The influence of various pre-sowing treatments on germination of akle (Albizia acle (Blanco) Merr.) seeds

A germination experiment of Vachellia karroo seeds was conducted at the Botswana University of Agriculture and Natural Resources, Department of Crop and Soil Sciences laboratory, from September to October 2018. Seeds were collected along the Segoditshane River in Gaborone to investigate the effect of different pre-sowing treatment methods on their germination. The experiment was laid out in a completely randomized design (CRD) with five treatments (control, mechanical scarification, boiling water, hot water and concentrated sulphuric acid (98.8%). Boiling water (30, 60, 180 and 300 seconds) and concentrated sulphuric acid (15, 30, 45 and 60 minutes) had four levels of exposure time. The highest significant (p < 0.01) cumulative germination percentages were recorded in seeds subjected to sulphuric acid for 45 and 60 minutes, mechanical scarification (shortest germination mean time of 2.0 - 2.3) and boiling water at 30 and 60 seconds (moderate germination mean time of 5 - 5.9) whereas, the control treatment had the least cumulative germination percentage of 2%. As expected, the same trend was revealed for germination index. The seeds possess seed coat imposed dormancy, which requires sowing treatments. The best treatments for releasing dormancy in V. karroo were sulphuric acid and mechanical scarification and because of the risks associated with the use of sulphuric acid, the researchers recommend mechanical scarification as the suitable treatment method in tree nurseries. Keywords: Seed dormancy, Germination mean time, Germination index, Pre-sowing treatment, Germination percentage, Germination rate, Tree nursery.

Burkea africana and Erythrophleum africanum are characterized by seed coat-imposed dormancy that prevents water entry and gaseous exchange, which are essential for the germination process. The objective of this study was to determine the best possible pre-sowing treatment method that maximizes seed germination of the two species. Seeds of both species were subjected to four experiments, containing 10 levels of presowing treatments: The control, mechanical scarification, soaking in concentrated sulphuric acid (for 15, 30, 45 and 60 min), immersion in boiling water (for 1, 3 and 5 min), and soaking in boiling water (and cooling down for 24 h). The germination data were subjected to ANOVA followed by Tukey&rsquo;s HSD Test to separate significantly different treatment means. The most promising results showed that seeds treated with mechanical, sulphuric acid and boiling water scarification had significantly higher mean percent germination than the controls for B. africana; whereas for E. africanum, mechanical scarification, exposure to sulphuric acid, boiling water (1 min) and immersion in boiling water (and cooling down for 24 h) had higher percent germination than the controls. &nbsp; Key words: Burkea africana, Erythrophleum africanum, germination percentage, pre-sowing treatment, seed dormancy. &nbsp

This study was conducted on a wild carob genotype grown in Al-Jabal Al-Akhdar area (Balagrae, Al-Baida, Libya). Seeds belonging to three individual trees chosen at random were collected. Seven different pre-sowing treatments (soaking in distilled water, boiling water 100C, soaking in sulphuric acid, mechanical scarification, mechanical scarification & soaking in distilled water, mechanical scarification & soaking in sulphuric acid and untreated seeds) were applied and examined for their effectiveness to stimulate carob seed germination. The results showed that mechanical scarification & soaking in distilled water treatment was the most effective method in increasing the germination percentage by (94.33%) compared to untreated seeds (5.99%). Mechanical scarification & soaking in distilled water treatment significantly decreased the mean germination time value (MGT) by (2.83 days). An MGT value was significantly higher in control treatment (23.22 days).

The effect of seed presowing treatment on Guibortia coleosperma and Amblygonocarpus andongensis was investigated. Seeds of both species were subjected to four experiments, containing 10 levels of presowing treatments: mechanical scarification, soaking in concentrated sulphuric acid (for 15, 30, 45 and 60 min), immersion in boiling water (for 1, 3 and 5 min), and soaking in boiling water (and cooling down for 24 h) and the control. The germination data were subjected to ANOVA followed by Tukey&rsquo;s HSD test to separate significantly different treatment means. The highest germination in G. coleosperma was recorded: mechanical scarified seeds, those soaked in sulphuric acid (15, 30, 45 and 60 min), hot water (and cooling down for 24 h) and the control seeds. For A. andongensis, seeds treated with mechanical scarification, exposure to sulphuric acid (15, 30, 45 and 60 min) and boiling water (1 min) had higher percent germination than the controls. Key words: Germination mean time, germination percentage, pre-treatment, scarification.

Seeds of the legume species are characterized by physical hard seed coat dormancy. Several pre-sowing treatments were tested of these species to enhancing seed germination. This study was carried out in the Malta Forest Nursery to increasing the germination percentage of (Robinia pseudoacacia) and (Ceratonia siliqua) seeds. The experiment was laid out in randomized complete design with four replications. Both species, seeds were soaked in hot water at (80 Cᵒ) for 30, 60 and 90 min, and mechanical scarification; the second trait seeds treated with factorial experiment which were seeds of both two species soaked in sulfuric acid for 30, 60 and 90 min, and then immersed in tap water for 24, 48 and 72h. The results showed that the seeds of Robinia pseudoacacia species treated with hot water for 60 min were increased germination percentage (63.75%), and the same result obtained of Ceratonia siliqua seeds treated with hot water for 60 min (61%). In the factorial experiment, the seeds of Robinia pseudoacacia species were treated with Sulfuric acid scarification at 90 min, then immersed with tap water for 24h were the best result of germination percentage (42.5%). In Ceratonia siliqu seeds were treated with sulfuric acid at 60 min and soaking with tap water for 24h increased the seed germination percentage (65%).

Malvella sherardiana (L.) Jaub & Spach (Malvaceae) is a perennial herbaceous plant listed as Vulnerable in the Red List of threatened plant species for Spain. The germination characteristics under controlled conditions of light and temperature of M. sherardiana seeds were studied. Mechanical scarification, cold stratification, liquid nitrogen, freezing, hot water, dry heat, sulphuric acid, soaking in distilled water and soaking in gibberellic acid were used as pre-sowing treatments applied for enhancing germination. The untreated seeds showed a high dormancy at all temperature regimens tested and sulphuric acid scarification drastically improved final germination percentage and germination rate. Germination of seeds soaked in concentrated sulphuric acid arithmetically increased as soaking time increased (from 5 min to 3 h), but seeds soaked in acid for more than 4 h failed to germinate. The application of a gibberellic acid solution (1000 mg l−1) increased the germination percentages for all tested soaking times in sulphuric acid. However, it was only significantly effective for the soaking time of 3 h. The other pre-sowing treatments resulted in some germination, but none resulted in greater germination than sulphuric acid. As embryos are fully developed and the seed coat is water permeable, we conclude that M. sherardiana seeds present physiological dormancy. The main conclusion of the study is that dormancy of M. sherardiana seeds is attributed to mechanical restriction of the embryo caused by the tough seed coat. This is the first report on germination requirements of the Malvella genus.

Bowdichia virgilioides Kunth is a tree species of the family Fabaceae. The species is well adapted to dry and poor lands, being indicated for reforesting activities, being widely used on wood structures for civil construction, and also as a species with high medicinal potential. This study aimed to evaluate methods for overcoming dormancy of B. virgilioides seeds through different types of scarification and water submersion. To do so, four treatments and control were used: T1 - seeds with no treatment, T2 – mechanical scarification with # 120 sandpaper; T3 – chemical scarification with concentrated sulfuric acid (98%) for 10 minutes; T4 – submersion in hot water (80°C) for 5 minutes; T5 – submersion in water at room temperature (approximately 30°C) for 48h. The experiment was conducted in a Completely Randomized Design (CRD) and the analyzed variables were: germination percentage (%G), average germination speed (VMG) and average germination time (TMG). Data was analyzed using the “GerminaQuant” software and results compared using Tukey’s test at 5% probability. Germination percentage was higher for treatments 3 and 4, with the decreasing sequence: T3 – 82%, T4 – 64%, T2 – 9%, T1 – 4% and T5 – 2%. Regarding average germination time, only T2 and T1 were statistically different from each other, T2 had the shortest time (10.33) and T1 the longest time (30.33). For VMG, T2 and T3 presented the best results, being statistically different from the other treatments, with 0.093 and 0.085 as respective results of T2 and T3. It could be concluded that treatments with immersion in sulfuric acid for 10 minutes (T3) and immersion in water at temperature of 80°C for five minutes (T4) are more efficient for improving germination percentage of B.virgilioides seeds, being the recommended methods for overcoming seed dormancy.

Cassia abbreviata and Senegalia nigrescens are indigenous trees found in North and Central regions of Botswana. However, inadequate knowledge of their silviculture and decline in population due to deforestation, expanding settlements, infrastructure and agriculture are major threats to most indigenous tree species in Botswana. Like many indigenous tree species, Cassia abbreviata and Senegalia nigrescens are slow-growing and are threatened by overexploitation for numerous uses. Because of the increased demand for medicinal uses, medicinal species such Cassia abbreviata are rapidly disappearing in many habitats and threatened to extinction. This study assessed the response of pre-sowing treatment methods on quiescency and germination of seeds of Cassia abbreviata and Senegalia nigrescens tree species found in semiarid Savanna Ecozone of Botswana. Pre-sowing treatment included immersion in 98% undiluted sulfuric acid (H2SO4) for 15, 30, 45 and 60 minutes, submergence in boiling water for one, two, three minutes and submerged in warm water for 24 hours, mechanical scarification of the seed coat and control. ANOVA showed that there is a highly significant difference (P &lt; 0.0001) among the treatments of C. abbreviata in seed germination and no significant difference among the treatments of S. nigrescens. The highest germination percentage of C. abbreviata seeds was 81%, which was found from seeds immersed in H2SO4 for 30 minutes, while for S. nigrescens seeds, the highest germination percentage was 99%, which was found from seeds treated with mechanical scarification and those immersed in H2SO4 for 15 and 45 minutes. The objective of this study is to determine the effect of pretreatment methods on germination of C. abbreviata and S. nigrescens seeds. Based on these results, we recommend sulphuric acid and mechanical scarification as suitable seed pre-sowing treatments for enhancing the germination of C. abbreviata and S. nigrescens, respectively.

Dry forests tree species such as Tamarindus indica and Diospyros mespiliformis are known for their diverse socioeconomic and ecological importance. Tamarindus indica and Diospyros mespiliformis play a critical role in maintaining ecosystem stability and supporting biodiversity, while contributing significantly to local livelihoods through their nutritional and income generation. Despite their actual and potential benefits, conservation of the species has received little attention and the species are being threatened by overexploitation and degradation. This study characterizes fruit and examines the seed quality and determines appropriate pre-sowing treatment for enhanced germination. The seed quality examination was conducted based on the International Seed Test Association (ISTA) standard testing procedures. The germination experiment was laid out in a completely randomized design (CRD) with five pre-sowing treatments (control, cold water, hot water, concentrated sulphuric acid (98%), and nicking) with four replications. The results revealed that the average number of seeds in T. indica and D. mespiliformis fruits varies greatly, averaging 5.55 ± 2.46 and 3.72 ± 0.8 seeds per fruit, respectively. Both the T. indica and D. mespiliformis species have orthodox seeds, with a moisture content of 7.91 ± 0.02% and 6.22 ± 0.02%, respectively. There were 1262–1273 seeds obtained in a kilogram of T. indica with seed purity ranging from 98.39–98.61%. For D. mespiliformis, a kilogram of seed contains 3154–3167 seeds with a purity range of 92.1–92.9%. Thus, based on the result from one kilogram of pure seeds of T. indica and D. mespiliformis, there can be raised 1242-1255 and 2905-2942 seedlings, respectively. The germination percentage, germination index, mean germination time, and germination period of both study species showed significant differences across treatments (P< 0.05), with the exception of D. mespiliformis’ germination period. For T. indica, nicking was resulted in the best germination (100%), followed by sulphuric acid 97.5 ± 4.62%, whereas the lowest germination of 60.0 ± 7.55% was obtained under the control. For D. mespiliformis, sulphuric acid was resulted the highest germination 66.22 ± 4.78%, whereas nicking yielded the lowest germination 10 ± 2.31%. Both species exhibit a physical seed dormancy associated with their hard seed coats. Thus, appropriate pre-sowing treatment is essential to break their seed dormancy and enhance germination. The findings of this study provide valuable insights for improving the germination of the species in nurseries for conservation, propagation and domestication efforts of species and future commercialization initiatives through cultivation. This in turn contributes to maximizing the ecological and food security and local livelihood contributions of these wild edible fruit tree species.

This study examined the effect of seed source and pre-sowing treatment on germination of Canarium schweinfurthii [Engl] seeds. The seeds were sourced from Unubi in Anambra state (T1) and Jos in Plateau state (T2) in Nigeria. The experiment was conducted at the University of Benin and lasted for 14 weeks. It was laid out in a completely randomized design (CRD) pattern using 2x7 factorial combinations of 2 sources and 7 pre-sowing treatments.&#x0D; The pre-sowing treatments were complete removal of seed coat (CR), partial cracking (PC), burning under dry grass (BG), 70% H2S04 (7H), 80% H2S04 (8H), 3 days (72 hours) soaking in water (SW) and control (CT). Germination parameters investigated were days to germination, germination percentage, germination energy, germination period and germination value. Data collected were subjected to Analysis of variance (ANOVA) at 5% significance and significant means were separated using LSD. There was no significant difference in the mean days to germination (20.7 days in T1 and 21 days for T2) and mean germination percentages (31.14% in T1 and 31.71% for T2) of the sources. The treatments days to germination were significantly different with CR being the first to germinate (12 days) while 7H germinated last (41 days). There was significant difference in the mean germination period (31.71 days in T1 and 23.57 days for T2), germination energy (1.24 in T1 and 2.38 for T2) and germination values (0.3 in T1 and 0.54 for T2) in the investigated sources, while the mean germination percentages of the pre-sowing treatments irrespective of source were significantly different. Treatments BG had the best mean germination percentage followed by treatment SW and CT while 8H had the poorest.&#x0D; It is therefore recommended that treatment BG is the best followed by SW for increase in germination percentage. But where seedlings are needed in little quantity within a short time, treatments CR and PC are recommended. Acid treatment is unsuitable for the seeds of Canarium schweinfurthii.

The imposition of pre-sowing treatment has been playing a crucial role for enhancing the germination percentage of the forest species and its succeeding growth stages. On this contention, a preliminary study was conducted to understand the impact of different pre-sowing treatments on Aquilaria agallocha Lam. (Agarwood) and its early growth behaviour. In this present study, the seeds were subjected to six different pre-sowing treatments. Among the pre-sowing treatments, soaking in water at room temperature for 24 hrs (T3) has resulted the maximum germination percentage (55.25%) as compared to other counterparts. On an average, there was an increase of 49%, 47%, 38%, 40% and 49% of germination percentage, germination capacity, germination energy, peak value and mean daily germination respectively in T3 over control (T6). Similarly, the early seedling growth of the agarwood was also influenced by imposition of different pre-sowing treatments. And all the seedling growth parameters viz., shoot length (cm), root length (cm), seedling length (cm) and seedling vigour index were recorded maximum in T3 as compared to rest of the treatments.

Effects of pre-sowing treatments and seed sources on seed germination of Phytolacca acinosa Roxb.

Pre-sowing seed treatment techniques of stratification and scarification were used in order to find the most appropriate method to overcome dormancy of wild asparagus (Asparagus acutifolius L.) seeds. An indoor and an outdoor experiment were carried out at the Agricultural University of Athens. For the indoor experiment, the pre-sowing treatments of stratification (fresh and stratified seeds) and scarification (non-scarified, mechanical scarification and chemical scarification with sulfuric acid) were used as the main treatments, and three different temperatures (15, 20 and 25 °C) as sub-treatments. For the outdoor experiment, there were only the treatments of stratification and scarification. The stratification of asparagus seeds was found to have a positive effect on germination and vigor indices compared to non-stratified (fresh) seeds. The highest germination percentage, vigor index I and II were recorded with the stratified seeds that had been mechanically scarified in both indoor and outdoor conditions. The results indicate that just the scarification cannot improve germination of fresh collected seeds of wild asparagus. Stratification increased the germination percentage from 2.7-6.6% to 45.1-75.3%. The mechanical and the chemical scarification had a positive effect on the root length compared to the non-scarified seeds that have been stratified. These pre-sowing treatments can increase the germination percentage and produce vigorous seedlings that can be used to establish plantations of this potential new crop.

Dwarf fan palm (Chamaerops humilis L.) is an important Mediterranean species well known for many uses such as gardening, environmental restoration, and technological uses. Dwarf fan palm is usually propagated from seed, which takes up to 100 days to germinate. The germination pattern of dwarf palm seeds was studied during a 100-days length period in relation to different pre-sowing treatments (hot water, sulphuric acid, or mechanical scarification) in comparison to untreated control. A covariance analysis was performed to test the effect of time within seed-treatment treatment. All germination patterns were significantly fitted by a S-shaped (sigmoidal) distribution function with the general equation y=β+α/(1+exp(-(x-μ)/s)). Treatment with sulphuric acid significantly increased the final germination in comparison to untreated control. No differences were observed in % germination among the other seed treatments. Seed treatments increased by three- to seven-fold the maximum germination rate and reduced by 26% the mean germination time in comparison to untreated control. The reduction in mean germination time, and the increase in percentage germination and germination rate may have economical implication in the production of dwarf palm and its involvement in environmental restoration strategies, with no need to use dangerous or expensive acid pre-treatment in order to increase the propagation success.

The Sesbania virgata (Cav.) Pers., Mimosa caesalpiniifolia Benth. and Cassia grandis L.f. species belong to the Fabaceae family, are characterized by their seeds present a dormant state, which limits the germination. The aim of this study was to evaluate the efficiency of pre-germination treatments to overcome dormancy these species. Seeds were collected from matrix trees, located in Agreste of Alagoas and the research developed at the Federal University of Alagoas – Campus de Arapiraca. Overcoming of dormancy was studied in laboratory and greenhouse, where they were employed eight treatments with four replications of 25 seeds, in a completely randomized design: immersion in sulfuric acid (in three periods of immersion, depending on species), scarification with sandpaper, immersion in hot water at 80 °C (2.5 and 5 minutes), imbibition for 24 hours in distilled water and control (seeds without the application of any treatment). The evaluation of the results was made through of germination and emergence percentage; germination and emergence speed index and germination and emergence average time. The pre-germination treatments, mechanical scarification with sandpaper and chemical scarification with sulfuric acid in different immersion times were the most efficient to overcome the seeds dormancy of Sesbania virgata , Mimosa caesalpiniifolia and Cassia grandis Independent of the studied environments.