PHYSIOLOGICAL CHARACTERS AND PRODUCTION TOWARD TAPPING PANEL DRYNESS OF PB 260

Abstract

Tapping panel dryness (TPD) is one of the most important issues in the cultivation of rubber trees. In fact, TPD starts gradually so that the planters are not aware about the incidence in the field. TPD is caused by abiotic, biotic and management exploitation. One of the factors is tapping and stimulation intensity. The purpose of this study was to study the effect of tapping frequency on the occurrence of TPD, production pattern, physiological characters, growth and grouping of main factors related to TPD. The experiment was carried out at Sembawa Research Station in 2010 and 2012, used PB 260 clone planted in 2004 with tapping frequency S/2 d1 6d/7, S/2 d2 6d/7, and S/2 d4 6d/7. Data analysis was done with principle component analysis. The results showed that daily tapping (d1) induced TPD on 5 months after opening and increased to 75% at 24 months after opening. The signal toward TPD was “overactive” metabolism where the latex yield and Pi increased significantly whereas sucrose content decreased. After TPD, yield was lower than on the healthy trees, and the girth increment was higher. Sucrose and Pi parameters can be used as an early warning signal of TPD occurrence. Keywords : PB 260, TPD, sucrose, Pi, thiol, TSC, yield, girth.