Shade in north-east Indian tea plantations. I. The shade pattern.
The influence of interplanted shade trees on the light regime at the surface of mature tea bushes is described. Most of the light reaching a tea bush was in the form of unmodified sunlight, either from large canopy gaps between trees or from sunflecks. The spectral composition of the shade light is analysed. The methods used made it possible to characterize the intensity and constitution of nearly all light on the bush surface in both clear and overcast conditions, as a basis for crop physiology studies. The rapid screening of possible shade trees and the use of foliage light patterns in planning mixtures and spacing of shade are outlined. Apparent contradictions between the results of natural and artificial shade experiments are discussed.