جستجوی مقالات مرتبط با کلیدواژه « تنش کم آبی » در نشریات گروه « زراعت »

Bitter vetch (Vicia ervilia L.) is one of the grain products of the legume family. The crop in Iran is one of the old legumes in the North and Northwest of the country and is grown alternately with cereal crops. Bitter vetch contains energy and protein, which makes it as a potential economic source for poultry feed. Drought is the most important abiotic stress and the most important limiting factor for crop growth which reduces the crop production in approximately 25% of the world's lands. Genetic diversity has a critical role not only for plant resistance against pests and diseases but also against the environmental stresses. In this study, the genetic diversity of 15 bitter vetch genotypes along with Kermanshah landrace was investigated using multivariate analysis methods.

Fifteen bitter vetch genotypes along with Kermanshah landrace were studied in a randomized complete block design with three replications at the research farm of Razi University, Kermanshah under two non-stress and water deficit stress conditions in 2016. The measured traits included phenological and morphological characters, yield and yield components. Combined analysis of variance (ANOVA) was performed using SAS 9.1 software, assuming the genotype and location as fixed effects. Correlation analysis, path analysis, factor analysis and clustering method were performed using SPSS 16 software.

The combined analysis of variance showed that the effect of environment was significant for all the traits except the number of sub-branches. The results of the correlation coefficient showed that there was a positive and significant correlation between the yield in non-stress conditions and the number of sub-branches, the number of seeds per pod, the number of pods per plant and the number of seeds per plant. Also, the yield under stress conditions was positively correlated with the number of seeds per pod and number of seeds per plant. Based on path analysis under non-stress conditions, the number of pods per plant had the greatest direct effect (0.54) on seed yield. Under stress conditions, the seed number in pod had the most direct effect (0.69) on the yield. The results of factor analysis in non-stress conditions led to the identification of three factors that accounted for 76.59% of the total diversity of the data. In the stress condition, four factors were identified, which determined 85.96% of the total diversity. In non-stress conditions, yield, yield components and phenological characteristics were important factors that accounted for the total variation. In cluster analysis, the grouping of the genotypes in the two conditions of non-stress and water deficit stress was partly different, showing the different reactions of the bitter vetch genotypes to the water deficit stress.

The grouping of the bitter vetch genotypes under non-stress and water deficit stress was partly different in the cluster analysis, showing the different reactions of the genotypes to the water stress. Under the water deficit conditions that happens from late flowering stage, earliness along with suitable vegetative growth should be noticed to achieve higher yield. Genotypes 13 and 2 were identified as semi-precocious and superior accessions under the non-stress and terminal water deficit stress conditions.

Climate change accelerated the negative effects on plant production; Therefore, agricultural researchers are focused on identifying strategies that minimize the effects of climate change on crop production. Black cumin (Nigella sativa L.) is an annual herbal plant belonging to the Ranunculaceae family. It has been used in traditional medicine in the past. Black cumin has a lot of industrial and medicinal uses. Nowadays, regarding the importance of medicinal and aromatic plants, such as black cumin, different strategies should be applied to improve their traits in different conditions. Drought stress is an effective climatic factor. Biochar as an ecological input is introduced in recent years. It was hypothesized that biochar may alleviate drought effects. Accordingly, the aim of this study was to investigate the effect of biochar on morphological characteristics, physiological parameters activity, and yield of black cumin affected by drought stress.

To evaluate the effect of biochar and different irrigation levels on the morpho-physiological traits of black cumin an experiment was carried out in the greenhouse of the University of Kurdistan in 2018. The experimental factors included three irrigation levels (100%, 70%, and 40% of the field capacity of the soil) and two biochar consumption levels (0, and 15 t ha-1). The experimental design was a factorial based on a completely randomized with three replications. The amounts of field capacity and permanent wilting point were separately calculated for two different levels of biochar. Fourteen seeds of black cumin were sown in each pot. All of the pots were irrigated after sowing. The morpho-physiological traits included relative water content, total chlorophyll, photosystem II efficiency, plant height, flowering and secondary branches number per plant, capsule and seed number per plant, and biological and grain yield were measured. The statistical SAS software (version 9.3; SAS Institute; USA) was used for ANOVA. The mean of treatments was compared with the LSD test.

The results showed that irrigation and biochar interaction had a significant effect on the morpho-physiological characteristics and yield of black cumin. Biochar application decreased the negative effects of drought stress. The greatest RWC (86.13) belonged to 100% irrigation and biochar application. Given the increased weights of pots containing biochar and increasing the leaf water potential, it can be concluded that biochar application ultimately increased RWC due to increasing water holding capacity. At the 40, 70, and 100% irrigation levels, biochar increased total chlorophyll by 1.43, 13.64, and 5.31% compared with non-application of biochar, respectively. The maximum (83.2%) and minimum (70.72%) photosystem II efficiency were observed in 100% irrigation with biochar and 40% irrigation and non-application of biochar, respectively. Biochar application enhances chlorophyll content consequently increasing photosynthesis compared with no biochar application under drought stress. The highest number of flowering and secondary branches per plant was obtained from 100% irrigation and biochar application and the lowest number of mentioned traits belonged to 40% irrigation and non-application of biochar. Drought stress reduced capsule number per plant. The minimum number of capsules was obtained from 40% irrigation level. Biochar increased capsule number per plant and seed number per plant at 70% and 100% of irrigation levels and 40% and 70% of irrigation levels, respectively. The greatest biological yield belonged to 100% irrigation and biochar application. This treatment increased biological yield due to enhancing morphological traits and yield components. At the 40, 70, and 100% irrigation levels, biochar increased grain yield by 33.51, 34.12, and 10.72% compared with non-application of biochar, respectively.

The usage of biochar improved the relative leaf water content, total chlorophyll content, photosystem II efficiency, morphological traits, biological and grain yield of black cumin under drought stress. Overall it can be said that biochar not only can reduce the negative impacts of drought stress but only improve the growth of black cumin. Therefore, biochar can be used as a useful input in sustainable agricultural systems under drought stress.

In order to investigate the use of biological and chemical nitrogen fertilizers in the conditions of limited water resources, a research was conducted in Arak during the crop years of 2016 and 2017 on the content of nutrients stored in the dry fodder of Maxima hybrid corn. This experiment was done in the form of a split-split plot and in the form of a basic design of randomized complete blocks in four replications, so that the irrigation levels were placed in the main plot and the nitroxin and nitrogen levels were placed in the sub-plots. The investigated treatments were irrigation at two common irrigation levels and applying water restriction, nitroxin at three levels of the control treatment, consumption of 0.5 and one liter of nitroxin per 30 kg of seeds consumed and nitrogen at three levels including the control treatment, consumption of 125 and 250 kg of nitrogen per hectare provided through 46% urea fertilizer. It was concluded that the effect of the year on the amount of nitrogen, protein and raw ash of fodder was significant and in the second year of testing the mentioned traits increased. The effect of irrigation factor on the yield of dry fodder, the amount of phosphorus and raw ash of fodder was significant, and the aforementioned traits increased under favorable irrigation conditions. Nitroxin treatment also showed a significant effect on experimental traits and with increasing the amount of nitroxin consumption, experimental traits often increased. The mutual effect of irrigation and nitroxin on all the measured traits was significant, and with the application of one liter of nitroxin under common irrigation conditions, the highest amount of these traits was obtained. In the conditions of applying irrigation restrictions, the use of 1 liter of nitroxin compared to the use of 0.5 liters and also the treatment without the use of nitroxin resulted in an increase in traits. The mutual effect of irrigation and nitrogen on all studied traits was significant except for dry fodder yield, so that the highest amount of these traits was obtained from the consumption of 250 kg of nitrogen under conventional irrigation conditions. The interaction effect of nitroxin and nitrogen on experimental traits was significant, so that the highest average of them was obtained by consuming one liter of nitroxin together with 125 kg of nitrogen. The interaction effect of all three treatments on all desired traits was significant, and in this regard, the highest amount of experimental traits was obtained as a result of consuming one liter of nitroxin with 125 kg of nitrogen under favorable irrigation conditions.

water deficit stress during growth and flowering is one of the most major environmental constraints, which influences seed grain filling and consequential germination and early growth stages of plants. In this study, the impact of foliar application of micronutrients (control, Fe, Zn, Fe + Zn, nano- Fe, nano- Zn, nano- Fe + nano- Zn) on quinoa at 2 reproductive stages (50% and 100% of flowering stage) were evaluated under 2 levels of water deficit stress, control (-0.03±0.045) bar and water deficit stress (-9±0.045) bar. The results showed that germination traits including percentage, rate, mean germination time, germination uniformity, seedling length and weight index as well as chlorophyll and carotenoid content were significantly affected by micronutrient foliar application, foliar application time and water deficit stress. water deficit stress decreased the percentage and rate of germination and seedling indices, but foliar application of micronutrients reduced the adverse effects of foliar application of micronutrients. Foliar application of micronutrients also increase the amount of photosynthetic pigments. The findings of this research show that foliar spraying with nutrients, especially nano-iron + nano-zinc, increases the germination indices to improve the germination and growth of quinoa seedlings under water stress conditions.

Water deficit stress is one of the most common abiotic stresses that reduce the growth and yield of crops such as oilseed rape. The utilization of micronutrients in oilseed crops is one of the most useful and effective approach for improving the grain yield and plant adaptation under drought stress conditions. Accordingly, the aim of this study was to investigate the effect of foliar application of selenium nanoparticles on physiological, biochemical and agronomic characteristics of oilseed rape under the end season drought stress.

To investigate the effect of selenium nanoparticles on on some physiological, biochemical and agricultural characteristics of oilseed rape under the end season drought stress, a split-plot experiment was conducted in a randomized complete block design (RCBD) with three replications at research farm station of University of Mohaghegh Ardabili in 2017-2018. The treatments were irrigation (normal irrigation and omitting irrigation at the flowering stage) as main plots and selenium nanoparticles foliar application ((0 (control), 25 and 50 mg/l) as sub-plots. The cultivar studied was Hayola 401. The measured traits included Chlorophyll a, Chlorophyll b, Total Chlorophyll, Carotenoid, F0, Fm, Fv, Fv/Fm, relative water content, ion leakage, malondialdehyde, Catalase and grain yield. Analysis of variance and comparison of their means using by LSD test were done by the SAS software (version 9).

According to the results, drought stress significantly reduced the amount of photosynthetic pigment, relative water content and grain yield while amount malondialdehyde, ion leakage and chlorophyll fluorescence increased under drought stress conditions. Foliar spraying of nanoselenium with a concentration of 50 mg/liter increased catalase enzyme activity (82%), relative leaf water content (29 %), total chlorophyll (64 %) and decreased electrical conductivity of materials leaked from leaves by 23% could reduce the negative effects of drought stress. so that the grain yield increased (45%) by spraying 50 mg/l selenium nanoparticles in under drought stress conditions. The most positive and significantc orrelations were observed between grain yield and chlorophyll a, total chlorophyll (96** %).

The results of this study indicated that the using of molybdenum oxide nanoparticles under favorable irrigation conditions and drought stress could improve photosynthetic indices and biochemical traits. Foliar application of selenium nanoparticles, especially at 50 mg/l concentration, reduced the effects of drought stress by increasing the synthesis of chlorophyll and improving the process of photosynthesis and improved physiological and biochemical indices, thus improving the grain yield in favorable and unfavorable environmental conditions.

This study was conducted as a factorial experiment in a randomized complete block design with three replications in the breeding center of buffalo in the northwest of Iran in 2020-2021 growing season. Experimental treatments included different irrigation conditions at three levels (irrigation after depleting of 40, 60, and 80% of available water) as the first factor and application of different fertilizer sources at five levels (chemical, biological, organic, nano fertilizer, and control) as the second factor. Crude protein, dry matter digestibility, water-soluble carbohydrates, and protein yield were improved under different fertilizer sources and different irrigation conditions compared to the control treatment. With delay in irrigation, dry matter, forage ash and relative feed value decreased, while water stress increased the amount of ADF and NDF. Also, the highest amount of dry matter, ash and the relative feed value were obtained in the nano fertilizer. Irrigation after depleting of 40% caused 24, 14, and 18% increase in dry weight of leaves, stems and forage yield, respectively, compared to 80% of available water. The highest dry weight of leaves, stems, and forage yield were obtained with 11738, 16764, and 27938 kg/ha in nano fertilizer, respectively. In conclusion, the results showed that nano-fertilizers and organic fertilizers were more effective in improving the quantitative and qualitative characteristics of fodder sorghum under water stress conditions compared to other fertilizer sources.

Beans are one of the most important legumes in many developing countries as one of the sources of human protein. Drought stress is also one of the factors limiting the growth and production of plants in arid and semi-arid regions, which has reduced the yield of plants, especially legumes. The use of antitranspirants is an effective tool in regulating transpiration with the aim of preserving water in the plant. The aim of the present study was to compare the effects of antitranspirants in the condition of irrigation cut off on seed yield and some physiological characteristics of Kosha cultivar pinto beans. The study was carried out in the form of split plots based on a randomized complete block design with three replications in the two crop years of 2019 and 2020 in agricultural lands located in Khoi city. Experimental treatments include irrigation at two levels; Normal irrigation (irrigation according to local custom) and irrigation cut off at the stage of filling the seeds in the main plots and spraying antitranspirants on eight levels in the sub plots included: salicylic acid (0.5%), phenyl mercuric acetate (100 μM), gibberellic acid (150 μM), cytovit (2%), chitosan (0.5%), castor oil (6%), gum arabic (0.5%) and distilled water (control). The traits measured in the experiment included plant height, number of pods per plant, number of seeds per pod, hundred seed weight, seed yield, biological yield, seed protein percentage, relative water content and proline content. The results showed that the cut off Irrigation had a significant effect on the number of pods per plant, hundred seed weight, seed yield, biological yield, protein percentage, relative water content and proline content of bean leaves. antitranspirants also had a significant effect on all traits except for the number of seeds in pods. The interaction effect of irrigation withholding and antitranspirants was significant in the number of seeds in the pod and the percentage of seed protein. The triple interaction of year, irrigation cut off and antitranspirants on the number of pods per plant and hundred seed weight was significant. In the condition of irrigation cut off, antitranspirants increased the seed yield and the highest seed yield was obtained in the salicylic acid treatment, which increased by 41.1% compared to the control treatment. It seems that by applying a stage of irrigation restriction and consumption of antitranspirants in the areas that faced with the problem of water deficit at the end of the growing season, by improving some morpho-physiological characteristics such as reducing the amount of proline and increasing the relative moisture content of leaves and biological function, it is possible to effectively the slope decreased the yield of pinto beans under drought stress conditions. Therefore, in areas with water deficit, especially due to the simultaneous limitation of water resources, peak consumption in other agricultural products, which causes psychological pressure on to deal with the problem of water deficit, using antitranspirants as an efficient tool and removing a irrigation phase at the end of the growing season can partially compensated for the the reduction of damage caused by water deficit.

To identify soybean with higher grain yield and stability in low water regions of the country, 14 superior soybean lines along with two control lines (Saba, Kowsar) were evaluated in two separate experiments in a randomized complete block design with three replications in two years 2015-16 in Karaj. In this study, both experiments were similarly irrigated until seedling establishment and the emergence of stage V4-V5, which coincided with the full development of the fourth to fifth leaflets. After that, in the first and second experiments, were irrigated every week and every other week, respectively. At the end of two years, the stability of the lines was evaluated by 16 stability methods and a three-dimensional graph of mean grain yield, rank and rank variance of stability statistics were investigated. The results of combined analysis of variance showed that the line effect and the interactions of year by stress, year in line and year by stress in the evaluated line were significant and lines G1, G3, and G2 had the lowest average of sum stability statistics (Ar) and standard deviation of rankings (SD) and had been higher yield than average yield and control regions cultivars of Kowsar and Saba and were identified as stable lines. Therefore, these lines can be selected and introduced as a high yield and sustainable cultivar for cultivation in low water areas.

Conservative tillage and drought resistant crops can be efficient solution to alleviate climate change impacts. We evaluated tillage effect, water deficit and nitrogen level on sorghum in a split-split plot experiment with three replications. Main plots were conventional tillage and no tillage, sub plots were 30, 60, and 90% of sorghum water requirement, and sub-sub plots were consisted of 0, 50, and 100% of recommended nitrogen. Results showed that the highest forage yield (12263 kg ha-1) was obtained with no till and 100% nitrogen. Also, the yield of sorghum in no till with moderate water stress was equal to the yield in conventional tillage with partial water stress. Under partial water stress, qualitative traits including crude fiber, acid detergent fiber and neutral detergent fiber in no till had lower values than conventional tillage. In addition, qualitative traits including digestible dry matter and water-soluble carbohydrates in no till treatment with 100% nitrogen were higher than conventional tillage. The highest percentage of crude protein in conventional tillage was obtained by using 100% nitrogen. It seems that conservation tillage can achieve acceptable yield and quality in sorghum with less water than conventional tillage, but it requires long-term and additional research.

Investigation of inheritance of agronomic traits, type of genes action and selection of appropriate breeding method is of great importance in order to achieve the maximum potential of breeding genotypes. In order to estimate the genetic components of important morphological traits were using generation mean analysis with mixed models in four basic generations (BC1, F2, F1, and BC2) resulting from crossing of maize inbred lines MO17 (drought tolerant) and B73 (drought sensitive), under water deficit stress factor at three levels of including well-watered, intermediate, and severe water deficit stress in field conditions were studied in the growing season in 2016 and 2017. The results of this research showed that the highest heterosis of F1 was observed in the well-watered for one grain weight (112%), in the intermediate stress for grain yield (59%), and in the severe stress for anthesis silking interval (59%). Average degree of dominance in well-watered for 100 grain weight trait, in intermediate stress for number of ears per plant and in severe stress for plant height and number of leaves per plant were positive and greater than one. Also, in three irrigation conditions, due to the greater dominance gene effects (dominance gene effects was obtained for grain yield in plant in well-watered condition 75, intermediate stress 115, and severe stress 63) and variance of dominance gene effects in genetic control of grain yield and important traits, the production of hybrid varieties is essential to exploit these effects.

Drought stress is known as one of the main factors limiting agricultural production. Investigation of the effect of drought stress on grain yield and other agronomic and physiological traits can be useful in identifying drought-tolerant cultivars. The aim objective of the present study was to study the effect of terminal drought stress on some of the agronomic and physiological characteristics in a set of promising barley lines.

This study was carried out at the Cereal Research Station located in Seed and Plant Improvement Institute, Karaj, Iran during 2020-2021 cropping seasons. The plant material consisted of 17 promising genotypes of barley along with a commercial cultivar (cv. Jolgeh). All genotypes were investigated in two separate experiments based on a randomized complete block design with three replications under two control and drought stress conditions.

The results of combined analysis of variance showed a significant difference between control and drought stress conditions in terms of all measured traits except spike length and the number of seeds per spike. Furthermore, a significant difference was observed among the tested genotypes in terms of all measured traits except initial chlorophyll fluorescence, maximum quantum yield of PSII, and maximum primary yield of photochemistry of PSII. However, the interaction effect between drought stress conditions and genotype was only significant for the number of days to physiological maturity, grain filling period, main spike length, and chlorophyll content.The results of principal component analysis (PCA) revealed that the first five components accounted for 84.80% of the total phenotypic variation, under drought stress condition. Considering the angle among trait-vectors indicated that some of traits such as number of days to anthesis and to physiological maturity, awn length, plant height, leaf area index, chlorophyll content, and number of seeds per spike positively correlated with grain yield in the drought stress condition. In general, our results showed that genotypes G2, G3, G6, G7, G12, and G18 were identified as the best genotypes compared with other tested genotypes.

According to results, genotype G7 due to its highest grain yield and ideal agronomic and physiological features can be candidates for further complementary investigations in multi-environmental trials with the aims of realization of a new commercial cultivar.

Soja (Glycine max L.) is the most important oil crop in the world. Soybean yield and its geographical distribution in the country can be severely limited by abiotic practices such as drought. There is a constant need to improve soybean cultivars with stable yields in different environments. In this study, the stability and adaptability of advanced soybean lines under water stress conditions have been investigated.

In this study, 14 top soybean lines that were superior in preliminary soybean yield evaluation experiments in different regions along with two cultivars, Saba and Kowsar, in two separate experiments. They were evaluated in a randomized complete block design with three replications in the two years of 2015-2016 in Karaj. Both experiments were similarly irrigated until seedling establishment and the emergence of the V4-V5 stage, which coincided with the complete development of the fourth to fifth of three-leaf. After that, the first experiment was irrigated weekly and the second one every other week (50-55 and 100-120 mm evaporation from Class A evaporation pan, respectively). At the end of two years, the stability and adaptability of the lines were evaluated by GGE biplot, AMMI, and the rank of the mean yield.

The results showed that the effects of genotype, environment and genotype × environment explained 20, 68, and 12% of the total squares, respectively. Also, the first two main components were significant and each of them accounted for 67 and 24% of the total squares, respectively. The results of this study showed that the highest seed yield in non-stress conditions was observed in G1, G3 and G2 lines, respectively. Also in drought stress conditions, the highest seed yield was obtained from G3 and G2 lines. The G3 line was known as a drought tolerant genotype with higher than total average yield in both non-stress and stress conditions.

According to the mean rank and standard deviation of seed yield rank of lines biplot diagram, G3, G1, G2, G7 had the least interaction with the environment and were identified as stable lines. in the first two main components biplot diagram, and the AMMI stability value (ASV) with the lines seed yield biplot diagram, G2, G6, G3, G1, G7 were recognized as more stable lines. Based on the GGE polygon diagram, lines G1, G6, G2, G7, G4, and G5 were also selected. Also, G3, and G8 lines showed good private adaptability with Karaj in stress-non stress conditions. The results showed that line G3, G1, G2 with higher seed yield than the total mean and control cultivars can be introduced as a suitable line for cultivation in low water areas.and they can also be used in future breeding programs.

In order to investigate the effect of humic acid on some of physiological characteristics and agronomic traits of rapeseed (Brassica napus L.) cultivars under drought stress conditions, the present experiment was carried out as Split-split plot design randomized complete blocks design with 4 replications in Kaleybar city in 2019. The main plot, sub plot and Sub-sub plot included irrigation after 60, 90 and 120 mm water evaporation from class A evaporation pan, bean cultivars divided into 4 categories of Hayola 420, Sarigol, Traper and RJS003, and humic acid application on 5 levels (0, 100, 200, 300 and 400 mg.Lit), respectively. The results showed that the simple effects of drought stress, humic acid and cultivars traits measured at a probability level of 1%. The interaction between water stress and humic acid on chlorophyll content, plant height, number of pods per plant, grain yield and oil yield were significant. The effect of dual interaction (drought stress × humic acid and drought stress × cultivars) on chlorophyll index, plant height, number of pods per plant, grain yield and oil yield were significant. With increasing drought stress, the relative moisture content (20.54%), number of grains per pod (25.32%), 1000-grain weight (16.58%) and oil content (6.75%) decreased; While increasing the proline concentration (35.13%). The highest oil yield and grain yield were allocated to 60 mm of evaporation and 400 mg/l of humic acid and the lowest amount of oil and grain yield was assigned to 120 mm of evaporation and no use of humic acid. Humic acid increased the relative moisture content, number of seeds per pod, 1000-seed weight and oil percentage and decreased the amount of proline (26.31%). As a result, spraying 400 mg/l humic acid at different levels of drought stress improved physiological characteristics and increased production components compared to the control (no spraying). In the four cultivars evaluated, Hayola 420 cultivar had the highest grain yield and yield components. According to the results, humic acid reduces damages caused by drought stress.

Dry matter Partitioning in vegetative and reproductive organs and yield of 11 sunflower hybrids were evaluated in different irrigation program during 2013 and 2013 in Karaj, Iran. Three separate experiments including irrigation after 60, 120 and 180 mm evaporation from evaporation pan, Class A as base of randomized complete block design were sutdied as control, mild and severe stress conditions, respectively. The results showed the plant height was decreased by 10.1% under mild stress and 17.2% under severe stress compared to control. Although, increasing of the height had a positive effect on grain yield, but the stem weight was more effective than head weight on grain yield. In control irrigation, plants produced thicker stems that made to translocate more dry matter to the grain. But under severe stress conditions, the  head diameter decreased, and the most of the dry matters were used in the head development. The highest grain to head weight ratio was obtained from mild stress. In severe stress conditions, the grain to head weight ratio  went up and it caused to rise linear growth of grain number and weight. Grain yield was diminished on average of 18% and 33% under mild and severe stress conditions, respectively. In the stress conditions, Barzegar hybrid had the highest grain yield for maintaining the number and weight of grain in the heads. The evaluation of strees susceptibility and tolerant showed that STI, MP and GMP indices had a positive and significant correlation to yield and, Barzegar and Sunbro hybrids were superior thant Cultivars and hybrids.

The present study was carried out in 2017 in the farm Milajard city, in order to investigate the effect of stopping irrigation and using Stacozorb superabsorbent on the morphological, quantitative and qualitative characteristics of Progress sunflower in the form of a split plot experiment based on a randomized complete block design with four replications. Irrigation treatment as the main factor in three levels of full irrigation, stop irrigation from the budding stage (45 days after planting) and stop irrigation from the flowering stage (55 days after planting) and use of super absorbent as a sub factor included four levels of no use of super absorbent, consumption of 30, 60 and 90 kg.ha. The highest yield of oil and grains and components of grain yield were obtained in the treatment of full irrigation and consumption of 90 kg.ha of superabsorbent, and the lowest amount of these traits in the treatment of interruption of irrigation was obtained from the stage of budding and no use of superabsorbent. Considering the importance of the economic characteristic of oil yield in sunflower, the stress of interrupting irrigation in budding and flowering stage caused a decrease, respectively, and these negative effects of water deficit stress were adjusted by using superabsorbent, so that the high amount of superabsorbent (90 kg.ha) had the greatest effect in improving the investigated traits under low irrigation conditions (according to the stress in budding and flowering stage) to the extent of (7.36 and 6.73 percent).

Environmental stresses including drought stress are one of the most important factors reducing performance and growth and development of plants. The use of soil microorganisms is a promising technique to increase plant resistance to water stress. This study was carried out in order to evaluate tall fescue (Festuca arundinacea cv. Tomahawk) drought stress tolerance potential under drought stress and inoculation of microbial treatment with root fungus Piriformospora indica.

The research was performed in the research site of the Department of Horticultural Sciences, Urmia University, during the years 2020-2021 as factorial-split plot in time based on randomized complete block design with three replications that experimental factors included inoculation and non-inoculation with P. indica and drought stress (30, 70 and 100% FC). After exerting drought stress, harvesting (sampling) was performed four times with an interval of 10 days. The measured traits included fresh and dry weight of shoot and root, relative water content, chlorophyll a and b content, activity of catalase and ascorbate peroxidase enzymes, potassium, phosphorus, and nitrogen amount in shoot and root tissue.

The shoot fresh, dry weight, and the relative water content decreased with drought stress and the lowest amount was recorded in 40% of field capacity. P. indica inoculation caused the preservation of these traits. P. indica treatment caused an increment of 20.27, 37.21, 16.32, 13.02, 11.1% in root length, chlorophyll a content, amount of shoot potassium, phosphorus, and nitrogen, respectively. P. In addition, P. indica with increasing the activity of antioxidant enzymes including catalase and ascorbate peroxidase causes preservation of the chlorophyll a, b content, and the shoot fresh and dry weight that reduced the effects of drought stress.

It is inferred that microbial inoculation with P. indica by improving the growth and biochemical characteristics of plants plays an important role in increasing the resistance to water deficit stress in Festuca arundinacea. Therefore, P. indica can be used as an effective environmentally friendly compatible in drought stress conditions in Festuca arundinacea cv. Tomahawk in the urmia weather conditions.Therefore, P. indica can be used as an effective environmentally friendly compatible in drought stress conditions in Festuca arundinacea cv. Tomahawk in the urmia weather conditions.K e y w o r d s: A n t i o x i d a n t e n z y m e s, W a t e r d e f fi ci t stress, Phosphorus, Microbial inoculation, Nitrogen.

This research was conducted with the aim of investigating the combined use of biological and chemical nitrogen sources under the conditions of limited water resources on some agricultural traits and the yield of fodder in the crop years of 2016 and 2017 in Arak. This experiment was done in the form of a      split-split plot and in the form of a basic design of randomized complete blocks in four replications, so that irrigation levels were placed in the main plot and nitroxin and nitrogen levels were placed in the sub-plots. The investigated factors were irrigation at two levels of regular irrigation and water restriction, nitroxin at three levels of the control treatment, consumption of 0.5 and one liter of nitroxin per 30 kg of seeds consumed and nitrogen at three levels including the control treatment, consumption of 125 and 250 kg of nitrogen per hectare through 46% urea fertilizer. The interaction effect of irrigation and nitroxine on all the measured traits except the number of rows in the cob and the number of seeds in the cob was significant, and with the application of one liter of nitroxine under normal irrigation conditions, the highest amount of these traits was obtained. In the conditions of applying irrigation restrictions, the consumption of 1 liter of nitroxin compared to the application of 0.5 liters and also the treatment without the use of nitroxin resulted in a slight increase in all investigated traits. The interaction effect of irrigation and nitrogen was significant on all studied traits except the number of cobs in the plant and the total number of seeds in the plant, so that the highest amount of effective traits was obtained from the consumption of 250 kg of nitrogen under normal irrigation conditions. The interaction effect of nitroxin and nitrogen on other traits was significant. The highest number of cobs per plant and higher fodder yield (with an average of 86.42 tons per hectare) were obtained as a result of the consumption of one liter of nitroxin combined with 250 kg of nitrogen per hectare, but regarding other traits, the highest average results were obtained from the consumption of one liter of nitroxin. along with 125 kg of nitrogen per hectare.

An experiment has been conducted in the form of split plots in a randomized complete block design with three replications at the Agricultural and Natural Resources Research Institute in Zahak to evaluate the effect of drought stress and potassium application on yield and morphophysiological traits of safflower (Goldasht cultivar) under saline irrigation conditions (EC 6 dS.m-1) in 2018-2019. Drought stress irrigation regimes have been tested at three levels (irrigation after 45% (control), 65%, and 85% of admissible moisture depletion) as the main factor, and potassium fertilizer at four levels (0, 75, 150, and 225 kg.ha-1) as the sub factor. According to the findings, drought stress has reduced plant height, number of heads per plant, number of seeds per head, seed and biological yield, and relative water content. The use of potassium, on the other hand, has increased the above traits greatly. Irrigation after 45% moisture depletion increases seed yield by 42.32%, compared to irrigation after 85% moisture depletion. Interaction of drought stress and potassium has had a significant effect on number of branches per plant, 1000-seed weight, leaf chlorophyll index, soluble carbohydrate content, and seed oil percentage, with the highest amount observed after 45% water drainage and application of 225 kg K ha-1.

In order to investigate the agronomic characteristics of Potato under water deficit stress conditions using line-source sprinkler irrigation method and potassium fertilizer amounts an experiment was done in Khorasan Razavi Agricultural and Natural Resource Research Center during 2015-2016 as split plot design based on completely randomized blocks design. Water deficit levels at 0.75m from line-source (control), at 3.75m from line source (very light), at 6.75m from line-source (light), at 9.75m from line-source (severe deficit), at 12.75m from line source (very severe deficit) were considered as main factor and potassium levels included 0, 90, 180, and 270 kg.ha-1 K2O were as subfactor. Studied traits were included, tuber yield, percent of small, medium and big tuber yield, number of tuber per plant, average of tuber weight, plant height and stem number per plant. The results showed that water deficit stress levels had significant effects on total traits and potassium nutrition levels had same effects except percent of small and medium tuber yield and stem number per plant. Higher water deficit levels significantly decreased the tuber yield, tuber number per plant and average of tuber weight that in very severe deficit these traits reduced 92.29, 84.32, and 53.81 percent respectively. The highest tuber yield (17.92 ton.ha-1), tuber number per plant (7.94) and average of tuber weight (38.73 g) resulted in 270 kg.ha-1 K2O. The highest and lowest tuber yields were in control with 270 kg.ha-1 K2O and very severe deficit with 0 kg.ha-1 K2O.

Various environmental stresses, especially water deficit stress have several and major effects on maize growth and production. Drought is one of the abiotic stresses that due to the great variety of rainfall conditions, it is known from Iran as the most important factor limiting the growth and production of crops. Therefore, the effect of water deficit stress on strategic plants such as maize is of particular importance.

In order to assess the effect of water-deficit stress on the activity of antioxidant enzymes and agro-physiological indices in the leaves in some of maize genotypes, a split-plot field experiment was conducted with three replications based on the Randomized Complete Block design (RCBD) was performed under field condition, it was performed on the farm of the Faculty of Agriculture, University of Tabriz. Three levels of irrigation (well-watered, intermediate and severe water-deficit stress) and 11 maize genotypes were considered as the main and sub-factors, respectively. After treatment, the electrophoretic analysis of three enzymes in maize leaves including superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were carried out on 8% horizontal acrylamide gel and some agro-physiological indices such as malondialdehyde (MDA), H2O2, chlorophyll index (SPAD), relative water content (RWC) and soluble protein content were measured.

Based on the our results, CAT enzyme increased by 100% under severe stress compared to well-watered and MDA content with 120.78% increase, the highest increase activity and leaf chlorophyll under severe water deficit stress showed the highest reduction(-24.05%) compared to well-watered condition. In general, the soluble protein content fluctuated with increasing stress intensity compared to well-watered condition, On the other hand, the difference between the total soluble protein content in the two genotypes SC704 and SC706 with increasing intensity of stress from normal to intermediate stress and severe stress showed the least significant difference inversely.

Examination of maize genotypes with antioxidant enzymes and physiological indices showed that SC704, SC703, AR70 and SC706 genotypes had the highest level of antioxidant enzyme activity and adequate physiological response to water deficit stress, also they showed higher stress tolerance than water deficit stress. In both stressful conditions, SC260 genotype showed the highest susceptibility under water deficit stress condition. Finally, CAT, POX1, SOD1 and SOD2 isozymes as well as H2O2 indices, soluble protein content and leaf chlorophyll could be introduced as efficient isozymes and indices and can be these indices were used to identify superior genotypes under water deficit stress in maize molecular breeding programs.