Buletin Kebun Raya

1-8

Authors: I Putu Agus Hendra Wibawa, Agung Kurniawan, Bayu Adjie

Dioscorea tuber has many benefits, for example as food or as traditional medicine. The high carbohydrate and protein contents make this plant suitable as a food. However, the presence of crystal oxalate, that causes irritation is an disadvantage aspect on the development of this species. Both of wild and cultivated species will assure the gene flow which is important in efforts to improve the tuber quality should be examine further. This research aimed to observe the biodiversity of Dioscorea in Bali and Lombok, to recognize the utilization and to reveal their nutrients (carbohydrate, protein and fat) and also the contents of calcium oxalate. The results showed that there are five Dioscorea spesies, namely Dioscorea alata L. (ubi) (11 cultivars), Dioscorea esculenta (Lour.) Burkill (ubi aung), Dioscorea hispida Dennst. (gadung), Dioscorea bulbifera L. and Dioscorea pentaphylla L. The highest carbohydrate content (87,42% ) is found in D. alata (ubi ungu cultivar) from Lombok, while the highest protein content (5,05%.) is found in D. alata (ubi dadap cultivar) from Singaraja, Bali. Furthermore, the highest percentage of fat content (0,85%) is found in D. bulbifera from Karangasem, Bali, whereas the high quantity of glaucomannan (44,52%.) id found in D. pentaphylla from Tabanan, Bali, while D. esculenta from Jembarana, Bali has the highest calcium oxalate (0,57%), and D. alata (ubi injin cultivar) from Karangasem, Bali has the least calcium oxalate (0,18%).

19-28

Authors: Ning Wikan Utami

This study was conducted to determine the effect of growth hormones and mycorhyza application on the growth of ramin cuttings. A Completely Randomized Design with 5 replicates was used in this study. The experiment consisted of two stages i.e hormon treatments (control, Rapid root, Root Up, IBA 250 mg/l, IBA 500 mg/l, IBA 1000 mg/l), Fusarium and mycorhyza applications. The result showed that the highest number of root was obtained from Root Up (12,83 cm), while the lowest was from Fusarium treatments (4,67 cm). IBA 250 mg/l enhanced the number of roots and the length of root significantly but not stimulate the development of new leaf. While mycorhyza application improving the growth of the new leaf and the root development of ramin.

46-52

Authors: Iyan Robiansyah

While quadrat shape of 10 x 10m has been commonly used in tree studies, the efficiency of this shape compared to the other shapes of size 100 m2 has not been tested. In this study, effect of various shapes of 100 m2 quadrat on measurement of Scots Pine (Pinus silvestris L.) density and basal area would be assessed. The aim was to assess the effect of quadrat shapes of 10 x 10m, 5 x 20m and 2 x 50m on the estimation of density and basal area of the pine in two woodlands in Norwich and to find the most efficient shape, statistically and with respect to sampling time. The results from all quadrat shapes similarly showed that the density and basal area of the Pines between two woodlands were significantly different. In site with lower pine density, the density and basal area measurement were not affected by variety of quadrat shapes. In site where the density of the Pine was higher, however, mean density and basal area measurement using 2x50m quadrat gave higher value than of the other two shapes. In term of efficiency, all shapes were not significantly different in statistical precision and sampling time. Shape of 5x20m, however, was more preferable as it required fewer samples before the mean of density and basal area always falls inside the 95% confidence interval of whole samples mean.