Abstract
Four clones TRI 2023, TRI 62/9, (vigorous), TC 9 and DT 1 (slow growers) were used to estimate the manner and efficiency with which applied N is used by young tea plants grown in sand culture. Uptake was initially slow and increased as the plant grew. Leaf area was directly related to uptake. There was a noticeable increase of uptake immediately preceding the opening of buds following a dormant phase. TRI 2023 and TRI 62/9 absorbed consistently greater quantities of N throughout; they recovered 75 to 85 per cent of the total N applied, while DT 1 and T 9 accounted for about 50 to 55 per cent. The total absorbed N and N in percolates and leachates accounted for about 95 per cent of the applied N. Though efficiency of uptake of differed markedly between the vigorous and less vigorous clones, the dry matter production per unit of N absorbed appeared to be similar for all four clones. The N uptake patterns are discussed in relation to fertilizer recommendations for clones of differing growth vigour.
