Response of Low Frequency Harvesting Systems of Rubber Under Drier Climatic Conditions in Sri Lanka

RESPONSE OF LOW FREQUENCY HARVESTING SYSTEMS OF RUBBER UNDER DRIER CLIMATIC CONDITIONS IN SRI LANKA K.V.V.S. Kudaligama1*, V.H.L.Rodrigo1, K.M.E.P. Fernando2 and P. A. J. Yapa
1

Department of Biochemistry and Physiology, Rubber Research Institute, Sri Lanka 2 Department of Botany, University of Sri Jayewardenepura, Sri Lanka * [e-mail], Tel-++ 94 34 2247426, Fax- ++ 94 34 2247427
Abstract

Escalating cost of production (COP) and inadequate supply of skilled harvesters are among the major issues that natural rubber industry face today. Low frequency harvesting (LFH) systems of which trees are tapped in a lesser frequency than once in two days, are considered to be one of the solutions to overcome these issues. With the focus given to expand rubber in drier climates, the present study was aimed to investigate on the yield response of LFH systems, viz. harvesting trees once in three (d3), four (d4) and six (d6) days in the intermediate zone (IZ) with the stimulation protocols developed for the wet zone (WZ). With the decrease in harvesting frequency in IZ, yield per tree per tapping (GTT) increased, however yield per tree per year (YPT) decreased. No such declines were observed in WZ. Stimulation had no negative impact on percentage dry rubber content in latex (%DRC) or incidence of Tapping Panel Dryness. Whilst only the S/2 d3 system is acceptable for IZ in the present form, stimulation protocols are to be revised in other LFH systems. Bark consumption was reduced significantly by LFH resulting in several long-term beneficial effects. Effect of stimulation on latex physiology is also discussed. Keywords: Climate change, Ethephon, Hevea, Low frequency harvesting, Rubber

1. INTRODUCTION Being the second largest plantation crop in the country, rubber (Hevea brasiliensis) covers ca. 122,000 ha and produces ca. 129million kg of raw rubber (ref). More importantly, it provides ca. 500,000 direct and indirect employments. The total export earnings

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