Harvesting rubber latex is rather labour intensive since trees are traditionally tapped half spiral, once in two days (S/2 d2) resulting in unnecessary waste of tree bark. High cost of production, shortage of harvesters and reduced economic lifespan are the key issues in rubber plantations related to harvesting. Low intensity harvesting (LIH) systems (i.e. either reduction in harvesting frequency and/or tapping cut length) of rubber appear to be a practical solution to these issues by bringing down the labour requirement and the cost of production. Of these, only the reduction in harvesting frequency has been tried in Sri Lanka. Hence, the present study was aimed to develop new LIH systems with shorter tapping cuts.
This study comprised two stage stimulant (Ethephon) based field trials to evaluate a wide range of LIH systems. The overall yield given by traditional S/2 d2 was used as the standard in evaluation. Stimulation protocols of different harvesting systems were adjusted from time to time to achieve this standard. In addition, growth and physiological parameters of latex and the financial viability of the principal system were also assessed.
Among the LIH systems tested, S/4 d3 (tapping quarter spiral once in three days) was successful in providing benefits, such as increase in both overall profits and harvesters' income and reduction in harvesting cost and overall cost of production. The overall bark consumption was also greatly reduced. Above all, it allows tapping the virgin bark of base panels for over 24 years. Popularization of this approach is proposed after large scale commercial testing.
J.Natn.Sci.Foundation Sri Lanka 2012 40(4):283-291