TY  - BOOK
AU  - Thanh Do Kim
AU  - Choo Wong Kai
AU  - Sivakumaran S
TI  - Long-term effect of tapping and stimulation frequency on yield performance of rubber clone GT1
PY  - 1996///
PB  - Journal of Natural Rubber Research
KW  - GT1
KW  - Tapping
KW  - Yield
N2  - A fourteen-year experiment was conducted to study the yield responses and dryness incidence of rubber clone GT1 to half-spiral tapping at frequencies d/2 (alternate daily), d/3 (third daily) and d/4 (fourth daily) in combination with stimulation frequencies of 0/y (unstimulated control), 2/y (two rounds/year), 3/y (three rounds/year), 4/y (four rounds/year) and 6/y (six rounds/year) of ethephon at 2.5;concentration applied by groove method. Mean dry rubber yield/tree/tapping (g/t/t) and mean dry rubber yield/hectare/year (kg/ha/year) over 14 years of tapping were affected by interaction between tapping and stimulation frequencies. Under high stimulation frequencies of 4/y and 6/y there was a progressive increase in g/t/t with reduction in tapping frequencies from d/2 to d/4. This has led to comparable kg/ha/year among the three tapping frequencies. In spite of lesser number of tappings, d/3 tapping frequency produced cumulative yield (kg/ha) comparable to that of d/2 tapping frequency. Positive responses of g/t/t, kg/ha/year and cumulative kg/ha to stimulations 4/y and 6/y were obtained only under low tapping frequencies of d/3 and d/4. Virgin and renewed tapping panels responded in a similar manner to the tapping and stimulation treatments. Dryness incidence was not significantly affected by any of the treatment combinations
ER  -