Spectral characterization and LAI modelling for the tea (Camellia sinensis (L.) O.!Kuntze) canopy

Understanding the spectral characteristics of tea plants is important in monitoring tea plantations by remote sensing. Westhall tea estate, Kataboola, situated in the Kandy district in Sri Lanka, was selected as the study site. The Leaf Area Index ( LAI) of the tea canopy and spectral reflectance of different types of tea clones for different pruning ages were studied in 50 tea fields in the estate. An empirical model between Normalized Difference Vegetation Index (NDVI) (spectrophotometer derived) and LAI (field measured) of the tea canopy was developed. This study has revealed that different tea clones have unique spectral characteristics depending on the tea canopy structure, size, greenness and maturity of the leaves. These spectral variations were also studied using IRS-1C image acquired on the sampling date. Satellite sensor records have shown variation in spectral characteristics for different types of clonal and seedling tea, but these variations are not as prominent as the result offered by spectrophotometer-based observations.