Soaking In Sulphuric Acid Research Articles

Germination of Senegalia mellifera seeds in response to presowing treatments

This study aimed to evaluate the size of Senegalia mellifera seeds and determine the most effective scarification techniques to improve germination. The experiment, conducted at Botswana University of Agriculture and Natural Resources, involved ten presowing treatments, including control, nicking, soaking in sulphuric acid for different durations, and boiling water for varying periods. A completely randomized design (CRD) was used for the experiment. Germination data was transformed using arcsine to meet normal distribution requirements and then analyzed using analysis of variance (ANOVA). The results showed that the presowing treatments had a statistically significant effect on germination (P<0.00001). Seeds treated with sulphuric acid, nicking, and those left untreated exhibited the highest germination rates, while seeds treated with boiling water showed the lowest germination percentages. These findings indicate that the seed coats of S. mellifera are permeable to water and air, and presowing treatments do not show any significant effect on the successful germination of S. mellifera seed.

Breaking seed dormancy in Searsia pentaphylla (Anacardiaceae)

Seeds (true seed plus endocarp) of Searsia pentaphylla, a species with significant medicinal, ecological and horticultural importance, have an extremely hard and water impermeable endocarp. Hence, effective dormancy-breaking techniques are crucial for enhancing its cultivation and ensuring successful establishment in both natural and managed environments. This study evaluated the effects of mechanical scarification, chemical scarification (sulphuric acid soaking for 30, 60, 90 and 120 minutes, hydrogen peroxide soaking for 10 minutes), hot water soaking for 10 minutes, and heat treatment for three minutes at 200°C on final germination percentage (FGP), mean germination time (MGT), time to 50% germination (T50), coefficient of velocity of germination (CVG) and mean daily germination (MDG). Compared to the control group (untreated seeds), the most effective treatment was 120 minutes of sulphuric acid soaking, achieving a FGP of 92%, a MGT of 7.28 days, a CVG of 13.7%, a T50 of 6.67 days and a MDG of 6.57%. Mechanical scarification yielded a FGP of 36.5%, with poorer MGT, CVG, T50 and MDG values. Other methods, including hydrogen peroxide and heat, were less effective. These results highlight the importance of aggressive scarification techniques to enhance germination in S. pentaphylla.

Improvement of Germination in Retama Sphaerocarpa and Ziziphus Lotus for the Rehabilitation of Degraded Rangelands in Algeria

Abstract The shrubs of Retama sphaerocarpa (Fabaceae) and Ziziphus lotus (Rhamnaceae) form populations in the Aurès region of Algeria that can provide a large supply of forage when dry season grazing shortages are prevalent. However, the percentage of natural regeneration of these species was estimated at 3%-7%. The final germination percentage (FGP) and total seedling length (TSL) were taken into consideration in this study to determine the impact of wet scarification on the germination of these two species. Pre-sowing treatments included immersion in concentrated sulphuric acid for 1, 2 and 3 hours; immersion in boiling water for 15 minutes, and soaking for 24 hours in water at 25°C (± 2°C). For each pretreatment, four replicates of 50 seeds and kernels were sown in plastic containers for a 21-day period. The principal component analysis of data showed that the best treatment was 3 hours of soaking in sulphuric acid, resulting in 94% of FGP and 22.2 cm of TSL for R. sphaerocarpa. This same pretreatment improved the germination of Z. lotus to 86% FGP and 25.6 cm TSL. In both species studied, a very insignificant percentage of FGP (2%) was observed in untreated seeds and kernels, as well as in pre-treatments with water. These results indicate that R. sphaerocarpa seeds and Z. lotus kernels exhibit a type of physical seed dormancy and require specific pretreatment to improve imbibition and germination. In conclusion, pretreatments significantly (p< 0.0001) affected FGP and TSL in both species. These findings should motivate plantation plans for R. sphaerocarpa and Z. lotus in both agriculture and forestry.

Effect of Seed Size and Different Pretreatment Methods on Germination of Albizia zygia (DC.) J. F. Macbr

Albizia zygia produces valuable timber which has received some level of prominence in the international market. However, the seeds are dormant, and the tree species remain undomesticated. This study was conducted to evaluate the effect of seed size and presowing on the germination of Albizia zygia in a nursery. Seeds were grouped into four categories in regard to their length, small (≤0.5 cm), medium (> 0.5 < 0.8 cm), large (≥0.8 cm), and mixture of small, medium, and large seeds. The seeds were subjected to five main seed pretreatment methods, namely, soaking in sulphuric acid (H2SO4) for 2 minutes, mechanical scarification, soaking in hot water for 5 minutes, soaking in cold water for 24 hours, and control where seeds were sown without any treatment. The results indicate that combination of mechanical scarification and large seeds produced the highest (100%) germination. Hot water treatment was effective in large seeds producing 69.0% germination. The increased germination for mechanically scarified seeds suggests that seed dormancy in Albizia zygia is mainly due to its hard seed coat. Therefore, it is recommended to farmers to adopt use of mechanical scarification and large seeds, since it is safe and effective.

English

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’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.

Effect of scarification treatments on seed germination of guava (Psidium guajava)

The present study was carried out to investigate the effect of pre-sowing and scarification treatments on seed germination and seedling growth of guava (Psidium guajava L.) in the laboratories of the Department of Seed Science and Technology, CCS HAU, Hisar during the year 2015. There were three scarification methods with different treatments under study, i.e. water soaking (for 24, 48 and 72 hr), hot water soaking (at 70, 80, 90 and 100ºC) and sulphuric acid soaking (at 10, 20, 30, 40 and 50% concentration). Duration for hot water soaking and sulphuric acid soaking was kept as quick dip (5 seconds), 1 min. and 3 min. The study revealed that pre soaking the seeds in hot water and sulphuric acid greatly increased germination, especially soaking of seeds in 20% sulphuric acid solution for 3 min., which showed up to 72% germination. Parameters like germination%, mean germination time, seedling length and seedling vigour were positively affected by all the scarification treatments. Seed viability decreased but the standard germination efficiently increased due to scarification treatments. Hot water soaking at 80ºC temperature for 1 min. improved germination and resulted in maximum seedling length (6.03 cm) in laboratory. Seeds treated with higher sulphuric acid concentrations or soaked in hot water at higher temperature showed poor germination as well as poor vigour. Seeds without any scarification treatment showed poor germination.

Morphological and physiological characterization of seed heteromorphism in Medicago denticulata Willd.

Under natural conditions, Medicago denticulata produces heteromorphic seeds differing in seed coat colour—cream and brownish black. The present study was conducted in order to determine morphological and physiological differences among heteromorphic seeds of M. denticulata in relation to dormancy and germination behaviour. Brownish black seeds with high moisture content were non-dormant and germinated to a high percentage. However, cream seeds with low moisture content were dormant and exhibited lesser germination without dormancy breaking treatments. Scanning electron microscope studies revealed papillose surface pattern in both seeds. However, brownish black seeds differed from cream seeds by having small cracks scattered all over the surface. Various dormancy breaking treatments viz., sandpaper scarification, soaking in sulphuric acid and hot water significantly increased the germination of cream seeds indicating seed coat imposed dormancy in these seeds. Accelerated ageing of brownish black seeds for 20 or more days resulted in complete inhibition of germination. Whereas, some cream seeds (~ 13%) aged for 20 days were still able to germinate. With accelerated ageing, both seeds recorded decrease in starch and total soluble proteins with concomitant increase in membrane leakage, total soluble sugars and free amino acids. Persistence studies under field conditions revealed that cream seeds present on soil surface or at a burial depth of 2 and 10 cm were able to germinate up to 12 months; but no germination was observed in brownish black seeds buried for 12 or more months. Results of accelerated ageing studies and field persistence suggest longer persistence for cream seeds as compared to brownish black seeds.

Seedling Growth Pattern of Guava (Psidium guajava L.) as Influenced by Different Seed Scarification Treatments

Plant growth studies involve seed germination studies and this depends on seed viability and dormancy aspects, besides essential require-ments and factors for the same. Of the various factors involved in seed germination, dormancy plays a significant role. In guava, seed dormancy is more of physical nature (due to hard seed coat) than being physiological. An experiment was conducted from March-November, 2015 at the experimental orchard of the Department of Horticulture, CCSHAU, Hisar to study effect of different scarification treatments on guava seed germination and their effect on subsequent seedling growth. Three scarification methods were used i.e. water soaking (for 24, 48 and 72 hrs), hot water soaking (at 70, 80, 90 and 100°C) and sulphuric acid soaking (at 10, 20, 30, 40 and 50% dilution). Duration for hot water soaking and sulphuric acid soaking was kept as quick dip (5 seconds), 1 minute and 3 minutes. All these treatments significantly decreased days to emergence of seedling over control. Among the various scarification methods and durations used, treatment of guava seeds with 20%sulphuric acid for 3 minutes was judged best with maximum germination per cent (51.7%), Quick dip of guava seeds in 30%sulphuric acid resulted in better seedling growth with a maximum seedling height (42 cm) while maximum fresh weight of shoot (22.6 g) and maximum dry weight of shoot (8.81 g) was recorded in seedlings which were subjected to scarification treatment with quick dip at 90°C.

Effects of surface treatments of recycled tyre crumb on cement-rubber bonding in concrete composite foam

The uptake of recycled tyre crumb (RTC) in concrete can result in a significant loss of strength because of weak adhesion between cement and rubber. Five RTC surface treatment methods (cement coating, silica fume coating, sodium hydroxide, potassium permanganate and sulphuric acid soaking) were used to mitigate strength loss in concrete composite foam with RTC. All five methods yielded strength improvements between 27% and 56%, with sulphuric acid and silica fume coating having the largest improvement. Silica fume coating, a treatment method used for the first time, improves strength because of the better adhesion between RTC and mortar. In addition, the formation of low Ca/Si gels was observed at the rubber-mortar interface based on SEM-EDS analysis. A reduced water contact angle on rubber showed that the three soaking methods were able to successfully reduce the hydrophobicity of RTC. Microscopic analysis of sulphuric acid treated RTC revealed etching of the surface and possible formation of polar zinc sulphate crystals. Silica fume coating provides an economically feasible solution with less safety and environmental risks associated compared to the chemical treatments.

INFLUENCE OF PRE GERMINATION TREATMENTS ON OVERCOMING SEED DORMANCY AND SEEDLING GROWTH OF BAOBAB (Adansonia digitata L.)

There is an urgent need to overcome seed dormancy especially in some multi-benefit tree like baobab, which can be successfully cultivated in Southern Egypt, in order to improve their regeneration. Therefore, this study was carried out to investigate the effects of some pre-germination treatments i.e., soaking in tap water, boiling water or sulphuric acid at 98.5% for either 30 or 60 min, mechanical scarification with sandpaper alone or combined with soaking in sulphuric acid 98.5% for either 30 or 60 min, on germination characters and seedling traits of Adansonia digitata L. Results revealed that all pre-germination treatments significantly increased all germination parameters, growth performance and some chemical traits compared to the untreated seeds, except for soaking seeds in tap water. The descending order of pre-sowing treatments was scratching baobab seeds then soaking in sulphuric acid 98.5% for 60 or 30 min ˃ soaking in sulphuric acid 98.5% for 60 or 30 min˃ mechanical scarification with sandpaper ˃ boiling water. In the same order was minimized number of days from sowing until the emergence of the plumule from 68 to 6 days and increasing germination (%) from 9 to 94% for untreated and soaking in tap water without significant differences in between and scratching seeds then soaking in sulphuric acid 98.5% for 60 min, respectively. There were increments in seedling height (from 4.27 to 57.58%) and in stem diameter (from 21.67 to 61.48%) for seeds soaked in tap water, and scratching seeds then soaking in sulphuric acid 98.5% for 60 min, respectively. Generally, all previous treatments except soaking in tap water led to breaking baobab seed dormancy. The best treatment was scratching seeds before soaking in sulphuric acid 98.5% for 30 mints.

Influence of pre-sowing seed treatments on the germination of moringa (Moringa oleifera Lam.)

Moringa (Moringa oleifera Lam.) is widely used by communities in South Africa and for human health and nutrition. Consequently, the demand for seedlings of moringa has increased tremendously. Although moringa can be propagated by cuttings, the use of seeds remains dominant among farming communities because it is easy and cheap. This study investigated the influence of five pre-sowing seed treatments (control, abrasion against sandpaper, soaking in sulphuric acid for 2 min, hot water for 10 min, cold water-for 24 h, and 10% gibberellic acid (GA3), a growth stimulator, for 24 h), on the germination of mature seeds of a local landrace of moringa. Twenty mature seeds of each treatment were germinated on moist filter paper in a petri dish at 27°C using a completely randomised design with five replicates. Germination (protrusion of radicle by 2 mm), the mean germination time (MGT), percentage germination (PG) and time to 50% germination percentage (T50) were calculated and exposed to analysis of variance (ANOVA) after transforming the PG using arcsine. The ANOVA showed significant (P gibberellic acid > hot water > cold water > acid > control. These results suggest that the establishment of Moringa oleifera seedlings can be enhanced by pre-treating the seeds. It was concluded that the potential exists for promoting the propagation and cultivation of Moringa oleifera trees through mass production of seedlings using the most efficient pre-sowing seed treatments.

Effects of Various Pre-Sowing Treatments on Seed Germination of Carob (Ceratonia Siliqua L.) From Al-Jabal Al-Akhdar Area (Balagrae, Al-Baida, Libya)

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).

Perspectives in restoration: storage and pretreatments of seeds for better germination of Sudanian savanna-woodland species

Insufficient knowledge of the germination ecology of local species is one of the main constraints to restoration of degraded rural lands. We tested seeds from fourteen Sudanian savanna species targeted for restoration for their response to two different pretreatments (conventional and prolonged acid pretreatments) and two different storage conditions (ambient room conditions and refrigerator at 4 °C). For 6 of the studied species, longer soaking in sulphuric acid significantly improved germination rates and also reduced the germination time of some species. Storage condition, in general did not affect germination rates except for two species where cool storage depressed germination. The practical implication is that, for the species tested, when mature seeds are collected for plantation in the upcoming rainy season, there is no need to invest in infrastructure and energy for storing in cold conditions. The study also revealed that in general when seeds are stored in ambient conditions from the time of collection up to seeding time, although germination rate does not increase, germination time is shortened and this could be of great interest in synchronizing germination in real field conditions.

Effect of Seed Size and Pretreatment Methods on Germination of Albizia lebbeck

Albizia lebbeck is a multipurpose tree species prioritised for conservation in Malawi. The different plant parts are used in traditional medicine to treat different diseases. However, the seeds are dormant, and the tree species remain undomesticated. A study was conducted to evaluate the effect of seed size and presowing on the germination of Albizia lebbeck in a nursery. Seeds were grouped into four categories in regard to their length, small (≤0.5 cm), medium ( cm), large (≥0.8 cm), and mixture of small, medium, and large seeds. The seeds were subjected to five main seed pretreatment methods, namely, soaking in sulphuric acid for 2 minutes, nicking, soaking in hot water for 5 minutes, soaking in cold water for 24 hours, and control where seeds were sown without any treatment. The results indicate that combination of nicking and large seeds produced the highest (100%) germination. Hot water treatment was effective in large seeds producing 67.5% germination. The increased germination for mechanically scarified seeds through nicking suggests that seed dormancy in Albizia lebbeck is mainly due to its hard seed coat. Therefore, it is recommended to farmers to adopt use of nicking and large seeds, since it is safe and effective.

Conditions and Stimulation for Germination in Glycyrrhiza uralensis Fisch Seeds

Evaluation of seed quality is the key to seed distributing and seeding of Glycyrrhiza uralensis Fisch, as an important species for pharmacy and soil conservation. Here, we study the effects of light and temperature on seed germination and mechanical and chemical scarification on breaking the seed coat. Seeds were collected in 2004, 2005, and 2006, placed in Petri dishes, and incubated at constant temperature 20, 25, and 30°C, and alternating temperature 15-25, 20-30, 15-30, and 20-35°C under either an 8 h photoperiod or total darkness for 28 consecutive days. Different methods were used to break the dormancy owing to hard seededness in this species such as chemical scarification by immersing in concentrated sulphuric acid for 5, 10, 15, 20, 25, 30, 45, and 60 min, in 0.2% KNO 3 solution to saturate the seedbed, and prechilling for 7 d at 7°C and mechanical scarification by cutting. The results showed that alternating temperature at 20-30°C with 8 h photoperiod and 16 h darkness was optimum for G. uralensis seed germinating in the laboratory. Hard seeds were broken by concentrated sulphuric acid soaking or mechanical scarification by cutting. Germination of seeds harvested in two different years was both promoted by immersing for 30-45 min in concentrated sulphuric acid. KNO 3 solution was ineffective for reducing hard seeds. During seed germinating, the first count was on the 7th day and the last count was on the 14th day.

Tratamentos para acelerar a germinação e reduzir a deterioração das sementes de Ormosia nitida Vog

O trabalho foi conduzido no Laboratório de Sementes do Centro de Ciências Agrárias da Universidade Federal do Espírito Santo, objetivando avaliar tratamentos para acelerar a germinação e reduzir a deterioração de sementes de Ormosia nitida. Foram conduzidos dois experimentos em delineamento inteiramente casualizado, com quatro repetições. No primeiro estudo, feito em papel substrato, os tratamentos foram sementes intactas, escarificação mecânica e escarificação química com H2SO4 durante 10 min. No segundo estudo feito em placas de Petri, os tratamentos utilizados foram sementes intactas (controle); escarificação mecânica; escarificação mecânica + pré-embebição por 24 horas; H2O2 no substrato; e escarificação química com H2SO4 durante 1, 5, 10,15, 20, 25 e 30 min. Foram avaliados o vigor, através do índice de velocidade de germinação, e a germinação, através da porcentagem de plântulas normais. A todos os tratamentos pré-germinativos foram apresentados respostas positivas na porcentagem e velocidade de germinação em relação ao controle. A escarificação mecânica e o H2O2 no substrato proporcionaram aumento significativo na velocidade e porcentagem de germinação das sementes, com redução da deterioração.