جستجوی مقالات مرتبط با کلیدواژه « sulfuric acid » در نشریات گروه « زراعت »

Althaea officinalis L. is one of the most important plants of the Malvaceae family which is used in traditional medicine and as a drug to treat the disorders of digestive and respiratory systems. The fresh seeds of Althaea do not have a good growth potential. This experiment was performed to evaluate the different methods of seed dormancy breaking on the improvement of A. officinalis L. seed germination.

An experiment was conducted in a completely randomized design with three replications at the agricultural laboratory of Payame Noor University Tehran, Shahriar Center in 2017. The experimental treatments included 10 treatments (control, seed coat removal, seed coat removal + gibberellic acid (500 and 1000 ppm), seed coat removal + potassium nitrate (0.1 and 0.2%), seed coat removal + sulfuric acid (30 and 60 minutes), sulfuric acid (30 and 60 minutes).

The results showed that the highest germination index with averages of 433.3 was observed in seed coat removal + 30- minutes of sulfuric acid treatment. The highest germination rate (44.7 seed/day) was observed in seed coat removal + 60-minute sulfuric acid treatment. The highest germination percentage (86.6%) was observed in seed coat removal+ 0.2% potassium nitrate treatment. Also, the highest mean germination time (20.2 day) was observed in both control and seeds coat removal treatments. The highest plumule and seedling length and fresh and dry weight were observed in seed coat removal + 30 and 60- minute sulfuric acid, and seed coat removal +0.2% potassium nitrate treatment, without significant difference. The highest radicle length was obtained in seed coat removal +30- minutes sulfuric acid treatment and seed coat removal + 0.2% potassium nitrate treatments.

Since all three sulfuric acid, potassium nitrate and gibberellic acid treatment along with seed coat removal treatment significantly affect the measured traits compared with control. It may be suggested that A. officinalis L. seed has a type of physical and physiological dormancy and seed dormancy breaking treatments (especially 30- minutes sulfuric acid) can be used to increase germination the fresh seeds of this plant.

Highlights:

In A. officinalis plant, removal of seed coat using chemical treatments is very effective in applying seed dormancy treatments.
 Development of A. officinalis seed cultivation and propagation is possible by applying seed dormancy breaking methods.

Myrtus communis is a medicinal plant that its seeds have primary dormancy. Therefore, in current study, firstly effect of various types of scarification (treatment with H2SO4 70 or 90% or sand paper for 5 and 10 min, blade and soaking in hot water for 10, 20 min) were evaluated on seed dormancy breaking. Results showed that without scarification, seed germination was very low, whereas various types of scarification significantly increased final seed germination. Among various levels of treatments, the highest seed germinatin obtained by soaking in hot water for 20 min (33%), treatment with  H2SO4  90% for 5 min (59%), sand paper for 10 min (63%) and blade (65%). The next experiment showed that myrtle seeds were photoblastic and He-Ne laser more than white or red light increased germination of scarified seeds by above methods. He-Ne laser irradiation reached seed germination of scarified seeds by sand paper and blade to 80%. Results of the last experiment also showed that application of concentrations of 0.5% KNO3 and 100 µM sodium nitroprusside (SNP as a NO donor) also increased seed germination, seedling length and vigor of seedlings grown from all scarified seeds and seed germination of scarified seeds by sand paper and blade achieved to 80%. These results showed that myrtle seeds have combination of physical and physiological dormancy that can be attenuated with scarification by sand paper and treatment with SNP or He-Ne laser irradiation.

Weeds reduce crop growth and yield through interference and competition with the crop. Polygonum convolvulus L. is an annual weed from the Polygonaceae family. In order to investigate the effect of different treatments in breaking the P. convolvulus seed dormancy, a study was conducted in the weed research laboratory of Gorgan University of Agricultural Sciences and Natural Resources in 2020. The treatments included after-ripening (for seven months), different concentrations of gibberellic acid and potassium nitrate, hot water treatment, mechanical scarification with sandpaper, sulfuric acid (98%), chilling at 4 °C and cutting the seed coat. The results showed that after-ripening, gibberellic acid and potassium nitrate, immersion of seeds in hot water and scarification with sandpaper had no effect on seed germination. Treatment of P. convolvulus seeds with sulfuric acid as well as chilling caused germination in the seeds. Also, scarification the P. convolvulus seed coat around the embryo caused maximum seed germination (87%). The highest germination percentage of P. convolvulus seeds was observed in combined treatment of sulfuric acid treatment (20 minutes) and chilling (15 day) (91.66%) and scarified the seed coat (87%), which were not significantly different. According to the obtained results, it can be stated that the mechanical resistance of seed coat against embryonic growth is the main cause of dormancy in P. convolvulus seeds.

Natural habitats of licorice have decreased dramatically while the demand for this plant rises. Licorice seeds exhibit a low germination rate due to secondary dormancy imposed by the hard seed coat. In this study, conducted in the spring of 2021 at Shahid Bahonar University of Kerman, Iran, the interaction effect of sulfuric acid (95-97%, 60 min) scarification with gibberellic acid (GA) concentrations (0, 100, 250, 500, and 1000 mgL-1) has been studied in a factorial experiment based on a completely randomized design with four replications. Results show that although there has been no difference in germination between GA levels for scarified seeds, GA at 250 mg L-1 improves germination by 36%, compared to the control in non-chemically scarified ones. In contrast, increasing in GA concentrations increased seedling length, plant height, number of leaves and compound leaves, leaf area, fresh and dry weight of shoot and root, while decreased chlorophyll index (SPAD). As a result, chemical scarification, application of GA at 1000 mg L-1, and germination at room temperature can effectively increase the germination rate and uniformity as well as early growth of licorice plant.

Guava (Psidium guajava L.) is one of the most important fruit crops of tropical and subtropical regions. Guava (Psidium guajava L.) can be propagated by seed, layering, grafting, cutting or tissue culture. Propagation by seed is used for the production of seedlings usable in breeding programs or rootstock production for grafting. Guava seeds germinate poorly and unevenly and require more time for seedling emergence. The dormancy in seeds might be due to hard seed coat and different methods are used for breaking dormancy in seeds to improve germination. The aim of this study was to evaluate efficiency of the different pretreatment on seed dormancy breaking and germination characteristics of guava.

The experiment was laid out in a completely randomized design with three replications on guava seeds in genetic and breeding laboratory of Date Palm and Tropical Fruit Research Center at the summer of 2018. Treatments consisted of distilled water (24 and 48 h), 0.5 and 1% potassium nitrate (KNO3) for 24 h, warm water (70 ° C) for 5 and 10 min, 25% and 50% sulphuric acid for 5 min, and control (non-treated). In this study, the traits of germination percentage, germination rate and mean of daily germination, seed vigour index and fresh weight and length of seedling were measured.  Data analysis was done using the SAS 9.2 software and the Duncan's test at 5% probability level was used for mean comparison.

Results showed that the effect of treatments on seed germination indices (germination percentage, germination rate and mean of daily germination, seed vigour index) of guava was significant at p<0.01. The greatest germination percentage (53.1%), germination rate (6.6 seed/day) and seed vigour (2636.7) were observed in treatment of 1% potassium nitrate (KNO3) for 24 h. The lowest Mean time to germination (14 days) was obtained in distilled water for 48h. Warm water treatments at 70 °C and 25% and 50% sulfuric acid were not effective in improving seed germination compared to control. The highest seed length and weight were observed in 1% potassium nitrate and 0.5% potassium nitrate pretreatments, respectively.

the results of this study show that among the different treatments, pre-treatment of seeds with 1%potassium nitrate may be considered as an effective way to improve seed germination of guava. Also, pretreatment with distilled water for 48 hours is an easy, low cost and effective way to increase guava seed germination indices.

To evaluate the effects of different treatments on seed dormancy breaking of Notobasis, two separate experiments were conducted at Agricultural Sciences and Natural Resources University of Khuzestan, in 2017 with three replications. The first experiment included nine physical, mechanical and chemical treatments (control, surface scarification, intense scarification, one and two weeks of chilling at 4°C, soaking into hot water for two hours without scarification , soaking in 25°C distilled water for two hours with scarification  and acid treatment for six and 12 minutes) based on completely randomized designs (CRD). The Second experiment was hormone priming arranged as a factorial experiment based on completely randomized design with gibberellin concentrations (0, 200, 400, 600, 800 and 1000 ppm) and priming duration (12 and 24 hour) as the treatments. The highest seed germination (40%) obtained from 12 minutes of acid treatment. Results showed that seed germination reached to 100% after priming seeds with GA3 concentrations for 12 hours. However, increase the priming durations to 24 hours, significantly declined seed germination to 47% in 200 and 400 ppm of GA3 concentrations. The Increase of GA3 concentrations in 12 hours led to a linear reduction of T50 from 31 hours in 200 ppm to 19 hours in 1000 ppm). In 24 hours of priming treatment, T50 followed a Gaussian function and the highest T50 (92 hours) was obtained from 600 ppm. It is recommended to immerse the seeds for 12 minutes in sulfuric acid and prime with 400 ppm GA3 acid for 12 hours to break dormancy and increase the vigor index.

Due to the presence of phenolic and antioxidant compounds in the Albizia julibrissin, it has been studied extensively in traditional medicine. Due to the impermeable cover of the seed of this plant and the problems related to germination, this study was carried out in vitro to compare the effects of mechanical (hot water) and chemical (bleach and sulfuric acid) dormancy failure on seed germination of A. julibrissin. Treatments included hot water with temperature (55, 65, 75 and 85 ° C) for 10 minutes, bleach for (30 minutes, 1, 12, and 24 hours), different levels of sulfuric acid (0, 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20 and 22.5%) and control treatment (distilled water) with 4 replications. During different days, the number of germinated seeds was counted until it reached a constant level. Finally, the average germination rate, seed germination percentage, seed vigor index, and allometric coefficient were calculated for different treatments. The results showed that the best germination performance was in the treatment of hot water and sulfuric acid, but the treatment of bleach did not have a significant effect. As a result, it can be said that hot water and sulfuric acid treatment by softening the husk can greatly improve the performance of seed germination indices and in species that do not germinate under normal conditions, their use is recommended, however, the optimal temperature and dose for improving germination performance varies according to plant type and environmental factors which require further research in the future.

An important step in weeds control are to identify the ecophysiological characteristics of the seeds of these plants. In order to investigate different methods of dormancy breaking of wild mustard seed (Sinapis arvensis L.) an experiment was conducted on a completely randomized design with three replications in 2019 in the Faculty of Agriculture and Natural Resources of Mohaghegh Ardabili University. Experimental treatments included control, chilling, placing in gibberellic acid solutions with four concentrations of 500, 1000, 1500 and 2000 parts per million for 24 hours, placing in concentrated sulfuric acid solution (98 Percent) for 1, 2 and 3 minutes and placing the seeds in ultrasonic for 10, 20 and 30 minutes. The results showed that the measured traits were affected by experimental treatments. Gibberellic acid 1500 parts per million (ppm) was measured at with the greatest effect on germination and growth components. Compared with the control treatment, gibberellic acid 1500 parts per million (ppm) increased 80 percent of wild mustard seed germination. However, in most of the studied traits, sulfuric acid had a negative effect on germination and growth components. The results suggest that despite the positive effect of gibberellic acid on germination of wild mustard seed, concentrated sulfuric acid has a detrimental effect on their and can be used as one of the methods for effective in controlling weeds.

White Astragalus (Astragalus gossypinus Fisherr.) is one of the valuable plants for producing gum, which is of critical importance in soil conservation and the economy of the country. This plant is propagated by seed; its seeds are in the natural state of dormancy. Therefore, recognizing the factors affecting dormancy and creating optimal conditions for seed germination of this plant is necessary for the cultivation and reclamation of rangelands. This study was conducted with the aim of finding the best treatment for breaking the dormancy and improving seed germination under various chemical and physical treatments.

The experiment was carried out as a factorial based on a completely randomized design with four replications at the gene bank of cereal and legume Lab of Ilam University, 2017. The factors included two levels of scarification chemical (with and without sulfuric acid (H2SO4) for 10 minutes), three levels of stratification (control, moist chilling at +4 °C and dry chilling -20 °C), potassium nitrate in two levels (zero and 1% KNO3) and gibberellic acid in two levels (zero and 5 ppm GA3). Germination indices including germination percentage, germination rate, seedling and radicle length, seedling fresh weight and vigor index were measured.

Initial assessment of vital indices in seed such as germination and primary growth showed that the simultaneous application of scarification by sulfuric acid and moist chilling at +4 °C has the most impact on removing dormancy and increasing germination percentage. The highest germination rate was observed in moist chilling at +4 °C, which was 32.19 percent more than that of the control treatment. Scarification by sulfuric acid reduced the mean germination time in moist chilling at +4 °C. Scarification by sulfuric acid increased the fresh weight of the seedling by 55.25 percent, compared with the control. Pre-treatments with potassium nitrate undre control conditions, moist chilling at +4 °C and dry chilling at -20 °C increased the fresh weight of seedlings, at 52.66, 30.94 and 17.18 percent, respectively. Application of potassium nitrate increased root length by about 60.7 percent, compared with control. The highest radicle length (78.71 mm) was obtained when the seed was treated with sulphuric acid with wet chilling at 4 ° C for two weeks, which was 30 percent higher than control. The highest seedling length (84.88 mm) was obtained in scarification with sulfuric acid, wet chilling, and potassium nitrate and gibberellic acid. The highest seed vigor index (61.85 %) was observed in the treatment of scarification with sulfuric acid under moist chilling, and pre-treatments of gibberellic acid and potassium nitrate.

In general, it can be concluded that seed dormancy of Astraglus gossypinus involves both physical and physiological dormancy. The best treatment for removing the dormancy of this species seems to be scarification with sulfuric acid for 10 minutes puls concentrated stratification in moist chilling at +4 °C for two weeks.

Determination of the optimal seed dormancy techniques of white Astragalus for the purpose of increasing seed germination percentage.. Comparison of the efficiency of different dormancy breaking techniques.. The combined effect of sulfuric acid, chilling and priming with gibberellic acid and potassium nitrate on germination indices.

In addition to dormancy, seeds of Allium hirtifolium have a weak emergence in the field. Among methods for improving the efficiency and emergence of seeds, nutritional priming can be considered for its performance on weak seeds. The presence of micronutrients is one of the factors that may affect the efficiency of the seeds. Therefore, the aim of this study was to investigate the effect of priming with nutrients on optimization of dormancy status, germination, and enhancement of shallot seeds for its conservational, restoration and domestication programs.

In order to study effects of nutrients on germination and emergence of Allium hirtifolium, a CRD factorial experiment was conducted with four replications at Seed Science and Technology Lab of Shahrekord University in 2015. Two dormancy breaking treatments (sulfuric acid and sulfuric acid + gibberellic acid) as the first factor and nine nutrition treatments including four levels of ZnSO4 (5, 10, 50 and 100 mM) and four levels of FeSO4 (0.5, 1, 1.5 and 2%) versus control were compared on shallot seeds.

The results showed that dormancy breaking treatments, nutrient pretreatment of seeds and their interaction had significant effects on germination percentage, germination rate, time to reach l0% and 50% germination, germination uniformity, seedling length and vigor index I at 1% probability level. Sulfuric acid and FeSO41% increased germination versus control. Application of gibberellic acid affected the behavior of iron but did not indicate significant effects for zinc. The concentration of 5 mM ZnSO4 increased the rate of germination, compared with the control but decreased with higher concentrations. The gibberellic acid did not show any sharp effects on germination rate. Time to reach 50% germination was also affected by FeSO4 0.5% and 1% and lower levels of zinc. Application of gibberellic acid did not show any significant impact on the germination time reduction, compared with control and increased T50 in higher concentrations. Although germination traits were rarely affected by gibberellic acid, seedling length and vigor index were positively influenced with GA, and the highest seedling length was achieved at 0.5 and 1% of iron and gibberellic acid.

Seed priming with nutrients can improve germination and plant vigur indices. Different concentrations of iron and zinc showed different impacts on the seeds, which showed interaction with dormancy breaking methods. Although application of gibberellic acid did not have an effective role in increasing germination rate and reducing the time to reach 10% and 50% of germination, it enhanced seedling length and vigor index I, especially for iron.

Addition of iron and zinc sulfate to shallot seeds whose dormancy was broken with sulfuric acid caused higher germination rate of  25.54%, compared with the control. Gibberellin compensated for zinc effect in germination and was able to replace it, but had a slight synergic effect with iron sulfate. Although gibberellin application did not affect germination traits, the seedling length and vigor index showed a positive response to it.

  Iris spuria subsp. Musulmanica is a rhizomatous herb growing as wild in Iran, Turkey and, Caucasia. This species is important from ornamental and medicinal perspective and could be used as flowering pot plant, cut flower and landscape plant. A few of Iris seeds germinate under natural conditions. Therefore, an experiment was designed to improve germination of Iris seeds using different treatments that could be accessible for floriculture purpose. This experiment was carried out based on completely randomized design with 10 treatments and 4 replications (each replication contains 25 seeds). Treatments were control without treatment, priming in hydroxide sodium 20M for 10 minutes, priming in sodium hydroxide 15M for 20 minutes, W100-10: in water 100°C for 10 minutes, W80-15: in water 80°C for 15 minutes, priming in sulfuric acid 98% for 10 minutes, priming in sulfuric acid 98% for 15 minutes, stratification for 30 days, stratification for 60 days, and stratification for 90 days. For all treatments, germination variables including germination, germination rate, mean germination time, seed vigor index, mean germination daily, shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight, and root dry weight were measured. Treatment effect on germination variables was significant (p<0.05). The results improvement of that treating seeds with 20 mM of hydroxide sodium solution for 10 minutes led to improve the seed germination parameters like germination percentage, germination rate, seed vigor index, shoot and root length, fresh and dry weight of root and shoot compared to control. In three levels of stratification treatments, germination percentages were less than control treatment. Also, the results showed that treating seeds with sulfuric acid for 10 minutes improved as partially seed germination and other germination variables in comparison with control treatment. Previous studies revealed that the seed coating played an important role in seed dormancy of Iris species. In this study, scarification treatment with hydroxide sodium resulted in increased germination which may correspond to the reduced seed mechanical inhibitory and the improvement in gas and water exchange. Moreover, sodium hydroxide solution facilitated the seed germination via the elimination of seed coat and increasing the seed capsule Intercellular space which finally promoted the exchange of materials between seed and its surrounded environment. Like too many Iris species, a non-deep morphophysiological mechanism may play the most important role in dormancy of I. spuria subsp. Musulmanica.

Extended abstract Malva (Malva neglecta) is one of perennial plants of the Malvaceae family. One of the most important mechanisms for survival of the plants is dormancy, rest or distance in germination and growth; in this case, despite favorable conditions for germination, the seed remains at rest for an indefinite period of time. Seed dormancy is a consistent feature in some seeds, especially weed seeds to optimize distribution of germination over time. Seed dormancy has a very important role in ecological management. The cause of the physical dormancy lies in skin cells outside tier structure that is impermeable to water. In physical dormancy, the seed coat is so hard that it does not allow the embryo to grow during germination. The chemical dormancy of the plants seeds is caused by the presence of inhibitor substances in the outer shell of many fruits and seeds and may also be due to an Enamel layer that blocks the exchange of oxygen. It goes without saying that understanding the ecology of weed germination and dormancy can contribute to long-term management. Therefore, this study was conducted to determine the effects of breaking seed dormancy and the impact of chemical and mechanical treatments on the germination of the Mallow seeds. In order to recognize the effects of chemical and mechanical treatments on breaking seed dormancy and some of the most important features of seed germination of Malva, the experiment was conducted based on a completely randomized design with 4 replications at Crop Physiology Lab, Razi University, during 2016. Treatments were distilled water (control), sulfuric acid 98% (for 2, 3 and 4 minutes), potassium nitrate 3% (for 3, 4 and 7 days), hydrogen peroxide 30% (for 2, 3 and 4 minutes) and scarification with sandpaper and prechilling (for 1, 2 and 3 weeks). Germination percentage, germination rate, length and dry weight of hypocotyl, length and dry weight of radicle, seedling total dry weight and vigor index were evaluated. Group comparisons, analysis of variance and comparison of means were run based on LSD at 5% level, using SAS software (version 9.4). The results showed that the highest and the lowest germination percentage were 82% and 5% in scarification with a chilling for 3 weeks and control treatments, respectively. The results of treatment group comparisons also showed that using scarification with a chilling had the greatest impact on seed dormancy breaking. The most hypocotyl length (34.92 mm), hypocotyl dry weight (2.60 g), seedling dry weight (3.29 g) and seed vigor index (58.13) were observed in scarification with a chilling for 3 weeks. The highest germination rate (5.21 in day), radicle length (34.92 mm) and radicle dry weight (0.85 g) also belonged to sulfuric acid 98% for 2 minutes. It seems that seed dormancy of Malva was a combination of physiological and physical dormancy, because the effectiveness of the treatments evaluated in both metabolic and physical processes brought about the increase in the seed germination percentage. Out of the treatments examined and given the results of group comparisons, scarification with sandpaper and prechilling had the most effect on breaking Malva’s seed dormancy. As scarification with chilling had the main role in breaking seed dormancy, it could be said that the dormancy is physiological and factors contributing to this dormancy are the embryo, the existence of inhibiting factors or both. The results indicated that the germination of Malva (Malva neglcta) seeds mechanically scratched with scarification increased. Therefore, seed dormancy is due to hard coated seeds. The seed coat is as one physical barrier against growth of embryo or radicle that inhibits absorption of water and gas exchanges.


Highlights: 1- Investigating dormancy breaking and germination traits of neglcta species of Malva.
2- Evaluation of efficiency of different chemical and mechanical treatments in the germination traits of Malva

In order to recognize effects of chemical and mechanical treatments on some of the most important features of seed germination of Myagrum, an experiment was conducted based on completely randomized design with four replications at Razi University. The experiment treatments were distilled water (control), sulfuric acid (98% for 2, 3 and 4 minutes), potassium nitrate (3%for 3, 4 and 7 days), hydrogen peroxide (30% for 2, 3 and 4 minutes) and scarification with sandpaper and prechilling (for 1, 2 and 3 weeks). Germination percent, germination rate, length and dry weight of epicotyl, length and dry weight of radicle, seedling total dry weight and vigor index were evaluated for Myagrum seed. Results showed that the most germination percent was related to hydrogen peroxide treatment for3 minutes (91 %) and scarification with a chilling for 3 weeks (84 %) and the lowest germination percent was observed in sulfuric acid treatment. The results of treatment group comparisons also showed that using hydrogen peroxide had the greatest impact on seed germination of Myagrum. The most germination rate (4.5) and epicotyl dry weight (1.6 g) was observed in hydrogen peroxide for 3 minutes. The most epicotyl length (22.7 mm), radicle length (36.6 mm), radicle dry weight (1.1 g), seedling dry weight (2.5 gr) and vigor index (49.9) were related to seed scarification along with chilling for 3 weeks. Our results also indicted that application of sulfuric acid due to extreme damage onembryo leaded to death of Myagrum seed. It seems that lack of appropriate germination in Myagrum seed could be due to embryo physiological factors because all evaluated treatments had more impact on seed metabolic and harmonic processes.

Given the medicinal and ornamental properties of Hawthorn (Crataegus spp.), and given that there are some problems in its propagation, which is due to the hard cover of the seeds and immature embryo, working out techniques that can facilitate the process of seeds’ germination is of great import. Thus, the present study sought to identify the best method for the purpose of breaking the seed dormancy of 8 species of native hawthorn of Iran. The study was carried out as factorial with a completely randomized design and had three replications. The first, second and third factors were, respectively species of Hawthorn in eight levels, sulfuric acid in three levels (half and an hour versus non-treated (control) and chilling treatment in three levels (90, 105 and 120 days, respectively). The results showed that the highest percentage of germination (32%) and germination rate (9.1 day-1) were obtained under the interaction of sulfuric acid treatment for one hour, followed by a 120-day chilling period in C.turkestanica, which had a significant difference with other treatments. It is concluded that hawthorn seeds have deep endocarp and physiological dormancy. The interaction of Sulfuric acid treatment and moist chilling play an important role in increasing the percentage and speed of germination of Hawthorn seeds.

This study aimed to select the most suitable chemical and physical treatment for germination and breaking seed dormancy of Crataegus pontica. The experiment was set up in a completely randomized with 5 replications and 12 treatments in laboratory conditions. In this study, each replication involved 30 seeds. Treatments were hot water - sulfuric acid, sulfuric acid for 15 and 20 minutes, gibberellic acid for 24 and 48 hours, scarification, chilling wet seeds (-20 °C for for 2 weeks), freezing seeds in water (-20 °C for for 2 weeks), nitric acid for 20 and 25 minutes, hot water and cold water and control. In this study, characteristics such as germination rate, germination value, speed of germination and Kotowski's coefficient of velocity, germination vigour, mean daily germination and mean germination time were measured. According to the ANOVA, significant differences were detected between treatments in term of mean germination time, Kotowski coefficient of velocity, speed of germination, mean daily germination, germination rate and germination vigour. The highest amount of germination rate, germination value, speed of germination, germination vigour, mean daily germination and mean germination time was related to hot water - sulfuric acid treatment while the lowest one was related to control treatment.

Nitrogen fertilizers are one of the most important factors in the production of greenhouse rose flower. Nitrate and ammonium are main mineral nitrogen sources, that can be absorbed by higher plants roots. Plants can absorb both nitrate and ammonium ions, but some of species are not able to have an optimum growth with ammonium as a sole nitrogen source. The form and application of fertilizers not only affect nitrogen uptake but also improve the absorption of other nutrients. In this research, the effect of form of nitrogen and application of sulfuric acid on growth and some nutrient elements absorption was investigated by rose plants ( Rosa hybrid L. cv. Grian Bdprex). With attention to alkalinity soil in most of agricultural area in Iran, aims of this research was determination of the best fertilizer and its application method for this area and increasing of elements absorption by plant and practical recommendation for rose producers. The experiment was carried out as completely randomized design with 5 treatments and 4 replications. Treatments were organic fertilizer sulfuric acid ammonium sulfate, organic fertilizer sulfuric acid calcium nitrate, organic fertilizer calcium nitrate distilled water, organic fertilizer ammonium sulfate distilled water and control (without fertilizer or acid water). Examined plants were 3-years-old rose cv Grian Bdprex. Plants irrigated every 4 days and used soil was clay loam. The results showed that, nutrition with Cultan method that was combination of organic fertilizers, ammonium, and sulfuric acid, in soil with high pH, led to an increase in vegetative growth (leaf fresh and dry weight, flower fresh and dry weight, stem fresh and dry weight, root fresh and dry weight, flower stem length) flower diameter, vise life, chlorophyll a, carotenoids and nitrogen, potassium and iron elements concentrations, and a decrease in zinc concentration in the plant. For instance, 85 percent increase was observed in leaf dry weight at nitrate calcium acid treated plants compared to control. Application of nitrate fertilizer with acid in comparison with nitrate fertilizer increased vegetative growth, flower quality, iron, nitrogen and potassium elements concentration, but decreased Zn element concentration. Therefore, we concluded that due to positive effect of Cultan method on growth, nutrient concentration, chlorophyll a, rose flower yield, and vase life of cut flowers, this method could be used for growing rose flower ( Rosa hybrid L. cv. Grian Bdprex), especially in soils with high pH.

A vast area of Iran is covered by sand dunes. Biological control is an appropriate method for sand dune fixation. So, it is essential to recognize characteristics of psammophyte plant species and introducing suitable species for sand dunes. Ammodendron persicum is one of the important and compatible species in desert ecosystems. The current research was carried out to investigate the effect of different treatments on seed dormancy breaking and germination stimulation of Ammodendron persicum in order to determine the most effective treatment in enhancing of germination and primary growth of seedlings. The experiment was done in a completely Randomized Design. Our experimental design was included10 random attendance namely: soaking of Ammodendron persicum seeds in gibberellic acid (300ppm) for 48 hr, seed scratching scarification with acid in two interval times of 20&30 min, incorporation of later with sand paper scratching scarification, seed scratching with gibberellic acid (300ppm) and time period of 48hr Ammodendron persicum seed sand papering combined with gibberellic acid soaking, wetting Ammodendron persicum seeds with high temperature water (80°C) for 5&10 min then scratching them by sand paper and also using distillated water as control treatment evidence. Experimental results showed, 30 minutes sulfuric acid soaking combined with sand papering can increase germination to 90% of the laboratory. In addition, seed scratching with gibberellic acid (300ppm) and time period of 48hr Ammodendron persicum seed sand papering combined, wetting Ammodendron persicum seeds with high temperature water (80°C) for 5&10 min, the percentage of germination, respectively, 45/15, 45/8, 17/10 and 68/28 respectively. Moreover 30min high density sulfuric acid caring improves Ammodendron persicum, seed vigor, power of greenhouse and lab samples to 450 and 510 respectively. Finally, authors reported scratching and acid soaking combination as an efficient, caring method in this research.

An experiment was conducted to study the effect of sulfuric acid, temperature scales and the source of seed on to break hardness alfalfa seed (MedicagoscutellatacvRobinson). This study was carried out as a factorial experiment based on randomized complete design with four replications at the agricultural collage of Lorestan University in 2005. Acid treatment as the first factor (to rinse with acid and without rinsing) and temperature scales treatment as the second factor (5, 15, 30, 45 centigrade degree) and the source of seed as the third factor (Khoramabad and Karaj) were applied. The results showed that to rinse seed with sulfuric acid to break hardness alfalfa seed. Seed hardness was not significantly affected by exposing in fixed temperature, but germination percentage decreased in 45 centigrade degree treatment. Radicle length increased under temperatures around base temperature. Seed hardness was affected by soil texture type, so that the highest germination percentage was obtained from sandy soil.

In order to study different methods of separating the seeds of cantaloupe (Cucumis melo L. var. reticualus) from the sorrounding fleshy tissues (placenta) and the effects of various treatments on seed germination characteristics, an experiment was conducted in Agricultural and Natural Research Center of Varamin, Iran, in 2009. In this research, which was based on a randomized complete blocks design with three replicates, three methods of seed separation including fermentation (for 24 and 48 hours), sulfuric acid (0.5, 1, 2, 12, 24, 49 and 98 percent) and hydrochloric acid (0.5, 1, 2, 4.8, 9.5, 18 and 38 percent) were used. The results showed that 98% sulfuric acid treatment was able to finish the seed separation process within 5 minutes, and with germination rate of 0.058 seeds per day was among the best treatments. In hydrochloric acid treatment, especially at high concentrations (18 and 38 percent), though seed separation was performed at acceptable rate and had positive effects on seed germination rate and percentage, but the electrical conductivity of seed solution showed that these treatments increased leakage of cellular materials, in addition to significant reduction of radicle and plumule length. Fermentation treatments had positive effects on separation and germination characteristics, except that they prolonged the time required for seed separation (24 and 48 hours). Among the treatments, the 98% sulfuric acid was superior to other treatments due to faster separation of seeds from the fleshy parts and its positive effects on seed germination characteristics.