Effect of method of transplanting young budded plants on growth of rubber tree (Hevea brasiliensis Muell. Arg.)

Planting materials used for the establishment of new rubber fields in Sri Lanka are young buddings. At planting, it is recommended to remove the polythene bag fully. This is a high labour demanding exercise and has inherited shortcomings of lateral root systems getting damaged when making the vertical cut along the sidewall to remove the bag. Attempts were made to transplant the young budding plants with the bag and four other methods together with the currently recommended method as the control. Treatments tested were, planting with the whole bag intact, planting with the bag but without the base of the bag, four slits made on the sides of the base removed bag and with the whole bag intact and only four slits made on the sides of the bag. Two whorled young budding plants of clone RRIC 121 were used. The experiment was carried out according to a Complete Randomize Design (CRD). Each treatment had twenty replicates.

 

The growth data up to six years from planting revealed that girth values are not significantly different. The field establishment rates were 100% with all treatments. The labour requirement is low when the plants are transplanted with the bag, which guarantees that the root system is not disturbed or damaged and hence no casualties. Also, when large extents are planted it is extremely difficult to follow the correct step by step procedure to remove the polybag and a certain percentage of casualties are expected and reported. The differences in the growth and the timber volume were not significant among treatments 20 years after planting. It was found in this study that planting without the base of the polythene is equally effective as removing the whole bag.