Studies on growth and functions of root system in tea plants. VI. Influences of root pruning intensity on root regeneration.

Abstract

The influences of root pruning intensities were investigated as to the root regeneration and the most efficient pruning intensity was discussed. The root pruning treatments were conducted in five degrees of intensities in late September 1982, using 4-year old plants (Camellia sinensis (L.) O. Kuntze cv. Yabukita). The amount of roots removed by pruning ranged from 20% (Treatment V) to 80% (Treatment I) of the total weight of roots per plant (Table 1). The weight of the lignified roots sampled in the treatment I and II were considerably below as compared with those in the treatment III-V and the weight of the white roots in the treatment III was greatest, inclusive the control. The prominent increase in white roots was recognized not only around the pruned part but in the basal part of decapitated lignified roots. To estimate the root regenerating potential after pruning, index (a), (b), (c) and (b×c) were invented. Although index (b) increased with thickness of decapitated lignified roots, index (a) and (b×c) were maximum in the treatment III and minimum in both treatments I and II. It is concluded that root pruning intensity is one of the factors controlling the effects of root pruning practiced for effecient rejuvenation of root systems.