Yield damage functions for tea sector in Sri Lanka and India: An empirical estimation

A Yield damage function helps to illustrate by relating yield damage and some independent parameters of soil such as top soil depth and organic matter content. This study was focussed on three tea growing district, Passara and Watawala sub district of Sri Lanka and the Nilgiris of India where considered 208 tea fields from Passara tea growing region, 52 tea fields from Watawala/Ginigathena tea growing region and 96 tea fields from the Nilgiris tea district covering 66 and 30 tea fields from TANTEA Plantations corporation and four private tea plantations respectively. The results of the study show that the Passara region is responsible for higher yield damage due to top soil reduction and the region shows very shallow soil depth and poor ecological condition. If the Nilgiris is in a condition to manage the issue, Passara tea region of Sri Lanka is required immediate actions to control the problem for sustainability of tea industry of the region.