مرتضی گلدانی

Increasing the tolerance to drought and nitrogen stress in tomato cultivars is essential for the sustainable and environmentally friendly production of this product. Also, knowing the morpho-physiological, biochemical and molecular responses to drought and nitrogen stress is important for a comprehensive understanding of plant water tolerance mechanisms and nitrogen limitation conditions in higher plants. Therefore, the purpose of this study was to investigate the effect of different levels of irrigation and nitrogen fertilizer on the quantitative and qualitative characteristics of tomatoes in different Cluster rows under greenhouse conditions.

The experiment was conducted at the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad, in two years, 2021-02 and 2022-03. The experiment was set up as split-plot layout based on randomized complete block design with three replications. Irrigation levels were considered as the main plot at three levels: 75% (I75), 100% (I100), and 125% (I125) of the crop water requirement. Nitrogen fertilizer was considered as the subplot at four levels: control (no nitrogen), 75 kg ha-1 (7.5 g m-²), 150 kg ha-1 (15 g m-²), and 225 kg ha-1 (22.5 g m-²) from urea as the nitrogen source. Tomato seeds (Newton cultivar) were sown in polyethylene seedling trays with a coco peat and perlite mixture as the substrate. The seedlings were transplanted to the main field at 15 cm height with 3-4 true leaves. In all stages of growth, consistent agricultural practices were applied, including weed control, pest and disease management. Fertilization for tomato plants was based on soil analysis. Initially, after transplanting the seedlings, a complete fertilizer with high phosphorus (NPK 10-52-10) was applied at a ratio of 1.5 kg per thousand plants. In the subsequent stages, complete fertilizers (NPK 20-20-20) and high-potassium fertilizers (NPK 20-20-36) were applied through irrigation. Throughout the plant's growth stages, to prevent potential deficiencies and harm to growth and fruit development, micronutrients were applied as foliar sprays.

 The results for all three Clusters showed that although nitrate accumulation was higher in the first year compared to the second year, in both years, nitrate accumulation was higher at I75 and 225 kg ha-1 nitrogen compared to the other treatments. The highest nitrate accumulation in the sixth (6.12 mg.kg-1) and seventh (6.29 mg.kg-1) Clusters was observed in I75 and 225 kg ha-1 nitrogen treatment in the first year. In the eighth Cluster, contrary to the sixth and seventh Clusters, the highest nitrate accumulation was obtained in I100 and 225 kg/ha nitrogen (6.43 mg.kg-1) in the first year. Chlorophyll decreased with stress but increased with nitrogen levels. In all four Clusters, the highest chlorophyll a content was obtained in I100 and 225 kg ha-1 nitrogen, with values of 3.75, 3.70, 3.30, and 3.85 mg g-1 fresh weight, respectively. The highest fruit number per square meter was obtained in I125 and 225 kg ha-1 nitrogen treatment in the second year (260 fruits), although there was no significant difference compared to the first year. Furthermore, this treatment produced 11% more fruits than the highest fruit number at 100% moisture. The highest single fruit weight was obtained in I125 and 225 kg ha-1 nitrogen treatment in the first year of the experiment (254 g), although there was no significant difference compared to the second year. Additionally, this treatment showed no significant difference in fruit weight compared to the 225 kg ha-1 nitrogen and I100 treatment in the first year but was 11% higher in the second year. The highest yield (65.1 kg m-²) was obtained at I125 and 225 kg ha-1 nitrogen. However, in the control treatment without fertilizer, there was no significant difference in yield at I100 and I125. Furthermore, the highest water use efficiency was observed at I100, followed by I75. In all fertilizer treatments, I125 treatment had the lowest water use efficiency. The highest water use efficiency (285 kg m-³) was obtained at I100 and 225 kg ha-1 nitrogen.

 In general, the results demonstrated that while excessive nitrogen fertilizer increased nitrate accumulation at different irrigation levels, the increased use of irrigation water reduced nitrate accumulation in tomato fruits while improved yield. Moreover, no significant difference in fruit yield was observed between I125 and I100, but optimum yield and favorable water use efficiency were obtained with less water consumption. Based on the results of this experiment, the recommended treatment under greenhouse conditions is irrigation at 100% of the FC and the use of 250 kg ha-1 nitrogen.

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.

 Since the beginning of the industrial revolution, the indiscriminate consumption of fossil fuels has led to a dramatic increase in the concentration of atmospheric carbon dioxide. Over the past few decades, the concentration of atmospheric carbon dioxide has increased from 280 to 370 ppm and is expected to increase by about 1.8 ppm each year. Carbon dioxide, such as light, appropriate temperature, water and nutrients, is one of the essential nutrients needed by plants, which is currently less than required by plants. In general, plants need to absorb water from the soil and carbon dioxide from the atmosphere and use it in photosynthesis, which This is done by absorbing carbon dioxide through the through the pores. In general, stomatal properties have a major influence on the response of plants to carbon dioxide treatment. Leaf  morphology, including stomatal density, may have a significant effect on the response of plants to carbon dioxide. There seems to be a great deal of variation among plant species in terms of how stomata density changes with increasing CO2 concentration. The opening and closing of the stomata through carbon dioxide absorption, regulates the amount of water wasted when adverse environmental conditions. In fact, increasing carbon dioxide in plants reduces stomatal conductance and transpiration, increases water use efficiency, photosynthesis rate and higher light utilization efficiency. 

 This study was conducted as a split plot experiment based on a completely randomized design with three replications in the research greenhouse of Ferdowsi University of Mashhad. Treatments included three concentrations of carbon dioxide (380 ppm as control, 700 and 1050 ppm) as the main plot and two species of ornamental ficus (Benjamin and Elastic) as sub plots. At first, cuttings were rooted in boxes containing washed sand infused with carbendazim for 8 weeks. After rooting, the cuttings were transferred to culture media containing appropriate soil mixture and exposed to different concentrations of carbon dioxide for 16 weeks. Were affected. Mean daily temperature of 25 and mean night temperature of 18 °C and 65% humidity were considered equal for all treatments. Then, after the treatments, Stomatal traits were measured.

 The results showed that high concentrations of carbon dioxide can affect the anatomical traits of Ficus ornamental species. In this study, the results obtained from the analysis of variance of the studied traits showed that the effect of different concentrations of carbon dioxide was not significant only for the stomatal index, but for other traits studied in this study. The main effect of carbon dioxide concentration was significant at 1% probability level.The results showed that the traits of stomata diameter in plant species and different concentrations of carbon dioxide were significant at 5 and 1% probability levels, respectively. Also with increasing the concentration of carbon dioxide the diameter of the stomatal decreased so that the highest stomatal diameter was related to the concentration of 380 ppm and the lowest to the concentration of 1050 ppm. In fact, increasing the concentration of carbon dioxide from the level of 380 to 1050 ppm led to a decrease of 19.91 percent in the diameter of the stomatal. Increasing the concentration of carbon dioxide in the environment of plants, initially increases the slope of the concentration of carbon dioxide between the surrounding air and the chamber under their stomata, and then more carbon dioxide through the pores leads to a decrease in the slope due to the abundance of carbon dioxide in the chamber below the stomata, This action reduces the diameter of the stomatal. As the concentration of carbon dioxide increased the stomatal cell density and stomatal area. Among the high concentrations of carbon dioxide the concentration of 700 ppm affected most of the traits, including stomatal diameter, stomatal area, epidermal cell density, stomach length and stomach width. though there was no significant difference between high concentrations of carbon dioxide (700 and 1050 ppm). According to the results of this study, it seems that anatomical traits are influenced by environmental factors and are not recognized as a hereditary factor. Among the species, the elastica species showed the most reaction to carbon dioxideal. 

 In general, clarifying the stomatal response to carbon dioxide concentration is important for understanding the stomatal physiology and gas exchange between vegetation and the In general, stomatal properties have a major influence on the response of plants to carbon dioxide treatment. Carbon dioxide at appropriate concentrations can increase growth and also affect the stomach properties to allow the plant to adapt to environmental conditions.

Salinity stress is one of the most important abiotic stresses which results in significant damages to agricultural production, which has affected about 20% of the world's agricultural lands, and its constantly increases. Plant responses to salinity stress have been depending on the severity, species, and even genotype. Different accessions of a species may also use different mechanisms to cope with salinity stress and complete their life cycle. Therefore, the identification mechanism of salt-tolerant plants is necessary to select plants for high salinity conditions. With the development of the cultivation of tolerance plants in saline soils, it is possible to use the soil more efficiently; but salt tolerance is controlled by complex physiological and genetic processes, and understanding these mechanisms is essential to improving yield in saline soils. Different strategies can be used to prevent a decrease in yield in these areas. Plant adaptation to salinity stress in low or medium salinity stress has been suggested as a way to increase plant yield in saline soils. Considering the importance of salinity stress and also the beneficial environmental effects of legumes on crop rotation as well as the role of physiological and antioxidant characteristics in salinity tolerance and genetic diversity between lentil genotypes, this study was conducted to select lentil genotypes under salinity in a controlled environment.

This study was carried out in hydroponic conditions in the greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad Iran in 2019. The experiment was performed as split plots in a randomized complete block design with three replications. The 24 lentil genotypes were selected in the pretest and two salinity stress levels 12 and 16 dS.m-1 and 0.5 (control) were investigated. Seeds of lentil genotypes were prepared from the seed bank of the Research Center for Plant Sciences, Ferdowsi University of Mashhad. Seeds were sown in the hydroponic environment in the greenhouse with light and dark periods according to natural day length, day and night temperatures of 25 and 18 °C respectively with ±5 °C variations and natural light conditions. One week after planting, salinity stress was applied. Four weeks after applying salinity stress, traits including photosynthetic pigments, DPPH radical activity, malondialdehyde, total phenol, soluble carbohydrates, catalase, peroxidase, ascorbate peroxidase, osmotic potential, and proline were measured. To calculate the percentage of survival before salinity stress, the number of plants was recorded and before harvest, the number of live plants was recorded and the percentage of survival was calculated.

The results showed that at the salinity of 12dSm-1 MLC6, MLC12, MLC26, MLC120 and MLC178 had a survival of over 60%. Under 16dSm-1 salinity except for MLC57, MLC73, MLC94, MLC104, and MLC108 genotypes, other genotypes survived and MLC178 and MLC26 genotypes had the highest survival with 30% and 25%, respectively. With increasing salinity stress levels, the content of chlorophyll a, total photosynthetic pigments, and total phenol in all genotypes had a decreasing trend. Chlorophyll a content increase with an increase salinity from controll (0.724 mg.g-1 Fw) to 16 dSm-1 (0.220724 mg.g-1 Fw). Osmotic potential with increasing salinity was a more negative state of values at 16dSm-1 of MLC178     (-3.91 MPa) and MLC26 (-5.62 MPa). Increasing salinity stress from 0.5 to 16 dS.m-1 increased inhibition of the free radical activity of DPPH, activity of catalase, peroxidase, and ascorbate peroxidase in MLC117 and MLC178 genotypes. Also, except for two genotypes, MLC5 and MLC14, the other remaining genotypes had a good ability to reduce the osmotic potential at the salinity of 16dSm-1. Principal component analysis (PCA) showed that the first component explained 50.14% of the changes and properties related to photosynthetic pigments and osmotic potential and the second component explained the antioxidant properties, metabolites, and survival percentage with 12.66%.

Generally, results showed the superiority in most of the studied traits of the MLC6, MLC12, MLC26, MLC117, MLC120, and MLC178 compared to the total average. Due to the relative superiority of this genotypes of genotypes, it is recommended that perform additional studies to evaluate their salinity tolerance in field conditions.

This study was conducted as split-plot based on Complete Randomized Block Design with three replications in 2019 at Ferdowsi University of Mashhad. Salinity as the main plot (eight, 12 and 16dS m-1) and 13 chickpea genotypes were allocated to sub-plots. Salinity levels of eight and 12dS m-1, two genotypes of MCC606 and MCC643 had the highest survival percentage and at salinity level of 16dS m-1, only three genotypes of MCC539, MCC606 and MCC658 survived. Relative water content (RWC), Membrane Stability Index (MSI) and concentration of chlorophyll-a, were decreased in all genotypes as salinity level increased. Among the genotypes, MCC606 had the highest values of RWC, MSI and carotenoids at salinity levels of 12 and 16dS m-1. Proline content was increased in all genotypes as salinity level increased from eight to 12dS m-1. Results of the cluster analysis indicated the superiority of MCC539, MCC658 and MCC606 compared to total mean in all parameters. Principal component analysis showed that the first component explained 64.49% of changes in DPPH, carotenoids, MSI and biomass in three genotypes of MCC539, MCC658 and MCC606. Since this experiment was conducted in controlled conditions, field assessment of freezing tolerance of the superior genotypes is recommended to confirm the results of the present study.

In order to investigate the response of rapeseed to the application method of nitrogen fertilizer, a factorial experiment was conducted in a randomized complete block design with three replications in the 2015-2016 crop season. The first factor was two canola cultivars (Hayola 401 and RGS003) and the second factor was four application method of nitrogen fertilizer treatment as F1: three stages fertilization in soil used, F2: three stages foliar spraying application, F3: four stages of fertilization in soil used and F4: four stages of fertilization as foliar spraying. The results showed that the highest plant height was obtained by applying F3 treatment with 144.8 and 161 cm per plant in the second and third sampling, respectively. The highest leaf dry weight and leaf area was obtain by application F3 treatment in all sampling stages. The same trend was observed for the dry weight of lateral branches, so that in the third stage of sampling, the highest dry weight of lateral branches with 59.4 g.plant-1 was obtained by consuming of F3 treatment. The highest biomass and grain yield were obtained from F3 treatment with 1029 g.m-2 and 332 g.m-2 respectively. The highest number of pod (145 pod per plant), biomass (1105 g.m-2), oil yield (121 g.m-2) and seed yield (358 g.m-2) was obtain from application F3 in Hayola 401 cultivar. In general, the results showed that all morphological and yield indices of the plant were obtained from application of nitrogen fertilizer in four stages at the soil used that Hayola 401 cultivar showed more positive response to this used method of fertilization.

Fenugreek (Trigonella foenum-graecum) is an annual plant belong to Fabaceae and is one of the traditional medicinal plants worldwide. It can provide seed and protein suitable for human's nutrition as well as animals. Water scarcity is a key threat in twenty-first century. On average, 40% of the world land surface are drylands, while this surface area is 90% in Iran. Supplying water requirement of Fenugreek through irrigation is an important factor affecting its growth and yield.

The experiment was conducted as split plots based on randomized complete block design with three replications at the Research Farm, Faculty of Agriculture of shahed university, Iran, in 2014 and 2016. The main-plot was three levels of drought stress, included severe drought stress (20% field capacity), moderate drought stress (40% field capacity), mild drought stress (60% field capacity) and non-drought stress (80% field capacity) as control. Sub plots were nine Fenugreek ecotypes including Neyshabur, Shirvan, Mashhad, Tabriz, Roudsar, Isfahan, Hamadan, Ardestan and Shiraz. At maturity, and the plants were harvested from the soil surface and the plant height and number of lateral branches, number of pod per plant, number of seed per pod, 1000 seed weight, seed yield and aboveground biological yield were measured in the lab. Statistical analysis carried out using SPSS version 16 software. Significant difference was set at p ≤ 0.05 by using Duncan’s multiple range test.

Results of stepwise regression showed that the traits including biomass, harvest index, branch length and number of pods per plant explained 96.7% of grain yield variation, respectively. Factor analysis for morphologic, yield and component yield traits showed the first three independent factors explained 93.48% of total variance in all genotypes. Days to maturity with 36.47% of total variance had the highest amount in the first factor, while, number of seeds per plant and seed yield with 29.74% and 27.07% of total variance were ranked as second and third factors, respectively. Cluster analysis by Ward’s minimum variance, clustered ecotypes into three groups including 1- Isfahan, Ardestan, Hamedan and Shiraz 2- Mashhad and Tabriz 3- Shirvan, Rudsar and Neyshabur. The results showed that, the plant height, Internode length, number of pod and seed per plant, 1000 seed weight, biological and seed yield and harvest index significantly affected by drought stress and ecotypes. The highest plant height, number of pods, 1000 seed weight, biomass, seed yield and harvest index was recorded in Shirvan ecotype while, the longest day to maturity and height of first pod were observed in Neyshabur ecotype at 80% FC. The highest plant height, the first formed pod, 1000 seed weight, seed yield and harvest index in Shirvan ecotype were observed in the 40% FC.ConclusionDrought stress reduced all studied traits in all Fenugreek ecotypes in this experiment. For seed yield, the performance of shirvan ecotype was the best compare to other ectypes in control and mild and moderate stress condition. The highest distance of the first pod from the soil surface in the control condition was observed in the Neyshabur ecotype but in the moderate stress condition in Shirvan ecotype, this trait is important for the mechanized cultivation. Based on the results, there is a reliable variation amongst different Iranian Fenugreek ecotypes and they could use for breeding programs against drought stress. It also seems that Shirvan ecotype of Fenugreek can be considered for stable seed and biomass production under moderate drought stress and normal conditions.

Due to the increasing demand for organic products, the use of growth-promoting bacteria, which play an important role in the sustainability of agricultural ecosystems, has been considered for the last two decades, and there are limited studies to determine the best efficiency of their consumption method. Accordingly, this study was conducted to investigate the most effective method of application biofertilizers on morph physiological, biochemical and yield traits of Tomato plants in greenhouse conditions.

In order to investigate the effect of consumption method and type of biofertilizers on morphophysiological, biochemical and yield traits of Tomato, a factorial experiment was conducted in a completely randomized design in the Research Greenhouse Khorasan Razavi Agricultural and Natural Resources Research and Education center in 2020. The first factor was three methods of application (seed inoculation with foliar feeding, foliar feeding and soil consumpation and the second factor was types of biofertilizer (control, nitroxin, biophosphate, fertile potassium and a mixture of nitroxin and biophosphorus (rate 1:1).

Analysis of some physical and chemical properties of soil at the beginning and end of the experiment showed that the application of biofertilizers without the use of any chemical fertilizers improved soil fertility and high availability of macronutrient, which showed an improvement in soil health indices. The soil texture remained constant at the end of the experiment but the soil saturation percentage was increased which indicated an increase in the volume of water in the soil compared to the volume of pores during the test period. Almost all properties were better condition at the end of the experiment than at the beginning, including electrical conductivity and soil acidity, which decreased by about 0.5 and 0.3 units, respectively. The results showed that the maximum plant height (176 cm) was obtained by using a mixture of nitroxin and biophosphorus from soil application. The lowest dry plant weight (23.7 g) was recorded from non-use of biofertilizers and the use of a mixture of nitroxin and biophosphorus produced about 52% more dry weight of the plant in compare of control. The application of biofertilizers had a significant effect on increase dry weight of root, so that the root dry weight was increased about 53% in compare of control by using mixture of nitroxin and biophosphorus. In the soil application method with the application of all biofertilizers, the number of fruits per plant was more than 137, the highest of it (145) was obtained from a mixture of nitroxin and biophosphorus. The highest fruit weight per plant (449 g plant-1) was obtained from the application of a mixture of nitroxin and biophosphorus in soil application. The highest amount of photosynthesis (18.2 μmol CO2 m-2s-1) and stomatal conductance (20.0 mmol CO2 m-2s-1) were obtained from the effect of combined nitroxin and biophosphorus fertilizer on seed inoculation and foliar feeding. The highest amount of lycopene (7.69 mg 100-1g FW) and the amount of vitamin C (57.7 mg 100-1g FW) were obtained from the soil consumption of nitroxin biofertilizer.

Increasing diversity in soil microorganisms leads to increased soil fertility. In soil application method, the metabolic activities of bacteria are improved due to the availability of suitable temperature, oxidation and reduction conditions, minerals, organic carbon as a source of energy and water, which leads to the release of nutrients from organic materials. The results showed that due to the high growth of bacteria in the presence of different substrates in the soil and the high surface-to-volume ratio in them, the use of biological fertilizers as soil application was increase morphological and physiological characteristics, yield traits of Tomato plant.

Salinity tolerant of 24 lentil genotypes was investigated in a split-plot based on a randomized complete blocks design with three replications. Salinity levels (0.5, 12, and 16 dS m-1) were arranged as the main plot and lentil genotypes as the subplot. Results indicated that salinity levels of 12 and 16 dS m-1 reduced the survival percentage of all genotypes compared to control. MLC57, MLC73, MLC94, MLC104, and MLC108 genotypes were not able to tolerate the 16 dS m-1 salinity level. Morphological traits were affected by salinity stress as plant height, number of branches per plant, dry weight, and leaf survival percentage in most genotypes were decreased. Compared to control, the lowest reductions of plant height, number of branches per plant, plant dry weight, and leaf survival percentage were observed at salinity level of 16 dS m-1 in MLC13, MLC120, MLC4, and MLC12 genotypes, respectively. Also the lowest increase in Na+ (5.5 times) and the highest increase in Ca2+ (4 times) were observed at salinity level of 16 dS m-1, in MLC108 and MLC78, respectively. In other words, these genotypes were able to reduce the adverse effects of increased NaCl in higher salinity levels. Principal component analysis (PCA) showed that all genotypes of the first group (MLC6, MLC12, MLC26, MLC117, MLC120, and MLC178) were superior for most traits as compared to the total mean. Generally, it could be concluded that this group of genotypes has a better survival percentage and growth characteristics in salinity conditions, which may be used to select salinity tolerant lentil genotypes in subsequent studies.

With the increase of population, migration to cities and expansion of urbanization, improvement of living standards, and expansion of industries have caused a large volume of sewage to be produced in limited areas that the environment can not be refined. However, this high volume of wastewater can be considered a source of water, materials, and energy. Today, many countries make optimal use of water resources and advance their national development programs by recycling them. The use of wastewater in agriculture should not be based on a general rule. Still, it should be based on water, soil, and environment characteristics and establish a proportion between the quality of the wastewater and the type of wastewater application according to economic issues. This subject requires access to executable standards, instructions, and criteria for each of the different sections to be used to observe environmental standards. Of course, wastewater as a stable water source in irrigation of agricultural products and obedience to ecological considerations should be considered part of sound management for the water crisis.

A factorial experiment was conducted in a complete randomized design with 15 treatments and four replications in the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad. For this experiment, 60 pots, 6 kg containing sandy loam soil were used. Treatments include urban water (W), treated wastewater (TWS), untreated wastewater (WS), combined urban water and treated wastewater ratio of 50:50 (W + TWS), and combined urban water and untreated wastewater (W + WS) (50:50) as irrigation water and three levels of irrigation were 100, 70 and 40% of the plant's water requirement. First, treated wastewater samples, untreated wastewater, and urban water were taken to the laboratory for water quality analysis. The seedlings were transferred to the desired pots in the three or four-leaf stage. After 150 days, the plants were harvested from the pools, and traits such as leaf number, leaf area, chlorophyll a, chlorophyll b, carotenoids, and proline were measured.

According to the analysis of variance tables, the results show that the simple effect of water quality treatment on the leaf number, leaf area, chlorophyll a and b at the level of one percent probability have a significant difference, but there was no significant difference in proline and carotenoid traits. In simple effect of deficit irrigation treatment, all measured characteristics have a considerable difference at the level of one percent probability. But, in the interaction effect of water quality and deficit irrigation, leaf number, leaf area, chlorophyll a and b, and carotenoids trait were significant at the level of one percent probability, and proline trait was not significantly different. Therefore, due to the interaction of water quality and deficit irrigation treatments, the most leaf number related to the treatment of 100% of the plant's water requirement with untreated wastewater, and the least leaf number belongs to the treatment of 40% of the plant's water requirement with urban water. In the leaf area, the most amount is related to 100% of the plant's water requirement with untreated wastewater. The least amount is related to 40% of the plant's water requirement with urban water. In chlorophyll-a trait, the most amount of chlorophyll a is associated with the treatment of 100% of the plant's water requirement with untreated wastewater. The least amount of chlorophyll is associated with 100% of the plant's water requirement with treated wastewater. In chlorophyll b, the most amount is related to the interaction treatment of 100% of the plant's water requirement, and the combination of urban water and untreated wastewater in the ratio of 50:50 and the least number is related to the treatment of 100% of the plant's water requirement with treated wastewater. Also, in the carotenoid trait, most carotenoids were related to 100% of the plant's water requirement with untreated sewage. The least amount of carotenoid was linked to 40% of the plant's water requirement with untreated wastewater.

According to the results, it can be concluded that the leaf number, leaf area, chlorophyll a, and chlorophyll b in the treatment of urban water with untreated wastewater was more than the control, and the quality of irrigation water on proline was not significantly different. Also, it is concluded that the plant's natural response to drought stress depends on the amount of water and can be short-term or long-term physiological responses. Thus, the lack of access of tomato plants to enough water reduces physiological traits such as leaf number, leaf area, and photochemical traits such as chlorophyll a, chlorophyll b, and carotenoids. But deficit irrigation increases the amount of proline, and with the drought stress intensifies, the number of proline increases. Thus, in conditions of deficit irrigation, the plant reduces its osmotic potential to absorb more water by accumulating potential osmotic regulators such as proline and soluble carbohydrates in the leaf.

In order to investigate the effect of salicylic acid application on reducing the effects of cold stress due to delayed planting in rapeseed genotypes, this experiment was conducted as a factorial-split plot during the 2014 and 2015 growing seasons in the Faculty of Agriculture, University of Zanjan, Iran. Interaction of the sowing date (11th September and 7th October) and salicylic acid (control (spray with distilled water), 250 µM and 500 µM) were as the main-plot and rapeseed genotypes (Karaj-3, L14, Okapi, Zarfam) were assigned to subplots. The effect of planting date* salicylic acid* genotype on winter survival percentage, grain yield and its components, harvest index, and biomass was significant. Delayed planting reduced survival percentage of all rapeseed genotypes; but the severity of reduction varied depending on the genotype. It was also found that the decrease in survival percentage due to delay in planting can be partially compensated for by the use of salicylic acid, which varied depending on the salicylic acid concentration and genotype. Delayed planting date reduced grain yield in all genotypes and salicylic acid application had the opposite effect and increased grain yield. Karaj-3 had the highest grain yield on 7th October planting date and 500 µM salicylic acid, while Zarfam had the lowest grain yield on 11 September and 0 µM salicylic acid. Application of salicylic acid compensated for part of the reduction in yield due to delay in planting, so that the lack of application of salicylic acid and the use of 250 and 500 μM salicylic acid in planting on 7 October caused grain yield reduction in Karaj-3 genotype by 36, 31 and 18% respectively, compared to 11 September, while grain yield in L14 genotype showed 26, 21 and 8% reduction respectively, compared to 11 September planting date. The grain yield of Zarfam genotype at delayed planting date decreased by 9% and 5% and increased by 13%, respectively, in conditions of non-application and application of 250 and 500 μM salicylic acid compared to the 11 September planting date. There was a positive significant correlation between grain yield components and winter survival percentage. Although delayed planting reduced grain yield, yeld components, harvest index, and biomass in all genotypes, the severity of the decrease varied among the genotypes. Consumption of salicylic acid moderated the effect of delay in planting and this modulatory effect was higher in the application of salicylic acid with a concentration of 500 μM than 250 μM. In general, the results showed that in both planting dates, the Karaj-3 genotype had the highest grain yield in all salicylic acid levels, so it is recommended for planting in areas with similar conditions.

Concurrency of cereals late-season irrigation with early irrigation of sugar beet season and lack of water resources at this time, has made some farmers to delay sugar beet cultivation. The planting date plays a key role in growth, quality and yield of sugar beet. Delayed cultivation leads to reduced sugar beet yield. In late cultivation of sugar beet (Beta vulgaris L.), the use of nitrogen fertilizer and growth promoting bacteria can be of great importance in accelerating growth and compensating for lost time. The aim of this study was to find a sustainable way to increase the growth rate of sugar beet in delayed cultivation, so as to compensate for the delayed growth season as possible.

This experiment was conducted as a split split plot in a randomized complete block design with 6 replications on Arta sugar beet cultivar at the Research Farm of Ferdowsi University of Mashhad in 2018. The factors included planting date (regular and delayed sowing) as main factor, nitrogen fertilizer (based on recommendation and 25% less than recommended) as sub-factor and Nitrobacter application and non-Nitrobacter were considered as sub-factors.

The results showed that the inoculation effect of Nitrobacter on leaf area, total dry matter, root yield and sugar content increased by 13, 20, 9 and 8 percent, respectively. Also, Nitrobacter treatment had the least effect on the amount of sodium, potassium and nitrogen of root in both sowing dates. For delayed planting date, using nitrogen fertilizer plus growth promoting bacteria can offset the delay in planting date. Therefore, this recommendation can reduce water consumption by reducing sugar beet growing season and reduce fertilizer use. It seems that the combination of chemical and biological fertilizers is effective on sugar beet delayed cultivation in order to compensate for lost time.

The combination of chemical and biological fertilizers is effective on sugar beet delayed cultivation in order to compensate for lost time.

One of the ways to increase the quality of irrigation water is to magnetize it. Research in the research greenhouse of Ferdowsi University of Mashhad in 2018.The experiment was completely random in the form of a factorial design and three treatments included irrigation method (usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying and three levels of magnetic water). This included: ordinary water, one-time magnetic water with a Tesla intensity of 0.367 and Tesla 0.633). Examination of the experimental results showed that in the usual irrigation method and magnetic water with a Tesla intensity of 0.367, the highest plant height (110 cm) , Dry weight of aerial limbs (41.9 g.plant-1, dry weight of roots (17/1 (g.plant-1 and root volume (137 cm3.plant-1) and in the usual irrigation method and water Tesla's magnitude of 0.633 was the highest leaf area (25.24 cm2), total fruit weight (508.18 g), lycopene (48.6 (mg.gfw-1). fixed partial root-zone drying magnetic water with .0.367 intensity Tesla The highest amount of chlorophyll b (0.489 mg.gfw-1) and single fruit weight (48.03 g) and in the intensity of Tesla 0.633, the highest percentage of dried fruit (%11.1) was observed. The highest water use efficiency Total biomass (36.6 g / liter) was observed in fixed partial root-zone drying and control water. alternative partial root-zone drying and magnetic water with Tesla 0.367 intensity, maximum leaf-stem ratio (1.37 g.plant-1), air-to-underground ratio (3.14 g.plant-1) and root length (53.2 cm) was observed, but the highest content of relative moisture content of leaf water in alternative partial root-zone drying and magnetic water showed Tesla with a intensity of 0.633. Among the irrigation methods, the highest total fruit weight in each pot was observed in usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying was observed as variable and both Tesla 0.367 and 0.633 intensity of magnetic water were able to improve traits. It is recommended to reduce the effects of drought stress, it is recommended to use this method that is safe, easy and safe for the environment.

In order to evaluate the effect of the duration of water in the magnetic field on the qualitative and quantitative characteristics of radish plant, a research was conducted in the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad, in a completely randomized design with three treatments and three replications. Treatments included distilled water (control), distilled water magnetized with a duration of 30 minutes, and distilled water magnetized in one hour with a field intensity of 0.6 Tesla. The results showed that magnetized water with duration of one hour caused an increase of 29%, 46%, 46%, 43%, 19%, and 82% in leaf area, tuber circumference, chlorophyll a, and carotenoid, fresh weight of shoot and dry weight of the tuber, respectively. Also, this treatment increased tuber mass and fresh weight by about 100%. In general, the treatment of the magnetized water with the duration of one hour was the best treatment. According to the results, the duration of irrigation water magnetization in the magnetic field can affect radish plant characteristics.

Magnetic water increases net plant production by increasing seed stimulation for germination and increasing plant growth rate and strength. This study aimed to investigate the effect of magnetic water on water productivity, germination and yield of (Spinacia oleracea) under deficit irrigation in both laboratory and greenhouse as a factorial experiment in a completely randomized design at Ferdowsi University of Mashhad. In the first experiment, the treatments included three levels of magnetic water (normal water as a control treatment, magnetic water with an intensity of 0.3 Tesla, magnetic water with an intensity of 0.6 Tesla) and 7 moisture potentials (potential 0, -0.1, -0.3, -1, -3, -6 and -9 bar) and in the second experiment, four levels of deficit irrigation were included: 100% irrigation, 80% irrigation, 60% irrigation and 40% irrigation. The results show that the use of drought treatment reduced plant germination traits including seed vigor index, germination and speed percentage, wet and dry weight of stems and roots, length of stems and roots. The use of magnetic water increased the yield of spinach and reduced the negative effects of deficit irrigation. Overall, the results showed a 25 and 31% increase in shoot fresh and dry weight, 41% increase in leaf area, 36% and 20% increase in fresh and dry root weight, 24% increase in root volume, 11% increase in relative leaf water content, decrease Proline was a 33% increase in water productivity index. The use of low irrigation also improved the fresh and dry weight traits of shoots and water productivity index.

Climate change and inappropriate management activities have put pressure on limited freshwater resources. Water scarcity has led to better allocation of irrigation and it is expected that the allocation of water to the plant is planned according to the environmental conditions and growth stage of the plant. In order to investigate the effect of irrigation interval on morphological characteristics, yield components, yield and oil content on Evening Primrose (Oenothera biennis L.) plant, an experimental was carried out in randomized complete block design with five replications at Khorasan Razavi Agricultural Research and Education Center in 2019. Treatments included: irrigation intervals at three levels of 7, 10 and 14 days. The results showed the highest number of canopy (2833 cm2), dry weight of areal part (98 g/plant) and yield components, highest number of capsules per plant (427), seed weight per plant (5.33 g), grain yield per hectare (1921 kg), oil percentage (0.73%) and oil yield per hectare (275 kg) resulted from 10 days irrigation interval. With increasing irrigation interval from 7 days to 10 days was increased values in aforementioned traits and all studied traits was decreased by incremental irrigation interval from 10 days to 14 days. It seems that cultivated media containing fine textured soil due to the increase in surface area of soil constituents to their unit of weight has improved the favorable growth conditions in 10-day irrigation compared to 7-day irrigation. Therefore, application of irrigation treatment in 10 days increased water productivity efficiency in evening Primrose Flower in Mashhad weather condition.

Seed germination is a crucial step in the seed life cycle, and the use of various techniques to produce more robust seedlings helps plant survival and improve water productivity. The effect of magnetized water is affected by the field's intensity, the type of plant, and the water used. Since no similar experiment has been performed on the radish plant as a high-consumption and water-repellent plant, this experiment was conducted to investigate the treatment's interaction effect. Priming and irrigation with magnetized water on radish seeds' germination traits were performed in a completely randomized design. Treatments included four types of priming and three types of water. The results showed that the interaction effect of priming and irrigation treatments with magnetic water for one hour increased 25, 27, and 71% in shoot length, shoot fresh weight. Root, respectively, and also caused a significant increase in root dry weight. According to the obtained results, priming and irrigation with magnetic water for one hour can be considered as the best treatment in this experiment. Finally, it can be concluded that seed hydropriming, especially with magnetized water, has positive effects on radius seed germination indices.

Delayed planting of sugar beet, use of nitrogen fertilizer and growth promoting bacteria are important in accelerating growth and compensating time loss. To study this subject, a split split plot experiment was conducted in a randomized complete block design with 3 replications and 8 treatments in 2018 at the Research Farm of Ferdowsi University of Mashhad. The factors under study consisted of planting date with two levels (regular planting, D1, and delayed planting, D2) as the main factor, nitrogen fertilizer with two levels (use of nitrogen fertilizer based on recommended rate, N1 and 25% less than recommended rate, N2) as a subfactors and bacterial growth stimulant with two levels (bacterial inoculation, B2, and without its use, B1) were considered as sub-sub- factors. Growth indices under study were leaf area index, total dry matter, crop growth rate, relative growth rate and net assimilation rate. In this study, highest leaf area index (3.5) and dry matter accumulation (2898 g.m-2) in thermal unit, as well as growth rate, relative growth rate and net assimilation rate under regular and delayed planting dates were due to the use of recommended rate of nitrogen fertilizer and bacterial inoculation treatments. The least amounts of these traits were obtained at both planting dates and use of nitrogen fertilizer, 25% less than the recommendation, and without using bacteria. Root yield and sugar content sugar beet under treatment of bacterial and nitrogen use, based on recommended rate, showed 8 to 10% higher than other treatments, under both regular and delayed planting date. It seems that the combined use of chemical and biological fertilizers is useful in delayed sowing, to compensate delayed time loss planting of sugar beet.

The increase in population in the country needs to increase the agricultural products. It is necessary to use new techniques to increase performance and make maximum use of available water resources. Priming decreasesthe cultivation period. Therefore, the total water requirement during the growing season will be reduced.The magnetized water has effects on some of the morphological characteristics of the plant, improve them. This study was conducted to investigate the effect of magnetized water and seed priming on growth characteristics of bell pepper in Ferdowsi University of Mashhad. This research was conducted as a factorial experiment in a completely randomized design with five replications and two priming factors with two levels (without priming and hydropriming) and magnetic field intensity with three levels (zero, 0.3 and 0.6 Tesla). The results have been shown that magnetized water was significant at 1% probability level on leaf area, shoot length, fresh and dry weight of shoot but on fresh and dry weight of leaf at 5% probability level Seed hydro priming was also significant on root diameter and stem length at 5% probability level. The interaction effects of treatments were significant on root length, root dry weight at 1% probability level, and on root surface, root volume, root fresh weight at 5% probability level.The use of magnetized water with 0.3 and 0.6 Tesla magnetic intensity increased the leaf area by 13.1% and 20.93%, 13.73% and 15.69% leaf fresh weight, respectively, and the highest stem fresh weight (0.27 g) in magnetizes water as irrigation was 0.6 Tesla and its lowest (0.2 g) was observed in ordinary water treatment. The highest root volume was observed in 0.6 Tesla magnetic intensity and seed hydro priming treatment (0.24 cm3). The highest (0.53 g) root fresh weight was observed in 0.3 Tesla and seed hydro priming and the lowest (0.39 g) in 0.3 Tesla, magnetic intensity, seed treatment without seed priming. As a result, irrigation with magnetized water and seed hydro priming resulted in improvement of morphological properties of bell pepper transplant.

Deficit irrigation is one of the limiting factors of crop production. An experiment in a split plot randomized complete block design with three replications on tomato in Ferdowsi University of Mashhad, Iran, during the 2018 cropping season. Treatments included; usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying (main plot) and deficit irrigation100, 75, 50% irrigation requirement (sub plot). Effect irrigation methods and different levels of deficit irrigation had significant on number, weight, diameter, firmness, vitamin C and pH fruit. Maximum shoot dry weight of 153.96 g.plant-1, number of fruits per plant (58), number of fruits per square meter (163), single fruit weight 46.03 g, fruit diameter 98.48 mm, vitamin C 9.47 mg.gfw-1, fruit yield 4.46 kg.m-2 was observed in usual irrigation method. The highest amount of lycopene was 84.85 mg.gfw-1, fruit firmness 3.93 Kg.cm-2, pH 4.58, water use efficiency of 4.46 kg.m-3, 2 was observed in fixed partial root-zone drying irrigation. The results showed that the highest yield among irrigation methods, respectively in conventional irrigation method, ; usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying and maximum water use efficiency in fixed partial root-zone drying irrigation method and 75% water requirement observed.

Deficit irrigation is one of the ways to increase water productivity in irrigated lands. This study was conducted as a split plot experiment in a randomized complete block design with three replications on flat tomato cultivar at the Research Farm of Ferdowsi University of Mashhad, Iran, during the 2018 cropping season. Treatments included three irrigation methods including; usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying as main plots and three levels of deficit irrigation (50, 75 and 100% of field capacity) as subplots. Results show that the highest and lowest concentration photosynthetic pigments observed in the alternative partial root-zone drying and the fixed partial root-zone drying respectively. Maximum plant height (68.8 cm) was observed in fixed partial root-zone drying. Results show that, the maximum leaf area index (2.15), stem dry weight (76.5 g.plant-1), leaf dry weight (72.6 g.plant-1) and fruit yield (4.50 kg.m-2) was found in 100% field capacity. According to the results of the present study, the best result observed in usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying respectively. Fruit yield in fixed partial root-zone drying was more than the alternative partial root-zone drying method.

Many scientists have discovered the useful effects of magnetic field in agriculture and are have become interested because cheap and eco-friendly technique. The purpose of this study was to investigate the effect of magnetized water and priming with magnetized water under drought stress on some morphological traits of radish plant. The experiment was carried out with factorial experiment in completely randomized design with three type water treatment, four priming treatment and three irrigation deficit treatment in four replications in greenhouse ferdousi university of mashhad. After harvesting, root cleaning was performed, and the most important morphological indices including fresh and dry weight of three plant parts, tuber length and diameter, leaf area, tuber density, root length and tuber volume and root volume were measured. Results showed that with increasing drought stress all measured traits decreased but the use of magnetic water has improved all the traits, So that the simple effect of magnetized water for one hour increased leaf area, shoot and tuber dry weight, shoot, root and tuber fresh weight, root length, diameter and tuber length and tuber and root mass by is respectively 15, 24, 56, 20, 48, 80, 11, 11, 31, 85 and 50 Percent but in priming treatment, leaf area, fresh and dry weight of shoot, tuber fresh and dry weight and tuber density had no significant effect. In general, the results showed that magnetized water protects radish plant as a protective agent against drought stress and cause increasing plant yield and decreasing water consumption.

In order to investigate the effect of low irrigation on some morph physiological and qualitative characteristics of Kochia plant, an experiment was carried out in split plot arrangement base on randomized complete block design with three replications in farm of Ferdowsi University of Mashhad, during of 2017. The main plots consisted of three levels of irrigation (50, 65 and 80% water requirement plant: WRP) and sub plots was two Koshia ecotype (Sabzevar and Boroujerd). The results showed that with decreasing irrigation water to 65 and 50% of PWR, the plant height reduction was about 15 and 26%, and the green area index was also declined about 25 and 38% in compare of irrigation in 80% of PWR.The highest fresh (27.9 t/ha) and dry (11.3 t/ha) forages weight were obtained from irrigation on 80% WRP treatment. Sabzevar ecotype was produced about 5.24 (t/ha) in fresh and 4.10 (t/ha)in dry forages more than another Koshiaecotype. The lowest amount of relative water content (70.5%) and maximum electrolyte leakage (54.2%) were observed from 50% WRP. The highest percentage of crude protein (13.2%) was recorded in irrigation with 65% WRP, the highest amount of NDF and ADF were obtained from irrigation on 80% WRP treatment and the lowest of them were recorded from 50% WRP, as 19.1% and 71.9%, respectively.Sabzevarecotype had more morphological traits (plant height, green area index, fresh and dry forage, relative water content) and forage nutritional value than Boroujerd ecotype. In both ecotypes, with reducing the amount of irrigation water lead toimproveforage nutritional value. The results of correlation coefficients showed that the forage yield had a significant positive correlation with plant height (r = 0.49 *) and green area index (r = 0.57 **).

The objective of this work was to evaluate the effects of periodic water stress on yield and yield components of Quinoa in the experimental research under greenhouse conditions. This research was conducted to study the effect of water stress on yield and yield components of Quinoa in the experimental research greenhouse of the Ferdowsi University of Mashhad during 2018-19. NQRC cultivar of Quinoa was planted and experimental design was completely randomized with five treatments and four replications. Treatments were full irrigation in all growth stages, water stress in a vegetative stage, water stress in flowering stages, water stress in the grain filling stage and deficit irrigation in all growth stage treatment with supplemental irrigation in time of planting. Results showed that the effect of periodic water stress on leaf number, leaf panicle, panicle length, stem diameter, plant height, SPAD index, 1000 kernel weight, grain yield, and water productivity were highly significant (P>0.01), but different irrigation regimes on branches number and panicle width were significant at 5 % levels. Results showed that the highest 1000 kernel weight (3.99 g), grain yield (21.2 g) and plant height (67.9 cm) were in full irrigation in all growth stage treatment and the highest water productivity (2.14 kg/m3) was in deficit irrigation in all growth stage treatment. With 50% reduction of water in vegetative stage, flowering stage, grain filling staged and deficit irrigation in all growth stage compared to full irrigation in all growth stage treatment, 1000 kernel weights were decreased by 19.0, 9.0, 4.5, and 26.6 % and Grain yield was decreased by 19.3, 11.8, 7.5 and 21.2% respectively.

Garlic is a medicinal and cool season plant, but there is not much information on its level of cold tolerance. Khorasan province is one of the suitable areas for growing garlic. The conventional planting date of garlic in this region takes place between 6 October and 5 December. Available evidences shows that garlic plants have been affected by cold stress due to inappropriate planting date. Some researchers have recommended the use of controlled freezing tests as a suitable approach to assess cold tolerance of plants. In this regard, it is stated that LT50su in wheat had the highest correlation with field survival index when the crown was exposed to cold stress. The present experiment was conducted to study cold tolerance and understanding the most critical growth stages of garlic ecotypes to cold stress under controlled conditions.

This experiment was conducted as a factorial based on completely randomized design with four replications in Agricultural Faculty of Ferdowsi University of Mashhad during 2012. The experimental factors included two levels of planting date (18 September and 21 October), garlic ecotype in four levels (Bojnurd, Torbat-e Heydarieh, Neyshabur and Khaf) and eight levels of freezing temperature (0, -3, -6, -9, -12, -15, -18 and -21°C). Plants that grown in outside conditions and acclimated to cold temperatures were transferred to the thermogradient freezer to apply cold stress. Survival percentage, Lethal Temperature 50% mortality according to the survival percentage (LT50su), plant height, leaf area, reduced leaf area temperature 50 (RLAT50), dry weight and reduced dry matter temperature 50 (RDMT50) were determined at three weeks after applying the stress.

In the first planting date, the survival of Bojnurd and Torbat-e Heydarieh ecotypes decreased 20% and 26% at -15 °C compared with zero temperature, respectively, while two other ecotypes disappeared at this temperature. In the second planting date, Khaf and Bojnurd ecotypes had a good survival at -15 °C while Neyshabur and Torbat-e Heydarieh ecotypes disappeared 60 and 67% at this temperature, respectively. Since the growth stage has an effect on cold acclimation and stress tolerance, this response can be due to difference in the growth stage of plants. However, this reaction was different depending on the ecotypes. With changing planting date from September to October, LT50su decreased 9.6 and 6 °C in Khaf and Neysabur ecotypes, and increased 3.9 and 2 °C in Bojnurd and Torbat-e Heydarieh ecotypes, respectively. In the first planting date with decreasing temperature from zero to -18 °C, the maximum and minimum decrease in height (90 and 27%) were observed in Torbat-e Heydarieh and Bojnurd ecotypes, and Neyshabur and Khaf ecotypes disappeared at this temperature. Also, in the second planting date with decreasing temperature from zero to -15 °C, plant height decreased 47, 52 and 30% in Khaf, Torbat-e Heydarieh and Neyshabur ecotypes, respectively. However, plants height of Bojnurd ecotype decreased only 4% under similar conditions. In the first planting date Bojnurd and Torbat-e Heydarieh ecotypes had the lowest decrease in leaf area (about 3 and 17%, respectively) at 12 °C compared with zero temperature, while Khaf and Neyshabur ecotypes assigned to themselves the highest decrease in leaf area (about 85 and 58%, respectively). Also, in the second planting date leaf area of Bojnurd ecotype decreased 18% at -15 °C compared with zero temperature, while in similar conditions Torbat-e Heydarieh, Khaf and Neyshabur ecotypes had 56, 38 and 58% decrease in leaf area, respectively. The lowest decrease in dry matter percentage was observed in Neyshabur (23%) and Bojnurd (22%) ecotypes in the first and second planting date, respectively, following decreasing temperature to -12 °C. Studies have shown that plants with faster growth before the frost were more sensitive to cold temperatures and as a result, damaged more. So, it seems that increasing growth of Khaf and Neyshabur ecotypes and their progress towards more advanced growth stages reduced cold tolerance of these plants in the first planting date.
 

Freezing stress decreased survival percentage and recovery of garlic ecotypes. In the first planting date Bojnurd and Torbat-e Heydarieh ecotypes had a better survival percentage and Khaf and Neyshabur ecotypes had lower survival percentage while in the second planting date Khaf and Neyshabur ecotypes had higher survival percentage than Bojnurd and Torbat-e Heydarieh ecotypes. Also, results of LT50su indicated that Bojnurd and Khaf ecotypes had higher freezing tolerance in the first and second planting date, respectively. Different reactions of garlic ecotypes at various stages of stress may be due to their genetic characteristics and geographic origin. In terms of recovery (height, leaf area and dry weight), the plants of the second planting date had more height and dry matter, as well. Based on the RDMT50 and RLAT50, moreover, Bojnurd ecotype in both planting date and Khaf ecotype in the first planting date were recognized as most tolerant and sensitive ecotypes, respectively.