فهرست مطالب جهانفر دانشیان

Selection of soybean cultivars that have a higher grain yield under water deficit conditions, reduces the damage to soybean producers.

The response of soybean genotypes to water deficit stress was investigated in terms of agricultural characteristics and grain yield in Karaj (Iran), during two years. The experiment was carried out as a split plot based on randomized complete block design in three replications, with three irrigation levels (control, mild stress, and severe stress)  based on 50, 100, and 150 mm evaporation from a  Class A evaporation pan as the main plot and 10 soybean genotypes as the sub-plot.

The results showed that mild and severe stress caused the node number and inter-node to decrease in comparison with control irrigation. Under control irrigation, the highest grain yield (2585 kg/ha) was obtained from the early-maturing Saba cultivar, with the highest seed number per unit area. The early-maturing genotypes had the highest grain yield under control irrigation, and their grain yield decreased significantly with increasing stress intensity. The grain yield of the Saba cultivar reduced under mild and severe stress by 32 and 59% compared to control irrigation, respectively. Under stress conditions, the late-maturing genotypes had the highest grain yield and water deficit stress caused a slight decrease in their grain yield. Under mild and severe stress, the late-maturing Williams×A3935 line had the highest grain yield and protein yield, respectively.

Under control irrigation, the Saba cultivar, and under stress conditions (mild and severe) the Williams×A3935 line is recommended in Karaj and similar climates (moderately cold region).

Drought stress is the main factor in reducing production and the area under soybean cultivation. In order to investigate the effect of drought stress on the biochemical and morphophysiological characteristics of soybean [Glycine max (L.) Merrill], an experiment was conducted with 19 soybean genotypes in two environments without drought stress (watering weekly) and drought stress (watering every 10 days) in the form of a randomized complete block design with three replications in Khorramabad in the summer of 2017. The results of the analysis of variance showed that drought stress decreased the amount of chlorophylls a, b, a+b and a/b (66.6%, 37.2%, 53.8% and 43.9%, respectively); decreased the amount of phosphorus, potassium, iron and zinc in aerial parts (39.7, 69.8, 24.4 and 38.4 percent, respectively) and decreased the amount of phosphorus and zinc in seeds (0.10 and 7.2 percent, respectively), but it resulted in an increase in peroxidase and catalase of the shoot (0.15 and 47.6 percent, respectively) and an increase in the amount of potassium and iron in the seed (11.8 percent and 4.7 percent, respectively). Among the genotypes, the highest amount of aerial organ chlorophyll a was obtained from genotype number 1 and the lowest amount was obtained from genotype number 16. The comparison of the means by the cutting method showed that in the normal environment, the highest amount of aerial organ peroxidase was obtained from genotypes No. 8 and 9 and the lowest was obtained from genotype No. 19. While, in the stress environment, the highest amount of aerial organ peroxidase was obtained from genotypes number 6 and 15 and the lowest from genotype number 8. The trend of changes in grain yield and soybean leaf area index at different levels of the interaction effect of drought stress and genotype followed a significant and negative linear relationship, but the trend of changes in leaf temperature and shade floor light intensity followed a significant but positive linear relationship. In general, based on the amount of seed production, genotype number 7 is recommended for conditions without drought stress and genotype number 9 for drought stress conditions under moderate climatic conditions such as Khorramabad.

In order to study the effect of using salicylic acid in inducing tolerance mechanisms to drought stress, a research was carried out in the field of Moghan Agriculture and Natural Resources Research Center in 2014 and 2015 as a split factorial in three replications. The main factor includes irrigation treatments based on evaporation from class A evaporation pan (100, 135 and 170 mm evaporation) and secondary treatments including soybean genotypes (Williams, L17 and D42X19) and salicylic acid foliar spraying (0, 0.4 and 0.8 mM). The results of composite analysis showed that drought stress significantly reduced plant height, number of nodes per stem, days to flowering and days to maturity in soybean genotypes. Seed yield was reduced by 38% in moderate stress and 46% in severe stress compared to control. Drought stress and application of salicylic acid, especially at a concentration of 0.4 mM, increased the concentration of amino acids such lysine and methionine. The highest amount of lysine was observed in Williams genotype under severe stress conditions and the highest amount of methionine was observed in D42XI9 genotype under moderate stress conditions. The highest level of activity of polyphenol oxidase enzymes in D42XI9 genotype and the highest level of glutathione reductase enzyme activity in Williams genotype was observed under severe drought stress conditions. Foliar spraying with salicylic acid (0.4 mM) increased the activity of these enzymes in both stressed and non- conditions. Intensity of stress caused an increase in concentration trihalose. But the effect of stress on the amount of trihalose in Williams genotype was more than other genotypes. With the application of salicylic acid, the concentration of trihalose increased in all genotypes, and the effective concentration of salicylic acid to increase trihalose was 0.8 mM. Drought stress and application of salicylic acid increased flavonoid accumulation in all genotypes and especially in L17 genotype. Drought stress significantly reduced plant height, number of nodes, days to flowering, days to maturity and seed yield in soybean genotypes, while the use of 0.4 mM salicylic acid improved the above traits, especially in the Williams genotype. In this study, Williams showed less sensitivity to drought stress (12% more seed yield than L17 genotype and 6% more than D42XI9 genotype) due to higher antioxidant enzyme activity and higher seed yield compared to other genotypes, and the use of salicylic acid in non-stressed and stressed conditions increased seed yield in soybean genotypes.

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.

In order to evaluate the effect of drought stress on some characteristics of germination and seed set of commercial soybean cultivars under water stress in the research farm of Karaj Seedling and Seed Breeding Research Institute, an experiment was conducted in 1400 using a standard germination test in the laboratory. The seed analysis of Karaj Seed and Seedling Registration and Certification Research Institute was carried out factorially in the form of randomized complete block design with 4 replications. The treatments include applying 4 levels of dry stress of polyethylene glycol 6000 with potentials of 0 (no stress), 3-, 6-, and 9-MPa, on the seeds of 4 commercial soybean cultivars, Williams, Hamilton x Essex, TMS, and Bunty, produced at 3 levels. The low irrigation stress of the mother plant, irrigation after the values of 50 (optimal irrigation and control), 100 (mild stress) and 150 (severe stress) mm of evaporation from the evaporation pan were class A). The examined characteristics include: percentage of final germination, percentage of normal seedlings, percentage of abnormal seedlings, percentage of hard seeds, percentage of rotten seeds, average daily germination, average germination time, seedling length and index The length and weight of the seedlings were. The results showed that the mutual effect of drought stress, low irrigation stress and variety had a significant effect on all the examined characteristics. In the treatment of 9-MPa drought stress and without water deficit stress, the Williams variety compared to the treatment without drought stress and without water deficit stress, the average germination time was 0.90 days, the percentage of rotten seeds, hard seeds and abnormal seedlings were 0.18%, 750 respectively. 5.5% and 0.60% increase and average daily germination of 1.28 days, final germination and normal seedling decreased by 1.28% and 4.92%, respectively. In general, among the studied cultivars, Williams variety showed the best and Bunty variety showed the weakest response to low irrigation and drought stress.

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 this study,drought tolerance of advanced soybean lines has been investigated. In this study,14soybean lines Along with two control cultivars of Saba and Kowsardar were separately carriedout in two experiments of a randomized complete block design with three replications in two years of2015-2016 in Karaj.These lines have been superior in preliminary experiments indicting in different regions.Both experiments were similarly irrigated until seedling establishment and the emergence of the V4-V5 stage,which coincided with the full development of the fourth to fifth leaves.Afterthat, the first experiment was irrigated weeklyand the second one aweek in between(50-55-and120-100-mm evaporation from ClassA evaporation pan,respectively).Different tolerance and sensitivity indices were used to evaluate the stress response.Indices were grouped by using principal component analysis and genotypes were grouped byusing biplot.Also,grouping wasperformed byusing SIIG indexand the resalt genotypes cluster was comparedwith Fernandez index.The resultsof mean comparison showed that three lines ColumbusxKrasnodar778(L.45),CrafordxLan(L.44)and WilliamsxKatool(L.3)in numberof pods perplant, numberof seeds per pod and1000-seedweight andseedyield had the highest value andwere superiorto both sensitiveand tolerant control cultivars.Bioplate diagram showedthat lines WilliamsxKatool(L.3).NemahaxSavoy(L.3),ColumbusxKrasnodar778(L.45)andSaba and Kosarcultivars were located near the vectorsof important drought resistance indices.Lines WilliamsxKatool(L.3)andCrafordxLan(L.44)tended tobe relatedto the yeildvector under stressconditions,indicating that the high values forthe drought tolerance index in these lines were mostly dueto its high yeild under stress conditions.Accordingto the SIIG index,the line WilliamsxKatool(L.3)was themost tolerant ofdrought stress.The results showedthat in each four methods,Sumof ranking,principal component analysis andSIIG index and fernandez diagram,linesWilliamsxKatool(L.3),CrafordxLan(L.44)andColumbusxKrasnodar778(L.45)werethe most tolerant and linesWilliamsxKatool(L.8),RVBxKatool(L.13)and were the most sensitive to drought stress.Therefore,using rankings for less complication can be effective in selecting tolerant genotypes.

Investigation of environmental factors and stresses on the fatty acid composition of soybean oil and identification of water deficit tolerant cultivars is one of the strategies to improve the fatty acid composition of its oil.Effect of water deficit stress on quality characteristics and oil yield of 13 soybean genotypes were evaluated as a split plot based on randomized complete block design in three replicates in Karaj in two years.In this work irrigation was conducted at three levels including routine irrigation (control),mild and severe stress were based on 50, 100 and 150mm evaporation from ClassA evaporation pan, respectively,in main plots and soybean genotypes in sub-plots.The results showed that effect of year×irrigation×genotype on oil yield, oil content, oleic acid, linolenic acid and arachidic acid was significant.Oilyeild of soybean decreased under mild and severe stress, 27 and 38%, respectively.Saba and Williams×A3935 had the highest oilyield with an average of 422 and 427 kg/ha, respectively. palmitic acid in mild and severe stress compared to control irrigation decreased by2.6% and 1.2%.While stearic acid increased by9.5% and 10.8%in mild and severe stress conditions, respectively.In control irrigation, L425002 line with 0.22%, in mild stress conditions,Williams×Century and L425002 with 24.6% and 24.1%, and in severe stress conditions, Saba and L425002 genotypes with 24.1% and 24.5%, had the highest percentages of oleic acid and high oil content.In control irrigation, Saba cultivar,in mild stress conditions,Saba cultivar and Williams×A3935 and in severe stress conditions Williams×A3935 had the highest oil yield.L425002 and Williams×Century had the highest oil quality in all stress conditions.

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.

In order to develop winter cultivation and improve crop rotation in the region, an experiment has been conducted to evaluate the effects of sowing date on sunflower cultivars seed yield. It is a split-plot based on completed randomized blocks design with four replications in Safiabad Agricultural and Natural Resources Research and Education Center of Dezful and has taken place during two years (2015-2016). The main plots are consisted of four sowing date levels (23rd Jan, 6th Feb, 20th Feb, and 6th Mar), while the sub plots include nine levels of cultivars (Azargol, Armavirski, Barzegar, Progress, Record, Shams, Farokh, Ghasem, and Gabor). Delay in the sowing date has decreased growth period length and plant height, with the greatest number of seeds per capitulum (684.17) belonging to record cultivar on the first sowing date in the first year and the maximum one (767.47) occurring again to this cultivar on the third sowing date in the second year. The maximum seed yield in the first (3850 kg.ha-1) and second (4088 kg.ha-1) year belong to the first sowing date (23rd Jan) and Azargol cultivar. Based on the results, Azargol cultivar have had the lowest rank, being considered as the cultivar with the highest seed yield on all sowing dates, followed by Record and Armavirski, in the second and third placed, respectively. In terms of stability, considering that Farrokh cultivar also has had the lowest standard deviation, it has been selected as the most stable cultivar.

In order to evaluate the planting date delay on phenological traits, yield components, grain yield, and linoleic and linolenic fatty acids of new sunflower hybrids, an experiment has been conducted as split plot in a randomized, completely block design, with four replicates at the field of oilseed section of seed and plant Improvement during 2014-2016 growing season. The treatments include seven sunflower hybrids (Barzegar, Farrokh, Haysan 36, Qasem, Shams, Azargol, and Haysan 25) on three planting dates (15 days after harvest of autumn (wheat), July 1, July 15, and July 30, respectively). The experimental results show significant effects of planting date on all traits except number of seeds per head and linolenic acid at the level of 1% and on the percentage of oil and linoleic acid at the level of 5%. The studied hybrids are significantly different in all traits except linoleic and linolenic fatty acids. The latest experimental hybrids include Barzegar and Azargol hybrids and the earliest hybrid is Farrokh. The highest grain yield is obtained from the date of the first sowing at the rate of 2840 kg / ha and in the case of delayed sowing the yield is reduced to 41%.

In order to investigate the morphophysiological response of soybean (Glysin max L.) to drought stress as second crop, an experiment was conducted in Lorestan Agricultural Research Center in the summer of 2017 and 2018 in two environments including normal and drought stress condition. In each environment, 19 soybean genotypes were studied in a randomized complete block design with three replications. The results showed that all traits except leaf temperature decreased due to drought stress. Mean comparison showed that the highest leaf temperature was obtained from genotype No. 9 in stress environment and the lowest was obtained from genotypes No. 4 and 15 in normal environment (27.5 and 13.2 ° C, respectively). The highest grain yield was obtained from genotype No. 7 in normal environment and the lowest from genotype No. 19 in stress environment (4894 and 275 kg/ha, respectively). The analysis of biochemical traits of shoots showed that the amount of unstructured soluble sugars and free proline increased with drought stress from (1.87 and 0.0028 mg, respectively) in normal environment to (3.77 and 0.0054 mg/g fresh weight, respectively) in stress environment. Among the genotypes, the highest and the lowest amount of shoot proline were obtained from genotype No. 4 (mg/g fresh weight) and genotype No. 1 (0.043 and 0.03777 mg/g fresh weight, respectively), respectively. In addition, genotypes No. 7 and 9 can be recommended for normal and stress conditions in moderate region such as Khorramabad.

The present study attempts to investigate the effect of Magnesium nanoparticle spraying solution on some morphophysiological traits of sunflower under experimental drought conditions. Hence, it conducts an experiment as split split plot in a randomized, completely block design, with three replicates at the field of oilseed section of seed and plant Improvement during 2017-2019 growing season. The treatments include drought stress at two levels: normal irrigation and drought stress. The studied sunflower cultivars include Farrokh, Shams, Qasem & Barzegar, and Magnesium nanoparticles application time at Three Levels: no spraying solution, spraying at flowering stage, and grain filling stage. Results show that drought stress reduces the amount of traits such as height, shoot dry weight, number of grains per head, 1000 grain weight, head diameter, grain yield, oil percentage, and oil yield; however, magnesium nanoparticle spraying solution improves the drought stress effect and increases morphological traits. Drought stress increases electrolyte leakage index and decreases relative water content of leaves by 13% and 9%, respectively. However, magnesium nanoparticles decrease the content of electrolyte leakage index by 9% and increase relative leaf water content by 10%. The cultivars’ response to stress levels has not been the same. In general, Barzegar, Shams, Qasem, and Farrokh cultivars show the highest tolerance to drought stress. Also the highest grain yield and oil percentage are related to Barzegar cultivar by 3427.53 kg/h and 43.96%, respectively.

Recent droughts, in addition to creating drought stress, have caused the phenomenon of aerosols, especially in the west of the country. The effect of drought stress and aerosols on the physiological characteristics of soybean (Glysin max L.) Kosar cultivar was investigated in an experiment based on a randomized complete block design as split plots with 4 replications in summer cultivation for two years. Drought stress through irrigation after 60 (optimal irrigation), 90 and 120 mm evaporation from Class A evaporation pan as the main factor and spraying of aerosols in three levels of non-application (control) and application of 50 and 100 mg in cubic meters of air were placed in subplots as simulations. The results showed that severe drought stress significantly reduced the amount of chlorophylls a and b, catalase of shoots and roots. The amount of light of the canopy floor and the relative water content of the flag leaf (from 89 to 70%), plant height, yield components and grain yield (from 2653 to 1167 kg per hectare) compared to the control treatment, but soluble sugars, proline content, shoot and root peroxidase and leaf temperature (from 18.4 to 27.6 °C) increased significantly. Although the effect of aerosols on any of the traits was not significant, but with increasing the concentration of aerosols, grain yield decreased linearly and proline content increased linearly. Overall, it was found that drought stress significantly reduced soybean production, but low aerosols settling on soybean leaves did not cause serious damage to the plant photosynthetic system and ultimately seed production due to leaves waxy nature.

The effect of water deficit stress has been evaluated on oil quality and yield of 11 sunflower hybrids in Karaj during 2012 and 2013. Three separate experiments have been carried out as the base of randomized complete block design with three replications to apply water deficit stress treatments. Irrigation of control, mild, and severe stress treatments are performed on the base of 60, 120, and 180 mm evaporation from Class A evaporation pan, respectively. Results show that seed yield has decreased about 18% and 33% in mild and sever water deficit stresses, respectively. Yield and oil percentage are affected by hybrids and the interaction of year and stress. Barzegar hybrid, with an average of 2846 kg/ha, has had the highest grain yield. It is also in the top group with 43.65% oil. Yield and seed oil percentage are affected by environmental conditions of years, while water deficict stress has no significant effect on oleic and linoleic acids. However, there is a strong negative correlation between oleic and linoleic acids. Hysun 25 and Sirena cultivars are suitable for oil production with higher oleic acid and Barzegar and G6×R-43 are suitable for oil production with higher linoleic acid.

The present experiment has been carried out as a split plot based on randomized complete block design with three replications in Safiabad Agricultural and Natural Resources Research and Education Center of Dezful between 2012 and 2014. The main plots is consisted of 3 sowing dates (November 5, November 25, and December 15) with the sub plots including 10 levels of foliar application (100, 200, 300 mg.lit-1 ascorbic acid, 100, 200, 300 μmol ascorbic acid, 10, 20, 30 vol% methanol, and the foliar application of distilled water as control treatment). The effect of sowing date and foliar application as well as their interaction has had significant effect on proline, soluble sugars, number of siliques per plant, and seed yield (P≤0.01). Comparing means of sowing date × foliar application shows that the maximum number of siliques per plant (68.96) has been formed in the first sowing date with the foliar application of ascorbic acid (300 mg.lit-1). There has been a significant difference between different sowing dates: the seed yield has decreased in the second and third sowing date, compared to the first one by 145% and 30%, respectively. However, foliar application of experimental treatments has increased the seed yield in all sowing dates, but it is recommended to use ascorbic acid (300 mg.lit-1) in the first and third sowing dates as well as salicylic acid (200 µmol) and methanol (10%) in the second sowing date.

Selection of suitable canola cultivars for winter cultivation and tolerant to late-season drought stress, are the basic strategies for the cultivation of the rapeseed in cold temperate regions with semi-arid climate.

A factorial split-plot based on complete randomized blocks design was conducted with three replications for two years (2014-2016) in Karaj. In this regards, sowing dates were divided into two levels of fall cultivation (Oct. 7) and winter cultivation (Feb. 4); irrigation was carried out in three levels of normal irrigation (control), irrigation interruption from flowering, and after pod formation stages and five canola cultivars include Sarigol, Dalgan, Jacomo, Jeromeh and Hyola401.    

The interaction effect of sowing date × irrigation × cultivar was significant on the traits of number of pods per square meter, number of seeds per pod, biological yield, seed yield, relative water content (RWC) of leaves and proline at the level of 1%, and on the traits of 1000-seeds weight, canopy temperature and chlorophyll b content at the level of 5%. Here we show that Dalgan cultivar was obtained with a seed yield of 3657 kg ha-1 and RWC of 92.42%, in the winter cultivation date and normal irrigation condition. Moreover, in winter cultivation and in the late season drought stress condition (irrigation interruption after flowering stage onwards), the Hyola 401 hybrid was obtained with seed yield of 2376 kg ha-1‎ and a RWC of 83.11%.  

In The winter cultivation and normal irrigation condition Dalgan cultivar and in the late season drought stress condition (irrigation interruption after pod formation stage), the Hyola 401 and Jeromeh hybridscan be used in the development of canola cultivation in the new status of winter cultivation (Feb. 4) and various irrigation conditions.

Soil bacteria plays an important role in bio-geochemical cycles that cause soil ecosystem dynamics to return nutrients to life cycles. In recent days, these organisms can serve as complementary or, in some cases, alternative fertilizers, to maintain the sustainability of the agricultural ecosystem. On the other hand, the production of high-yielding cultivars has increased the consumption of agricultural inputs, especially fertilizers, which has caused a crisis of environmental pollution. Bacteria are soil microorganisms that are involved in the nutrient cycle of the soil, can improve plant growth, and are known as growth promoting bacteria (PGPRs). Approximately two to five percent of root-borne bacteria are in the group of growth-promoting bacteria. These bacteria improve plant growth in a variety of ways, including nitrogen fixation, synthesis and production of iron-complex ingsiderophore, production of plant hormones, production of antibiotics and fungicide compounds. Soil has a wide range of organic phosphate sources that must be converted to its inorganic form by enzymes such as phosphatase, phytase and phosphonostat, and bacteria in the Bacillus and Pseudomonas groups can be produced by the production of acid phosphatases that dissolve phosphates to help absorb them by plant. Another group of bacteria such as Azotobacter and Azospirillum have the ability to stabilize nitrogen. Sesame (Sesamum indicum L.) is one of the oldest oilseed plants and has been named as the queen of oilseed plants and compatible with arid and semi-arid regions. Lowing sesame yield per unit area necessity to exerted agronomic management practice. The number of capsules is the main components of yield that has highly correlated with it. The aim of this study was to investigate the effect of biofertilizers on number of capsules per node of leaves sesame plant under field conditions.

An experiment was conducted as factorial arrangement based on a randomized complete block design with three replications at Mashhad Agricultural and Natural Resources Research and Education Center during two growing seasons (2017-2018 and 2018-2019). The first factors were: seeds single capsule and multi-capsule seed types and second factors were four Biofertilizers: 1) Nitroxin® (containing Azotobacter and Azospirillum bacteria), 2) Biophosphorus® (containing phosphatase-solubilizing bacteria of genus Bacillus and Pseudomonas), 3) Equal mixture of Nitroxin and biophosphorus and 4) control. At planting time, seeds were inoculated with biological fertilizers by standard method, away from direct light and foliar spraying was done in 50% reproductive stage with the bio fertilizer treatments. The morphological traits (plant height, number and length of lateral branches, number and dry weight of leaves, number of nodes, number of capsules, number of single and multiple capsules nodes were measure per plant and biomass and seed yield were measured per unit area. Data was analyzed using MSTAT-C and means was comparison with LSR at the 5% probability level.

Application of biofertilizers increased plant height by 11 to 19.9 cm compared to no fertilizer treatment (89.1 cm). In the second year, the number of nodes was about 43% higher than the first year. Triple interaction treatments showed that in the second year and in single capsule seeds the application of nitroxin and biophosphorus fertilizer had the highest number of nodes (85.7) and the lowest amount of it was observed in single seed capsule plants in the first year. The highest number of single capsule nodes was obtain in the application of biofertilizer (nitroxin+ biophosphorus) in single capsule seeds. In the second year, the number of single capsule nodes in both seed types was more than 29 per plant. In the second year, the highest number of multi-capsule nodes was recorded from multi-capsule seeds with use of nitroxin and biophosphorus combination fertilizers. Interaction between treatments of seed type and biofertilizer results showed that plant was growth from multi-capsule seed had a positive reaction to biofertilizer so that in multiple seed type the number of capsule per plant was more than 57 in application of biofertilizer. Both in the first and second year, in the multiple seed capsule type, the use of biofertilizers produced more grain yield per square meter than other treatments.

The results of this study showed that consuming of biofertilizers together that containing Azotobacter, Azospirillum, Bacillus and Pseudomonas had a positive significant effect on the plant height, number of capsules per node leaf, biomass and number of capsule that lead to increase of seed yield in sesame plant. Therefore, it is recommended that seeds inoculate with these bacteria in sowing time and applying one foliar spraying in mid-flowering time lead to enhance sesame yield.

Introduction

Abiotic stresses, in particular, water shortage pose immense challenges to crop production and can decrease crop yields by 50% worldwide (Mahajan Tuteja, 2005). Water deficit has negative impacts on growth, development and production of legumes, which may result in decreased chlorophyll a and b and increased proline content of leaf (Karimi et al., 2016). Aerosols are principal air pollutants that can greatly impact human health and plant development. This natural phenomenon, which mainly occurs in Iraq and Iran`s western regions, has exacerbated in recent years and caused a lot of damage (Marsafari, 2011). The objective of this study was to evaluate the effects of aerosol particles and drought stress on grain sorghum photosynthetic pigments, soluble sugars, proline, relative water content of flag leaf, leaf temperature and grain yield.

The research was conducted to investigate the effect of drought and aerosol stresses on morpho-physiological traits of grain sorghum (Sorghum bicolar L.) at Lorestan Agricultural and Natural Resources Research and Education Center in 2015. A split plot design based on RCBD was used with four replications. The main plots were allocated to four different irrigation regimes: watering after 60, 90 and 120 mm evaporation from pan class A. The subplots were assigned to three levels of aerosols derived from clay soil source) control treatment, 50 and 100 mg m-3 aerosol particles (. Chlorophyll a, chlorophyll b, soluble sugars, proline content, relative water content and leaf temperature were measured at flowering period and yield components and grain yield were measured at harvest time.

The results of the first year of the experiment showed that chlorophylls a and b were only affected by drought stress where they were linearly significantly decreased from 0.017 and 0.012 mg/g FW, respectively, in control treatment, to 0.0068 and 0.0065 mg/g FW in I120 treatment with increasing drought stress. Water stress triggered the production of active oxygen along with the reduction and decomposition of chlorophyll (Karimi et al., 2016). Soluble sugars and proline leaf concentration were not affected by aerosols, but were significantly affected by drought stress. Sugar content linearly and significantly increased from 4.3 mg/g under normal moisture conditions to 7.9 mg/g fresh leaf weight in I120 treatment. Proline concentrations were linearly and significantly increased from 0.25 mg/g under normal moisture conditions to 0.66 mg / g leaf fresh weight in I120 treatment. The results of two-year compound variance analysis indicated that grain number per panicle decreased but thousand grain weight increased due to drought stress. The change in grain yield was attributed to significant linear relationship and negative correlations with increasing drought stress. The highest average grain yield (8257 kg/ha) was obtained from the normal irrigation, which decreased to 6393 kg/ha under drought stress. The highest average relative content of flag leaf water was obtained from the normal irrigation, which was 2.80% and was reduced to 70.3% under drought stress.

In general, it was found that the amount of chlorophylls a and b and the relative water content of flag leaf and, as a result, grain yield were significantly decreased with increasing drought stress, but osmotic compounds (sugars solution and proline content of leaf) and leaf temperature increased significantly. Increasing drought stress decreased the number of grains per panicle and increased 1000-grain weight, but the increase in 1000-grain weight could not compensate for the decrease in the number of grains per panicle and consequently led to the decreased grain yield. Low concentration of aerosols on the sorghum leaves due to being vertical and waxy caused no serious damage to the plant's photosynthetic system and as a consequence to grain production.

This experiment was conducted to evaluate the effect of deficit irrigation on seed yield and its components of sunflower hybrids, and also identify tolerant hybrids. Twelve sunflower hybrids; Farrokh, Shams, Ghasem, Barzegar, G5 ×43, G6×43, Hysun25, Hysun36, Azargol, Sumbro, Euroflor and Sirena were evaluated under three irrigation treatments; normal irrigation (60 mm), mild drought stress (120 mm) and severe drought stress (180 mm) evaportation from Class A Pan, using split plot arrangements in randomized complete block design with three replications in Islamabad Gharb research station, Iran in 2012 and 2013 cropping seasons. Irrigation treatments were assigned to main plots, and sunflower hybrids were randomized in sub plots. Results of combined analysis of variance showed that irrigation treatments had significant effect on growth duration, stem diameter, head diameter, seed per head, 1000 seed weight and seed yield, but had no significanteffect on seed oil content. Sunflower hybrids were significantly difference for growth duration, 1000 seed weight and seed yield. Interaction effect sunflower hybrid×irrigation was not significant for any of measured traits. Mean comparison showed that seed yield of sunflower hybrids was more affected by irrigation treatments than other traits, as average seed yield in normal irrigation, mild drought stress and severe drought stress were 4470, 3637 and 2832 kg ha-1, respectively. Reduction in seed yield was due to cumulative reduction in yield components such as head diameter, seed per head and 1000 seed weight. Sunflower hybrids were also different for growth duration, plant height, non-filled seed, head diameter, seed per head and 1000 seed weight. Barzegar and Sumbro hybrids had the highest and lowest seed yield (4091 and 3362 kg.ha-1, respecrively) and the the highest seed oil content was obtaind in Hysun36 hybrid (45.6%). The results showed that Barzegar hybrid had the higher seed yield in both full irrigation and deficit irrigation conditions, therefore it can be recommended to be grown under these conditions.

Khuzestan province is one of the important regions for sugarcane production with more than 100,000 hectares under sugarcane cultivation. Sugarcane monoculture is common all over the world and continuing this system gradually reduces the yield and soil fertility. Monoculture systems, by creating unfavorable biological and physicochemical conditions in the soil, reduce the amount of organic carbon and nutrients in the soil. However, in an agricultural system, suitable agronomic selection, proper management of agronomic operation specially plowing, proper use of chemical and organic fertilizers, preservation of vegetation and proper management of plant residue have a decisive role in the amount and dynamics of mineral and organic elements. Various studies showed that rotation, particularly with green fertilizers, have led to breaking the pathogenic cycle and improving the physical and chemical properties of soil, including soil organic matter.

In order to evaluate the changes in the amount of carbon and organic matter, nitrogen, phosphorus and potassium residue in soil under different crop rotation conditions, this study was performed in a randomized complete block design with three replications during 2014-2016 for three consecutive years in the field of Amirkabir sugarcane Agro-Industry. The experiment treatments consisted of ten alternatives: 1) wheat-clover-sugarcane; 2) rapeseed-clover-sugarcane; 3) barley-clover-sugarcane; 4) sorghum-clover-sugarcane; 5) clover-vetch-sugarcane; 6) clover- clover- sugarcane, 7) clover- clover (third aftermath)- sugarcane, 8) clover- soybean- sugarcane, 9) clover- corn - sugarcane, and 10) fallow- fallow- sugarcane. The results showed that there was no significant difference between the changes in phosphorus in three years of experiment at both soil depths, but the amount of potassium and organic carbon was decreased during the third year of experiment. Analysis of variance showed that the amount of P, N and organic carbon content were significantly different in both soil depths under crop rotations. Also, under crop rotation, potassium and C/N ratio were different in 0-30 cm and 30-60 cm soil depths, respectively. The highest amount of nitrogen, phosphorus and carbon to nitrogen ratio were observed in clover-clover- sugarcane, fallow-fallow-sugarcane and sorghum-clover-sugarcane.

The results showed that the changes in the phosphorus content during three years of implementation of the project based on variance analysis even at 0-30 C depth, or at a depth of 60 to 30 cm, did not have a significant difference and the amount of phosphorus was remained almost constant.NitrogenThe results showed that the process of nitrogen changes during three years of experiment was based on analysis of variance at 0-30 and 30-60 cm of soil depths has significant difference and the amount of nitrogen has changed.Organic matter, Organic carbon and C:NOrganic matters of the soil is as the most effective factor in the sustainability of pasture and forest ecosystems, soil protection layer against erosion, temperature regulator, habitat and food supply for soil organisms and the main place of mineral nutrition.Potassium Potassium plays an important role in soil fertility. The statistical analysis of soil potassium showed that the amount of potassium had significant differences in two studied soil layers during three years of project implementation.Sugarcane yieldThe results showed that the highest yields were related to the crop rotation of clover-mung bean-sugarcane and clover- clover (third aftermath)-sugarcane rotations with 124 and 121 t.ha-1, respectively. Also, the lowest yield was related to the varieties of fallow-fallow-sugarcane and clover-corn-Sugarcane, with 95 and 98 t.ha-1, respectively.

The results showed that phosphorus in the soil did not change significantly during the experiment, but the amount of potassium, organic carbon and soil organic matter during the first and the second years remained constant but it decreased during the third year. Also, the implementation of different crop rotation affected soil nutrient elements. The highest amount of nitrogen, phosphorus and carbon to nitrogen ratios were observed in clover-clover- sugarcane, fallow-fallow-sugarcane and sorghum-clover-sugarcane. The impact of crop rotation on sugarcane yield also showed that cultivating legumes of clover and mung bean before sugarcane has a great influence on sugarcane yield.

To investigate the effect of humic acid application on agronomic characteristics of canola (Brassica napus L.) genotypes in different plant densities, a factorial split-plot experiment was performed using a randomized complete block design with three replications in the Seed and Plant Improvement Institute, Karaj, Iran. Plant density at three levels of 40, 60 and 80 plants/m2 and humic acid at two levels of 0 (non-application) and application of 0.3% were considered the main plots and canola genotypes including RGS003, Zafar, Julius, Jerry, Zabol10 and Hyola4815 were the sub-plots. The interaction effect of plant density × humic acid × cultivar was statistically significant for seed yield, oil yield, number of seeds per pod, number of pods per plant, biological yield and harvest index. Moreover, the interaction effect of plant density × cultivar was significant for oil percentage, 1000 seed weight, chlorophyll a, chlorophyll b and total chlorophyll. Generally, increased competition at the highest plant density caused an adverse effect on the tested traits of the canola cultivars. The Jerry cultivar with 40 plants/m2 (lowest density) and application of humic acid had the highest numbers of seeds per pod and pods per plant (with an average of 24.6 and 200.7, respectively) and 1000 seed weight (with the average of 4.9 g). Moreover, in the lowest plant density (40 plants/m2) and application of humic acid, the Jerry cultivar had the highest amounts of seed and oil yields (with an average of 5412 and 2196 kg ha-1, respectively). Accordingly, the examined canola cultivars had a positive reaction to the application of humic acid in different plant densities in particular at 40 plants/m2. Jerry cultivar had the maximum seed and oil yield under humic acid application condition when sown at 40 plants/m2.

To investigate the effect of salicylic acid on photosynthetic system and seed yield in soybean genotypes under drought stress a factorial experiment was conducted in a completely randomized design in both greenhouse and laboratory of Mohaghegh Ardebili University in 2015. The factors consisted of water stress at 3 levels (85, 65 and 45% of field capacity), salicylic acid at 3 concentrations (0, 0.4 and 0.8 mM) and three soybean genotypes, Williams, D42X19, and L17. The results showed that the relative water content, stomatal conductance, chlorophyll a and b, chlorophyll a/b ratio, leaf area, maximum fluorescence and quantum yield decreased as the result to drought stress, while Williams showed more tolerance to drought stress as compared to other two genotypes. Application of 0.4 mM salicylic acid as compared to high concentration (0.8 mM) and control was the most effective treatment on reducing the adverse effects of drought stress. It could be said that this may increase the relative water and chlorophylls contents, leaf area, quantum yield and stomatal conductance under drought stress conditions. It seems that carotenoid contents as a result of drought stress and application of 0.8 mM salicylic acid were increased in soybean genotypes, especially in L17. SLA was also increased due to drought stress, which was higher in L17 genotype than other genotypes. According to the results of this study, williams genotype was the most tolerant to drought stress as compared to the other genotypes, and the application of salicylic acid would enhance tolerance to drought stress in soybean genotypes.