جستجوی مقالات مرتبط با کلیدواژه « آب شور » در نشریات گروه « زراعت »

Nowadays, the cultivation of plants adapted to adverse conditions, such as drought and salinity, in the country has been considered. Meanwhile, Kochia scoparia, one of the forgotten plants, due to its classification in the group of halophytes, has specific characteristics suitable for cultivation in low-water and saline areas (Salehi, Kafi, & Kiani, 2012). This plant is known as an important annual forage crop, and its grains also have high nutritional value and oil, which can be considered for future industrial applications (Salehi et al., 2012). Studies on the salinity tolerance of the Kochia plant have shown that it is suitable for cultivation in saline areas, and in terms of quantity and quality, can compete with conventional forage plants. The use of natural organic materials, such as humic acid, has received more attention. These materials, as part of soil organic matter, are influenced by physical, chemical, and microbiological changes in biological molecules (Sabzevari & Khazaei, 2009; Dong, Córdova-Kreylos, Yang, Yuan, & Scow, 2009). Additionally, nitrogen is the most important element needed for plant growth and development. It is also a key component in many biological compounds, including proteins, nucleic acids, some hormones, and chlorophyll. Nitrogen plays an essential role in photosynthetic processes and the final function of plants (Kaur, Gupta, & Kaur, 2002; Taiz, Zeiger, Møller, & Murphy, 2015). As a result of this research, a combination of nitrogen and humic acid can be used as nutritional resources in salt stress conditions.

This experiment was conducted in the form of split plots based on the randomized complete block design with three replications in the Saline Research Farm of Ferdowsi University of Mashhad in the 2015 growth season. The main plot included drought stress with a four-week interruption of irrigation at three levels of control (irrigation until the end of the growing season), after establishment (50 days after planting), the beginning of flowering (71 days after planting) and late flowering (82 days after planting) The subplot was included nitrogen application at three levels of zero, 100 and 200 kg.ha-1 from urea fertilizer source. The optimum level of humic acid (2 per thousand) was done as seed at the time of planting for all treatments.

The results showed that the drought stress during vegetative and reproductive growth stages had a negative effect on the Kochia plant. However, its effect in the early stages of vegetative growth (after establishment) was greater than the stress at the end of the season (late flowering). Drought stress has a negative effect on Kochia grain yield by reducing the concentration of chlorophyll a, altering the chlorophyll a to b ratio, decreasing carotenoid concentration, and affecting relative leaf water content. However, seed treatments of humic acid and its combination with 100 kg.ha-1 nitrogen level by increasing the concentration of total phenol, soluble carbohydrate concentration, and DPPH free radical scavenging capacity improved photosynthetic pigments and finally kochia grain yield. In general, the most suitable treatment for use in drought stress and saline water source conditions was the combined method of sowing humic acid seeds with 100 kg.ha-1 nitrogen fertilizer.

In general, the occurrence of drought stress in vegetative and reproductive growth stages had a negative effect on the kochia plant. However, its effect in the early stages of vegetative growth (after establishment) was greater than the stress at the end of the season (late flowering). The most suitable treatment was using the combined method of seed of humic acid with 100 kg.ha-1 nitrogen fertilizer.

Quinoa (Chenopodium quinoa Willd.) is a beneficial plant with high nutritional value with high tolerance to salinity and drought stress. Most of the experiments performed on the study of quinoa salinity stress tolerance in pot and greenhouse conditions were not comparable to the results of cereal experiment such as wheat and barley performed in field conditions. The purpose of this experiment is to determine the threshold value of quinoa to salinity stress under field conditions.

An experiment was performed as a split plot in a randomized complete block design with three replications on August 7, 2017 at Sadough Salinity Research Station of Yazd National Salinity Research Center. Experimental treatments including five quinoa genotypes including three quinoa lines (NSRCQE, NSRCQB, NSRCQC) with Titicaca and Sadough cultivars as subplots and irrigation water salinity at five levels of 2, 5, 10, 15 and 17 dS m-1 in the main plot. During the growing season, soil samples were taken from the plant root development area. Seed yield and yield components were measured. The percentage of saponin, seed vigor, 1000-seed weight and grain size were also measured.

The results of analysis of variance of the measured traits showed that the effect of salinity stress on plant height, 1000-seed weight and grain yield was significant at the level of 1%. The effect of salinity stress on grain size was not significant. Differences between genotypes in terms of plant height, grain yield, 1000-seed weight, biomass and grain size were significant at the level of 1% and panicle length and number of lateral panicles at the level of 5%. The interaction effect of genotype and salinity on biomass was not significant at 5% level and on other traits was not significant. The percentage of saponin between genotypes was significant at the level of 5%. The interaction effect of salinity and genotype on biomass and saponin percentage was significant at 5% level. The percentage of grain saponin increased significantly with increasing salinity in NSRCQB genotype and was not affected by salinity stress in other genotypes. Biomass of all genotypes except Titicaca was not significantly different up to salinity of 10 dS m-1. The highest biomass production in non-saline conditions was related to NSERCQE and Sadough cultivar and These two genotypes had the lowest decrease in biomass production with increasing salinity. Seed viability was not affected by salinity increase except in NSRCQB genotype seed vigour decreased by 15%. The lowest 1000-seed weight in non-saline conditions was related to NSRCQB genotype and the trend of 1000-seed weight loss with increasing salinity was similar to all genotypes and decreased by an average of 16%. The results of mean comparison showed that the highest yield at all salinity levels was observed in Sadough cultivar. Based on the results of the fitted linear equation, changes in quinoa seed yield to salinity showed that the salinity tolerance thresholds of quinoa genotypes were 4.3, 8.7, 4.1, 4.8, and 6.8 dS m-1 of electrical conductivity of saturated soil extracts, respectively. The soil and slope of the line were 3.5, 2.4, 0.1, 0.7 and 0.9%. Fifty percent reduction in wheat yield of Kavir and barley cultivars of Marvdasht cultivar has been reported at 15 and 20 dS m-1  of soil salinity, while Quinoa Sadough cultivar at 24 dS m-1  of electrical conductivity of soil saturated extract was 80% seed yield in non-saline conditions. Sadaogh cultivar not only have suitable agronomic characteristics and high production potential in saline conditions, but also has a higher salinity tolerance.

Quinoa has a higher tolerance to salinity stress than wheat and barley and can be a promising plant for using saline water and soil resources that are not economically viable for crop production. There is also a good variety among quinoa genotypes to select for using saline water.
Acknowledgments
This project has been done with the financial support of the Researchers Support Fund and the Agricultural Education and Extension Research Organization (AREEO).

To evaluate safflower genotypes under saline conditions and select tolerant genotype(s), 18 safflower genotypes obtained from Dryland Agricultural Research Institute, Iran, were planted at three salinity levels (2, 6, and 12 dS m-1) as main plot and genotypes randomized in subplots using split plots arrangements in randomized complete block design with three replications in Sadough salinity research station, Yazd, Iran, in 2016-17 and 2017-18 growing seasons. Gentypes were selected based on their performance at different salinity levels as well as using stress tolerance indices. The mean reduction in seed yield in the first and second growing season at 12 dS m-1 salinity level relative to control was 36% and 51%, respectively. The STI, MP, GMP, HM, Yis, Yip and MSTI1 indices were highly correlated with seed yield in three environments. Using principal component analysis the first component designated stress tolerance and the second component was salinity stress susceptibility. The results of cluster analysis using stress tolerance indices that had high correlations with seed yield showed that genotypes 4, 26, 34 and 35 were superior to control (cv. Faraman) and grouped in one group, however, genotype 6 performed the same as control. Selected genotypes had higher seed yield in three salinity conditions. In conclusion, LRV-57-57, 26-S6-58-11, Local Kurdistan, Isfahan 4 and PI-537682 with average seed yield of 172, 120, 152, 155 and 141 g m-2, at 12 dS m-1 salinity level, respectively, were selected as salinity tolerant genotypes.

Today, maintaining the quantity and quality of irrigation water are the most critical challenges in the agriculture system, especially in arid and semi-arid regions of the world. Accordingly, to evaluate the growth and yield responses of bread wheat (Sirvan cultivar) to different levels of deficit irrigation and water salinity, a factorial experiment was conducted in a randomized complete block design with three replications in the Research Field of Agriculture Faculty of the University of Birjand, at Birjand (east of Iran) during the growing seasons of 2016-2017 and 2017-2018. The experimental treatments included irrigation at five levels (125, 100, 75, and 50% of wheat water requirement and rain-fed with two supplementary irrigation at the first growing season) and saline water at two levels (1.6 dS/m and 6 dS/m). The results showed that growth characteristics, yield components, biological yield, and grain yield were affected by deficit irrigation water and saline water. These treatments significantly reduced all of the measured traits. The lowest leaf area was observed in rain-fed with 6 dS/m saline water treatment, which suppressed this trait by 61% compared to 125% water requirement with 1.6 dS/m saline water treatment. The highest and the lowest biological yield and grain yield were observed in 125% water requirement with 1.6 dS/m saline water and rain-fed with 6 dS/m saline water treatments, respectively. Non-significant differences were observed in biological and grain yield between 125% water requirement with 1.6 dS/m saline water and 100% water requirement with 1.6 dS/m saline water treatments. Biological yield and grain yield were decreased in rain-fed with 6 dS/m saline water treatment compared to 125% water requirement with 1.6 dS/m salinity treatment by 72% and 88%, respectively. Results of this study showed that although the greatest amounts of yield attributes were obtained upon using the 125% water requirement treatment, but these attributes were not significantly greater than the 100% water requirement treatment. Consequently, in areas with scarce water and saline water (6 dS/m), reliance on the 75% water requirement with 6 dS/m saline water and 100% water requirement with 1.6 dS/m saline water treatments may suffice to achieve an acceptable grain yield and to save water under saline water condition.

In order to investigate the effect of irrigation water salinity on some characteristics of Ajowan (Carum copticum L. C.B. Clarke), a field experiment has been conducted in a completely randomized design with 3 replications in Isfahan, Iran during 2013. The treatments involve different levels of saline water, namely 2.5 (control), 6, 9, and 18 dS.m-1. The determined traits include the yield, biochemical parameters, mineral contents, and seed essential oil content and quality. Results show that increasing salinity decreases biological yield and seed yield. Changes in essential oil components, caused by salinity, have been low, showing no specific trend. The major compound in the seed essential oil of C. capticum is thymol (56.1% to 61.2% of the essential oil). The highest concentration of total protein (root: 3.6 and shoot: 8.2 mg g-1 DW) is assigned to the control treatment, dropping significantly as salinity levels rise. Increasing salinity enhances the amount of proline and reducing sugars so that the highest amount of root proline, equal to 12 mg g-1 FW, and reducing sugars (root: 30.5 and shoot: 62 mg g-1 DW) comes from salinity of 18 dS.m-1. Increasing salinity levels raises the amount of phenolic compounds in the shoot, though this increase has not been considerable. The treatment of 18 dS.m-1 has had the lowest concentration of K+ (root: 5 and shoot: 22 mg g-1 DW) and the highest concentration of Na+ (root: 54 and shoot: 64 mg g-1 DW).It can be concluded that by increasing salinity levels, the amount of resistant osmolytes rises.

Salinity is one of the environmental abiotic stresses and most important factors limiting the growth and production of plants around the world, which dramatically affect various aspects of plant growth and development through anatomical, morphological and physiological changes (Siringam et al., 2011). Saline environments decrease the growth and yield characteristics of plants and increase some physiological properties such as proline content and electrolyte leakage (Noreen et al, 2010). On the other hand, in the recent years, the role of symbiotic fungi and polyamines in plants tolerance to environmental stress such as saline conditions are pronounced. Morever, due to the importance of medicinal plants, many researches of plant sciences have focused on the various aspects of the application of these plants (Vafadar et al., 2018). Therefore, the present study was conducted to investigate the growth and physiological response of stevia (Stevia rebaudiana Bertoni) medicinal plant to inoculation with endophytic fungi and foliar application of spermidine polyamine under salt stress conditions.

This experiment was conducted at research greenhouse of Genetics and Agricultural Biotechnology Institute of Tabarestan (GABIT) at Sari Agricultural Sciences and Natural Resources University using factorial arrangement based completely randomized design with three replicates in spring and summer of 2016. The treatment consisted of salinity in three levels (0, 6 and 12 dS/m), fungal symbiosis treatments including four levels [non-inoculated (control), inoculation with Piriformospora indica (Pi), inoculated with Trichoderma virens (Trich) and co-inoculation of two fungi (Pi+Trich)] and foliar application of spermidine in three levels (0, 0.75 and 1.5 mM). Seedlings of stevia after inoculation with fungi transfered to adaptation chamber for 40 days and then moved to the greenhouse. Plants were irrigated with tap water until the end of vegetative stage and then irrigated with saline water treatments containing mixture of distilled and Caspian sea water. The Spermidine was foliar applied one week before salinity stress. Two weeks after salinity stress, leaf samples were prepared to measure leaf relative water content (RWC), electrolyte leakage (EL), proline content and soluble sugars. Finally, the plants were removed from the pots and the growth and yield traits were measured.

The result showed that in saline conditions, endophytic symbiosis, especially Pi+Trich, increased the stem dry weight (40-64%) and leaf dry weight (44-50%), relative water content (5-30%) and proline content (40-64%), and reduced EL (11-20%). Also spraying 0.75 mM spermidine signiticantly increased both leaf dry weight and plant height. Fungal symbiosis, especially Pi+Trich, and spermidine 0.75 mM resulted in an increase in the RWC. Also, spraying with polyamine spermidine at both concentrations of 0.75 and 1.5 mM increased soluble sugars and inoculated with endophytic fungi, particularly co-inoculation of two fungi, led to a reduction in the content of sugar (17%) in the stevia leaf. At the most levels of salinity and fungal treatments, spermidine, especially at the rate of 0.75 mM, led to increase in stem diameter (10-35%) and leaf area (35-46%).

In general, the results of the present study indicated a negative effect of salinity on the growth and physiological characteristics of the stevia plants. However, inoculation of endophytic fungi, particularly co-inoculation of Pi and Trich, improved the growth and physiological parameters and ameliorated adverse effects of salinity in stevia plants. Morever, the spermidine (especially 0.75 mM) induced salt stress tolerance in stevia plants and showed a synergetic effects with endophytic fungi in terms of the mentioned parameters.

To evaluate response of seed yield, oil content and oil yield of eight safflower (Carthamus tinctorius L.) cultivars; Goldashat, Parnian, Padideh, Golmehr, Sofeh, Mexico 6, Faraman and Mexico 13 to saline irrigation water (5.5-6.0 ds m-1) using randomized complete block design with three replications in Zahak agricultural research station, Iran, in 2014 and 2015 cropping seasons. Combined analysis of variance showed that there was significant (P < 0.01) differences between safflower cultivars for all traits. The highest seed yield belonged to cv. Goldashat, cv. Parnian and Faraman with mean of 2753, 2407 and 2326 kg ha-1, respectively. The highest oil content belonged to cv. Faraman and cv. Mexico 13, respectively. The seeds no. head-1 (r = 0.64**), 1000 seed weight (r = 0.60**), and oil yield (r = 0.91**) had strong significant positive correlation with seed yield. Goldasht had the highest seed no. head-1, 1000 seeds weight and highest seed yield in comparison with other cultivars. Therefore, cv. Goldasht was identified as a suitable safflower cultivar for being grown under saline irrigation water conditions in Sistan region.

Salt stress is one of the important reasons of different problems in agricultural productions. Also, because of competition between sodium (Na+) with essential cations that necessary for cellular function, salinity cause to limit in absorption of mineral contents and growth reduction. One way of exciting salt from soil profile is using organic amendments such as biochar that recently has been extremely considered as a result of the weather modifications and soil management. Due to the characteristics of organic matter biochar, in this research the effect of biochar on growth traits, sodium (Na+) and potassium (K+) concentration of summer savory leaf under salt stress resulting from irrigation with NaCl were investigated. In order to investigate the effect of biochar on growth characteristics, sodium (Na+) and potassium (K+) concentration of summer savory ( Satureja hortensis L.) leaf under NaCl stress, a pot experiment was performed as factorial based on completely randomized design with four replications in greenhouse condition at Horticultural Research Station, Ferdowsi University of Mashhad, Iran, in 2017. The factors of the test included three levels of biochar (0, 1 and 2 % w/w of soil of each pot) and irrigation with salty water in three levels of salinity (0, 40, 80 mM NaCl). In order to produce biochar, the woods of mulberry (Morus alba) three put in electrical furnace with 530 C temperature for 14 h. Then the biochar crushed in very small pieces, sieved and added to the soil. The growth parameters included height, number of branch let, stem diameter, number of nodule, stem fresh and dry weight, leaf fresh and dry weight were measured by common methods. The amount of Na+ and K+ from the leaf samples were also measured. Data analysis were done with Minitab 17 software. The results of analysis of variances showed that the interaction effects of salinity and biochar treatments on number of branch let, stem diameter, number of nodule, stem fresh and dry weight, leaf fresh weight, Na+ , K+ and K/Na ratio in P<1% and on height and leaf dry weight in P< 5% were significant. The mean comparison of data indicated that the highest plant height (32.17 cm), number of branches (18.92), number of nodule (10.25), stem diameter (11.88 mm), stem fresh (1.75 g/plant) and dry (0.6 g/plant) weight, leaf fresh (3.44 g/plant) and dry (0.82 g/plant) weight were observed at the treatment of 2% w/w biochar without salinity were observed. Furthermore, the highest Na+ (1.69% leaf dry weight ) and K+ (3.39% leaf dry weight) were observed at 80 mM NaCl without using biochar and the treatment without salinity and biochar (control( , respectively. With increasing salt concentration, the K/Na ratio decreased and at the highest salt concentration (80 mM) reached to the lowest amount (1.71%). Salinity stress through limitation in mineral element, disrupting ionic balance, deficit in available water of plant and toxicity of mineral element cause to reduce cell growth. Competition between Na+ and K+ is one of the important physiological mechanisms of salinity stress resistance. K+ deficit is one of the events that occur due to the competition between Na+ with K+ for absorption in the roots. Therefore, it seems that in this experiment application of biochar resulted in increasing the tolerance to salinity by decreasing absorption of Na+ with plant and increasing K/Na ration. The results of this study showed that salinity cause to reduce the growth of summer savory and application of biochar in this condition cause to balance the harmful effects of salinity. In the treatment 80 mM NaCl without using biochar, the highest reduction in studied traits was observed. Moreover, adding biochar by absorbing Na+ of soil cause to reduce Na+ of plant. Due to the results of this research, correct application of biochar could be a suitable biological way for increasing the tolerance of plants to salinity

Madder (Rubia tinctorum L.) is one of the crop plants that has been utilized as a salt tolerant crop and it has been cultivated by farmers for many years in different parts of the country. With regard to salt tolerance, madder is a salt tolerant crop which has a threshold salt tolerance of 4 dS/m a 2.3% of the slope of yield reduction for each unit of salinity. Although madder cultivation was used to extract useful compounds from its roots in many saline areas, especially in pistachio orchards, little research has been done on the agronomic aspects, including proper planting method. The aim of this research was determination of the best planting method for maximum madder yield and high water use efficiency in comparison to traditional method under saline conditions.

This research was conducted in Sadooq Salinity Research Farm to investigate different planting methods for madder production and compare them to the traditional method in the form of complete randomized block design with three replications, during 2011-2015. Treatments were traditional method (planting as a clump covering with sandstorm), planting as a clump covering with soil, planting over the ridge, planting at beside slopes of a ridge, planting at bottom of a furrow and planting as a row in a flat bed. For all treatments, the amount of seeds was 300 Kg/ha and all plots irrigated with saline water of 10 S/m with 10 Cm in depth, and continued at this level during the growing season. To control soil salinity, soil sample was taken during the growing season and average soil salinity of saturated extract of the root zone was determined. At the late time of growing season, in September, madder roots were removed from the soil and dry weighed.

Results of this experiment showed that in the method of planting over the ridge, the average soil salinity of saturated extract of root zone increased gradually with depths. Results of the average soil salinity of saturated extract of root zone during three years showed that the value of salinity was minimum for planting at bottom of a furrow and also planting as a row in a flatbed methods (10.99 dS/m), While it was significantly high, in the method of planting over the ridge (15.91 dS/m). Results showed that the maximum fresh and dry yield was related to rowing planting method (185.23 and 49.77 ton/ha, respectively) and the least was for planting over the ridge (13.10 and 3.41 ton/ha, respectively). As a whole, madder cultivation with rowing planting method, made an increase of 2.5 fold in root dry yield compared to traditional method. The highest water use efficiency (0.79 kg/m3) was obtained from rowing planting method, as well. It seems madder cultivation by rowing planting method as lines of 20 centimeters of each other, could improve root yield and water use efficiency and also better control of soil salinity under saline conditions. Therefore, based on the results of this research, rowing madder planting as 20 centimeters lines is recommended for higher yield, high water use efficiency, lower soil salinity and so on, under saline conditions.

Salinity stress is one of the most limiting factors in plant growth and physiological activities. To extend crop production in saline regions, application of plant promoting growth substances like Chitosan is necessary to modify the adverse effects of salinity. Milk thistle is an agro-medical plant that is familiar as a weed. However, Silymarin (which is produced by Milk thistle as a secondary metabolite) is one the most important material for treating such disease as; liver diseases, blood fat, diabetes, hepatitis, and cancer. Application of bio stimulants is one of the solutions for decreasing adverse effects of abiotic and biotic stresses on plants and increasing quality and quantity of plant yield production, so chitosan is a compound that induces defense mechanisms against stresses.
This experiment was conducted to evaluate the soil application of chitosan on vegetative, generative and physiological activities of Milk thistle in 2016. The experiment was conducted in Research Greenhouse of College of Agriculture the University of Tehran, Karaj, Iran. The experimental treatments were arranged as factorial based on a randomized complete block design (RCBD) with three replications. The first factor comprised of four saline irrigation water levels of control (Urban water with 1.2 dS m-1), 4, 8 and 12 dS m-1 and the second factor was application of different levels of Chitosan consisting of control (without chitosan application), 0.01, 0.05, and 0.1 percent of chitosan based on 1-kilogram dry soil weight in Rhizobags. Chitosan with high molecular weight was purchased from Sigma Aldrich. 12 seeds of Milk thistle were sown in each plastic pot (23×24 cm diameter and height) containing 8.0 kg of soil, at the depth of 2 cm. After 72 days planting, plants with a uniform growth were selected for experiments. At least three plants were randomly selected from each treatment. The plant root and shoot were cut at the base and weighed to determine the dry root and shoot weight. Samples were dried at 60οC for 48 hours, and their mean root and shoot dry weight were recorded for each treatment at each replicate. Also, Statistical calculations were done by SAS software, 9.1 version, and means were compared by Duncan multiple test with 5% probability.
The result showed salinity stress had significant effect on all of the growth, physiologic and ionic trait (p≤0.01). Mean comparisons in chitosan levels showed the maximum total biomass, leaf area meter, relative water content and membrane stability index were achieved with application of 0.05% nano chitosan. In 4 dS m-1 saline water, the highest total dry mass was obtained at 0.01% of chitosan by increasing of 21.6% compared to control (p≤0.01). In all of the salinity levels, chitosan application increased the leaf area index in compared to control (without chitosan application). The maximum leaf area index (4.264) was achieved in 0.05% chitosan concentration under non saline condition. Under 12 dS m-1 salinity, application 0.05% chitosan concentration decreased by 10.4% and 16.5% in sodium content and sodium potassium ration in shoot, respectively. The mechanism of action of chitosan on growth is not clear. It was also found that chitosan may induce a signal to synthesize plant hormones such as gibberellins and enhance growth and development by some signaling pathway related to auxin biosynthesis. Chitosan stimulates vital processes of plants on every level of biological organization, from single cells and tissues, through physiological and biochemical processes, to changes on the molecular level related to the expression of genes. The result of the experiment demonstrated the adverse effect of salinity on growth, physiological activity, and nutrient content in Milk thistle. Application of chitosan at 0.05% (v/v) in soil could modify the adverse effect of salinity on total biomass, leaf area index, relative water content, and membrane stability index; however, 0.01% chitosan concentration was more effective on photosystem II efficiency.
Based on the result of this experiment, salinity stress has negative effects on growth, physiology and mineral element contents of Milk thistle. Application of 0.01% of chitosan could modify the adverse effects of irrigation water salinity on Milk thistle. Generally, application of chitosan could decrease Na effects in the Milk thistle, so the rate of Na in the shoot and root was decreased under high levels of salinity. The present study demonstrated that chitosan can be used as an ecofriendly compound to protect milk thistle plants as well as to enhance growth and biochemical parameters under saline water.

In most saline and non-saline soils, nitrogen is the most restrictive nutrient for plant growth. In saline soils, interactive effects of salinity and soil fertility is very important from optimum production. Nutrient imbalance is one of the problems with saline soils. In these circumstances, the fertilizer application may to increase osmotic effect of salt, the question is whether fertilizer is necessary or not, in saline soils? In order to answer these questions, an experiment with factors of salinity and nitrogen were carried out on canola.
In order to evaluate the interaction of salinity and nitrogen, a factorial experiment in a randomized complete block design with factors of salinity and nitrogen were carried out on canola. Salinity treatments were included a non-saline water (0.3 dS m-1), and natural saline waters with salinity of 3, 6, 9 and 12 dS m-1. Nutrient nitrogen levels were four value: zero (N1), 75 (N2), 150 (N3) and 300 (N4) mg N per kg of soil as the ammonium nitrate. The soil texture used in this research was sandy loam containing low amounts of salinity and nitrogen.
The results showed that with increasing salinity, seed canola yield reduced and increased by adding nitrogen to the soil. In this experiment, nitrogen application even to the amount of 300 mg N kg, increased percentage of seed canola oil. The increase was little in the salinity of less than 12 dS m-1. Generally, with increasing water salinity and nitrogen application, nitrogen agronomy efficiency (NAE) decreased for oil production. NAE threshold for oil production in saline conditions depended on the amount of nitrogen application. NAE threshold for oil production in the first level of nitrogen equal to 0.3 dS m-1 and at higher levels of nitrogen increased to 6 dS m-1. By increasing nitrogen levels decreased sharply the percentage of nitrogen apparent recovery (NAR).
With increasing salinity, canola yield reduced and increased by adding nitrogen to the soil. In general, by increasing salinity (especially in high salinity), at all levels of nitrogen, nitrogen physiological efficiency (NPE) of canola increased. In the highest salinity value, N application, increased canola seed oil content so significantly. Nitrogen agronomic efficiency threshold for producing of canola oil in saline conditions depended on the amount of nitrogen application. According to the results, it is recommended to act more cautiously using large amounts of nitrogen in salt condition.

Most crops are sensitive to salt stress, however, this sensitivity was differ in different growth stages. In current research, the effect of varied salt stress levels (0.4, 4, 7 and 10 dS m-1) in different growth stages (5 leaf, stem elongation and flowering) was examined on morpho-physiological, and content of sodium and potassium in rape seed Sarigol cultivar in a controlled experiment based on a completely randomized design with three replications at College of Agriculture, Shiraz University in 2014. Salt stressed plants had the lowest amount of plant height (27%), leaf number (30%), leaf area (31%), shoot (45%) and root dry weight (40%) and shoot (47%), and root K concentrations (54%) and had the greatest amount of chlorophyll content index (20%) and shoot (5 flod) and root Na (1.8 flod) concentrations; which this change was intensified by increasing in salinity level. Salt stress changed sodium distribution, so that in saline conditions shoot/root Na was significantly more than non-saline conditions. With the delay in stress applying, the negative effect of salinity was reduced; 10 dS m-1 salinity at 5 leaves and flowering were respectively associated with 78.8 and 30.2 percent reductions in shoot dry weight and with 68.6 and 26.7 percent reduction in root dry weight, compared to control. Although salt stress at 5 leaves had more and at flowering had less impact; however, increasing in stress level in all three stages intensified negative effects of salinity. If the current results were confirmed in complementary and long term researches, rape seed could be irrigated with relative saline water at late of the growing season under limited fresh water regions.

To study the responses of seven rice genotypes (Khazar, SA13, Deylam, Sange Joe, Sepidrud, 831 and T5) to different levels of irrigation water salinity, and determining grain yield based on tolerance indices, a CRD based factorial pot experiment with five levels of irrigation water salinity (1, 2, 4, 6 and 8 dSm-1) and three replications was carried out at Rice Research Institute of Iran in 2011. Indices such as SSI, TOL, MP, GMP, HM, STI, YI and YSI were calculated and their correlations with grain yield were estimated for both stress and non-stress conditions. Results indicated significant differences among genotypes and the indices within both conditions. Results also showed that STI and MP indices could be considered as the best indices to screen salt tolerant genotypes. Among the genotypes used in the experiment, T5 produced the highest yield in both non-stress (19.71 g/plant) and stress (10.69 g/plant) conditions, while the lowest yield in normal (11.84 g/plant) and stressful (4.29 g/plant) conditions was recorded for Deylam and Khazar, respectively. The highest and the lowest percentage of yield reduction were found in Khazar (69.49%) and Sange Joe (31.48%) in stressful conditions, respectively. Overall, genotypes T5, 831, Sepidrud and Sange Joe can probably be considered as superior high yielding genotypes in both saline and non-saline conditions for further research.

Salinity is a major worldwide obstacle of crop production. A greenhouse experiment, using a factorial experimental based on Completely Randomized Design with three replicates was conducted to investigate the effect of the endophytic fungus of Piriformospora indica on responses of wheat under different levels of salinity stress (0.2, 4, 8 and 12 dS m-1). Salt stress decreased concentration of P, chlorophyll content and relative water content. Increasing in water salinity levels was accompanied in decreasing of relative water content. Plant colonized with the P. indica had a higher concentration of P and chlorophyll content. Yield and yield components of wheat were reduced under salt stress; however, application of the fungus decreased the negative effects of salinity and improved the yield. Number of grains per spike, grain weight and number of the spike per plant enhanced by the fungus treatment. Plants inoculated with P. indica had higher height and spike length compared to the non-inoculated plants under the highest salinity level. It is concluded that P. indica could reduce the negative effects of salinity stress in wheat plant.

Soil and water salinity are amongst the severe and progressive problems worldwide which affects most cropland areas of Iran. Using endophytic microorganisms (which are amongst the most important soil microorganisms) to alleviate the detrimental effect of environmental stresses such as salinity is recently globally considered. In order to test the effects of Azospirillum strains and fungus Piriformospora indica on wheat growth and physiological characteristics under salinity stress, a factorial experiment based on RCBD was conducted with three replications in the greenhouse of the College of Agriculture of Ilam University in 2011. Treatments included five bioinoculants (P. indica, salt adapted and non-adapted Azospirillum strains, dual inoculation of the both microorganisms and non-inoculated control) as well as four salinity levels (0.2, 4, 8 and 12 dSm-1). Results showed that P. indica had a significant positive effect on wheat growth, aboveground fresh and dry biomass, chlorophyll content and osmolite solutes of inoculated wheat plants under saline and non-saline conditions; so that fungus inoculation reduced the detrimental effects of salinity stress and caused an improved plant growth. Infested plants by Azospirillum strains resulted in higher biomass, higher osmolite solute as well as higher chlorophyll content. Biomass and chlorophyll content in plant infested by salt-adapted Azospirillum strains were higher than that of those inoculated with non-salt-adapted Azospirillum strains. Results obtained from the present study indicated that endophytic microorganisms might be used to increase the growth and yield of wheat plants under saline conditions.