جستجوی مقالات مرتبط با کلیدواژه « وزن خشک » 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.

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.

Drought stress causes reduction in growth and changes in biochemical indices of plants. In order to investigate the effect of arbuscular mycorrhizal fungi and selenium on reduction the detrimental effects of drought stress in Moldavian balm (Dracocephalum moldavica L.), a split plot-factorial experiment based on complete randomized block design with four replications was carried out under greenhouse condition. The main factor was three levels of drought [control, 0.75 Maximum Allowable Depletion (MAD) and 0.5 MAD] and sub factors included selenium at three levels (0, 100 μg per plant and 200 μg per plant) and inoculation with mycorrhizal fungi in two levels (non-inoculated as control and Glomus.verciforme). The results indicated that drought stress reduced height, dry weight and leaf area of plants. The lowest and highest value for all of these characteristics was obtained at 0.75 MAD and without drought stress, respectively. In non-stress condition, height, dry weight and leaf area of plants obtained from inoculation with mycorrhizal fungus and selenium were significantly higher than those of control. In all levels of drought stress, the content of catalase and peroxidase enzymes in plants inoculated with mycorrhizal fungus and selenium was significantly higher than that of control. The lowest content of catalase enzyme (25.06) was obtained in control and lowest content of peroxidase (14.81) was in the treatment with mycorrhizal fungus and selenium under 0.75 MAD drought stress. The highest content of catalase enzyme (53.62) was in inoculation with mycorrhizal fungus and 200μg selenium without stress, and the highest content of peroxidase (31.59) was obtained in 0.5 MAD stress and inoculation with mycorrhizal fungus and 200 μg selenium. Also, in condition of inoculation with fungus and selenium, the content of proline and MDA increased about 1 to 1.5 folds and about 1.3 to 1.5 folds, respectively, more than the control. Results showed that the presence of mycorrhiza and selenium in drought stress condition had a positive effect on growth and biochemical indices studied.

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

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.

Ornamental plants play a vital role in meeting the mental and spiritual needs of peoplethat considered significance from commercial point of view as well. Optimal production of agricultural products requires suitable soil and adequate and absorbable nutrients for plant. Organic materials are important because ofimproving soil physical properties and soil fertility. Soil fertility depends on the content oforganic matter as well as the quality, quantity and dynamics of these materials insoil. Organic acids are an important source of organic matter. One of the most abundant forms of organic matter in nature is humic compounds which can be found in all soil and water environment. They play an important role in cation exchange, nutrients release, phosphorus buffering capacity and metal and toxic organic molecules maintenance.
In order to evaluate the effect of humic substances on morphological characteristics of geranium, thisexperiment was conducted in research greenhouse of Ferdowsi University of Mashhad during the years 2014 and 2015. The experiment was carried out as factorial based on completely randomized design with two factors and three replications. The first factor hadfour levels of humic acid (0, 0.2, 0.5 and 1 g/l), and the second hadfour levels of fulvic acid (0, 0.2, 0.5 and 1 g/ml). Treatment was usedalong with irrigation. Morphological characteristics included the number of leaves, number of nodes, number of branches, plant height, root length, leaf area, fresh weight of shoot, fresh weight of leaf, fresh weight of root, dry weight of shoot, dry weight of leaf, dry weight of root, volume of shoots, volume of root, fresh weight of shoot were measured at the end of the experiment. Statistical analysis of the results was performed by using Jmp-8 software. Charts were drawn using Excel 2010 and difference among treatments means were compared with LSD test.
The results of means comparison showed that combined use of humic acid and fulvic acid hadpositive effects on growth traits such as height, internode length, root length, fresh weight of shoot, fresh weight of root, fresh weight of leaf, dry weight of shoot, dry weight of leaf, volume of shoot, volume of root and leaf area. Research had shown that the application of humic fertilizers increased nitrogen content in shoots of the plant. It wasreported that nitrogen compounds existed in humic acid are important factors affecting the growth of plants. Humic acid also increasedshoot growth by increasing the uptake of nitrogen, calcium, phosphorus, potassium, manganese, zinc, iron and copper as well as hormone-like properties. It wasalso found that humic acid enhancedplant growth by increasing the activity of the RuBisCO enzyme and the subsequent increase in photosynthetic activity. Furthermore, humic acid reduced the pH of alkaline soils and causedthe nitrogen to be absorbed to a greater extent. The use of humic substances increased the leaf area and thus photosynthesis, therefore leading to the production of more dry matter in plants. Humic fertilizers also had a significant effect on root growth. Researchers had suggested that the presence of oxygen groups in humic acid increased lateral root growth. Although humic acid increased the growth of both root and shoot, its effectiveness on the root system wasmore evident.
This experiment was conducted with the aims of evaluating the effect of humic organic fertilizers, reducing the harmful effects of chemical fertilizers and improving the quality of plant growth in geranium. According to the results obtained from the present research, it can be concluded that combined application of humic acid and fulvic acid had greater effects on the majority of traits compared to the sole application of aforementioned compounds.

Successful greenhouse and nursery production of plants is largely dependent on the chemical and physical properties of the growing substrate. An ideal potting substrate should be free of weeds and diseases, heavy enough to avoid frequent tipping over and yet light enough to facilitate handling and shipping. The substrate should also be well drained and yet retain sufficient water to reduce the frequency of watering. Other parameters to consider include cost, availability, consistency between batches and stability in the media over time. Greenhouse crops in general, have higher nutrient demands than field grown crops. Therefore, in order to optimize production it is essential to focus on the growing substrate and fertilization. The physical properties of the growing medium are important parameters for successful plant growth, as these are related to the ability to adequately store and supply air and water to plants. Humic acid is a principal component of humic substances, which are the major organic constituents of soil (humus), peat and coal. It is also a major organic constituent of many upland streams, dystrophic lakes, and ocean water. It is produced by biodegradation of dead organic matter. It is not a single acid, but it is a complex mixture of many different acids containing carboxyl and phenolate groups so that the mixture behaves functionally as a dibasic acid or occasionally as a tribasic acid. Humic acids can form complexes with ions that are commonly found in the environment creating humic colloids. Humic and fulvic acids (fulvic acids are humic acids with lower molecular weight and higher oxygen content than other humic acids) are commonly used as a soil supplement in agriculture. Humic Plus contains humic acid, fulvic acid, macro micro nutrients and proprietary constituents essential for plant growth. Organic matter soil amendments have been known by farmers to be beneficial to plant growth for longer than recorded history. However, the chemistry and function of the organic matter have been a subject of controversy since humans began their postulating about it in the 18th century. Selection of the proper media components is critical to the successful production of plants. So, the objective of this study was to assess the effect of humic acid foliar application and various substrate on quantitative and qualitative characteristics of tomato seedling.
Material and The experiment was conducted in a greenhouse at Bardsir Faculty of Agriculture , Shahid Bahonar University of Kerman in 2015, as a factorial arrangement based on completely randomized design with five replications. The experimental treatments were substrate in 7 levels (peat, coco-peat, leaf-soil, compost, vermi-compost, manure and clay soil), humic acid in two levels (foliar application and non- foliar application). After preparation of substrates, plastic boxes with 12 cm diameter and 10 cm height were chosen. After extracting gravity water, tomato (cv. Canyon) seeds were sown in pots. Rain irrigation was done daily. Foliar application of humic acid with concentration of 0.001 liter was performed from seedling emergence to transplanting every two days. The germinated seeds was daily counted and number and rate of seed emergence was estimated. Plant height, stem diameter, number of internodes, leaf area, shoot and root dry matter and chlorophyll contents were calculated at transplanting time of seedling.
The substrate treatment had a significant effect on rate and percent of germination, plant height, shoot dry matter, leaf area, number of internodes and, chlorophyll a and carotenoid contents. According to the results, the greatest and smallest rate and percent of germination ýwas found in peat and manure treatments, respectively. Also the greatest shoot dry matter (1.17 g), leaf area (125.9 ýcm plant-1), number of internodes (6.19), plant height (13.51 cm) and chlorophyll a concentration (2.55 µg/ml) ýwere observed for peat substrate. Manure and clay soil substrates showed the smallest of ýthese measurements and carotenoid contents. It seems that physical characteristics of peat was better than other substrates. Plant height, shoot dry matter, leaf area, number of internodes, chlorophyll a and carotenoid contents showed a significant effect by humic acid application. Foliar application of humic acid significantly increased the mentioned traits.
The results illustrated that between substrates in this study, peat was the best for seedling production of tomato. Foliar application of humic acid had a positive effect in improving growth characteristics of tomato seedling.