STUDIES ON EARLY GROWTH OF MANGOSTEEN (GARCINIA MANGOSTANA L.)

The growth of mangosteen seedlings was studied for a period of 24 months. Plant growth in terms of plant height and dry matter production of roots and shoots was slow until the 12th month but increased at a faster rate after that. There was a marked increase in the number of tertiary roots compared to the secondary roots from the 6th to the 14th month. No root hairs were detected during this period; presumably the tertiary roots took over the function of the root hairs. From the 14th month the change in fresh and dry weight of the roots showed that the weight of the tertiary roots increased tremendously but the secondary and tap roots increased at a much slower rate during the same period. The increase of the tertiary roots coincided with the faster growth phase of the shoot. The dry weight ratio of the shoot and root portions of the plant was high during the first 18 months of the growth period but reduced to 4.94 by the 24th month. The study thus showed that mangosteen seedlings should not be planted before being kept for at least 2 years in the nursery. The growth of the seedlings in different soil media was also studied. Soil mixture containing 3:2:1 (sand:soil:organic matter) was found to be most suitable for the seedlings, and increasing the organic matter content impeded the growth of the seedlings.