جستجوی مقالات مرتبط با کلیدواژه « dry weight » در نشریات گروه « باغبانی »

Environmental stress in plants, particularly due to heavy metal presence, poses a significant challenge to their growth. Manganese, an essential micronutrient, can become detrimental when accumulated in soil and plants. To assess the impact of silicon on linseed (Linum usitatissimum L.) under manganese stress, a factorial experiment was conducted. Linseed plants were grown in hydroponic culture with four different manganese levels (2, 250, 500 and 1000 μM) along with five silicon treatment levels (0, 0.5, 1, 1.5 and 2 mM). Results revealed that increasing manganese stress levels led to a rise in proline, soluble sugars content, and manganese in the root and shoot, accompanied by a decrease in other studied traits. Notably, the application of 2 mM silicon consistently yielded the highest values across all manganese levels for the examined traits. Silicon application enhanced proline and soluble sugars content in leaves, consequently increasing plant photosynthetic capacity and leading to greater root and shoot dry weights under various silicon levels. The use of silicon significantly ameliorated the harmful effects of manganese in linseed under manganese stress conditions. Therefore, 2 mM silicon is recommended as a beneficial solution in areas contaminated with manganese, which can lead to the reduction of this heavy metal in the root and shoot of plants.

Sour orange, among the cold, drought tolerant rootstocks, is suitable for planting in poor drainage soils. Since salinity is one of the destructive stresses on the growth of citrus plants,  providing a suitable solution can be effective in reducing its harmful effects. So, a factorial pot research as a completely randomized design with three replications was conducted to evaluate the impact of saline water and potassium phosphite on sour orange plant. Sour orange plants were healthy and free disease six-months seedlings (height about 60 cm). The treatments were included salinity (1.5, 3, 4.5 and 6 dS/m) and potassium phosphite (0, 1.5 and 3 g L-1). The results showed that the high level of salinity led to a decrease in stem fresh and dry weight (63 and 60.22%, respectively), nitrogen, potassium, phosphorus, calcium and iron contents (4, 15.7, 8, 18.6 and 12.2 %, respectively) in sour orange. Potassium phosphite treatment (1.5 g L-1) increased the potassium, phosphorus, nitrogen, iron (32.6, 20.6, 19.7, 46.5%, respectively) contents, the fresh and dry weight of the stem (63.9 and 60.2%, respectively), the fresh and dry weight of roots (58.18 and 61.01 %, respectively) and finally the harmful impacts of salinity stress were reduced in sour orange plant. Generally, the application of potassium phosphite (1.5 g L-1) improved morphological characteristics, absorption of elements and reduced the adverse effects of salinity in Sour orange.

The aquaponic cultivation system, which is a combination of aquaculture and hydroponic systems, is among the novel cultivation systems. In an aquaponics system, it is possible to simultaneously produce aquatic animals and vegetables. One of the most important components of each soil-free system is the selection of a suitable substrate. This substrate makes water and nutrients available for the root system and also contributes to the proper establishment of the plant. It must also be non-toxic and should not impair plant growth. Another point to consider in the selection of the substrate is its cost and availability, as the transport process will increase the costs of initial establishments in such systems. Amon vegetables, basil is a special crop with a short growing season and high economic value, which is also highly suitable for an aquaponic system. The present study was carried out with the aim of comparing some morphological and physiological traits of 'purple' and 'green' basil cultivars in different substrates in the aquaponics system.

 The present study was conducted as a factorial based on a completely randomized design with three replicates in a research greenhouse located in Zanjan city. The experimental treatments included 10 substrates (cocopeat, perlite, sand, pumice, cocopeat + perlite (50:50), cocopeat + pumice (50:50), cocopeat + sand (50:50), pumice + sand (50:50), pumice + perlite (50:50) and sand + perlite (50:50)) and two basil cultivars ('green' and pueple). The aquaponic system in this study comprised of a 300 L fish tank containing 100 common carps. The fish were nurtured twice a day with powdered fish feed containing protein, carbohydrates, lipids, vitamins, etc. The water in the fish tank was filtered and fish wastes were removed in a filtration tank before entering the aquaponics medium to be used by the plant root system. Chemical properties of the fish water including pH, and nitrite (NO2), nitrate (NO3), and ammonium (NH4) concentrations were controlled using diagnostic kits on a weekly basis. At the flowering stage, various traits including plant height, dry and fresh weights of roots and shoots, number of nods, number of leaves, and leaf area were measured to investigate the growth of basil plants. Also, physio-phytochemical traits including the contents of chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and anthocyanin were measured. Analysis of variance of the data was carried out using the SAS software. Also, the least significant difference method (LSD) was used for the comparison of means.

According to the results, the greatest plant height (60.57 cm), shoot fresh weight (90.57 g), root fresh weight (22.33 g), and leaf number (133.99) belonged to purple basil and the lowest value for these traits were observed in green basil cultivar. The results of the mean comparison for the morphological traits indicate the superiority of perlite + cocopeat compared with the other substrates. Basil plants cultivated in sand substrate exhibited the lowest values for growth traits compared to other treatments. Analysis of the interaction effect between substrate and cultivar revealed that the highest number of nodes (10.5), dry weight of shoots (25.17 g), dry weight of roots (4.67 g), and leaf area (17.13 cm2) were observed in the perlite + cocopeat substrate with purple basil. Conversely, the lowest values for these traits (5.23, 12.93 g, 1.46 g, and 11.03 cm2, respectively) were recorded in the silt substrate with the green basil cultivar. The results related to physio-phytochemical traits showed that the highest content of chlorophyll a (1.57 mg g -1 FW) and total chlorophyll (2.1 mg g -1 FW) were observed in the perlite + cocopeat substrate and green basil. Also, anthocyanin content was the highest (0.17 mg g -1 FW) when the purple cultivar was grown in the perlite + c cocopeat substrate. The lowest content of chlorophyll a and total chlorophyll were recorded in the sand substrate and purple cultivar with 0.96 and 1.17 mg g -1 FW, respectively. Also, the lowest content of anthocyanin was related to the green basil cultivar with 0.058 mg g -1 FW.

Overall, the 'purple' cultivar of basil was superior to the 'green' cultivar regarding most traits in the aquaponic system. Also, substrates containing perlite and cocopeat led to better results compared with the other substrates, whereas the basil plants grown in sand and pumice had lower growth, relatively.

Gerbera is one of the most beautiful and popular commercial cut flowers in the world and has taken the fourth place among this group of flowers. Considering the importance of flowers and ornamental plants, it seems necessary to improve the quantity and quality of these plants. A factorial experiment was conducted to investigate the effect of different concentrations of fulvic acid and iron nano-chelate on the morphological characteristics and the amount of leaf elements of Gerbera jamesonii ‘Dune’, based on a completely randomized design with two factors and three replications. The treatments included fulvic acid in 4 concentrations of 0, 50, 100 and 250 mg L-1 as drench and iron nano-chelate in 4 concentrations of 0, 1, 2 and 4 g L-1 as foliar application that applied in pot and in hydroponic conditions. The characteristics measured in this research were: the number of leaves, fresh and dry weight of leaves and roots, root volume, vase life and absorption rate of some nutrients. The results of the research showed that with the increase in the concentration of iron nano-chelate and fulvic acid, the number of leaves increased, so that the maximum number of leaves was obtained at the concentration of 250 mg L-1 of fulvic acid and 4 g L-1 of iron nano-chelate. Iron nano-chelate treatment alone caused an increase in leaf fresh weight, but this increase was significant only at a concentration of 4 g L-1 compared to the control. Root fresh weight was significantly increased in all fulvic acid and iron nano-chelate treatments. The root volume also increased with the application of different concentrations of fulvic acid, but its increase was significant only at the concentration of 100 mg L-1 of fulvic acid compared to the control. The amount of potassium absorption decreased with the increase in the concentration of iron nano-chelate and fulvic acid. Phosphorus absorption at a concentration of 250 mg L-1 of fulvic acid and iron and zinc absorption at a concentration of 2 g L-1 of iron nano-chelate with 50 and 250 mg L-1 of fulvic acid reached their maximum, respectively. The results of this research showed that fulvic acid and iron nano-chelate improve the growth characteristics of gerbera by affecting the optimal absorption of elements.

In order to study the effect of organic matter and type of culture medium on vegetative characteristics, enzymatic activity and essential oil of lemon balm under salinity stress, a factorial experiment based on completely randomized design with three replications in Jahrom city of Fars province carried out. The first factor was the medium culture at three levels (compost + soil, vermicompost + soil and compost + vermicompost + soil (all in equal proportions)), the second factor was organic matter at two levels (humic acid (HA) and effective microorganisms (EM)( concentration of 5 per thousand) and the third factor was salinity at three levels (515, 3656 and 7312 μm / cm). The results showed that with increasing salinity, proline content and activity of catalase and peroxidase enzymes increased and plant height, leaf number, chlorophyll and percentage of essential oil decreased. Co-addition of vermicompost and compost to soil on growth and physiological traits was more effective than either of these two substances alone. In general, the use of organic matter and effective microorganisms in the culture medium containing soil+ compost+ vermicompost reduced the negative effects of salinity on lemon balm and the use of organic matter and effective microorganisms can improved plant tolerance under salinity stress conditions and increased the growth characteristics and essential oil content of this medicinal plant.

Under salinity stress nitrogen and other plant nutrients uptake is reduced. In order to study the effect of nitrogen on growth and nutrient concentrations of Valencia orange grafted on lemon seedlings, a factorial experiment was carried out. The first factor was irrigation water salinity at four levels (0.86, 2, 4 and 6 dS m-1) and the second factor was nitrogen at five levels (50, 80, 120, 160 and 200 mg N kg-1 soil as ammonium sulfate). Salinity increased sodium and chloride ions concentration in plant leaf and roots to toxic levels and reduced the plant leaf and root dry weight. The highest level of salinity increased the sodium content in leaves and roots and also chlorine in leaves by 9, 5 and 20 times compared to salinity of 0.86, respectively. Although nitrogen had no significant effect on sodium concentration in plant leaves, at salinity levels of 2, 4 and 6 dS m-1, increasing the application of nitrogen from 50 to 200 mg kg-1 soil reduced 19, 16 and 18% of leaf chlorine and increased the corresponding dry weight of leaves by 117, 39 and 42%, respectively. Salinity decreased nitrogen, phosphorus, potassium, and micro nutrients concentration in plant leaf and in some cases reached them to sub optimal levels. In contrast, nitrogen alleviated this adverse effect by increasing the concentration of these elements in plant tissues. Based on the results, by taking into account of environmental considerations, nitrogen levels above the optimum limits can be used to reduce the adverse effects of salinity in saline conditions.

Iran has the most diverse and richest gene pool of pomegranate cultivars in the world. Drought is the most common environmental stress and the most important limiting factor of agricultural production in the world and limits production in almost 25% of the world's agricultural lands. One of the most harmful effects of dehydration stress is disruption of the process of absorption and accumulation of nutrients. Among nutrients, potassium is one of the most important cations required by plants, which has been reported to accumulate during osmotic stress. The role of this cation in osmotic regulation and stomatal control has been described. Due to the fact that drought stress is one of the limiting factors for agricultural production, therefore, research on the mechanism of plant resistance to water scarcity is important. Therefore, this study was conducted to investigate the response of six Iranian commercial pomegranate cultivars to drought stress based on the amount of some leaf nutrients.

The executive operations of this research were carried out in the research greenhouse of Lorestan Agricultural and Natural Resources Research Center with a temperature of 25 °C and a relative humidity of 70%. The experiments were performed due to similar climatic conditions of Lorestan and Kermanshah provinces. The plant materials used in this study were annual rooted seedlings of six pomegranate cultivars. This study is a factorial experiment with two factors: 1- Pomegranate cultivar in six levels (RababNeyriz, NaderyBadrood, ShishehcapFerdous, ArdestanyMahvelat, Malase Yazd and ShirinShavar Yazd) and 2- Drought stress in three levels including non-stress drought (80% of field moisture, control), moderate drought (60% of field moisture) and severe drought (40% of field moisture) were screened in a completely randomized design with three replications in the greenhouse. All data obtained from the experiments of this study were statistically analyzed by SAS-9.1 software and the comparison of the mean of the simple effect of the treatments was performed using Duncan's multiple range test. The comparison of the mean interaction of the treatments was performed by SAS and MSTAT-C software using Duncan's multiple range test. Graphs were drawn using Excel software.

The results of this study showed that the amount of nutrients in all studied cultivars was affected by drought stress, but the response to stress was different. The amount of nutrients of iron, zinc, copper, manganese, sodium and phosphorus based on dry weight decreased under drought stress conditions while the concentration of potassium under drought stress increased. Based on the results of this study, Rabab Neyriz and Malase Yazd cultivars had more tolerance to drought stress in terms of nutrient uptake compared to other cultivars, respectively. Highest levels of iron (126.9 mg.g-1), zinc (39.9 mg.g-1), copper (13 mg.g-1), manganese (51.8 mg.g-1) and potassium (2.11% was obtained from Rabab Neyriz cultivar. Therefore, the use of this cultivar in drought stress conditions is recommended. Among the studied cultivars, Naderi Badroud and Ardestani Mehvalat had the highest sensitivity to drought stress and Shirin Shahvar Yazd and Shishecap Ferdows cultivars showed moderate resistance in this regard.

Based on the results of this study, it showed that Rabab Neyriz and Malase Yazd cultivars have high tolerance to drought stress and are also able to show a better response to nutrient uptake under drought stress conditions. Between these two cultivars, Rabab Neyriz cultivar had higher absorption of iron, zinc, copper, manganese and potassium and was considered the superior cultivar in this regard.

This experiment was conducted to study the improvement of biological yield and physiological indicators of Ajwan by application of polyamines under salt stress conditions in 2018. A factorial study was conducted with a randomized complete design with two factors and three replications. The first factor included four levels of water salinity including the control (without salt stress) and salinities of 1000, 2000 and 3000 mg/l. The second factor included five levels of using zero polyamine, 0.5 and 1.5 mmol/l putrescine and 0.5 and 1.5 mmol/l spermidine. The results showed that increasing the salinity levels resulted in a reduction of the height, the biological yield, the lateral branch and the number of umbels in the plant. The lowest amount of chlorophyll a and b and the highest sodium and chloride content in the salt stress of 3000 mg/l was observed. Under salt stress of 2000 mg/l, the spermidine treatment as 1.5 and 0.5 mmol/l led to an increase in the proline content to the amounts of 44.56 and 40.16% as compared with that of the control. Also, the highest peroxidase in the spermidine treatment of 1.5 and 0.5 mmol/l was observed in the amounts of 3.60 and 3.20 micromoles per minute protein. Therefore, the polyamine compounds lead to the reduction of the salt stress effects through improvement in the physiologic characteristics, including increase in the osmotic adjusting compounds and the activity of antioxidant enzymes. Moreover, the polyamine compound of spermidine has a better function than putrescine.

To investigate the effects of foliar application of gibberellic acid (GA3) and salicylic acid (SA) on the morphophysiological, biochemical, and yield characteristics of Echinacea purpurea (L.) Moench, an experiment began as a factorial in a randomized complete blocks design with three replications at the research farm of Agriculture Faculty, Ilam University, Iran, by sowing the plants in 2018 and continued by evaluating the plant characteristics for the two consecutive years (2018 & 2019). The experimental treatments included the foliar spray of plants during vegetative growth period with GA3 (0, 100, and 200 ppm) and SA (0, 100, and 200 ppm) as well as their combinations. The results showed that the highest plant height, number of flowers, and fresh and dry weight of the plants (in both years) were obtained in the GA3-200 ppm treatment and the highest amount of total chlorophyll and carotenoids (in both years) in the GA3-100 ppm one. The highest capitol diameter and fresh and dry weight of flowers in the first year and the highest anthocyanins content in the second year were observed in the GA3-200 ppm treatment. Also, the highest capitol diameter in the second year and the highest anthocyanins content in the first year were obtained in the SA-100 ppm treatment. In addition, the highest fresh and dry weight of flowers in the second year was recorded in the SA-200 ppm treatment. The highest essential oil amount of flowers, shoots (without flowers), and total essential oil (in both years) were obtained in the GA3-100 ppm+SA-100 ppm combination treatment. Considering that increasing the plant dry matter yield as well as essential oil content were the most important objectives of this study, the GA3-200 ppm treatment for the plant dry weight increase and the GA3-100 ppm+SA-100 ppm combination treatment for the essential oil content increase could be suggested as the best treatments.

In order to investigate of the effects of topic and granstar herbicides with codacide adjuvant to weeds control of wheat fields an experiment was carried outwith 13 treatment and 4 replication  in 2012-2013, in Karaj. Experiment factor were granstar herbicide 3 dose (14,17,20 g/ha), granstar herbicide (14,17,20 g/ha+0.25% V/V Codacide) and topic herbicide(0.6,0.8,1 lit/ha) and topic herbicide (0.6,0.8, 1 lit/ ha+ 0.25% V/V codacide). These treatments were used in tillering time. The result of this experiment indicated that Granstar 17 gr/ha+ 0.25% herbicide had the best of effect on weed control.

Sweet basil (Ocimum basilicum L.) is one of the oldest spices belongs to the Lamiaceae family. It is a herbaceous annual plant, which is native to subtropical regions of Asia, Africa, America. Basil is an important economic crop and widely used in the culinary arts, food processing and pharmaceutical industries. Nitrogen is one of the most important nutrients for plant production that plays a major role in photosynthetic activities and crop yield capacity and its availability affects plants growth and biochemical processes. Nitrogen deficiency is often a limiting factor in vegetable production such as sweet basil. Nitrogen usage significantly can be increased the herb yield of basil grown in different environmental conditions. The nutritional and environmental factors are the most important factors for growth of the medicinal plants. In the present research, changes in yield, nitrate content, essential oil yield and some physiological traits have been investigated in four cultivars of sweet basil under different levels of nitrogen.

A field experiment was carried out in the Agricultural Research Station of Khorramabad during 2016 growing season. The experimental factors were arranged as a factorial-split-plot in time experiment based on randomized complete blocks design with three replications. Experimental factors were cultivars of sweet basil (O.basilicum var Italian Large Leaf، O. basilicum var Mobarakeh, O. basilicum var Sweet Thai and O. basilicum var Cinnamon) and nitrogen fertilizer (0, 100 and 200 kg ha-1 urea) assigned to the main plots as factorial and different cuttings (three harvests from each plot) considered as sub-plots. The half amount of nitrogen (as urea; 46% N) was distributed in experimental plots before planting the seeds and the rest used after the first harvest. Seeds of sweet basil were planted at May, 25th 2016 as five rows with 2m length and each main plot area was 5 m2. The space between rows was 50 cm. All plots were irrigated immediately after sowing. Subsequent irrigations were carried out every four days. The control of weeds conducted manually during the experiment time. The sweet basil plants were harvested three times in early flowering stage in July 12, August 15 and September 25. Samples of 1 m length were taken from the center of two rows located in the middle of each plot. Plants were cut from above ground and transferred to the lab for measuring total dry yield. The measured traits in this study included branches per plant, inflorescences per plant, plant height, leaf percentage, total dry yield, essential oil yield, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and nitrate content. SAS (version 9.1) and MSTAT-C statistical software were used to conduct analysis of variance (ANOVA) and comparison of means, respectively. The Duncan's multiple range test, at 5% probability level, was used to rank the differences among means.

The results indicated that the application of nitrogen fertilizer significantly improved all the studied traits. The highest and the lowest essential oil yield belonged to 100 kg ha-1 urea and control, respectively. Nitrogen fertilizer by providing the nitrogen needed for the basil plant during the growing season provides a favorable environment for the production of further biomass. Total dry weight of the all basil cultivars increased with application of nitrogen fertilizer in all harvests. The highest total dry weight and nitrate concentrations were achieved by Italian largel cultivar with application of 200 kg ha-1 urea in the second harvest. The increment in total dry weight of basil by application of nitrogen fertilizer could be attributed to the increment in chlorophyll content and better growth of plants and subsequently the better canopy development which ultimately leads to the better usage of solar irradiance, higher photosynthesis and finally higher dry weight in basil plants. Application of nitrogen chemical fertilizer could increase essential oil yield of sweet basil, mainly due to the increasing of total dry weight. Among basil cultivars, Italian large leaf cultivar had the highest leaf percentage and essential oil yield compared to the other cultivars. The lowest number of branches per plant, number of inflorescences per plant, leaf percentage, essential oil yield and total chlorophyll belonged to Mobarakeh cultivar. All the evaluated parameters were lower than the first harvest except leaf percentage and chlorophyll content.

According to the results, application of nitrogen fertilizer had a positive effect on growth, and consequently led to increase the plant vegetative yield. Due to the fact that in terms of more of the studied traits there was no significant difference between application of 100 and 200 kg ha-1 urea fertilizer and also reduce the consumption of chemical fertilizers generating pollution, Italian large leaf cultivar and application of 100 kg ha-1 urea are recommended to access an acceptable growth and quantitative and qualitative yield in sweet basil under the environmental conditions similar to Khorramabad.

One of the constraints in development of cowpea cultivation in growing areas of this crop is soil salinity. In order to investigate the effect of salinity on germination and seedling growth of cowpea (Vigna unguiculata), an experiment was conducted as factorial based on completely randomized design with 4 replications. The study was carried out June 2013 at the genetic and gene nation bank laboratory of Seed and Plant Improvement Institute, Karaj, Iran. Treatments were including of 4 levels of salinity (0, 50, 100 and 150 mM), 15 genotypes of cowpea (mashhad, omid bakhsh1, omid bakhsh 2, 001, 002, 7245, 7254, 7262, 7288, 7244, 7256, 7291, 7289, 7278 and 7305). The results showed that the effects of genotypes and salinity levels on different measured traits were significant at 5% probability level. Germination under saline conditions gave significant reductions for each treatment tested. The interaction effects of genotype and salinity, cultivar Mashhad in 150 mM NaCl salinity had the highest final germination percentage (84 %) and vigor germination (8.1). Also, the highest and lowest germination rate in high salinity (150 mM NaCl) had obtained in 7291 (5.3 seed per dar) and omid bakhsh 2 (3.7 seed per dar) cultivar, respectively. Increasing NaCl applications generally decreased the fresh and dry weight of Plumule and fresh and dry weight radicle. In high salinity level (150 mM NaCl), the highest of fresh and dry weight of Plumule had obtained in cultivar Mashhad (0.76 and 0.995 gr). Decrease in Plumule and radicle weight by NaCl application is due to increase in osmotic pressure of soil and decrease in availability of soil water because of NaCl Genotypes mashhad and 001 in NaCl salinity were evaluated as the most resistant and susceptible genotypes, respectively. Based on the results of this experiment, there is necessary genetic diversity among the Cowpea genotypes of Iran for selection of salinity resistant cultivars.

Recently, various methods have been used to alleviate the detrimental effects of pollutants. The application of biofertilizers with respect to their positive impacts on soil characteristics and environment can be served as a suitable alternative to many of these methods. In order to investigate the two-way effect of bacterium Pseudomonas fluorescens on plant growth, physiological and biochemical characteristics of dill (Anethum graveolens L.) under Pb stress conditions, a factorial experiment based on a completely randomized design with three replications was conducted at Mohaghegh Ardabili University. Experimental treatments included Pb stress at two levels (0 and 600 ppm) and bacterial inoculation at three levels (inoculation with Pseudomonas fluorescens strains150 and 159 separately and without inoculation (control)). The results of this study showed that the growth characteristics such as leaf number, plant height, and shoot fresh and dry weight were significantly affected by Pb contamination and shoot fresh and dry weight, leaf number and plant height decreased by 22, 31, 19 and 9%, respectively. The content of proline and carbohydrates in dill showed a significant increase under the influence of lead. Bacterial inoculation also increased the content of proline and plant carbohydrates, which was more pronounced in inoculation with strain150. The activity of antioxidant enzymes was significantly influenced by Pb contamination and bacterial inoculation. Pb increased peroxidase but decreased catalase activity, but inoculation with Pseudomonas bacteria, especially strain 150, significantly increased the activity of both enzymes. In addition, the bacteria were able to reduce the amount of Pb in dill. In general, the results of this experiment indicated that Pseudomonas bacterial inoculation was effective in alleviating the effects of Pb stress on dill via growth promotion and improving enzymatic activity.

Each year, with the onset of cold season and severe drop in temperature, the probability of frost bite and frost damage is a problem for landscaping plants. Many plant species, especially tropical and subtropical species, are damaged when exposed to frostbite, causing damage to their cells, tissues, and organs. Research has shown that by altering membrane properties during cold stress, metabolic balance is disturbed and with the increase in toxic metabolites, secondary damage to the plant can occur. At low temperature, decreases the efficiency of energy transfer to the center of the photosystem II. In addition, low temperatures are the main cause of the formation of reactive oxygen radicals. Also, lowering the temperature in the presence of light, due to the imbalance between light absorption and photosynthesis, increases the risk of light oxidation. Low temperature also reduces the activity of Rubisco. The amount of free proline in many plants increases significantly in response to environmental stresses such as frost stress, and stabilizes the membrane during cold stress.On the other hand, the use of some organic materials such as organic mulches increase temperature of the soil, and thus helps plant from frostbite. Use of organic mulch is widespread in agriculture due to the positive effect in soil temperature, weed control and moisture retention. Also, these mulches are effective in height, growth and flowering, early maturity and total yield of the products. Mulches in the warm seasons reduces soil temperature. Use of mulch can also help plants to withstand frostbite. Organic mulch decomposition in appropriate temperature and humidity conditions, liberates the nutrients gradually and provides for root plant and microorganisms of the soil. Organic mulches can reduce the effect of salt toxicity on plant growth and actively increase soil desalination. The most important benefit of mulch is the increase in soil temperature in the seed area, which accelerates the growth and yield of the product. Use of straw as mulch resulted in accelerated germination in cucumber. Use of straw mulch leads to an increase in temperature at night, thus protecting plants from temperature stress that has a positive effect on the growth and development of wheat.

In order to investigate the effect of freezing stress and using different types of organic mulch for Aquilegia plant, this experiment was conducted as a factorial experiment based on completely randomized design with four replications at Faculty of Agriculture, Ferdowsi University of Mashhad. The experimental treatments included four types of mulch (control (without mulch), 50% soil + 50% manure, 50% soil + 50% leaf needle + 50% soil + 50% rice bran) and five levels of freezing temperature (0, -5, -10, -15 and 20). Characteristics such as percentage of electrolyte leakage, relative water content, chlorophyll index and total chlorophyll, leaves number, leaf area, plant dry weight and proline leaf content were considered.

The results showed with decrease of temperature from 0 to -20 °C, stem diameter, leaf area and leaf number in bran mulch treatment decreased by 42.6%, 73.4%, 21.2% respectively, also stem diameter, leaf area and leaf number in mulch of leaf needle were 35.2%, 9/64%, 47.6%, in manure mulch were 20.20%, 46.4%, 7.8% and in the control of mulch decreased, 32.8%, 79.7%, 30.7%, respectively. At -5 °C, the amount of proline was 26% in the leaf and at -20°C, the amount of proline increased 50% compared to the control. Also, the lowest proline (0.73 μmol / g fresh weight) was obtained from the plants that treated with bran mulch. With application of, electrolyte leakage reached 63.6%, 68%, 61% and 57% in control conditions bran, needle and manure, respectively. In short, the least electrolyte leakage was observed in manure. On the other hand, when temperature dropped from 0 to -20 °C, the percentage of electrolyte leakage increased in Aquilegia. Relative water content of the leaf were 24% at 0°C, 38% at -15 °C and 23% at -20 °C. In terms of non-use of mulch, the relative water content was 36% and reached a 42% and 40% with application of manure and needle using mulch. By measuring the total carbohydrate found in Aquilegia leaf, it was observed that the amount of this trait was increased under frost stress. In general, although frost stress reduced the morphological traits of Aquilegia, use of organic mulch resulted in the improvement of these traits. The best results were observed in manure mulch.

In order to determine the effect of fulvic acid and NPK fertilizer on antioxidant activity, biochemical parameters and yield of basil, an experiment was conducted as factorial arrangement based on randomized complete block design. The results showed that the highest of anthocyanin (21.1 mg/g dry weight) with application of 3 per thousand of NPK fertilizer and the lowest anthocyanin (0.95 mg/g dry weight) were obtained from control treatment. The highest antioxidant activity (76.6%) was obtained from 5 kg/ ha fulvic acid and its lowest (70.6%) were obtained from control treatment(no fertilizerfulvic acid and NPK fertilizer). Also the highest anthocyanin (1.74 mg/g dry weight), chlorophyll b (1.52 mg/g fresh weight) and total chlorophyll (2.99 mg/g fresh weight) were obtained by application of 3 per thousand of NPK fertilizer and 10 kg ha-1 fulvic acid. Also result showed that the highest biological yield (22955 kg.ha-1)  and plant dry weight (483.8 gm-2) were obtained from treatment of 6 per thousand of NPK fertilizer and 10 kg ha-1 fulvic acid and the lowest amounts (14418 kg ha-1 and 259.5 gm-2) from control treatment (no fertilizerfulvic acid and NPK fertilizer(

In order to assess reduced nitrogen level impacts on butterhead lettuce (Lacttuca sativa L.) growth and yield, an experiment was done from May to August 2015 in research greenhouse of Shahrekord University. The experiment was conducted through randomized completed design with three replications and four treatments. The lettuce plants were grown in floating system using 60, 80, 100 and 120 mg/l nitrogen in nutrient solution. In every plot, ten plants were grown in wooden pool with 100 ×50 ×15 cm dimensions and plants were spaced 20×25 cm apart on polyester sheet. There was no significant difference among treatments in the leaf number, head weight, root fresh weight and leaf elements nitrogen, phosphor, potassium, magnesium and zinc, but significant differences were observed among treatments in leaf and root dry weight percent, stem length and diameter and leaf calcium, iron and manganese concentration. The largest fresh head mass were obtained from 60mg/l nitrogen (326 g/plant), but it had not significant difference with other treatments. The highest leaf and root dry weight percent, stem length and diameter was observed in 100 mg/l nitrogen concentration. Deceasing of nitrogen concentration until 60 ppm, did not reduce the weight of lettuce head

Strawberry fruit is soft and has a variety of vitamins, especially vitamin C and minerals. Parus is one of the most important short-day cultivars and suitable for the fresh produce market. Nitrogen is involved in vegetative and reproductive growth of most horticultural crops and excessive use of itdecrease yield and quality of products and increasing pollution of the environment. Humic substances are contained nutrients that improve the soil nutrients and increases the availability of food and therefore plant growth and yield. Studies haveshown that to adding a certain amount ofhumic acid fertilizer with nitrogen can improve the growth of roots, stems and leaves and enhances the yield and quality of products and increases the efficiency of nitrogen fertilizer consumption. On this basis, this research was performed aimed at achieving the best combination of treatments of humic acid and its application method and nitrogen in improving strawberry vegetative and reproductive growth cv. Paros. This study was conducted in the campus of Agriculture and Natural Resources University of Mohaghegh Ardabili at during 2015-2016. In early september, land preparation was carried out, and then were calculated base fertilizers 150 and 50 kg.ha-1 of potassium and phosphorus, respectively plus forty tons per hectare of manure. Stacks was prepared to dimensions of 1.5 × 1 m and the distance of rows was 40 cm. Strawberry seedlings were planted with distance of 25 cm on the row (10plants m-2)in late November.
The experiment was carried out as a split split plot based on complete randomized block design with the application of foliar and soil treatments of Humic acid levels (control, 2, 4 and 6 kg.ha-1) and nitrogen fertilizer (50, 100 and 150 kg.ha-1) with three replications. Nitrogen levels were placed in the main plots and the type of humic acid application in sub plots and humic acid concentrations in the sub- sub plots. Half of N(urea fertilizer) was used at the time of planting and 25 %on the early may and 25 %on the early June. To apply foliar and soil treatments, humic acid was used (Humaster tob with 85% of humic and fulvic acid, Yazd Golsangkavir Company) with the start of the growing season at the intervals of every 10 days once (four times total). In the soil method, humic acid is measured based on the desired treatments and then dissolved with deionized water and added to irrigation water. In the foliar method, after irrigation thehumic acid powder was solutioned with a certain amount of deionized water and it was sprayed on the plants in equal measure. In addition, only irrigation water and deodorizing water were applied to the control of soil and foliar treatments, respectively. Traits were as: leaf number and area, number of runners, fresh and dry weight of shoot and root, root volume, number of flowers and fruits, fruit weight average and yield per plant. Data analysis were performed by using SAS 9.1 and comparison of data by the LSD test at the 5% probability level. All results due to different concentrations of nitrogen, humic acid and methods of its application and their interaction on most traits were significant at 5% probability level. The highest values in the leaf number (17.91) and area (1304.34 cm2) obtained in 6 kg.ha-1 drench application of humic acid. Also,the most number of flowers (13.27) was observed in 100 kgN.ha-1combined with foliar application of humic acid and the highest number of runners (22.34) was obtainedin 150 kgN.ha-1with drench application of humic acid. The most flowers (17.55), fruits (14.5) number and yield (104.43 g.plant-1) observed in 100 kgN.ha-1with 4 kg.ha-1humicacid. The results trilateral interactions of nitrogen,humic acid and application methods showed that the highest values of fresh weight (48.32 g.plant-1) and volume (44.13 cm3.plant-1) of root, dry weight of shoot (21.08 g.plant-1) and root (16.28 g.plant-1) obtained infoliar application of 4 kg.ha-1humic acid.The most of shoot fresh weight (77.7 g.plant-1) also observed in drench application of 4 kg.ha-1humic acid and highestfruit weight average (11.68 g) obtained in foliar application of 2 kg.ha-1humic acid with 100 kgN.ha-1. Results showed that the majority of evaluated traits, the highest values have been achieved of 100 kgN.ha-1with foliar application of 4 kg.ha-1humic acid. On this basis, combined application of chemical and biological fertilizers can be the best strategy to achieve sustainable agriculture and reducing the pollution of soil and water resources along with increasing the product.

Birch (Betula pendula Roth.) is one of the most important species exposed to extinction due to the limited natural habitat and lack of regeneration. Plant tissue culture technique is an appropriate solution for asexual reproduction of this species and to protect it in controlled conditions. In this research, callogenesis of B. pendula was investigated using five types of explants (leave, stem, nodal, petiole and bark) in WPM and NT media enriched with two hormonal combinations including A) 1mg/l BAP, 0.1 mg/l 2,4-D and B) 0.1 mg/l BAP, 0.01mg/l TDZ). The results indicated that the minimum callogenesis was observed in nodal and petiole explants in NT medium enriched with A hormonal combination. Callogenesis, fresh and dry weight of bark, stem and leave explants were significantly decreased in WPM and NT media containing B hormonal combination as compared with A hormonal combination. The maximum callogenesis was observed in bark explant in WPM (81.14) and NT (70.36) media with A hormonal combination as compared with other explants. The average fresh and dry weight of this explant in NT medium was more than that of WPM medium with the same hormonal combination.

Salinity tolerance in plants can increase the importance of it as a result of the decreasing availability of high-quality irrigation water. Saline irrigation water can have many negative effects on crops. When irrigation water has high salinity, the salt may precipitate on the leaves as the water evaporates. Thus it can result in foliar uptake and phytotoxicity. The irrigation water may also cause accumulation of salt in the substrate, which may lead to salt uptake by the plants. Salt injury occurs when too much NaCl accumulates in the substrate. When excessive concentrations of NaCl are present in the soil, water uptake may be inhibited and it causing a physiological drought stress. However, potassium is required by plants in amounts (in kg unit) of similar or greater than nitrogen (N). K Uptake by the plant is highly selective and closely coupled to metabolic activity. At all levels in plants, within individual cells, tissues and in long-distance transport via the xylem and phloem, K exists as a free ion in solution or electrostatically bound cation. Potassium takes part in many essential processes such as enzyme activation, protein synthesis, photosynthesis, phloem transport, osmoregulation, cation-anion balance, stomatal movement and light-driven nastic movements. Potassium Chloride (KCl) is used as a source of nutrients in agricultural development and also used as relieve salinity stress.
In order to study the mitigation effects of KCl on salinity (NaCl) in mustard plant (Parkland and Goldrush), an experiment was carried out at the Research Greenhouse, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. The experiment was managed as a factorial arrangement based on completely randomized design in three replications. Treatments were included NaCl (0, 30, 60 and 90 mM) and KCl (0 and 20 mM) and two cultivars.
Relative water content was calculated by the following formula using leaf disc obtained from a young leaf of each plant.
(DW FW/ DW TW)*100FW=fresh weight, DW=dry weight, and TW=turgid weight
Electrolytic leakage was calculated by the following formula: EL=L1/L2 where L1 is electric conduction of leaf after putting in the deionized water in 25°C and L2 is the electric conduction of the autoclaved samples.
Leaf area was measured by Leaf area meter. Shoot and root dry weights were determined after drying the samples in 75°C for 48 h.
Chlorophyll concentration was calculated by the fallowing formula: Chla (μg/ml) = 15.65A666 – 7.340 A653
Chlb (μg/mml) = 27.05A653 – 11.21 A666
Analysis of variance was calculated using MSTAT-C.1software and means were compared by LSD test at probability level of 5%.
The results showed that the treatments of NaCl, KCl and interactions with cultivars were significantly different on dry weight, leaf area, photosynthesis, stoma conductivity and chlorophyll rate. The maximum shoot dry weight (3.44 g/plant) and photosynthesis rate was obtained from T2 (20 mMKCl and without NaCl). The maximum membrane stability index was obtained in Goldrush cultivar and T2. The minimum of these traits were observed in zero mMKCl and 90 mMNaCl. High level of NaCl (60 and 90 Mm) and increasing application of KCl could not improve all traits. According to the result of the analysis of variance increasing density of sodium chloride in planting areas has a special effect on the size of leaves, weight of dried plant and each leaf and dried root. This effect shows a meaningful variation between the weight of dried leaves and its dried root and shoots. The salty areas have a lot of negative ions like Magnesium, Chlorine, sodium and sulfate. These materials are harmful by themselves or cause affective disorder in plants metabolism. Salinity treatments applied to significant influence (p≤0.01) on the characteristics of photosynthesis, stomatal conductance and number of stomata was read out by SPAD. For example, sodium and potassium competition and chlorine and nitrate competition impairs the absorption of nutrients. The result of this reaction is that the plant needs more energy for producing organic matter so it loses most of its energy to resist against salt. This situation causes a low activity of the root and the growing of shoot consequently reduces. Also, weight and length of plant would reduce too. For example, existing potassium in salty lands causes the reduction of sodium in the shoot of plants. This research was done in a pot with the same amount of salt. Potassium causes the reduction of toxicity effects of sodium. This research showed that the potassium can regulate osmotic pressure and permeability of plant cell membranes and also cause to increase plant tolerance to salinity.
In salty condition, increasing the amount of sodium causes the reduction of potassium, compared with sodium. As a matter of fact this kind of reaction causes the reduction of potassium compared with sodium. We know that potassium can cause a suitable osmotic pressure and reduce the destructive effect of oxidation. So, amount of potassium more than sodium in salty lands is known as the standard resistance. In general, increasing the salinity of sodium chloride can decrease morphological and physiological traits of mustard. The use of potassium chloride in T2 treatment showed the best result. However, Goldrush cultivar showed better results compared with Parkland cultivar in salt tolerance.