Investigation of Temporal and Spatial Variability for Green Tea Growth Using Precision Agriculture Technology

Spatial and temporal variability of new shoots (number of shoots, dry mass and nitrogen concentration) were investigated under several conditions using precision agriculture technology. The growth and spatial variability of new shoots were both determined using the normalized difference vegetation index (NDVI). At harvest, there were differences in new shoots growth depending on variety, severe shading, and nitrogen fertilizer type. There were differences in new shoot for “Ten-cya” compared to that for “Sen-cya” and temporal variability of growth had a different tendency compared to spatial variability at harvest depending on several conditions. Coefficients of determination (R2) and root mean square error (RMSE) were established by the NDVI model. The accuracy was R2≥0.826 with RMSE≤15.0 g/m2 for “Sen-cya” and R2≥0.877 with RMSE≤13.6 g/m2 (vegetation coverage ratio ≤ 100%) for “Ten-cya”