Using a chlorophyll meter to estimate tea leaf chlorophyll and nitrogen contents

Abstract

A chlorophyll meter can conveniently estimate foliar chlorophyll and nitrogen (N) contents in many species. The objective of this study was to evaluate the utility of a chlorophyll meter to inform nitrogen fertilization rates of tea (Camellia sinensis L.) at different places and times. Plot-scale (5 × 20 m) experiments with three replications were conducted in 2010. Each plot was treated with 248 kg pure N ha -1 per year as urea. At the same time, a field-scale (32 ha) experiment, with the same fertilization rate, was conducted at the same plantation. Tea leaves were sampled in August and November and analyzed with a chlorophyll meter in situ and in the lab. The chlorophyll and nitrogen contents and chlorophyll meter (SPAD) readings of tea leaves in August were greater than in November, and plot-scale values were greater than field-scale values. SPAD readings could estimate the chlorophyll content of tea leaves regardless of temporal and spatial considerations. However, space and time must be considered when using SPAD readings to estimate the nitrogen content of tea leaves.

Effect of shading intensity on morphological and color traits and on chemical components of new tea (Camellia sinensis L.) shoots under direct covering cultivation

“…The exponential equations derived from the relationship between SPAD values and chlorophyll contents in this study (Fig. ) were similar to the equation for mature tea leaves reported by Liu et al . However, the residual errors of this exponential equation were higher at higher SPAD values.…”

“…Previous studies employed exponential equations to parameterize the relationships between SPAD values and chlorophyll contents, taking into account the effects of radiation scattering and nonuniform distribution of chlorophyll. 23,24 Liu et al 25 also derived exponential equations for estimating chlorophyll content of mature tea leaves from SPAD values. However, the relationship between SPAD value and chlorophyll content in a tea new leaf remains poorly understood.…”

Seasonal variations of leaf and canopy properties tracked by ground-based NDVI imagery in a temperate forest

“…Variations in the total chlorophyll or carotenoids can also indicate environmental stress in plants 35 , as well as senescence and damage. Chlorophyll readings made with SPAD can be used to monitor dynamic changes, since the SPAD values are highly correlated with lab extracted leaf chlorophyll concentration 35–38 (Fig. 4a).…”

Hyperspectral Measurements for Estimating Vertical Infection of Yellow Rust on Winter Wheat Plant

“…In comparison with traditional laboratory-derived tests, a chlorophyll meter can conveniently estimate foliar chlorophyll and nitrogen (N) contents in many species (Liu et al, 2012). SPAD-502 and Dualex 4 are the two commonly used meters, and both SPAD and Chl derived from the two devices can be used to present the relative chlorophyll content.…”