Test of double cut alternative (DCA) tapping system under on-farm trials in southern Thailand

To avoid adverse impact of high tapping frequencies, double cut alternative (DCA) tapping system has been introduced to optimize tapping frequencies by alternate tapping of two cuts. Test of DCA on-station trial used to be done in southern Thailand, it showed positive result. Therefore, it was also tested under smallholders' rubber plantation in two districts of Songkhla province: Hat Yai district (lowland area, sandy loam soil) and Namom district (hilly area, loamy sand soil) Comparative study of double cut alternative (DCA) tapping systems and conventional tapping systems was done in rubber clone RRIM 600. The on-farm trails were started in 2008 with 3 replicates (one plot per replicate) in each district. Results showed that DCA tapping system in Hat Yai district: 2X 1/3S d/2 (t,t) (low frequency) and Namom district: 2X 1/3S d/2.d/3 (t,t) (high frequency) provided significantly higher rubber production than those of the conventional tapping systems (25-28 and 20-22 % for production parameters of g/t and g/t/tapping, respectively). Bark consumption, girth expansion rate and tapping panel dryness were not significant difference between the treatments of DCA and conventional tapping system. It was suggested that the DCA tapping systems also provided the positive result with an increase of rubber productivity under on-farm trials. This study was the first test under on-farm trial in southern Thailand. Therefore, it would be interested to investigate further under different conditions of planting areas and tapping systems. (Résumé d'auteur