Md. Sah Alam
Minor Forest Products Division, Bangladesh Forest Research Institute P. O. Box 273, Chattogram - 4000, Bangladesh
M. Rafiqul Haider
Minor Forest Products Division, Bangladesh Forest Research Institute P. O. Box 273, Chattogram - 4000, Bangladesh
Calamus latifolius, Scarified seeds, Germination percentage, Survival potential, Pre-sowing treatment, Seedling growth.
In the nursery of Bangladesh Forest Research Institute (BFRI), Chattogram, Bangladesh
Seed Technology
Seed treatment, Seed germination
The research was carried out in the nursery of Bangladesh Forest Research Institute (BFRI), Chattogram, Bangladesh, over a period of four years from June 2014 to June 2017. The study area was located between 22°22·27´´ and 22°29·0´´ North latitude and 91°46·30´´ and 91°46·30´´ East longitude having a tropical climate, characterized by hot humid summer and cool dry winter. The maximum and minimum temperature in the area is 28.3 - 31.9°C and 15.2 - 25.2°C (Hossain and Arefin 2012). Relative humidity is usually low in winter (November - February) and high in summer (June - September). Mean annual rainfall is around 3000 mm mainly occurring from June to September.
Seed collection and pre-sowing treatments Ripe fruits of C. latifolius were collected from Salna seed orchard center, under Gazipur district of Bangladesh in the first week of June 2014. To determine the effect of pre-sowing treatment on seed germination and seedling growth performance, five different treatments of seeds were applied namely; i) seeds soaked in tap water for 24 h, ii) soaked in tap water for 48 h iii) soaked in 20% H2SO4 for 10 minutes iv) scarification by wire net and v) control (seeds were sown without any treatment). Seeds were cleaned by removing the scale and pulp by rubbing. The number of whole fruits and cleaned seeds per kg were 600 - 650 and 1200-1400, respectively. Then the seeds were sown in seed bed prepared with soil and decomposed cow dung mixed at a ratio of 3:1 by volume. Randomized Complete Block Design (RCBD) was adopted for the experiment with three replications. One hundred fifty (150) seeds were sown in each treatment at the rate of 50 seeds in each replication and a total of 750 seeds were required for five treatments of the germination trial.
Assessment of seed germination and seedling growth performance The effects of pre-sowing treatments on seed germination and seedling growth performance were recorded periodically by counting the germinated seeds and assessing initial growth performance of the seedlings. Cumulative germination was recorded at three days interval from the day of sowing and continued till completion of germination. Germination phase was determined by counting the number of days required for the commencement of germination and germination period is the number of days required for completion of germination from sowing the seeds. For assessing the growth performance, height of all seedlings were measured, and number of leaves counted at one month age of seedlings. Besides these ten seedlings from each replicate (30 from each treatment) were randomly uprooted and measured for total length (root length and shoot length separately). Seedling vigor index (VI) was calculated according to Abdul-Baki and Anderson (1973) through multiplying the germination percent by total length of seedlings (i.e. sum of shoot and root length).
Assessment of seedling growth performance in the nursery and the field Since, seed germination percentage and initial growth performance of seedlings was highest in the seeds scarified with wire net in the previous experiment, only the scarified C. latifolius seeds were sown for assessing the seedling growth performances in the nursery and field. Three thousand scarified seeds were sown in three blocks (considered as replications) in nursery bed for the purpose. When the seedlings were about one month old (with 2 - 3 leaves), they were transferred in to the polybags (23 cm x 15 cm ) filled with soil and cow dung mixture. The polybags were kept under full shade for one week and then placed under direct sunlight where they were allowed to grow. When the seedlings were about one-year old, 500 seedlings were out planted in five plots in the field at the beginning of the monsoon, e.g. June. Another 500 seedlings were allowed to grow in the nursery for one more year. Data on shoot and root length and leaf number of these seedlings were recorded at 3, 6, 12 and 24 months after transferring them in polybags. Seedlings in the field were planted at 2 m × 2 m spacing at Hinguli Research Station, Chattogram, Bangladesh. The soil was sandy-loam with a pH 5.7- 6.0. Average rainfall of the area was about 3200 mm and average maximum and minimum temperature was 34.7°C and 20.7°C respectively, indicating the suitable eco-physiological conditions for rattan plantations (Xu 1985). Weeding were done at every 3 months in the field. However, no fertilizer or water was added after planting. Data on height of all plants in each plot were recorded at 6, 12 and 24 months after planting. Survival percentage of the planted seedling in the field was determined 1 year after planting.
Data analysis Data were analyzed with Microsoft Excel to determine the significant (p≤0.05) variations among the treatments. Analysis of variance (ANOVA) and Duncan Multiple Range Test (DMRT) were carried out to analyze the data.
Bangladesh Journal of Forest Science Vol. 36 (1), 2020: 50-61
Journal