جستجوی مقالات مرتبط با کلیدواژه « کلروفیل » در نشریات گروه « اکولوژی »

Water stress is one of the main factors in crop growth in arid and semi-arid regions of the world, which limits the grain yield of the safflower (Carthamus tinctorius L.). To increase the soil fertility and yield of crops, it is necessary to pay sufficient attention to the use of biomass of organic matter, especially crop residues, and its conversion to biochar. This research aims to evaluate the biochar application produced from cotton and wheat residues under late-season water stress in the south of Fars province (Darab) on photosynthetic pigments, enzyme activity, yield components, and yield of safflower.
In order to investigate the biochar application and water stress on the amount of photosynthetic pigments, enzyme activity, and yield of safflower, a field experiment was laid out as split plots in the form of randomized complete block design with 3 replications in the 2019-2020 growing season. The experimental factors include the irrigation regime as the main factor in two levels (optimal irrigation and cutting off irrigation after the flowering stage), and the secondary factors were fertilizer treatment as subplot including control (without fertilizer), consumption of 3 tons of biochar from wheat residues per hectare, consumption of 3 tons of biochar from cotton residues per hectare, consumption of 150 kg of urea per hectare + 50 kg of triple superphosphate per hectare, consumption of 112.5 kg of urea per hectare + 37.5 kg of triple superphosphate per hectare, consumption of 112.5 kg of urea + 37.5 kg of triple superphosphate + 3 tons wheat biomass per hectare, and 112.5 kg of urea + 37.5 kg of triple superphosphate + 3 tons of cotton biomass per hectare. In this research, chlorophyll a and b, total chlorophyll, catalase, and peroxidase activities, yield components, and yield of safflower were calculated.
The results of the experiment showed that the measured traits were significantly affected by the irrigation regime and fertilizer treatment. Under cutting-off irrigation after the flowering stage, the fertilizer treatment of 112.5 urea + 37.5 phosphate + 3 tons of wheat biochar per hectare increased 55 and 40% chlorophyll a and total chlorophyll compared to the control, respectively. Water stress increased the carotenoid content, catalase, and peroxidase enzymes. The highest amount of catalase and peroxidase enzyme activity was obtained in the control under cutting-off irrigation after the flowering stage, which increased by 48 and 38%, respectively, compared to the control under optimal irrigation. The number of seeds per capitule and the number of fertile capitules per plant in the treatment of 112.5 urea + 37.5 phosphate + 3 tons of cotton biochar under water stress conditions increased by 8.8 and 19.51%, respectively. Also, under water stress, the application of 112.5 urea + 37.5 phosphates + 3 tons of cotton biochar improved and increased the relative content of leaf water, biological capitules yield, and grain yield compared to the control by %53, %22, and %34, compared to control, respectively.
Results showed that in both of the irrigation regimes, application of 3 tons of cotton or wheat biochar alone can increase the biomass and grain yield compared to control. Overall, the application of 112.5 urea + 37.5 phosphate + 3 tons of cotton biochar under water stress conditions improved the relative water content of the leaves, the number of seeds per capitule, the number of fertile capitule per plant, and finally, biomass and yield of safflower. With respect to water shortage under late season in southern parts of Fars province, and in order to decrease the detrimental effects of water stress, farmers can use the biochar of cotton combined with reduced dosage of urea and triple superphosphate fertilizers.

Salinity stress is an important abiotic stress threatening the production of cotton in arid and semi-arid regions of the country and the world, which can be reduced by the proper use of organic materials. Cotton is the most important fiber product, which is widely cultivated for agricultural and industrial purposes in temperate and hot regions of more than 15 countries of the world. Although cotton is known as a salinity-tolerant plant, not only is the resistance to salinity limited in this plant, but different stages of development also show different reactions to salinity. One of the effects of stress is disturbing the nutritional balance in the plant. Proper nutrition during times of stress can partially help the plant deal with various environmental stresses. In this regard, by using fertilizers containing micronutrient elements, firstly, plant yield increases, secondly, increasing the concentration of these elements in agricultural products plays an important role in improving the quality of food consumption. Using organic fertilizers, especially organic and animal manure such as humic acid, can improve the performance and performance components of different products under stress conditions.

To study the effect of manure and humic acid on some of the physiological qualities of cotton under salt water salinity stress, an experiment was conducted as factorial split plots (factorial split plot) in which different levels of irrigation water salinity at three levels (2.5, 5.5 and 8.5 ds.m-1) as the main factor and two treatments of manure at two levels (0 and 20 t/h) and humic acid at two levels (0 and 200 gr/100 kg of seeds) as sub-factor in 4 replications in a farm located in Boshrouyeh city in 1398 years. The software SAS (V9.1) and Excel were used to analyze the data and draw the figures. Means were compared using the FLSD test at a 5% probability level.

Analysis of variance results showed that the simple effects of three experimental factors (salinity stress, manure, and humic acid) were significant on all studied traits (on the relative water content, Electrical conductivity and membrane stability, chlorophyll a and b contents, and proline content). With increasing salinity level, increased proline content (286.5%), membrane Electrical conductivity (4.2%) and carotenoids (88.79%) and decreased chlorophyll a (20.7 1 %) and b content (39.38%), relative water content (23.16%) and membrane stability (13.54%). The application of animal manure and humic acid increased the relative water content, membrane stability and chlorophyll content under stress conditions, which indicates the modifying effect of these fertilizers in reducing the adverse effects of salinity stress. The interaction effects were significant, too.

The results of this research showed that the use of water with high salinity, such as salinity of 8 ds.m-1, caused significant changes in the physiological traits of the plant, including relative leaf water content, membrane stability, membrane electrolyte leakage, chlorophylls, and proline. With increasing salinity levels, the amount of proline, membrane electrolyte leakage, and carotenoid increased, and the content of chlorophyll a and b, relative water content, and membrane stability decreased. The application of animal manure and humic acid increased the relative water content, membrane stability, and chlorophyll content under stress conditions, which indicates the moderating effect of these fertilizers in reducing the adverse effects of salinity stress. Considering the positive effects of using organic fertilizers in this experiment, it is recommended to test and investigate the use of humic acid during the growing season in addition to the use of animal manure before planting and the use of humic acid in bulk Thus, it is suggested to use humic acid and animal manure in cotton cultivation to adjust the salinity levels.

Vetches are especially important due to their resistance to cold and water-deficient stresses, and due to the high amount of crude protein and detergent fibers, they have the same nutritional value as alfalfa and clover. Planting vetch can increase soil nitrogen due to the symbiosis of its root nodes with Rhizobium bacteria. No-tillage reserves more moisture in the soil than other tillage systems. No-tillage and reduced tillage significantly increase mycorrhizal fungi in soil compared to conventional tillage. Increased leaf area index (LAI) and dry matter in plants under reduced and no-tillage systems have been observed, too. Also, increases in chlorophyll concentration, decreases in canopy temperature, increases in plant height and improvements in forage quality in plants under a no-tillage system have been reported. This experiment evaluated the effects of different types of tillage on morpho-physiological traits related to yield and quality of vetch forage to protect the soil and select the best tillage system.

This experiment was carried out in Saral Rainfed Agricultural Research Station located 55 km north of Sanandaj county, Kurdistan province, in the west of Iran. The effects of reduce tillage (RT), no-tillage (NT) and conventional tillage (CT) systems were evaluated on rainfed vetch in rotation with wheat during two years (2018-02019). Sowing date was 18 and 9th of October in the two experimental years respectively. All sampling of rhizobium nodules, relative leaf water content, leaf area index, chlorophyll and carotenoids, chlorophyll fluorescence, canopy temperature, enzymes, proline, hydrogen peroxide, malondialdehyde, leaf soluble proteins and carbohydrates, leaf elements took place in early seed filling stage. The combined (2-year data) analysis of variance (ANOVA) was performed using SAS software by the general linear model (GLM). The means value were compared using Duncan’s range test at P ≤ 0.05.

In this study, the yield of dry forage in reduced and no-tillage systems increased by 14 and 24%, respectively, compared to CT. A significant relationship (R = 0.75*) was obtained between the relative leaf water content and dry forage yield. According to the results, vetch in the no-tillage system had the highest percentage of colonization (30.16%), the number of fungal spores (179.8), and rhizobium nodes (12.16) on the roots. The high symbiosis of mycorrhizal fungi in RT and NT compared to CT was probably due to higher water uptake and higher RWC. In the present study, vetches under the NT system probably had higher chlorophyll a and b concentration due to more moisture and higher nitrogen and phosphorus in leaves. The results showed that the tillage treatments had significant effects on the activity of reactive oxygen species (ROS), which was directly related to the amount of plant moisture and antioxidant enzymes. The lowest activity of enzymes was in vetches under a no-tillage system. 

In this experiment, reduced and no-tillage systems increased yield compared to conventional tillage. Significant increases in relative leaf water content and canopy temperature difference were observed in different types of tillage. Chlorophyll content and carotenoids in plants grown in the conventional tillage were lower than in reduce and no-tillage systems. The percentage of colonization, sporulation of mycorrhizal fungi, and the number of rhizobium nodes were higher in no-tillage system. The levels of antioxidant enzymes, hydrogen peroxide, malondialdehyde, and proline increased in CT compared to RT and NT. Types of tillage in rainfed conditions due to biological and structural changes in the soil cause positive morpho-physiological changes and forage quality in rainfed vetch seem to be effective in increasing yield and improving growth conditions.

Intercropping reduces the application of chemical pesticides to control pests and weeds, reducing the environmental risks associated with chemical pesticide application (Himmelstein et al., 2017). Biochar is a soil amendment because of its potential to retain water and nutrients, prevent nitrogen leaching, increase soil fertility, and improve plant growth (Fang et al., 2018; Munoz et al., 2016). Other benefits of vermicompost are increased stability of soil resources, maintenance of production, reduction of environmental pollution, and increased soil biological activity too (Demir, 2019). Therefore, the purpose of this study was to investigate the quality of forage turnip (Brassica rapa var. rapa) leaves in different intercropping ratios of forage turnip and basil (Ocimum basilicum) using biochar as soil amendment and vermicompost.

A biennial study was conducted on the quality performance of forage turnip (Brassica rapa var. Rapa) in the form of split-plot factorial in a randomized complete block design with three replications in the research farm of Islamic Azad University of Karaj in two years (2018-2019). The treatments of this study include: intercropping in four ratio (100% forage turnip (monoculture), 90% forage turnip + 10% basil, 80% forage turnip + 20% basil, 70% forage turnip + 30% basil), in main plots, and vermicompost in two levels (15, 18.5 ton.ha-1) and biochar in two levels (No consumption and 5 ton.ha-1) which was placed in subplots. The forage turnip cultivar was PacFB05. In this study, Photosynthetic pigments were measured by the Arnon  (1967) method, membrane permeability (Ferrat and Loval, 1999), relative moisture content (Bertin et al., 1996), soluble leaf sugars (Sheligl, 1986), catalase (Dazy et al., 2008) and soil respiration (Isermeyer, 1952). Using SAS software (Ver.9) for data analysis of a two-year experiment and analysis of means was done with Duncan’s test in significance at 5% probability level. Excel software was used to plot the graphs.

The results of this study indicated that by increasing the ratio of basil in intercropping, the quality traits of forage turnip leaves increased. Consumption of biochar and application of vermicompost at the level of 18.5 ton.ha-1 increased the quality of forage turnip leaves. The highest chlorophyll a ((17.52 mg.g-1Fw), chlorophyll b (8.76 mg.g-1Fw) total chlorophyll (26.38 mg.g-1Fw), carotenoids (6.91 mg.g-1Fw), relative water content (59.54%), of soluble sugars (69.43%), catalase (0.018 micromole Fresh weight/min) were due to the interaction of (70% forage turnip + 30% basil) × vermicompost 18.5 ton ha-1 × application of biochar. The highest value of membrane stability index was related to 100% forage turnip × vermicompost 15 ton ha-1 (4.85 (mol.ml-1.s-1)). The highest amount of soil respiration is associated with the interaction of vermicompost 18.5 ton.ha-1 × 70% forage turnip + 30% basil with value of 0.28 (micromole.gsoil-1.hour-1)), interaction of biochar ×70% forage turnip + 30% basil (0.32 (micromole.gsoil-1.hour-1)), and interaction of vermicompost of 18.5 ton.ha-1 × biochar 0.31 (micromole. g soil-1.hour-1). Due to the potential of biochar (water and food retention and prevent of nitrogen leaching) it can increase the availability of water and nutrients for the plant, which leads to increased photosynthesis of the plant and thus the quality of forage turnip leaves (Akhtar et al., 2015; Hammer et al., 2015). Vermicompost increases soil organic matter and the uptake of zinc, copper, iron, phosphorus, potassium, and nitrogen in soil. The presence of these elements in the soil and their absorption by the roots increases vegetative growth and leaf production in the plant, which causes the level of light absorption, photosynthetic level, the formation of hydrocarbons in the leaves, and the resulting growth also increases leaf quality (Theunissen et al., 2010).

The results of this study indicated that the application of vermicompost ​​18.5 ton ha-1 and biochar increased forage turnip quality, which is due to the availability of water and nutrients for forage turnip. The best intercropping ratio was related to 70% forage turnip + 30% basil, which can be said to be due to the increase in the percentage of basil and the competition of plants for better use of intercropping components of growth sources such as light, water, and food.

  This research was carried out to investigate the effect of different substrate and spraying of seaweed extract on growth, yield and nutrient content of karla .

this research was carried out in a factorial design based on completely randomized design with four replicate in pots under hydropnic condition in rUniversity of Researcher Ardabil University. The first factor includes combination of substrate 50: 50 ratios (100) ratios (sawdust + cocopes, sawdust + perlite, sawdust + vermiculite, perlite + cocopeat, cocopeat + vermiculite, vermiculite + perlite) and second factor of leaf spray with Ascophyllum nodosum seaweed extract in four Concentration (0, 0.5, 1 and 2 grams per liter) and in control treatment was sprayed with distilled water.

The results showed that the highest amount for plant height (3.79 m) in vermiculite-cocopeat substrate and seaweed extract concentration of 1 g / l and the highest value for plant fresh weight plants (575.49 grams), dry weight (27.29 g), root fresh weight (149 / 81 g) and fruit yield (1492/50 g) were obtained in vermiculite-perlite treatment with a concentration of seaweed extract of 1 g / l, also in plant dry weight traits (138.36 g), fresh weight of fruit (33.36 g) In combination of vermiculite-perlite substrate and foliar spraying of 2 g / l from seaweed extract and .

 the results of this study indicated that the use of seaweed extract and perlite-vermiculite had the greatest impact on growth of karla in comparison to other treatments

This experiment was performed to investigate the effects of drought stress and nitrogen fertilizer on yield, yield components and some physiological characteristics of four wheat cultivars.

The experiment was carried out in double split plots in a randomized complete block design with three replications in the research farm of Isfahan University of Technology. Experimental factors include two irrigation regimes (irrigation 100 and 50% of plant water requirement for normal and drought stress, respectively), two levels of nitrogen fertilizer (soil content and use of 150 kg urea per hectare) and wheat cultivars (Pishtaz, Bahar, Sepahan and Star).

Drought stress decreased grain and biomass yield by decreasing the content of chlorophyll a, b, carotenoids and leaf relative water content as well as increasing the amount of ion leakage. The use of nitrogen under normal irrigation conditions increased grain and biomass yield, but under drought stress conditions increased biomass and decreased grain yield. Pishtaz cultivar had the highest grain yield (4710 kg / ha), and Star cultivar had the highest amount of biomass (11639 kg / ha). Also, the highest grain and biomass yield were observed in normal irrigation and nitrogen treatment.

The use of nitrogen to increase yield depends on the amount of water available to the plant, and under drought stress conditions, the use of nitrogen is not only a good way to reduce the impact of water stress and yield, but also intensify stress and reduce grain yield of studied wheat cultivars.

For centuries, medicinal, functional, and nutraceutical herbs have been used for food and medicinal purposes. Lallemantia species are versatile and can be used for lightening, varnish, painting, food, and medicine. The genus is distributed in several countries, including Afghanistan, Pakistan, India, China, Syria, Iraq, Turkmenistan, Tajikistan, Kyrgyzstan, Kazakhstan, Uzbekistan, Russia, and some European countries. Lallemantia iberica belongs to the Labiatae family, which has about 220 genera and almost 4000 species worldwide, with 46 genera and 410 species and subspecies in Iran. Dragon’s head seed is a good source of polysaccharides, fiber, oil, and protein, with medicinal, nutritional, and human health properties. Its high mucilage content allows it to absorb water quickly, producing a sticky, turbid, and tasteless liquid, which can be used as a novel food hydrocolloid in food formulations. Given the increasing consumption and high economic value of dragon’s head medicinal plants, research on planting factors of this plant is necessary. The aim of this study was to evaluate some traits, such as grain yield, oil yield, percentage, and mucilage yield of five dragon’s head medicinal plant accessions.

The experiment was carried out in the research farm of Lorestan Agricultural and Natural Resources Research and Training Center in the 2018 crop year. The research farm's geographical coordinates are longitude 48°35′N and latitude 33°48′E, elevation above sea level is 1147.8 meters, average rainfall is 525 mm, and average temperature is 14.13 °C. Khorramabad region has a subtropical climate with hot and dry summers and a temperate climate based on long-term statistics. The experiment was performed on a randomized complete block design with three replications, including five dragons’ head accessions (Takab, Kaleibar, Kurdistan, Nazarkahrizi, and Jolfa). Traits evaluated included grain yield, biochemical traits, and photosynthetic pigments. Data analysis was done using SAS 9.1 statistical program, and means were compared using Duncan's multiple range test at the 5% probability level.

Analysis of variance showed that grain yield, oil yield, mucilage yield, 1000-grain weight, biological yield, and harvest index were affected by mass. According to the comparison, the highest mean of grain yield, oil yield, biological yield, and mucilage yield were obtained in Kaleibar mass and ranked next in Takab mass. The lowest grain and oil yield were obtained in Julfa mass. In the dryland conditions of Khorramabad region, Kaleibar massif was superior to other masses in terms of the studied traits. Correlation analysis in rainfed conditions showed that grain yield had the highest correlation coefficient with oil yield, mucilage yield, and biological yield. Pearson correlation between the studied traits and grain yield showed a significant correlation between grain yield and oil yield, mucilage yield, biological yield, and harvest index. Grain yield also correlated significantly with oil content, mucilage percentage, 1000-grain weight, chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids. The highest positive and significant correlation was observed between chlorophyll b content and total chlorophyll content.

The study found that mass had a significant effect on the evaluated traits.ConclusionThe study found that mass had a significant effect on the evaluated traits.  The highest grain mucilage yield, grain oil, biological yield and also grain yield were observed in Kaleibar mass and then in Takab mass. There was a significant difference with other dragon’s head accessions. The lowest grain yield, mucilage yield, grain oil yield and biological yield were also obtained in Julfa massif. According to the experimental findings, in dryland conditions of Khorramabad region, Kaleibar mass are suitable for cultivation first and then Takab mass and have acceptable yield and can be recommended for cultivation in similar conditions.

The appropriate amount of nitrogen consumption and the positive effects of wheat straw mulch in medicinal plants are important to reduce the negative effects of drought stress and achieve high yield.

In this study, the growth and yield of black seed by combining nitrogen and wheat straw mulch at different irrigation intervals. This research was conducted as a split plot in a randomized complete block design. The first factor is different irrigation intervals in three levels including 25, 50 and 75% moisture drainage and the second factor in six levels includes 50 and 100 kg of urea per hectare in combination with mulch and consumption alone, mulch and control.

Increasing irrigation intervals decreased the amount of leaf elements. Also, an increase in ion leakage and decrease in the relative leaf water content were observed in 75% of moisture depletion. Application of wheat straw mulch was able to reduce ion leakage of black seed under drought stress conditions. Urea was effective in increasing nitrogen uptake and as a result increased the amount of photosynthetic pigments. At 25% moisture discharge, shoot dry weight per 100 kg of urea with wheat mulch and consumption alone showed an increase of 8.7% and 7.1%, respectively, compared to the control. The highest harvest index and yield components were observed in the use of mulch in combination with urea.

In total, the application of 100 kg of urea per hectare in combination with wheat straw mulch for planting black seed is recommended.

Crop residue management is one of the main pillars of production in agriculture and in the long run plays an important role in increasing or decreasing crop yields. Adequate amount of potassium sulfate fertilizer in the soil modulates the osmotic pressure in the soil. in this way, the plant's ability to withstand drought increases. Due to the fact that sour tea is one of the most important medicinal plants in Sistan, so it needs more study and research. Therefore, this experiment was conducted to investigate the effect of tillage systems combined with crop residue management and application of potassium fertilizer on yield and some physiological characteristics of sour tea in Sistan climate.

In order to investigate the effect of tillage systems with crop residue management and application of potassium fertilizer on yield and some physiological characteristics of sour tea, an experiment was conducted in the research farm of zabol university agricultural research institute in 2018-2019 as a split plot-factorial in the form of complete block design. randomization was performed in three replications. experimental factors including tillage systems at three levels without tillage, reduction tillage (disc) and conventional tillage (plow + disc) as the main factor and the combination of plant residues at three levels (zero, 30 and 60%) with potassium sulfate fertilizer at three levels (no fertilizer, 75 and 150 kg  ha-1) were considered as secondary factors. measurements were: economic yield, biological yield, harvest index, chlorophyll a, b and carotenoids, anthocyanins, flavonoids and protein.  statistical analysis of data was done with SAS software version 9.1 and mean comparison with duncan test was conducted at 5%.

The results showed that the use of tillage systems and their interaction on the studied characteristics were significant, However, plant residue treatments and their interaction on the studied characteristics except harvest index and anthocyanin were significant, Potassium sulfate treatment and its interaction on the studied properties except harvest index and flavonoids were significant. The highest economic yield of sour tea was equal to 3221.7 kg  ha-1 in the reduced tillage system with 60% of crop residues and 150 kg  ha-1 of potassium sulfate and The highest amount of sepal anthocyanin was obtained from conventional tillage treatment and combined use of 30% residues and 75 kg  ha-1 of potassium sulfate and Conventional tillage and combined use of 30% residues and 75 kg  ha-1 of potassium sulfate increased chlorophyll a, b and carotenoids. Also, non-tillage and conventional tillage treatments increased the amount of flavonoids and protein at the branches. The results of comparing the means of interaction of tillage systems with crop residue management and application of potassium sulfate show that the highest increase in chlorophyll a and carotenoid content of conventional tillage is + 30% of crop residues and 75 kg  ha-1 of potassium sulfate And the highest increase in chlorophyll b was the simultaneous use of conventional tillage + 60% of crop residues and 150 kg  ha-1 of potassium sulfate. the highest amount of protein was related to conventional tillage treatment with zero percent of crop residues and potassium sulfate, the results of comparing the means on the interaction of the treatments showed that the simultaneous application of no-till treatment with zero percent of crop residues and potassium had the best effect on the amount of flavonoids.

The results indicate that the effect of tillage systems combined with crop residue management and application of potassium sulfate in increasing quantitative and qualitative characteristics has had the best results. Under conservation tillage, by reducing tillage operations and maintaining a sufficient amount of plant residues in the soil surface, while improving soil structure and increasing water efficiency and nutrient efficiency, that increased quantitative and qualitative characteristics. Despite the dry climate in the country and the limitations and shortages of water and reducing soil fertility on the one hand and increasing environmental pollution on the other hand, the need to use conservation agricultural systems to maintain yield and stability and ultimately stability and balance of environmental factors is necessary it seems.

This study is to investigate the effect of Thiobacillus inoculant and sulfur bio bacteria on less water stress in Khatouni melon plants.

the aim of the experiment was conducted with split plots in a three-replication randomized complete block design.Irrigation regime as the main plot with levels of 100, 75 and 50%of melon water requirements and fertilizer treatments as a sub-plot with three levels of thiobacillus (without inoculum, 250 and 500 kg sulfur per hectare along with 5 and10 kg of bacterial with a population of 107 bacteria per gram inoculum).

The results study indicate that all studied agronomic traits affected by stress, so that drought stress had a significant impact on all traits. On the other hand, sulfur plus thiobacillus reduced the negative effects of water stress and led to significant increases in total chlorophyll content, carotenoids, number of fruits per plant, and fruit weight at various levels of drought.Thus,application Third level of sulfur, A significant effect of drought stress interaction with the sulfur application was seen on all traits studied except for conductance at level of one percent.

The application of sulfur and thiobacillus can improve growth traits and increase yield, irrespective of its irrigation level. Moreover, the use of sulfur and thiobacillus in the treatment of dehydration results in 75% of the water requirement of 500 kg sulfur per hectare with 10 kg of Thiobacillus. It was also observed that with increasing dehydration stress , effect of sulfur and thiobacillus on improving growth traits declined.

Background & Adjective:

 In the recent years, studies have been focusing on the use of safe and biocompatible compounds to reduce the damage caused by drought stress. In this study, the effect of exogenous application of methyl jasmonate in modulating the effects of drought stress on Physalis plants and improvement of antioxidant activity was evaluated.

In the present study, drought stress at 3 levels (100, 75 and 50 % of field capacity) and different concentrations of methyl jasmonate at 3 levels (0, 10 and 100 μM) were used as the experimental factors.

According to the results, drought stress significantly reduced fresh and dry weight, relative water content, chlorophyll a and b, carotenoids and beta-carotene in physalis leaves while total phenol and flavonoid content and antioxidant activity (fruits and leaves), soluble sugar, proline and malondialdehyde (leaves) increased under drought stress conditions. Foliar application with methyl jasmonate reduced the negative effects of drought stress in physalis plants by affecting the relative water content, chlorophyll content, membrane stability (decrease of malondialdehyde), and increasing compatible solutions (soluble sugar and proline), total phenol and flavonoids and antioxidant activity so that the fresh weight of the fruit increased (54.73%) by spraying 100 μM methyl jasmonate in the second level of stress.

In general, the results of the study showed that foliar application of methyl jasmonate, especially at 100 μM concentration, reduced the effects of drought stress on the physalis plants, and improved antioxidant activity and fruit weight, thus improving the yield.

Following climate change, drought stress has become the most important limiting factor for crop production and. Plants become under dry when the water available to the roots is limited or the water loss through transpiration is very high. Decreased photosynthetic active radiation absorption, impaired light consumption efficiency and reduced harvest index are the most important factors reducing yield in soil moisture deficit conditions. On the other hand, the adverse effects of the use of chemical drugs in recent years have led to much attention to the cultivation of medicinal plants, which with the increase in their use requires the development of cultivation, management and proper planning. Bio-fertilizers as an alternative in some cases and in most cases as a complement to chemical fertilizers can help to ensure the sustainability of agricultural production systems.

 The study was aimed to evaluate the effect of nitroxin biological fertilizer on ecotypes of black cumin under drought stress. The experiment was conducted as a split-split plot with three replicates at Ilam University during growing season of in 2018. Drought stress levels including no stress (Irrigation based on 100% of plant water needs), moderate stress (Irrigation based on 50% of plant water needs) and severe stress (Irrigation based on 35% of plant water needs) as main plot, nitroxin fertilizer treatments including no nitroxin (control) and application of 1 liter ha-1 nitroxin as sub plot and ecotype treatments including Neyshabour, Mashhad, Semirom and Isfahan Sub-plots were considered as sub-plots. Measured traits included plant height, number of sub-branches, yield, grain yield components (number of follicle and number of seeds per follicle), relative leaf water content, ion leakage and photosynthetic pigments.

 The results showed that the main effect of drought stress, nitroxin and ecotype on all treats were significant (p≤0/01). The highest plant height and the first sub-branch height of Mashhad ecotype were obtained under Irrigation based on 100% of plant water needs conditions under moderate stress. The highest number of branches per-plant of Neyshabur ecotype was obtained under nitroxin under drought stress conditions. The highest number of capsules per plant was obtained from Mashhad ecotype treatment with no nitroxin and Irrigation based on 100% of plant water needs. The highest number of seeds in main capsule, seed yield and harvest index were obtained from Semirom ecotype under nitroxin under Irrigation based on 50% of plant water needs. The highest biological yield was obtained in Isfahan ecotype, nitroxin consumption and Irrigation based on 50% of plant water needs.The results of this study showed that drought stress caused a significant reduction (p≤0.01) in the values of chlorophyll a, b and total chlorophyll traits and relative moisture content of leaves Meanwhile, the use of nitroxin biological fertilizer in most cases improved these traits in different ecotypes, which can be due to the positive effects of biological fertilizer in helping to better absorb water and nutrients under drought stress and reduce the negative effects of water deficiency on Physiological traits of the plant.

 Since better absorption of nutrients depends on the existence of an extensive root system, it seems that the lack of expansion of the plant root system under drought stress and the lack of use of chemical fertilizers, the ground for the activity of microorganisms. This has led to the improvement of the root system and consequently better absorption of water and nutrients needed by the plant in conditions of moisture stress. In general, the results of this study indicate that the application of biological fertilizers may have had a positive effect on improving the yield and quantitative properties of the herbicide under drought stress conditions, however, this issue needs further investigation. From the results it can be concluded that moderate drought stress can be applied in weather conditions Ilam province in addition to reducing water consumption will lead to better outcomes.

To evaluate the effects of organic fertilizer (control, 30 ton/ha cow manure and 15 ton/ha vermicompost) and foliar treatment (control, 50 mgL-1 Salicylic acid (SA), 2CC/Litter alge extract) on the growth and productivity of two native (Tabriz and Esfahan) pumpkin clone, a factorial experiment as randomized complete block design with 3 replications was conducted during the 2018- 2019 under field condition.

The reults showed that plant heights, leaf area, leaves number, total flower number, fruit number, P and K content were effected by the organic feartilizers, and foliar spray with algal extract. P content was affected by the plant clone and the higher amount was belonged to Tabriz. The freash and dry weight plants, total flower number and fruit number affected by the individual effects of organic fertilizer and interactions of year × plant clone. Plant weight was influenced by organic fertilizer × marmarin and SA spray. The yield was impacted by the interactions of year × clone, year ×fertilizer, clone × fertilizer and the individual effects of organic fertilizer. Soil based organic fertilizer with foliar used marmarin and the organic fertilizer × SA increased chlorophyll a and b content. Chlorophyll a content was affected by the year as well as the second year had the more data. Silisium content was responsive to the sole effects of organic fertilizer interaction of clone × organic fertilizer.

This study was to investigate the effect of biochar and salicylic acid on sorghum (Sorghum bicolor var.Speed feed) physiological and biochemical changes under lead stress conditions

The experiment was carried out as a factorial experiment in a completely randomized design with 4 replications in greenhouse in 2019. The treatments of this experiment include five levels of lead (0, 400, 800, 1200 and 1600 mg of lead per kg of soil from lead nitrate source), two levels of biochar (no consumption and consumption of biochar 20 g of biochar per kg of soil) and two levels of acid salicylic acid (including non-foliar and 2 mM salicylic acid foliar).

The results showed that consumption of biochar and salicylic acid increased chlorophyll a by 5.25 and 4.81%, respectively. The highest amount of carotenoids was obtained in the combined treatment of biochar consumption and salicylic acid foliar application. Phenol levels increased with increasing lead levels, which was greater in plants sprayed with salicylic acid. Also, the amount of flavonoids increased by 10.57% under the influence of biochar consumption. The interaction of biochar and salicylic acid increased proline, and this increase was 88.48% compared to the control.

Therefore, the use of these cheap and available materials in the soil can be a suitable and cost-effective method to reduce soil contamination to increase the metabolic activity of sorghum plant, improve plant resistance to lead stress.

In order to investigate the effect of density and urea fertilizer on agronomic characteristics of corn hybrids and dry matter accumulation in pigweed.

The Experimental during two cropping years, a factorial split plot was used as a randomized complete block design with four replications. The main factors included corn cultivars (Single Cross hybrids of 370 and 704) and sub factors included different levels of corn densities (60000, 70000, 80000 and 90000 plant/ha) and different levels of nitrogen fertilizer including 200, 300, 400 and 500 Kg.ha-1.

The results showed that effect of density on all traits was significant, but the effect of cultivar on chlorophyll and nitrogen effect on number of ear per square meters were not significant. Corn cultivar of 704 had significantly higher number of grain per spike, 1000-grain weight and grain yield compared to cultivar 370 but the number of spikes per square meters was significantly lower than that of cultivar 370 and there was no significant difference in chlorophyll index between the two cultivars. The highest grain yield was obtained at densities of 80000 plants pet hectare and application of 400 kg N per hectare. The lowest weed biomass was obtained at density of 90,000 plant/ha and application of 200 kg N per hectare. However, cultivar 704 significantly decreased pigweed biomass compared to cultivar 370.

Based on the results, it is recommended that farmers in Miandab region use 80,000 plant/ha and 400 kg nitrogen per hectare for optimum yield.

The aim of this study was to investigate the effect of planting date, biofertilizers and nitrogen levels on the quantitative and qualitative characteristics of sweet corn (Ksc403su hybride).

This experiment was conducted as a factorial in form of a randomized complete block design with three replications in Takestan during the two cropping years 2016-2017 and 2017-2017. Planting date as first factor in two levels: d1: usual planting date of the region (June 15), d2: delayed planting date (July 15), application of nitrogen fertilizer as second factor in two levels: n1: recommended amount of nitrogen (300 kg.ha-1) and n2: 20 percentage less than the recommended amount (240 kg.ha-1) and the use of bio-fertilizer as third factor at four levels: b1: no bacteria (control), b2: bio-super phosphate, b3: azotobacter + azospirillium + Pseudomonas and b4: azotobacter + bio-sporphosphate were considered.
 

The results showed that the treatment of Azotobacter + Azospirillium + Pseudomonas with an average of 22219.8 kg.ha-1 had the highest grain yield, which had a 19% increase in yield compared to the control treatment (no use). Also, Azotobacter + Azospirillium + Pseudomonas and Azotobacter + biosphere phosphate treatment at 300 kg.ha-1 Nitrogen showed an average grain yield of 2377 and 2279 kg.ha-1, respectively. In terms of consumption of 240 kg.ha-1 nitrogen, the same combination of treatments had the highest grain yield, which was relatively superior to non-use of biofertilizer even in application of 300 kg.ha-1 nitrogen conditions. The first planting date is suitable for seed production. 

The combined use of nitrogen and phosphate stabilizing biofertilizers can reduce nitrogen fertilizer application by up to 20% to achieve maximum yield.

Salt stress is one of the main environmental factors restricting horticultural crop production. Exogenous salicylic acid (SA) can alleviate salt stress in plants. The objective of this study was to improving growth and physiological chracteristics in salt stressed Lantana camara Linn. by application of exogenous salicylic acid. 

In a factorial experiment and completely randomized design (CRD), three levels of SA (0, 0.5 and 1 mM) and five levels of salinity (0.5, 3, 5, 7 and 9 dS.m-1) with three replications per treatments were applied. 

The results showed that by increasing salinity levels, growth characteristics, chlorophyll a and b and potassium concentration significantly decreased, while the number of necrotic leaves, Sodium and the ratio of sodium to potassium increased. At high salinity levels, application of salicylic acid improved the growth characteristics of the plant such as height, final diameter of the main branch and shoot dry weight and relative water content of the leaves and reduced sodium content in compared to the control. Maximum number of plant branches (4.66), final diameter of main branch (6.11 mm), final diameter of cuttings (9.92 mm), number of leaves (28.66) and fresh and dry weight of shoots (14.80 and 7.46 g) were obtained in plants treated by 0.5 mM salicylic acid and in salinity of 0.5 dS. m-1. 

The use of 0.5 mM salicylic acid at high salinity levels significantly improved the growth and flowering characteristics of the lantana plant. Therefore, the use of 0.5 mM salicylic acid can significantly reduce the damage caused by the negative effects of salinity stress.

The study was performed to investigate the nutritional effects of elemental sulfur with Thiobacillus on morphophysiological and agronomic responses of mung bean.

The experiment was conducted in the form of a randomized complete block design with three replications in two experimental farms in Karaj city (Alborz province) and Shahriyar city (Tehran province) in the 2017 crop year. This experiment consisted of three treatments of sulfur fertilizer (control (S0), sulfur at 100 kg/ha with 2 kg of thiobacillus (S1), sulfur at 300 kg/ha with 6 kg of thiobacillus (S2)).

The results showed that all studied traits were significantly affected by sulfur fertilizer so that the highest amount of all tested traits was obtained in (S2) treatment in mung bean. The results also showed that all the studied traits except the number of seeds per pod, 1000-seed weight, protein percentage were significantly affected by the main effect of location so that the highest amount of all traits the test was obtained in the Shahriar area. The interaction of sulfur fertilizer and location also had a significant effect on the number of pods per plant, number of seeds per pod, grain yield, biological yield, harvest index, plant height, and total chlorophyll.

Therefore, it can be concluded that the nutritional effect of the combined application of sulfur and thiobacillus has improved the morphophysiological and agronomic characteristics of mung bean.

The pear is one of the most important fruit trees in temperate regions and is salt-sensitive trees. Studies have shown that the use of Piriformospora indica as an endophytic fungus reduces the adverse effects of salinity stress on plants and improves morphophysiological traits.

In the present study, the experiment was performed as a factorial completely randomized design with 5 replications on the pyrus rootstock CV Pyrodvarf in pot culture experiment. The first factor includes two levels of P. indica fungus (inoculation and non-inoculation) and the second factor is four salinity levels of soil (1.7, 3, 4.5 and 6 dS.m-1) using sodium chloride. After inoculation with the fungus, the salinity levels were applied to the plants.

The results showed that the interaction effect of salinity × fungi on morphophysiological characteristics, total chlorophyll content (P <0.05), branch diameter growth, electrolyte leakage, proline, soluble sugars, peroxidase and polyphenol oxidase enzymes and root colonization percentage (P <0.01) were significant. At the highest salinity levels (6 dS/m), fungal inoculation caused an increase in surface-to-root dry weight ratio (38.81%), branch diameter growth (31.14%), total chlorophyll (27.72%), peroxidase (100%), polyphenol oxidase (62.5%) and root colonization percentage (100%) and decrease in electrolyte leakage rate (19.34%), proline (10.34%) and soluble sugars (8.77%) ) compared to non-inoculated control plants.

In general, the results of this study showed that the coexistence of P. indica can modulate the destructive effects of salinity on this pear cultivar.

Nowadays, the risk of degradation of wetlands is one of the main environmental challenges in the world, so continuous and long-term monitoring of ecological changes in wetlands can play a key role in their protection and proper management. In the present study, the trend of monthly changes in some of the most important ecological indicators of the aquatic environment of Shadegan wetland including WST, NDVI, MVWR, VWR, LSWI, MNDWI and Chlorophyll-a concentration (during 2003-2017) was evaluated using MODIS satellite imagery. The Mann-Kendall and Sen’s slope tests were used to analyze the trend and its magnitude, respectively. Results showed a significant increasing trend in the volume of water in Shadegan wetland, while the vegetation of the wetland had a significant decreasing trend during the study period (p <0.05). Also, the change in the monthly trend of NDVI, MVWR, MNDWI and LSWI time series was observed around October 2012, which approximately coincided with the development of aquacultural facilities in the northern part of this wetland. In addition, a strong inverse correlation (about -0.86) was observed between vegetation and water indices. Results further provided evidence of an inverse sequence and critical conditions in Shadegan wetland. Integrating remote sensing techniques and statistical methods in this study (to provide continuous time series of ecological indicators) can help to better understand the dynamics of wetland ecosystems (at different temporal and spatial scales). This approach is also applicable in evaluation, modeling and prediction of ecological changes in Shadegan wetland.