Evaluation of the Use of SPAD-502 Chlorophyll meter for non-destructive estimation of nitrogen status of tea leaf (Camellia sinensis L. Kuntze)

Efficient nutrient management requires estimating factual fertilizer requirements. This study was aimed to test the use of
chlorophyll meter SPAD-502 to estimate the nitrogen status of tea maintenance leaf. The test was carried out by correlating
the SPAD readings with destructively measured leaf nitrogen content using samples oGbtained from nitrogen fertilizer
dosage experiments. Observations were made at 15, 32, 45 and 62 days after the application of N fertilizer treatments. The
results showed that the SPAD readings and total nitrogen leaf content correlated significantly with the time of observation.
Estimation of leaf N content based on the SPAD readings follows linear line equation y = 0.0311x + 1.5856 with coefficient
determinant (R²) = 0.62 significantly at P<0.01. It was concluded that SPAD-502 chlorophyll meter is reliable to assess the
leaf nitrogen content of tea maintenance leaf and is adequate to predict future nitrogen fertilizer requirements.