Impact of tapping quality and harvesting practices on the sustainability of the rubber industry in Sri Lanka

Abstract

Maintaining the tapping quality in rubber fields is the key requirement to obtain potential yield with minimum harm to the tree. It also determines productivity and the economical lifespan of 30 years and sustainable rubber industry. The length of the tapping cut, the depth, the thickness of the bark shaving, and the slope of the tapping cut are the main factors determining the tapping quality. Use of a stencil according to the intended tapping frequency, i.e. d2, d3, d4, etc., to mark the guidelines to maintain the proper tapping angle of 30 degrees to the horizontal, and the bark consumption allowed for one year, are all equally contribute to maintaining the tapping quality. About 5000 ha. was surveyed to assert the tapping quality and to make recommendations. The average bark consumption rate per panel was four years deviating from recommended six years under d2 tapping. The monitory loss per hectare under this bark consumption rate is Rs.2.5 million at a productivity level of 1000 kg/ha/y and Rs.350.00 per kg of rubber. Trees affected by tapping panel dryness varied and was over 70% in some extreme cases. Introducing a quarter cut on the upper opposite panel of the tree ceased the situation to a greater extent.