maintain high the minimum air temperature near the soil surface at the occurrence time of the injury.2. The previous ridging did not also restrain the occurrence of the injury but the tea plants damaged after ridging showed good growth and high rate of survival later, probably because the most important basal stem was protected from the injury by ridging.3. The ridging just after the injury remarkably accelerated callus formation at wounded parts and consequently reduced the damage.4. From the above findings, the forehand ridging for prevention is advisably practiced in the regions where severe injury is anticipated, while the post-injury ridging is also a valid method for remedy.