PERFORMANCE OF ONCE IN THREE DAYS (S/2 d3) AND FOUR DAYS (S/2 d4) TAPPING SYSTEMS IN MARGINAL DRIER AREAS IN SRI LANKA
With the beginning of tapping in the first ever rubber lands planted in drier climates, low frequency tapping (LFT) systems i.e. tapping half of the tree circumference once in three (S/2 d3) and four (S/2 d4) days were tested together with traditional once in two days (S/2 d2) system in rubber smallholdings established in marginal drier areas in Eastern Province of Sri Lanka. Generally, yields given by LFT systems were comparatively higher than that in traditional S/2 d2 system. A prominent seasonal distribution of rubber yields was shown in all three taping systems. Throughout the period dry rubber content of latex did not fall below 35%. When compared to wet areas sucrose, inorganic phosphorous, thiol and total solid content of latex were considerably higher with a prominent variation between wet and dry seasons. When reducing the tapping frequency latex sucrose content reduced whilst latex inorganic phosphorous content increased confirming the higher metabolic activity in laticifers to increase daily latex yield per tree. Lowering of the plugging index in trees taped with LFT systems, significantly increase the daily latex volume. Low frequency tapping systems did not effect on the growth of rubber tree, incidence of tapping panel dryness and quality of rubber produced. Converting to LFT increased the profitability and time availability of farmers for their traditional farming activities.
Keywords : Cost of production, Hevea, low frequency tapping, rubber, tapping