The root system of tea comprises of two types of roots, “feeding roots” and “extension roots”. The fibrous roots of tea are thin 0.3 to 3.0 mm in diameter and much branched .The white and cream portion of the fibrous roots are designated “feeding or feeder roots” and the reddish brown portion as “extension roots”. The young roots of tea are white and as they get older the colour of the roots changes to cream and finally to reddish-brown, due to suberisation of the endodermis and primary cortex.
The capacity for absorption of water and nutrients is maximum in the white roots below the root cap. The absorbing capacity diminishes gradually as the root ages and colour changes from white through cream to red. The red portions have very little capacity for absorption.
Tea is a mycorrhizal plant. A mycorrhizal plant species either do not have root hairs or their occurrence is very scarce. In tea roots also, root hairs are very scanty and poorly developed. The young roots are associated with vesicular-arbuscular (VA) endotrophic mycorrhizas. These fungi associated with tea roots, belong to genera Glomus, Gaigospora and acualospora of the family Endogoneceae. Mycorrhizal mycelia are found in the cells of the primary cortex throughout the white and cream portions of the roots, except in the root tip. In the nutrition of tea plant, the mycorriza plays some important role.
In tea root system, about two thirds of the feeding roots are confined to the top 30 to 40 cm of the soil and the quantity of fibrous roots decreases with depth. The depth of thicker roots depends largely on local conditions as influenced by physical and chemical properties of the soil, rainfall and its distribution, depth of permanent water table etc. Tea root may grow upto 5m depth.