Factors associated with Declining Yield in Corporate Sector Tea Plantations in Ratnapura and Kegalle Districts

The contribution to the Sri Lankan tea industry from the low grown tea is substantial. However, a recent study revealed that the corporate sector tea plantations of Ratnapura and Kegalle districts were experiencing a yield decline at a rate of 3.6% and 2.4%, respectively per year. This study attempted to find out the possible reasons for such yield decline.Primary data collection was done mainly by reviewing the estate records and through field observations in tea plantations owned by Regional Plantation Companies (RPCs) of the respective regions while the secondary data were collected from the “Diagnostic Survey” conducted in 2010. Data were analysed using statistical tools such as correlations, descriptive methods, log-linear and chi-square techniques. Results showed no direct relationship of rainfall and ambient temperature with present yield decline. However, the senility of tea and low rate of replanting were found to be core contributory factors for the yield decline. The labour scarcity too, has contributed by disrupting the planned capital work, harvesting and executing the good agricultural practices. Debilitation of tea bushes resulting from the damage caused by Wood-rot, Shot-hole borer and Canker seem to have contributed to the yield decline.  The poor adoption of post pruned sanitary measures and poor shade management practices were also contributed to the yield reduction. This study has also elucidated the relationship between low levels of soil organic carbon and low productivity of young tea. Hence, it could be concluded that the yield reduction in Ratnapura and Kegalle districts can be attributed to multiple reasons.