Dey et al. /Journal of Tropical Forestry and Environment Vol. 11, No. 02 (2021) 37-47 37 *Correspondance:somadeyfor32@gmail.com Tel: +8801533369754 © University of Sri Jayewardenepura Effect of Pre-sowing Treatments on Germination and Initial Growth of Terminalia citrina: A Medicinal Tree Species in Bangladesh S. Dey1, M. K. Hossain1, R. Nandi1, M. Saifullah2 1Institute of Forestry and Environmental Sciences, University of Chittagong, Chittagong, Bangladesh 2Bangladesh Agricultural Research Council, Farm Gate, Dhaka, Bangladesh Date Received: 22-09-2021 Date Accepted: 28-12-2021 Abstract Terminalia citrina (Gaertn.) Roxb. ex. Fleming (local name-Hatiyal) is an important medicinal tree species naturally grown in Sal and hill forests of Bangladesh. An experiment was conducted at the Institute of Forestry and Environmental Sciences, University of Chittagong, Bangladesh, to find out the effects of pre-sowing treatments on germination and vigor seedling production capability. Seeds were treated with six pre-sowing treatments, e.g. T0-seeds without any treatment (Control), T1-seeds soaking in normal water for 24 hours and sown in polybags (24º C), T2-seeds soaking in normal water for 48 hours and sown in polybags (24º C), T3-fruits sown in seedbed, T4-seeds soaking in hot water for 1 minute and sown in propagator house (80º C), and T5-seeds sown in propagator house. Highest germination percentage (95.83%), germination energy (37.5%), and germination value (1.0506) were found in T5 treatment (seed sown in propagator house) and significantly (p<0.05) different from other treatments. Collar diameter and leaf number were recorded after three and four months of seed germination. After 3 months of the last germination, maximum shoot height (46.6 cm) was revealed in T2 (seeds immersed in normal water for 48 hours and sown in polybags) treatment. Collar diameter (6.02 mm) and leaf number (12.6) were recorded highest in T2 treatment. The lowest diameter (4.23 mm) and leaf number (5.8) were found in T4 treatment (seeds soaking in hot water for 1 minute and sown in propagator house). Finally, seeds sown in the propagator house (sand media) revealed comparatively better germination behaviour but low growth performance. Seeds treated with normal water for 48 hours treatment revealed appropriate for vigour and quality seedlings production for T. citrina. Keywords: Treatments, germination, vigour, seedlings, medicinal 1. Introduction Medicinal plants are the life-saving elements of forest products and play a significant role in the health care of rural people all over the world. They offer essential raw materials for the production of conventional and modern medicines and important therapeutic agents (Ghani, 2003; Islam et al., 2016). As stated by World Health Organization (WHO), there are almost 21,000 medicinal plant species all over the world (Penso, 1980). In Bangladesh, around 500 plant species including trees, herbs, and shrubs used as medicinal plants because of their therapeutic properties (Ghani, 2000). In another study, Yusuf et al. (2009) documented 747 plant species have therapeutic properties in Bangladesh. Terminalia citrina (Gaertn.) Roxb. ex. Fleming, belonging to Combretaceae family, a valuable medicinal tree of Bangladesh. The medium to large sized deciduous tree having very young shoots are shining, rusty hairy, soon glabrate. Bark light grey, vertically fissured, exfoliating in large flakes, inner bark light yellow, turning brown. Leaves sub-opposite, elliptic to oblong-lanceolate. Flowers small, dull-yellow, sessile in terminal spikes. Fruit a drupe, oblong-lanceolate, about 5 cm long, smooth, orange-yellow when ripe, obscurely 5-cornered when dry (Das and Alam, 2001). It is originated in deciduous forests throughout the greater part of India, Myanmar, Sri Lanka, Pakistan, and Bangladesh (Hossain et al., 2005). In Bangladesh, the species occurs naturally in the forests of Sylhet, Chattogram, Chittagong Hill Tracts, Dhaka, Mymensingh and also planted as avenue tree (Das and Alam, 2001). The fruits are used for medicinal purposes in combination with Emblica officinalis and Terminalia bellirica, known as the name of “Triphola”. The Ayurvedic recipe ‘Triphola’ is effectively and widely used in various ailments such as skin diseases, eye disorders, constipation, chronic lung disease, acidity, digestion, and assimilation (Kanjilal et al., 1984; Ara et al., 1997). Seeds are used in stomach aches and intestinal diseases (Lev and Amar, 2000). The plants also used in asthma, diarrhea, anemia, arthritis, cough, cardiac disease, infections, hepatomegaly (Soe and Ngwe, 2004). The timber is very hard, fairly durable, and used for building structures, furniture, agricultural implements, carts, and other purposes. Because of the hard seed coat and thick fleshy pulp, germination percentage of seeds is low (<50%) and requires more time to germinate (up to 2-3 months) (Luna, 1996). Suitable nursery and plantation techniques, management systems of the species are pre-requisite to make a plantation program fruitful. Lately, interest in producing quality seedlings by application of upgraded and modern nursery techniques has augmented (Gera and Ginwal, 2002). In the case of region-specific biodiversity conservation and restoration plans, integrated information of the seed collection, storage, seed germination requirements, and seedlings growth performance of native tree species are crucial (Khurana and Singh, 2001; Smith et al., 2008), but most of the studies are concentrated on fast-growing species only. The selection of appropriate pre-sowing treatment is vital for quick and maximum seed germination (Thapa and Gautam, 2006). Hard coated seeds need more time to germinate and thus, direct sowing is not effective (Anon., 1972). Proper pre-sowing treatments of seeds can stimulate germination time and germination process (Azad et al., 2006; Azad et al., 2011; Azad et al., 2012). The effect of pre-sowing treatments on seed germination of a few tropical forest tree species have been informed by several authors (Khan et al., 2001; Haider et al., 2014; Nandi et al., 2020 and Dey et al., 2020). Therefore, an endeavour has been made to study the effect of pre-sowing treatments on seed germination to identify appropriate pre-sowing treatment for Terminalia citrina. 2. Materials and Methods 2.1 Study site The study was carried out in the nursery of the Institute of Forestry and Environmental Sciences, University of Chittagong, Chattogram (lies between 91°50´E longitude and 22°30´N latitude) (Hossain et al., 2005) (Figure 01). The climate is tropical monsoon with an average monthly highest temperature of 29.75° C and a monthly lowest of 21.24° C. The maximum temperature usually occurs in May at 32.60° C and the minimum in January at 14.10° C (Peel et al., 2007). 38 Dey et al. /Journal of Tropical Forestry and Environment Vol. 11 No. 02 (2021) 37-47 Figure 01. Map showing the location of University of Chittagong in Bangladesh 2.2 Seed collection T. citrina fruits were collected from Kalurghat Forest Depot Area, Chattogram, Bangladesh during February 2019. Mature seeds were collected from selected plus trees. Seeds were extracted manually from mature fruits by depulping method. Then dried in the open sun for three days. Randomly selected seeds and fruits information like length, width and weight was recorded. Only healthy seeds were used for the experiment. 2.3 Experimental design The soil used for filling polybags were collected from the forest floor, dried and sieved well (<3 mm) and mixed with decomposed cow dung in a ratio of 3:1. 15×10 cm size polybags were used for the experiment. The media used in the propagator house were fine Sylhet sand. Forest topsoil was used in the open nursery bed. The study was made up of 6 treatments (including control) with 3 replications (15 seed per replication) in a Randomized Complete Block Design. Forty-five (45) healthy seeds were chosen randomly for each treatment. Daily germination progress was recorded as soon as the seeds start germination. Seedlings raised in open nursery bed and propagator house were transferred to polybag after one month of the last germination of seeds. The pricked-out seedlings were kept in shade for 2 weeks and then transferred to sunlight. Proper care and maintenance were done regularly. At the end of two and three months of seed germination, three vigor seedlings from each replication were selected for measuring shoot height, collar diameter and leaf number of the seedlings. The pre-sowing treatments are as: T0-Seeds without any treatment (Control) T1-Seeds soaking in normal water for 24 hours and sown in polybags (24º C) T2-Seeds soaking in normal water for 48 hours and sown in polybags (24º C) 39 T3-Fruits sown in seedbed T4-Seeds soaking in hot water for 1 minute and sown in propagator house (80º C) T5-Seeds sown in propagator house Figure 02. Fresh fruits of Terminalia citrina Figure 03. Dry fruits of T. citrina Figure 04. A seedling of T. citrina Figure 05. T. citrina seedlings raised in polybag 2.4 Data collection and analysis 2.4.1 Germination percentage The number of seeds out of 100 seeds from the starting of germination to the termination of germination (Kumar, 1999). Germination % (GP)= No of seed germinated No. of seed sown ×100 2.4.2 Cumulative germination % (CGP) It assessed at the end of seed germination by summed up daily germination (Hasnat et al., 2019). CGP= Cumulative number of seeds germinated Number of seeds sown ×100 2.4.3 Germination energy (GE) It is measured by computing the daily germination percentage of its peak time (Dwivedi, 1993). .4.4 Germination index (GI) According to AOSA (1983), GI was calculated using this formula. GI = No.of germinated seeds Days of first count +…+ No.of germinated seeds Days of first count (1) (2) (3) 40 Dey et al. /Journal of Tropical Forestry and Environment Vol. 11 No. 02 (2021) 37-47 2.4.5 Mean germination time (MGT) It calculates the rate and the time-spread of germination (Bewley et al., 2013; Soltani et al., 2015) and it should determine the time to half of the germination. The formula; MGT= 𝛴𝐷𝑛/𝛴𝑛, (4) where, D=the number of days counted from the starting of germination, n=the number of seeds that were germinated on day D (Ellis and Roberts, 1981; Afzal et al., 2005). 2.4.6 Germination Uniformity (GU) It was calculated by using the formula. GU= Σn (Σ(Fn-t)^2×n) where, t is the time in days, beginning from day 0, the day of germination, and n is the number of seeds germinated at t and F are alike to MGT (Abdolahi et al., 2012). 2.4.7 Germination value (GV) It was calculated by multiplication of the peak value of germination and mean daily germination (Hasnat et al., 2019). GV=Peak value of germination×mean daily germination 2.4.8 Germination capacity It is the percentage of seeds germinated in an experiment from the starting to end. It was classified as follows: a) 90-100%-very good, b) 70-90%-good, c) 50-70%-average, d) 30-50%-poor, e) 20-30%-very poor, and f) less than 10%-extremely poor (Kumar, 1999). 2.5 Statistical analysis All the recorded data were analyzed statistically by using computer package software SPSS ver. 23. Duncan’s Multiple Range Test (DMRT) was employed to define the statistical significance and it was shown by different letters in different tables. 3. Results 3.1 Morphological features of seeds The average length and width of fruits were found 2.412±0.051 cm and 1.054±0.013 cm respectively. Around 714 fruits were found per kg. The average length and width of seeds were 1.732±0.089 cm and 0.784±0.02 cm respectively. Around 2,173 seeds were found per kg (Table 01). Table 01. Seed length, width and number of seeds per kg of T. citrina Length (cm) Width (cm) Weight/seed (g) Number/kg Fruit 2.412±0.051 1.054±0.013 1.4±0.045 714 Seed 1.732±0.089 0.784±0.02 0.46±0.02 2,173 The results indicated that three tree species had variable effects on the soil composition and it varied by the depth of the soil layer (Table 01). The data were expressed as the mean for soil depth, sampling site, and type of species. 3.2 Germination performance The germination behaviour of T. citrina seeds was affected by different pre-sowing treatments in this study. Seed germination starts first in T5 and T4 (42 th day) after the seeds was sown and T3 required maximum time (47th day) to initiate germination. Maximum germination percentage (95.83%) was recorded in T5 (seeds sown in propagator house) followed by 75% in T4 (seeds soaking in hot water for 1 minute and sown in propagator house), 58.3% in T2 (seeds soaking in normal water for 48 hours and sown in polybags), and 33.3% in T0 (control). Germination percentage was lowest (16.7%) in T3 and significantly (p<0.05) different from other treatments. The minimum germination period (43.3 days) was found in T4, T5 respectively and maximum (5) (6) 41 germination period (54.3 days) was recorded in T0 (Table 02). Table 02. Germination response of T. citrina seeds in different pre-sowing treatments Treatments Germination start after (days) Germination end after (days) Germination period (days) Germination (%) Germination capacity T0 43 59 54.33 a* 33.33 c Poor T1 44 72 52.00 a 20.83 c Very poor T2 44 71 50.00 ab 58.33 b Average T3 47 56 52.23 a 16.67 c Extremely poor T4 42 57 43.33 b 75.00 b Average T5 42 59 43.33 b 95.83 a Very good *Means followed by the same letter(s) in the same column do not vary significantly at p<0.05, according to Duncan’s Multiple Range Test (DMRT). The maximum germination index (0.5569) was recorded in T5 and significantly (p<0.05) different from other treatments. Highest germination energy (37.5%) was found in T5 and lowest (16.7%) in T1 and T3. The germination uniformity revealed no significant difference among the treatments. Maximum germination value (1.0506) was recorded in T5 which is significantly (p<0.05) different from other treatments and minimum (0.0387) in T3. Mean germination time was maximum (56.67) in T1, followed by T2 (55.43) and lowest in T5 but MGT showed no significant difference among the treatments (Table 03). Table 03. Germination response of T. citrina seeds in different pre-sowing treatments Treatments Germination Energy (%) Germination Index (GI) Mean Germination Time (MGT) Germination Uniformity (GU) Germination value T0 20.83 ab* 0.0514 b 52.89 a 0.0007 a 0.1299 c T1 16.67 b 0.02999 b 56.67 a 0.0007 a 0.0477 c T2 25.00 ab 0.0889 ab 55.43 a 0.0012 a 0.3428 c T3 16.67 b 0.0259 b 51.67 a 0.0013 a 0.0387 c T4 29.17 ab 0.1302 ab 46.78 a 0.0013 a 0.7080 b T5 37.50 a 0.5569 a 46.73 a 0.0011 a 1.0506 a *Means followed by the same letter(s) in the same column do not vary significantly at P<0.05, according to Duncan’s Multiple Range Test (DMRT). 3.3 Mean cumulative germination percentage To obtain cumulative germination percentage for each treatment, daily germination percentages were summed. The cumulative germination of T5 treatment starts after 42 days of seed sown and rose rapidly and continued germination up to 96 % within 60 days. In T0 treatment, germination starts at 43rd day and reached 33.3% gradually. T3 showed lowest cumulative germination percentage (16.7 %) (Figure 06). 42 Dey et al. /Journal of Tropical Forestry and Environment Vol. 11 No. 02 (2021) 37-47 Figure 06. Cumulative germination percentage of T. citrina seedlings in different pre-sowing treatments 3.4 Growth performance of the seedlings Different treatments affect the morphological growth of T. citrina seedlings differently. After 3 months of seed germination, the highest mean shoot height (46.6 cm) was recorded in T2 (seeds soaking in normal water for 48 hours and sown in polybags) and the lowest (30.23 cm) was observed in T4 (seeds soaking in hot water for 1 minute and sown in propagator house). T0 treatment revealed 42.30 cm shoot height (Figure 07). Figure 07. Growth performance of T. citrina seedlings in response to different pre-sowing treatments Collar diameter and leaf number were recorded at 3-and 4-months old seedlings. The highest collar diameter (6.02 mm) attained in T2 treatment (seeds soaking in normal water for 48 hours and sown in polybags) and lowest (4.23 mm) in T4 treatment (seeds soaking in hot water for 1 minute and sown in propagator house). Maximum number of leaf (12.6) produced in T2 and minimum (5.8) in T4 treatment (Table 4). 0.00 20.00 40.00 60.00 80.00 100.00 120.00 4 2 4 4 4 6 4 8 5 0 5 2 5 4 5 6 5 8 6 0 6 2 6 4 6 6 6 8 7 0 7 2 7 4 7 6 7 8 8 0 C u m u la ti v e g e rm in a ti o n % Days after seed sown T0 T1 T2 T3 T4 T5 26 23.17 35.7 25.74 20.34 21.56 42.3 36.44 46.6 39.45 30.23 31.45 0 10 20 30 40 50 60 T0 T1 T2 T3 T4 T5 sh o o t h e ig h t (c m ) Treatments 2 month 3 month 43 Table 04. Mean collar diameter and leaf number of T. citrina seeds in different pre-sowing treatments Treatments Collar diameter (mm) Leaf number 3 months 4 months 3 months 4 months T0 4.92±0.20 5.81±0.36 9.2±0.66 11.6±0.81 T1 3.9±0.17 5.01±0.09 6.4±0.24 9.8±0.80 T2 5.26±0.48 6.02±0.28 10.4±1.17 12.6±1.12 T3 3.88±0.15 4.74±0.20 7.6±0.51 9±0.71 T4 3.02±0.14 4.23±0.17 4.8±0.37 5.8±0.66 T5 3.32±0.06 4.58±0.19 6.4±0.51 7.8±0.97 4. Discussion The science of seed biology encompasses the development and physiology of seeds until they finally germinate or fail to do so (Schmidt, 2000). Germination and seedling establishment are critical stages that affect both quality and quantity of crop yields (Subedi and Ma, 2005). The present findings of the study on Terminalia citrina found that seeds sown in propagator house provide the highest germination percentage (95.83%). Seeds soaking in normal water for 48 hours was 58.3% and in control 33.3% germination respectively. Highest germination energy (37.5%), germination value (1.0506), germination index (0.5569), and lowest mean germination time (46.73) observed in propagator house. The minimum germination period (43.3 days) was found in propagator house and maximum (54.3 days) recorded in control treatment. This study supports the findings of Acacia spp. where sand is a suitable medium for seed germination (ISTA, 1993). Sand as a germination substratum is preferred for large seed-producing tree species (Magini, 1962). Lithocarpus elegans showed the highest germination percentage in propagator house (Nandi et al., 2019). Maximum shoot height (46.6 cm), collar diameter (6.02 mm), and leaf number (12.6) recorded in T2 (seeds soaking in normal water for 48 hours and sown in polybags) treatment and T4 (seeds soaking in hot water for 1 minute and sown in propagator house) showed the lowest performance. Dey and Hossain (2019) reported that Suregada multiflora seedlings raised in propagator house showed the highest germination and survival rate, but the growth rate was lowest as sandy media failed to provide sufficient nutrients for growing plants. According to Hossain et al., (2005) T. chebula fruits de-pulping at two ends and soaking in cold water for 48 hours treatments revealed the highest germination (66.70%) and growth performance. Whole fruits of T. chebula soaking in cold water for 48 hours with successive treatments by 10% dilute H2SO4 for 20 minutes revealed 70% germination (Rashid et al., 1990). Ara et al. (1997) showed that clean seeds revealed maximum germination (50%) and initial growth. Nainar et al. (1999) applied different pre-sowing treatments in T. chebula seeds and the highest germination percentage (60%) recorded in mechanical scarification treatment. Hasnat et al. (2019) revealed soaking in water at room temperature for 48 hours is the best treatment for Castanopsis indica species. According to Haider et al. (2014) Acacia catechu obtained the highest germination percentage (80-81%) soaking in cold water for 24 hours. So, from the study for Terminalia citrina species, sandy media is suitable to get maximum germination but not vigor seedlings production. For a successful plantation program, seedling's morphological features such as collar diameter, shoot height, leaf and node number, etc. should be considered. Hence, seeds soaking in normal water for 48 hours and sown in polybags is suggested for vigour seedlings production of T. citrina species. 5. Conclusion Seed’s pre-sowing treatments significantly affect the germination of Terminalia citrina. Seeds sown in the propagator house showed maximum germination percentages but lowest growth performance. In contrast, seeds treated with normal water for 48 hours and sown in polybags produced vigour and quality seedlings at the initial stage. The result of the present study recommends that nursery 44 Dey et al. /Journal of Tropical Forestry and Environment Vol. 11 No. 02 (2021) 37-47 owners or other seedling producer organizations treat T. citrina seeds with water for 48 hours at room temperature and sown in polybags in large-scale plantation programs. Acknowledgment The authors are highly grateful to the NATP Phase 2 Project ID#074 IFESCU Component supported by the Natural Resources Division of Bangladesh Agricultural Research Council (BARC) for providing financial support and necessary suggestions under project titled "Exploration, Identification, Characterization, Multiplication and Ex-situ Conservation of Endangered Forest Genetic Resources including Medicinal Plants of Bangladesh”. The authors would like to thanks all staff of “Seed Research Laboratory” and nursery of the Institute of Forestry and Environmental Sciences, University of Chittagong. References Abdolahi M., Andelibi B., Zangani E., Shekari, F. and Jamaatie-Somarin, S., 2012. Effect of accelerated aging and priming on seed germination of Rapeseed (Brassica napus L.) cultivars. International Research Journal of Applied and Basic Sciences 3:499-508. Afzal I., Basra S.M.A., Iqbal A., 2005. The effects of seed soaking with plant growth regulators on seedling vigour of wheat under salinity stress. Journal of Stress Physiology and Biochemistry 1:6-14. Anonymous, 1972. The wealth of India. 9:225-227. AOSA, 1983. Seed vigour testing handbook. Contribution No. 32 to the handbook on seed testing. Ara R., Merry S.R., Siddiqi N.A., 1997. Cultivation and uses of twelve medicinal plants of Bangladesh. Bulletin 7, Minor Forest Products Series, Bangladesh Forest Research Institute, Chittagong. 27-31. Azad M.S., Islam M.W., Matin M.A., Bari M.A., 2006. Effect of pre-sowing treatment on seed germination of Albizia lebbeck (L.) Benth. South Asian Journal of Agriculture1 (2):32-34. Azad M.S., Manik M R., Hasan M.S., Matin M.A., 2011. Effect of different pre-sowing treatments on seed germination percentage and growth performance of Acacia auriculiformis. Journal of Forestry Research 22 (2):183-188. Azad M.S., Biswas R.K., Matin M.A., 2012. Seed germination of Albizia procera (Roxb.) Benth. in Bangladesh: a basis for seed source variation and pre-sowing treatment effect. Forestry Study in China 12 (2):124-130. Bewley J.D., Bradford K.J., Hilhorst H.W.M. and Nonogaki H., 2013. Seeds: physiology of development, germination and dormancy. 3rd Edition, Springer, New York. Das D.K., Alam M.K., 2001. Trees of Bangladesh. Bangladesh Forest Research Institute, Chittagong, 1-342. Dey S., Hossain M.K., 2019. Containers effects on seed germination and initial growth performance of Suregada multiflora (Ban-naringa) seedlings: a native lesser-known tree species in Bangladesh. Indian Forester 145(4):381-386. Dey S., Hossain M.K., Miah M.D., 2020. Germination and initial seedlings growth response of Ehretia serrata in different pre-sowing treatments. International Journal of Forestry, Ecology and Environment 2(1):78-85. Dwivedi A.P., 1993. A text book of silviculture. International Book Distributors. 9/3 Rajpur Road, Dehradun-248001, India. 1-505. Ellis R.H., Roberts E.H., 1981. The quantification of aging and survival in orthodox seeds. Seed Science and Technology 9:373-409. Gera M., Ginwal, H.S., 2002. Preliminary observations on field trial of root trainer raised seedlings, Indian Forester 128 (1): 19-26. Ghani A., 2000. Vheshaja oshud (herbal medicine), Bangla Academy, Dhaka, Bangladesh. 279. Ghani A., 2003. Medicinal plants of Bangladesh. Asiatic Society of Bangladesh, Dhaka. 603. 45 Haider M.R., Alam M.S., Hossain, M.A., 2014. Effect of pre-sowing treatment on seed germination and seedlings growth attributes of Acacia catechu Willd. in nursery and field conditions. International Journal of Latest Research in Science and Technology 3(4):214-219. Hasnat G.N.T., Hossain M.K., Alam, M.S., Bhuiyan, M.K., Hossain M.A., 2019. Germination and initial seedling growth performance of Vitex peduncularis Wall. ex Schauer - a threatened native tree species of Bangladesh. Journal of Bioscience and Agriculture Research 20(2):1700- 1708. Hasnat G.N.T., Hossain M.A., Hossain M.K., Uddin, M.M., 2019. Effect of pre-Sowing treatments on germination and initial seedling growth of Castanopsis Indica- an endangered tree species in Bangladesh. Journal of Forest and Environmental Science 35(4):223-231. Hossain M.A., Arefin M.K., Khan B.M., Rahman, M.A., 2005. Effects of seed treatments on germination and seedling growth attributes of Horitaki (Terminalia chebula Retz.) in the nursery. Research Journal of Agriculture and Biological Sciences 1(2):135-141. International Seed Testing Association (ISTA), 1993. International rules for seed testing, Seed Science and Technology 21:1-288. Islam S.A., Miah M.A.Q., Alam M.M., Rasul M.G., 2016. Initial growth performance of ten woody medicinal tree species in eastern coastal belt of Bangladesh. Journal of Bioscience and Agriculture Research 11(1):930-935. Kanjilal U.N., Kanjilal P.C., Das A., 1984. Flora of Assam. Vol. I-VI. Dehra Dun, India. Khan B.M., Koirala B., Hossian M.K., 2001. Effect of different pre-sowing treatments on germination and seedling growth attributes in Ghora Neem (Melia azedarach L.). Malaysian Forester 64 (1): 4-20. Khurana E. and Singh J., 2001. Ecology of seed and seedling growth for conservation and restoration of tropical dry forest: a review. Environmental Conservation 28:39-52. Kumar V., 1999. Nursery and plantation practices in forestry. Scientific Publishers, 5A, New Pali Road, P.O. Box 91, Jodhpur-342001. 65-159. Lev E., Amar, Z., 2000. Ethnopharmacological survey of traditional drugs sold in Israel at the end of the 20th century. Journal of Ethnopharmacology 72(1-2):191-205. Luna R.K., 1996. Plantation trees. International Book Distributors, Dehra Dun. 975. Magini E., 1962. Forest seed handling, equipment and procedures. II. Seed treatments, storage, testing and transport. Unasylva 16(1):20-35. Nainar P., Sundharaiya K., Ponnuswamy, V., 1999. Germination studies in kadukkai (Terminalia chebula). South Indian Horticulture 47(1-6):373-374. Nandi R., Dey S., Hossain M.K., 2020. Conservation of a native threatened tree species Quercus gomeziana A. Camus in Bangladesh. Journal of Forest and Environmental Science 36(1):1-6. Nandi R., Dey S., Hossain M.K., 2019. Germination and seedling growth response on Lithocarpus elegans (Fagaceae) seeds to pre-sowing treatments and fertilizer application. Asian Journal of Research in Agriculture and Forestry 4(4):1-7. Peel M.C., Finlayson B.L., McMahon, T.A., 2007. Updated world map of the Köppen-Geiger climate classification. Hydrology and Earth System Sciences Discussions 4(2):439-473. Penso G., 1980. The role of WHO in the selection and characterization of medicinal plants (vegetable drugs). Journal of Ethnopharmacology 2(2):183-188. Rashid M.H., Mohiuddin M., Ara R., Alam, M.J., 1990. Medicinal plant and its cultivation. Bulletin 4, Minor Forest Products Series, Bangladesh Forest Research Institute, Chittagong. 17. (in Bangla). Schmidt L., 2000. Guide to handling of tropical and subtropical forest seeds, Danida forest seed center, Humleback, Denmark. 1-510. Smith N., Zahid, D.M., Ashwath, N., Midmore, D.J., 2008. Seed ecology and successional status of 27 tropical rainforest cabinet timber species from Queensland, Forest Ecology Management 256 (5):1031-1038. 46 Dey et al. /Journal of Tropical Forestry and Environment Vol. 11 No. 02 (2021) 37-47 Soe K., Ngwe, T.M., 2004. Medicinal plants of Myanmar, Combretaceae, Forest Resource Environment Development and Conservation Association (FREDA). Series-1. Soltani E., Ghaderi-Far, F., Baskin, C.C., Baskin, J.M., 2015. Problems with using mean germination time to calculate rate of seed germination. Australian Journal of Botany 63: 631-635. Subedi K.D., Ma B.L., 2005. Seed priming does not improve corn yield in a humid temperate environment. Agronomy Journal 97:211-218. Thapa H.B. and Gautam S.K., 2006. Augmentation of germination in Sapindus mukorossi due to acid scarification in Jhanjhatpur nursery, Banko Janakari 16(1):14-20. Yusuf M., Begum J., Hoque M.N., Uddin, C.J., 2009. Medicinal plants of Bangladesh. Bangladesh council of scientific and industrial research laboratories, Chittagong. 47