Abstract:
A field experiment was carried out at St. Coombs Estate, Talawakele, for a period of three months to
examine the effect of different amounts of zinc sulphate applied as foliar on the yield and nutrient
composition of tea (Camellia sinensis). The experiment was conducted to evaluate the effects of different
rates of zinc application on tea yield and leaf nutrients relationships over a three-month period, and to
identify the optimum zinc rate. The treatments consisted of five zinc sulphate application levels: 0
kg/ha/yr, 2.75 kg/ha/yr, 5.5 kg/ha/yr, 8.25kg/ha/yr, 16.5 kg/ha/yr. The highest fresh leaf yield was
obtained from the treatment 5.5 kg/ha/yr with which recorded a 26.7% increase compared to the control.
The treatment 16.5 kg/ha/yr with showed the highest quadrat yield, possibly due to enhanced shoot
growth stimulated by zinc through its role in the production of indole-3-acetic acid (IAA). According to
the results, no significant interrelationship was observed between different rates of zinc application and
the concentrations of nutrients such as Mg, Ca, P, Mn, and Fe. Potassium (K) and nitrogen (N) showed
intermediate and weak correlations, respectively. Leaf zinc concentration increased significantly with
increasing zinc application rates, with the maximum zinc concentration (46 mg/kg) recorded at the
highest application rate of 16.5 kg/ha/yr. Since the recommendation are made on annual basis, as tea is a
perennial crop, the short duration of the study was insufficient to draw firm conclusions.
