M. Rafiqul Haider
Minor Forest Products Division, Bangladesh Forest Research Institute P.O. Box No-273, Chattogram 4000, Bangladesh
Mohammed Mukhlesur Rahman
Minor Forest Products Division, Bangladesh Forest Research Institute P.O. Box No-273, Chattogram 4000, Bangladesh
Md. Sah Alam
Minor Forest Products Division, Bangladesh Forest Research Institute P.O. Box No-273, Chattogram 4000, Bangladesh
Tamarindus indica, Pre-sowing treatment, Dormancy breaking, Germination rate, Growth performance.
Resource Development and Management
Seed germination, Seeding
The study area The study was carried out in the nursery of Bangladesh Forest Research Institute (BFRI), Sholoshahar, Chattogram and Hinguli Research Station, Mirsari, Chattogram, Bangladesh over a period of two years from June 2017 to July 2019. Geographic position of the study area is situated between 220 22' 27" and 220 29'0 North latitude and 91046'30" and 91046'30" East longitudes. The climate of the study area is tropical in nature and characterized by hot humid summer and cool dry winter. The maximum and minimum temperature in the area varies from 28.31 to 31.9 0 C and from 15.2 to 25.2 0 C respectively (Hossain and Arefin 2012). Mean annual rainfall is around 3000 mm mainly occurred from June to September.
Seed collection and growing media The seeds were collected in the middle of March 2017 from 20-25 years old matured healthy trees from Kaptai National Park of Rangamati Hill district, Bangladesh. Then the seeds were dried in the sunlight for 2-3 days and stored in air tight polybag. Shrinked, discolored and damaged seeds were separated from collected seeds and only healthy seeds were used for the experiment. The number of seed per kilogram was 220 to 240. The germination trail was carried out by sowing seeds in bed filled with soil and decomposed cow dung at the proportion of 3:1 by volume. Seeds were sown in the seed bed at the depth of 0.5-1.0 cm.
Experimental design and different treatments Experiments were conducted in Completely Randomized Design (CRD) with five replications. Four treatments were applied to determine their effect on seed germination and seedling growth attributes. The treatments were i) soaking in cow urine for 24 hours, ii) soaking in cow-dung slurry for 24 hours, iii) soaking in hot water (1000 C) for 30 second followed by soaking in tap water for one hour, iv) soaking in tape water for 24 hours and v) control. In each replication 50 seeds were sown and in total 1250 seeds were used for germination trial in the seedbed of the nursery. Watering was carried out manually when necessary.
Assessment of seed germination and seedlings growth performance in seed bed The effect of different treatments on seed germination and seedlings growth was explored periodically through counting the germinated seeds and measuring initial growth performance of seedlings. Germination data was collected at two days intervals starting from sowing and continued till ending of germination. For assessing the growth performance, above ground height all seedlings were measured and number of leaves were counted when the seedlings were one month old. Besides these ten seedlings from each replicate (50 from each treatment) were randomly uprooted and measured their total length (root length and shoot length separately). Vigor index (VI) was calculated according to Baki & Anderson (1973).
Assessment of seedling growth performance in the nursery (polybag) and in the field When the seedlings were about 30-45 days old (with 5-6 leaves), they were transferred to the polybags (23 cm × 15 cm in size) filled with soil mixed with cow dung (3:1). The polybags were kept under full shade for one week and then placed under direct sunlight and allowed them to grow there. Data on shoot length, root length and leaf number of seedlings were also recorded at three months, six months, and twelve months after transferring them into polybags. When the seedlings were one year old, 225 seedlings were out planted in the field at the beginning of the monsoon (June- July). Equal number of seedlings (225), were allowed to grow in the nursery for one and half year more. Seedlings in the field were planted at 1.5 m × 1.5 m, 2.0 m × 2.0 m and 2.5 m × 2.5 m spacing at Hinguli Research Station, Chattogram, Bangladesh. The soil was sandy-loam with a pH 5.70-6.00. Average rainfall of the area was about 3200 mm and average maximum and minimum temperature was 34.70 C and 20.70 C respectively. Weeding was done every month in the nursery and water was added after planting. Data on the heights of each plant were recorded at six months and twelve months after planting. Survival percentage of the seedlings in the field was determined one year after planting the seedlings.
Data Analysis All data were analyzed with computer software IBM SPSS var. 21 to conduct Analysis of variance (ANOVA) and Duncan’s Multiple Range Test (DMRT) in order to determine the significant (p ≤ 0.05) variations among the treatments.
Bangladesh Journal of Forest Science Vol. 36 (1), 01-09, 2020, ISSN 1021-3279
Journal