جستجوی مقالات مرتبط با کلیدواژه « b » در نشریات گروه « زراعت »

Dracocephalum moldavica L. is a herbaceous, annual plant from the Lamiaceae family that is native to Central Asia and domesticated in Central and Eastern Europe. Essential oil of this plant has antimicrobial and bacterial properties and has many uses in the pharmaceutical, cosmetic, food and perfumery industries. Lead stress in plants causes disturbances in mitosis, leaf chlorosis, decreasing of the vegetative and productive growth stages and reduces photosynthesis and enzyme activities. One of the effects of lead toxicity is due to the similarity of the structure of calcium ions and lead, and for this reason, lead ions disrupt many mechanisms related to calcium ions and prevent the activity of key enzymes.Photosynthesis is one of the most sensitive metabolic processes to lead toxicity, and several studies have reported the inhibition of photosynthesis under lead stress in various plants. Lead prevents the absorption of elements such as magnesium and iron. These elements play a role in the structure of chlorophyll and the oxygen-releasing complex in photosystem II. Heavy metals such as lead inhibit chlorophyll biosynthesis by inhibiting the enzymes gamma-aminolevalonic acid dehydrogenase and protochlorophyll reductase. Also the availability of different nutrients in the soil changes significantly under the influence of environmental stress so that using of vermicompost can be useful in stress condition as well as Jasmonate. Jasmonate is the final oxidation product of unsaturated fatty acids such as linolenic acid, that is effective in increasing the activity of plant defense systems under environmental stress conditions such as lead stress. In order to study the effect of pb (0, 100, 200, 300, 400 mg kg-1 soil) and jasmonate (0, 50, 100, 150 mmol l-1) on Dracocephalum moldavica L. under controlled conditions in soil enriched with vermicompost and without vermicompost an experiment designed and it was done under greenhouse conditions.

This test was done in a random factorial design with 4 repeats and indices including CO2 assimilation rate, transpiration rate, stomatal conductance, water use efficiency(WUE), PSɪɪ photochemical efficiency (Fv/Fm), photosynthesis quantum performance, electron transfer rate (ETR), were measured in vegetative and reproductive growth stages.

In the conducted study, it was found that CO2 assimilation rate, water use efficienty, stomatal conductance and Fv/Fm were significantly decreased as lead concentration was increased. Also jasmonate treatment significantly increased CO2 assimilation rate, water use efficienty, stomatal conductance and Fv/Fm in lead stress condition. So that plant treated with 400 mg kg-1 soil pb and 0 mmol l-1 jasmonate showed the lowest CO2 assimilation rate, water use efficienty, stomatal conductance and Fv/Fm while plant treated with 0 mg kg-1 soil pb and 150 mmol l-1 jasmonate showed the highest CO2 assimilation rate, water use efficienty, stomatal conductance and Fv/Fm. transpiration rate was significantly increased as well as increasing pb concentration so that plant treated with 400 mg kg-1 soil pb showed the highest transpiration rate. Also jasmonate treatment significantly decreased transpiration rate in lead stress condition. Vermicompost increased CO2 assimilation rate, water use efficienty, electron transfer rate (ETR) and significantly decreased transpiration rate in lead stress condition.Jasmonate reduces the destructive effects caused by stress on photosynthetic indicators such as the amount of chlorophyll and carotenoids and also increases the performance of photosystem II and consequently increases plant photosynthesis under stress conditions. It has been reported that methyl jasmonate can maintain the concentration of chlorophyll in the reaction center, thereby improving the speed of electron transfer and increasing the efficiency of photosystem II. In addition, jasmonate can prevent the severe reduction of stomatal conductance under stress conditions and increase the quantum efficiency of photosynthesis.In the response of plants to stress, jasmonates act as genes encoding inhibitory proteins such as theonine, hydroxyproline and proline, and in general, by activating defense mechanisms, they help the plant in reducing the absorption and accumulation of heavy metals. Organic fertilizers can also improve plant performance under environmental stress conditions. Vermicompost fertilizer increases porosity, increases absorption and retention of nutrients, improves ventilation, drainage and microbial activity in the soil.

Having nutritious mineral elements and plant growth hormones can improve plant growth in the presence of environmental pollutants such as heavy metals by influencing the physiological characteristics. It can be said based on the results obtained lead stress decreased photosynthesis index through effect on electron transport chain and photosynthetic pigments while jasmonate treatment and Soil enriched with vermicompost can reduce the destructive effects of lead stress. So that using of jasmonate and vermicompost in lead stress condition Recommended.

Water limitation is one of the most important abiotic factors that can limit plant growth and yield due to production of reactive oxygen species (ROS) like H2O2 and the reduction of chlorophyll content. To protect against oxidative stress, plant cells produce both antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX), and non-enzymatic antioxidants such as low weight molecules like proline, sugars and ascorbate. Also water limitation disturbs the mineral-nutrient relations in plants through their effects on nutrient availability and numerous of physiological and biochemical destruction in the vegetative and reproductive periods of plant development. Several strategies have been suggested in order to improve yield under abiotic and biotic stresses in plants, among them application of Plant Growth Promoting Rhizobacteria (PGPR) and nano particles such as nano iron-silicon oxide play a key role in yield improvement. A better understanding of physiological responses under water limitation may help in programs which the objective is to improve the drouht resistance of crop. During the course of these stresses, active solute accumulation of compatible solutes such as proline and the activities CAT, POD and PPO enzymes are claimed to be an effective stress tolerance mechanism. Therefore, the aim of this study was to evaluate the effects of bio-fertilizers and nano iron oxide and nano oxide on some physiological and biochemical (i.e., antioxidant enzyme activity, chlorophyll, protein, soluble sugars and proline) responses of triticale under water limitation conditions.

An experiment was conducted as factorial based on randomized complete block design with three replicates at the research farm of faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2021. The experimental factors were included of irrigation in three levels (full irrigation as control, irrigation withholding at 50% of booting and heading stages as severe and moderate water limitation respectively (BBCH 43 and 55 respectively), application of bio fertilizers in four levels (no application as control, application of Azospirilum, Pseudomonas, both application Azospirilum and Pseudomonas) and nanoparticles foliar application at four levels (foliar application with water as control, nano iron oxide foliar application (1 g.L-1), nano silicon oxide (50 mg.L-1), both application nano iron-silicon oxide). Psedomunas and Azospirilum were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. For inoculation seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. The strains and cell densities of microorganisms used as PGPR in this experiment were 1×108 colony forming units (CFU). In each plot there were 5 rows with 2 m long. In each experimental plot, two marginal rows and 0.5 m from beginning and ending of planting lines were removed data were measured from the middle lines. The used nano silicon-iron oxide had the average particle size less than 30 nm and special surface of particles was more than 30 m2.g-1. They were product of Nanomaterial US Research which was provided by Pishgaman Nanomaterials Company of Iran. Nano iron oxide and nano silicon powder added to deionized water and was placed on ultra sonic equipment (100 W and 40 kHz) on a shaker for better solution. Foliar application of nano silicon oxide and putrecine were done in two stages of period growth BBCH 21 and 30.

The results showed that total chlorophyll content (48.16%), quantum yield (36.05%), relative water content (35.83%) and grain yield (43.28%) increased in dual application of bio fertilizers and nano particles foliar application under full irrigation conditions compared to no application of bio fertilizers and nano particles under irrigation cut off at booting stage. But under such conditions, electrical conductivity, hydrogen peroxide and malondialdehyde content decreased 35.67, 53.16 and 56.32% respectively compared to no application of PGPR and nanoparticles under irrigation withholding in booting stage. Also, the application of PGPR and nanoparticles under irrigation cut off in booting stage increased the activity of catalase, peroxidase and polyphenol oxidase enzymes (47.06, 55.69 and 36.53% respectively), proline and soluble sugars content (45.41 and 46.93% respectively) compared to no application of PGPR and nanoparticles under full irrigation conditions.

Based on the results of this study, the application of plant growth promoting rhizobacteria and nonoparticle can increase grain yield of triticale under water limitation conditions due to improving biochemical and physiological traits.

Water shortage has become a global problem and has caused many problems in agriculture and food supply for the growing world. Barley (Hordeum vulgare L.) as the fourth mostly-cultivated cereal, is one of the most strategic crop plants which is produced almost all over the world as a source of and important staple food and animal feed (Thabet et al., 2020). Food uncertainty is a comprehensive obstacle becomes more serious hazard all over the world in particular in developing countries for the sake of overpopulation and dwindling accessibility of croplands, water and other resources related to agricultural scopes. Water scarcity, results in plenty of disturbances in plant functions like cell division and elongation, water and nutrients relations, photosynthesis, enzymes activity, stomata movement, assimilate partitioning, respiration, oxidative damage, growth, and productivity, as several types of researches show that water shortage in the soil cause many disorders in plant tissues, which in turn leads to a punctual diminish in the photosynthesis rate (Todorova et al., 2022). In such a trouble circumstances, most of the plants are not capable to absorb abundant water, which is required for optimized growth (Danish et al., 2020).

To investigate the impact of different irrigation regimes as well as foliar application of methyl jasmonate on growh, physiological and biochemical characteristics of barley varieties, an experimental research using factorial split plot design in 3 replications was carried out in experimental farm of the faculty of agriculture at the University of Zanjan in 2021-2022 cultivation season. In this experiment, irrigation regimes as the main factor, including complete irrigation as the control, withholding water in flowering stage, withholding water in grain filling period and complete dry farming, varieties as the secondary factor including Bahman, Sahand, Jolgeh, Abidar as well as Ansar, and foliar application of methyl jasmonate including without spraying (control) and spraying 50 μmol of methyl jasmonate were investigated. Results showed that the effect of irrigation regime had significant impact on almost all of the characteristics except chlorophyll a/b.

Varieties showed considerable difference from the aspect of height, concentration of soluble sugar and grain yield. Effect of Methyl jasmonate on the relative water content (RWC), photosynthetic pigments, soluble sugar content, proline content, Malondialdehyde (MDA) and grain yield was significant. The highest grain yield (4762 kg ha-1) was detected when variety of Jolgeh was irrigated normally and was sprayed by 50 μmol of Methyl jasmonate and the lowest grain yield (432 kg ha-1) was seen when variety of Bahman was dry-farmed without foliar application of methyl jasmonate.

The current study illustrated that barley can be grown in drought stress conditions if the right management is set on its cultivation. Methyl jasmonate showed a significant impact on the growth characteristics, biochemical and physiological attributes of the barley, despite the fact that drought had substantial adverse effects on the studied parameters of barley. However, drought resulted in different properties in barley varieties.

The combination of the effects of drought stress and soil salinity causes a severe limitation in the production of agricultural crops. Irrigation with saline water has caused the expansion of more saline lands. Salt tolerant genotypes are very important in the development of agricultural systems suitable for saline lands. Soil salinity through soil amendment and or the cultivation of tolerant crops can be adjusted. Of course, soil amendment is a costly process and the cultivation of tolerant species and varieties is the most practical solution in conditions where soil salinity is low. It is clear that the genotypes show a significant difference in response to salinity stress. One of the ways to deal with salinity is to select and find salinity-tolerant cultivars through the use of breeding methods. It is also possible to select and modify salinity-tolerant species in some fodder plants of temperate regions. This research was modified, with the aim of evaluation of selected barley genotypes from past years' experiments, under salinity stress conditions and identification and introduction of tolerant genotypes and direct and indirect use of them in breeding programs.

In this experiment, the genotypes were evaluated during two crop years in the form of a rectangular lattice design with three replications at the research station of South Khorasan Agriculture and Natural Resources Research Center, Birjand. The experiment was conducted under normal conditions and salt stress separately. In order to compare these genotypes with modified cultivars, six cultivated barley cultivars, including two salinity-tolerant controls, including Mehr and Khatam cultivars and the semi-sensitive Yusuf control, were also included in the experiments (Table 1). In addition to evaluating the phenological traits of days to flowering and days to maturity, the traits of plant height, seed yield, and 1,000-seed weight were recorded. Stress indices including stress tolerance index (STI) were calculated based on grain yield in barley genotypes.

The combined analysis of phenological, morphological and agronomic traits in the evaluated genotypes in two cropping years and two normal conditions and salinity stress showed that the interaction effect of year, salinity stress and genotype on the traits is significant. This showed that the reaction of genotypes was different in different years and different salinity conditions, so the results in different years were analyzed separately. In the salt research station in the first year of the experiment, genotypes number 31 (TN4006), 30 (TN3947), 50 (TN5008) and 28 (TN3646) along with Yusuf, Nusrat and Gohran cultivars, in terms of agronomic traits and stress indices were superior. While in the second year, the top genotypes were genotypes No. 44 (TN4904), 25 (TN3477), 23 (TN3470) and 32 (TN4104) along with Nimroz and Mehr cultivars.

The information related to the trend of temperature changes and rainfall in different months in Birjand showed that the amount of rainfall was significantly higher in the first year of the experiment. In addition to reducing the salinity of the soil by adjusting the temperature, it reduces the amount of evaporation and transpiration and the intensity of the salinity stress. Therefore, it seems that the level of salinity stress was milder in the first year and more intense in the second year, and this was also observed in the stress intensity index. Based on this, the difference in the results in the two years of the experiment can be justified, in other words, in the first year, tolerant genotypes were introduced in mild stress and in the second year, tolerant genotypes were introduced in severe stress. Overall, these results showed that climate changes in different years have a great impact on the response of genotypes to salinity stress.

Plants in the environment are affected by various stresses, depending on the duration, intensity and growth stage of the plant, these stresses can reduce the process of photosynthesis and affect their growth and performance. However, traditional methods, even technically advanced ones such as the measurements of photosynthetic rates through the gas exchange (CO2, H2O, and O2), are time-consuming and provide incomplete information on overall photosynthetic function. The development of knowledge in the field of chlorophyll fluorescence shows that this indicator has a high ability to study the photochemical efficiency of plant photosynthesis.

For measuring the chlorophyll fluorescence in plants, leaves were dark-adapted for 30 minutes using leaf clips provided by the producer of handy-PEA. Measurements were performed on the middle of plant leaves following the standard protocol with illumination with continuous red light (peak in 650 nm wavelength; the spectral line half-width of 22 nm) provided by an array of three light-emitting diodes. The light pulse intensity used was 3500 μmol(photon).m–2s–1 and the duration of the light pulse was 1 s. The measured data were used for the calculation of the photosynthetic parameters using Biolyzer v. 3.06 HP software (a software provided with handy-PEA). Some of the parameters we discussed in this article due to their significance are FO = minimum fluorescence, FM = maximum fluorescence, FO/FM = The maximum quantum yield of basal non-photochemical energy losses, FV/FM = the maximum quantum efficiency of PSII, VJ = the relative variable fluorescence in step J after 2 ms, VI = the relative variable fluorescence in step I after 30 ms, N = the number of QA redox turnovers until FM, SM = the pool size of the electron acceptors on the reducing side of PSII, PIABS = performance index.

The study of chlorophyll fluorescence can analyze with high detail the function and state of PSII reaction centres, and light-harvesting complexes. This index has a high correlation with other physiological parameters under different environmental stresses. In this article, an overview of the results of chlorophyll fluorescence analysis of crops underenvironmental stressesis given, and the key steps to stresses are presented. Under drought stress the ratio of active reaction centers in chlorophyll, primary photochemical reactions, and electron transfer are affected. By salinity stress in crops, the values of variable and, maximum fluorescence, the energy required to close the reaction centers, and the photosynthetic efficiency index decrease, while the time required to reach the maximum fluorescence increases. Under cold stress conditions, electron transfer flow per reactive centers, the quantum performance of photosystem II, and the efficiency of the water splitting complex in photosystem II decrease. Potassium affects light-dependent steps such as the size of receiving antennae and the electron connection of photosystem II reaction centers. The electron acceptor part of photosystem II is the main site of inhibition of photosynthetic electron transfer under the application of herbicides.

Conclusion and Implications:

This article has provided an overview of the information about the wide opportunities of using the chlorophyll fluorescence technique in plant science, agriculture and ecological research. The measured parameters of chlorophyll fluorescence are called the JIP-test and its analysis can be used to evaluate the effects of environmental stresses on plants. This technique requires more practical studies in biotic and even non-biotic stress conditions to provide reliable information to investigate the growth and development of plants, and this leads to an increase in our knowledge of the physiological basis of crop photosynthesis under stress conditions.

Under water stress conditions, intercropping can be used as a strategy for maximum use of sunlight and limited water resources. Due to the difference in morphological and physiological traits, the two plants corn and mung bean may be suitable for intercropping under drought stress; Therefore, this research was conducted with the aim of investigating the effects of drought stress on the physiological traits and yield of corn and mung beans in monocultures and intercropping in order to study the possibility of reducing water consumption in this production system.

An experiment was carried out as a split plot based on randomized complete block design with three replications at Ilam University during 2019-2020 growing season. The main plot were four water regimes including (40, 60, 80, and 100% of the plant's water requirement) and the subplots were include the planting pattern at four levels (additive intercropping series 100% corn + 50% mung bean, replacement intercropping series 50% corn + 50% mung bean and monocultures of mung bean and corn). The application of drought stress started after the establishment stage of the plant and continued until the harvest. At the end of the growth period, some physiological traits of both plants were measured, including photosynthetic pigments, photosynthesis rate, transpiration rate, intercellular CO2 concentration, proline amount, leaf relative water content and grain yield. Finally, analysis of variance (ANOVA) was performed using Minitab 14 and SAS 9.1 softwares and the means compared by HSD test at 5% probability level (p≤0.05).

The results showed the highest rate of photosynthesis (25.4 µmol CO2.m-2.s-1) was obtained in the treatment of 100% water requirement and the lowest rate of photosynthesis was obtained in 40% water requirement, which showed a decrease of 68.5% compared to the well-watered conditions. The rate of photosynthesis of corn in the replacement intercropping of 50% corn + 50% mung bean was 18.3% higher compared to monocultures corn. The highest rate of mung bean photosynthesis was observed in replacement intercropping under conditions of 100% water requirement and additive intercropping series under 80% water requirement, and the lowest rate of mung bean photosynthesis was observed in intercropping under conditions of 60 and 40% water requirement. Dehydration stress decreased the amount of total chlorophyll in mung beans and corn. The highest intercellular CO2 concentration (475.5 mmol of CO2.m-2.s-1) and the temperature of the corn leaf (36.7 °C) belonged to the 40% water requirement treatment. The rate of transpiration of corn and mung bean decreased by 55.56 and 61.43% in the condition of 40% water requirement compared to well-watered conditions. Water stress reduced the relative water content of corn and mung bean. The highest proline in corn and mung leaves (46.3 and 45.23 µmol.g-1.FW-1, respectively) was obtained in the treatment of 40% water requirement, which had no significant difference with 60% water requirement. Corn grain yield in the treatment of 40% water requirement showed a decrease of 52.76% compared to 100% water requirement. Monocultures (3945.8 kg.ha-1) and intercropping (3875.1 kg.ha-1) had the highest corn grain yield, and the lowest corn grain yield in replacement intercropping was 2700 kg ha-1. At all irrigation levels, the highest grain yield of mung bean was obtained in monocultures, and the yield decreased in additive and replacement intercropping, and additive intercropping had the lowest grain yield. The values of land equality ratio of all intercropping patterns were greater than one, which indicates the advantage of corn and mung bean intercropping patterns to use land and increase yield.

Considering the occurrence of recent droughts in arid and semi-arid regions of the country and the need for forage in these regions, the cultivation of forage plants, especially corn, is inevitable. Therefore, one of the appropriate strategies to protection in management and water consumption is the intercropping of this plant with plants of the legume such as mung bean. Intercropping can partially moderate the effects of drought stress on plant water conditions. In general, it seems that the patterns of intercropping and substitution, due to having higher grain yield potential, is a suitable strategy for producing higher yield and stability of this plant compared to monocultural under well-watered and stress water.

To evaluate and identify high yielding triticale lines syuiable to cold, temperate and warm agro-climatic conditions of Fars province, a field experiments were carried-out in Eqlid, Zarghan, and Darab agricultural research stations in 2012-2013 growing season. Twenty-nine triticale advanced lines (received from CIMMYT) were cultivated along with Juanilo 92 variety (check) in randomized complete block design with three replications. Each plot was four meters long with 1.2 meter in width. Fertilizers were applied based on soil analysis. The results showed that the highest grain yield (7450 kg ha-1) obtained from Darab and the lowest (2800 kg ha-1) from Eqlid. In Zarghan, Juanilo 92 variety had the highest grain yield (7300 kg ha-1). In Darab, the highest grain yield belonged to lines no. 2 and 21 with 8966 and 8900 kg ha-1, respectively. The results showed that the average grain yield of lines no. 8, 7 and 21 in all three locations were 1.8, 3.5 and 12.9 percent higher than Juanilio 92, respectively.

To study the adaptability and yield stability of 19 selected potato clones along with four cultivars, Agria, Marfona, Savalan and Khavaran a field experiment was carried out in randomized complete block design with three replications in five locations; Karaj, Ardabil, Hamadan, Esfahan and Mashhad, in 2015 and 2016. GGE Biplot based on environment scaling showed that Isfahan, Ardabil and Hamadan, respectively, were closer to the ideal location and KSG23, KSG82, KSG31, KSG64 and KSG300 clones with mean tuber yield of 30.71, 29.76, 29.38, 27 and 26.68 kg plot-1 (nine square meters), respectively, were more suitable for being grown in ideal areas. The relative superiority coefficient of KSG23, KSG302, KSG81 and KSG107 clones were 2.87, 6.98, 7.81 and 12.49, respectively, and they had relatively good tuber yield stability. The relative superiority coefficient of KSG31, KSG82 and KSG64 clones were 18.07, 15.76 and 13.67, respectively, and almost similar to the Agria control (17.22) and they were superior to the Agria (control) for tuber yield. AMMI analysis revealed that the genotypes reacted differently in different environments and the sum of squares of the genotype × environment interaction was 4.8 times larger than that of the genotypes. KSG81, KSG64, KSG300 and KSG107 clones, and cv. Agria (control) had reasonable tuber yield stability. Based on the adaptability and tuber yield stability, KSG302, KSG82 and KSG31 clones were identified suitable for spring planting in different regions of Iran, KSG23 and KSG57 for Khorasan, KSG64 and KSG48 for Hamadan and Ardabil, respectively, KSG81 for Isfahan and Ardabil.

The present research was conducted to evaluate the response of different almond cultivars to drought stress. The experiment was carried out as split plot arrangement is in randomized complete block design with three replications in the Agricultural and Natural Resources Research Center of Chaharmahal and Bakhtiari, ShahreKord, Iran, in 2020 and 2021. Different irrigation periods based on the available soil moisture; 70%, 50%, 30% and 10% of field capacity were assigned to the main plots and 13 commercial almond cultivars; Mamaei, Rabie, Saba, Araz, Eskandar, Aidin, Shahrood 6, 7, 8, 10, 12, 13, 21 and GN clonal rootstock, were randomized in the subplots. All commercial almond cultivars were grafted on GN clonal rootstock. The plants were under water stress for four months and antioxidant enzymes activity was measured at the middle (two months after application of stress) and the end (four months after application of stress) of drought stress period. The results showed that drought stress significantly decreased fresh and dry weight of the above-ground parts of all cultivars. The lowest effect of drought stress was recorded in cv. Shahrood 8 and GN clonal rootstock. Malondialdehyde content and electrolyte leakage in all almond cultivars significantly increased with increasing drought intensity. In both the middle and end of drought stress period, cv. Shahrood 8, cv. Shahrood 12 and GN clonal rootstock showed the highest chlorophyll index and the lowest malondialdehyde content and electrolyte leakage under severe drought stress (10% FC). Under severe drought stress, the highest antioxidant capacity of enzymes was recorded in cv. Shahrood 12, cv. Shahrood 8 and GN clonal rootstock. Considering the results of this research, under different levels of drought stress, cv. Shahrood 8, cv. Shahrood 12 and GN clonal rootstock had the highest above-ground fresh and dry weight, chlorophyll index and antioxidant enzymes activity, and the lowest peroxidation level that showed the high level of tolerance to water deficit stress.

This study aimed to investigate the effect of sowing date and enviromental factors during different growth stages on some phenological characterisitcs and grain yield of commercial bread wheat cultivars. The experiment was carried out as split-plot arrangements in randomized complete block design with three replications at the Darab reaesrch field station in 2018-19 and 2019-20 cropping cycles. Five sowing dates: October 27, 11, and November 26, December 11, and 26, were assigned to the main plots. Five commercial wheat cultivars: Mehregan, Barat, Khalil, Sarang, and Setareh, were randomized in the subplots. Results showed that the late maturity cultivars, Khalil and Brat, had higher grain yield in earlier sowing dates. Early maturity cultivars, Setareh and Mehregan, had less yield reduction in later sowing dates. The highest and lowest mean grain yield obtained from November 11 (6934 Kg ha-1) and December 26 (5775 kg ha-1), respectively. Number of days and required growing degree-days (GDD) decreased with delaying sowing date. The decrease of required GDD to reach commencement of stem elongation, anthesis and maturity stages from the first to fifth sowing date was 181, 282 and 528 GDD, respectively. Simultaneous effect of weather variables and sowing date on some characteristics revealed that the first two components explained approximately 41% of total variation. Results showed that temperature was the most important factor controlling the phenological stages duration. Despite the importance of temperature, changes in sowing date can alter the required GDD for phenological stages due to other environmental factors. In general, the results of this study can provide an insight into bread wheat cultivars responses to different climatic conditions and development of new bread wheat cultivars adapted to target environments.

In this research, the role of shading net on some fruit quality characteristics of quince cv. Isfahan was investigated. The experiment was carried out on quince cv. Isfahan grafted on the Hawthorn rootstock in the quince orchard of Fajr Agricultural Company located in Natanz city in Isfahan province, Iran. Trees were about 20 years old. Fruits were harvested 193 days after flowering and were transferred to a cold store with temperature of 0±1°C and relative humidity of 95%. At the harvesting time and five months after harvest, the fruit quality characteristics were examined. The pectin content and total phenol content after five months of storage did not show significant difference between inside and outside of the shading net. However, the TSS (18.35%) and the fruit taste index (6.44) swere higher in the fruits under the shading net after five months of storage. Lower weight loss (6.41%) and browning (1.83%) were observed in the fruits under the shading net after five month storage.

Phaseolus vulgaris L., commonly known as the common bean, is an important legume crop, responsible for 85% of global bean production. Nevertheless, soil salinity represents a significant challenge that severely impairs its productivity. Soil salinity represents one of the most detrimental constraints on crop growth and production. Conversely, beans are regarded as one of the most susceptible crops to salinity stress. However, the detrimental effects of salinity on crops can be significantly mitigated by the use of certain substances. Salinity exerts a significant negative influence on the primary plant processes, including photosynthesis and the production of photoassimilates, which ultimately results in a reduction in plant production. The application of an appropriate quantity of salicylic acid (SA) enhances the plant's tolerance to abiotic stresses, thereby reducing the destructive effects of stress and increasing tolerance to abiotic stresses. It has been demonstrated that the external application of salicylic acid can induce the tolerance of crop plants to a range of abiotic stresses, including salt, drought, heat, cold, and heavy metals. Furthermore, SA can be an effective substance against plant abiotic stresses, as it can regulate a variety of phytohormones, and it may play a key role in free radical scavenging and nutrient uptake. Furthermore, the utilization of biochar represents an efficacious approach to mitigating the consequences of abiotic stresses, such as salinity. Biochar, a carbon-rich material, is employed to enhance soil carbon sequestration, reduce CO₂ emissions, and augment soil microbial diversity and activity. It has been postulated that biochar has the capacity to adsorb some of the toxic ions, such as Na and Cl, thereby reducing the toxic effects of salinity.

A two-year glasshouse study was conducted using a randomized complete block design, with four replicates in each treatment. The study was conducted at the Faculty of Agriculture, University of Mohaghegh Ardabili, Iran over two consecutive years (2022-2023). The experiment included three levels of salicylic acid (SA): SA0 (0 mM), SA0.5 (0.5 mM) and SA1 (1 mM), four levels of biochar, including no biochar application as the control treatment (B0), recommended biochar (Rb) by application of 2.5% biochar. The treatments included 5% (w/w) of modified biochar with phosphoric acid (PA), 1.25% of modified biochar with sulfuric acid (Sb), and salt stress (SS) using NaCl in three levels: SS0 (distilled water), SS4 (4 dS m-1), and SS8 (8 dS m-1). In this experiment, the salinity treatment was applied in two stages: at the planting time and when the seedlings had fully established themselves in the soil. Salicylic acid was applied foliarly at two stages: early and late flowering, according to the predetermined levels.

Salinity had a detrimental impact on the biochemical attributes of bean plants, yet this effect was alleviated by the application of the SA treatment. Furthermore, salt stress resulted in a reduction in relative water content, membrane stability index, leaf area and photosynthetic pigments, which in turn led to a reduction in current photosynthesis and remobilisation of photoassimilates. Nevertheless, the application of biochar and the use of SA were found to alleviate the negative effects, resulting in a higher grain yield compared with the control plants, i.e. at the absence of biochar and SA application at the end of the experiment. The combined application of biochar and SA resulted in a higher relative water content, photosynthetic pigments and an enhanced rate of photosynthesis. The greatest accumulation of chlorophyll-a and carotenoids was observed in response to the application of SA1 without biochar in non-stress conditions. Furthermore, the lowest photosynthetic rate was observed in response to SS8. Moreover, the greatest anthocyanin accumulation was observed in response to the addition of biochar to the soil in the absence of SA under salt stress conditions.
Our research has demonstrated that the combined application of biochar and SA can significantly mitigate the adverse effects of salinity stress on common beans. Furthermore, the results demonstrated that SA significantly enhanced grain yield of plants under both saline and non-saline soils. The results indicate that the excessive use of biochar and SA may lower the mentioned effectiveness, as the biochar increases soil porosity, which negatively impacts water availability. Furthermore, application of high doses of SA has been shown to have a negative impact on the biochemical and enzymatic attributes of the plant under salinity conditions.

Although the study on the effects of biochar and SA on common beans under salinity stress provides valuable insights, it is important to consider the limitations of the study. Consequently, the findings may not be directly extrapolated to the natural agricultural settings, where multiple environmental factors interact.

Olive (Olea europaea L.) is the most famous species of Oleaceae family that has edible fruits. The olive tree has a tendency to alternate bearing, leading often to the production of massive fruit yield in one year (on) and a very low fruit yield in the next year (off). Knowing the changes of nutrients in different stages of olive fruit growth and development in the “on” and “off” years provides the possibility of timely and correct application of fertilizers. This research was conducted in order to investigate the changes in the concentration of mineral elements, starch, and protein of olive fruit in the on and off-years.

This research was carried out in the years 2018-2019 at Olive Dalaho Research Station in 2018 and 2019 at Dalahu Olive Research Station in Kermanshah (Lat. 32° 30´ N, Long. 45° 51´, Alt. 560 m.), west of Iran. The experiment was carried out in the form of a randomized complete block design with three replications and three local olive varieties, namely Deira, Zagros and Meshkat. All tested 11-year-old trees were under similar conditions in terms of pruning, drip irrigation, fertilization and pest and disease control. Measurement were carried out on N, P, K, Zn, B, starch, and protein in young leaves, fruits, old leaves, and roots from the time of kernel hardening (in early June) until fruit ripening (in mid-November) every 40 days using both "on" and "off" year trees. The samples included 20 broad leaves from the middle part of one-year-old and newly-formed vegetative branches, the growing fruits of the current year, and the feeding roots of 30 cm depth under the canopy of the tree crown. Measurements on potassium concentration were made by a flame photometer (model PFP7 made by JENWAY, England), phosphorus by colorimetric method using spectrophotometer, nitrogen and protein by Kjeldahl method, boron and zinc elements using an atomic absorption device (Perking Elmer model 31/40). Starch concentration of the dry matter was measured by Morley's method.

Monthly changes of mineral elements in leaves and young fruits, starch, and protein concentration in old leaves and roots were significant in the on and off years. The monthly changes in the concentration of the mineral elements corresponded to the pattern of the fruit growth curve (double sigmoid). The concentration of N, K, B, and Zn in young leaves decreased from the beginning of June to the middle of July (the time of endocarp hardening) and then increased slightly. The monthly changes in concentration of mineral elements in leaves and young fruits, starch, and protein in old leaves and roots were significant in the on and off years. The monthly changes of the mineral elements corresponded to the pattern of the fruit growth curve (double sigmoid). The concentration of N, K, B and Zn in young leaves decreased from the beginning of June to the middle of July (the time of endocarp hardening) and then increased slightly. Mashkat cultivar had the highest and Deira and Zagros cultivars had the lowest concentration of nitrogen in young leaves. The concentration of nitrogen has a direct effect on vegetative growth, fruit formation, fruit yield, and shoot growth. There was a positive and significant relationship between fruit nitrogen and phosphorus and zinc concentration of the fruit, but young leaf nitrogen had a negative and significant correlation with phosphorus and zincof the fruit. Deira cultivar had the highest and Meshkat the lowest zinc concentration of the young leaves. Zinc plays a significant role in the function of enzymatic systems, synthesis of nucleic acids, protein and auxin metabolism. There was a positive correlation between phosphorus concentration in young leaves with phosphorus concentration in fruit and leaf starch, but there was a negative correlation with leaf and root protein concentration. The concentration of starch in the old leaves and roots increased and then decreased in the on-year until June. The concentration of root starch decreased slowly from June to November in off-year trees. The concentration of protein in old leaves and roots followed a double sigmoid curve, it decreased sharply until mid-July. From the mid-July to the end of August, the protein concentration of the old leaves slowly and strongly in old leaves and roots, respectively.

Considering the observed changes in the concentration of mineral elements in the leaves and fruits according to the fruit growth pattern, especially in the spring, soil application of nitrogen, phosphorus, and potassium in January (before flowering), foliar spraying of nitrogen, potassium, zinc, and boron in June (after fruit set) and nitrogen and potassium amendments in August (after endocarp hardening) is recommended for the olive orchards of the studied region.

Alfalfa is one of the most important fodder plants, being able to produce a high quantity of forage dry mass with high concentration of protein and to symbiotically fix atmospheric nitrogen. Having a deep and extensive root system, it reduces soil erosion and improves water penetration in agricultural soils (11). The results of the previous researches showed that the use of Nitroxin and Phosphate Barvar-2 bi-fertilizers had a significant effect on plant protein concentration and the highest protein (22.3%) was obtained when the plants were inoculated with Phosphate Barvar-2 and received organic amendment in the form of mushroom compost. Also, the use of Nitroxin and Barvar-2 bi-fertilizer increased the efficiency of nitrogen consumption, and inoculation with Nitroxin had the highest (22.8%) nitrogen use efficiency (5). Our study aimed to shed light on the nitrogen physiological efficiency and some agronomic traits of alfalfa in the presence of bio-fertilizers and organic manures in Kashan, central Iran.

This study was carried out in Aran and Bidgol, central Iran, in 2014. The experiment was conducted with a factorial arrangement in a randomized complete block design with three replications. Treatments were 4 levels of bio-fertilizers (control, Nitroxin, Phosphate Barvar-2, and Nitroxin+Phosphat Barvar-2) and animal manures (control, cattle manure, sheep manure, and poultry manure in 10 tons/ha). Stems/m2, grains/m2, 1000-grains weight, days to 10 percent flowering, accumulative fresh weight, nitrogen content, protein content, protein yield, physiological efficiency of nitrogen and nitrogen use efficiency were evaluated.

Application of bio-fertilizers enhanced all examined attributes, compared to control, the extent of enhancement in a majority of attributes being greater for Nitroxin + Phosphate Barvar-2. The highest and lowest grains/m2 and 1000-grains weight belonged to application of Nitroxin+ Phosphate Barvar-2 + 10 tons/ha cattle manure and control treatments, respectively. The highest nitrogen content, protein content, and protein yield were obtained by the application of Nitroxin and poultry manures. The highest physiological efficiency of nitrogen was recorded under the conditions of control and cattle manure (3.19 Kg/Kg). The highest nitrogen use efficiency was observed in the presence of cattle manure and Nitroxin+ Phosphate Barvar-2. The application of Nitroxin + Phosphate Barvar-2 with an average of 68.4 tons/ha led to 15.63% increase compared to other levels of bio-fertilizer. Therefore, the combined application of Nitroxin and Phosphate Barvar-2 has been able to produce a high-quality animal feed in successive harvests than the sole application of each of these bio-fertilizers. Among the different levels of organic fertilizers, application of cow manure with an average of 67.08 tons/ha and no use of organic fertilizer with an average of 62.37 tons/ha produced the highest and lowest cumulative fresh weight of alfalfa, respectively. Also, the highest physiological efficiency of nitrogen (with an average of 3.40 kg of grains produced per kg of nitrogen applied) was achieved when 10 tons/ha of cow manure was applied.

The combined application of Nitroxin and Phosphat Barvar-2 bio-fertilizers was more effective than the sole application of each of these biofertilizers. Among the levels of organic manure (10 tons per hectare), cow manure was found to be more effective in enhancing the examined traits. Application of poultry manure had a more favorable effect on nitrogen and protein concentrations and protein yield of alfalfa. Therefore, combined application of Nitroxin and Phosphat Barvar-2 bio-fertilizers is recommended for producing alfalfa in the climatic conditions of Kashan.

Citrus decline is a significant deteriorating factor in citrus cultivation, imposing costly damages to many orchards worldwide, including in Iran. Key factors contributing to citrus decline include environmental stresses such as the physical and chemical conditions of the soil, soil nutritional status, soil moisture condition, and biotic stresses. Environmental stresses, particularly mineral deficiencies and water stress, appear to play a crucial role in citrus deterioration. The Jiroft region is one of the major agricultural centers in south of Iran. Despite its pivotal role in citrus production of the country, the region's orchards experience widespread deterioration, causing considerable annual losses. However, no research has yet explored the potential benefits of simultaneous use of management and nutritional treatments in these orchards.  Therefore, this study aims to investigate the effect of management and nutritional treatments on alleviating both biotic and abiotic stresses and reducing citrus fruit deterioration.

The current study employed a randomized complete block design over two years in Jiroft, south of Iran, incorporating the following treatments: 1. Control: No intervention. 2. Optimal Management: This included timely irrigation, fertilization (chemical and organic amendments based on soil and leaf tests), and gardening practices (pruning, fruit thinning, and weed removal). 3. Optimal Management + Potassium Silicate: This treatment received optimal management plus potassium silicate fertilizer applied through irrigation water three times at a rate of 30 L ha-1 (as determined by soil test). 4. Optimal Management + Shading: This treatment consisted of optimal management with shading (integrated or individual) at approximately 25% during the hot season, along with plant mulch. 5. Optimal Management + Biocontrol & Fungicides/Nematicides: This treatment combined optimal management with Mycorrhizal and Trichoderma fungi, along with fungicides and nematicides. 6. Optimal Management + Calcium Nitrate Injection: Trees received calcium nitrate injection (30%) directly into the trunk twice a year. 7. Optimal Management + Calcium Nitrate Fertilizer & Foliar Spray: This treatment involved optimal management with calcium nitrate fertilizer applied three times (500 grams per tree, one-month intervals) through irrigation water supplemented by foliar sprays containing calcium chelate and micronutrients (zinc, manganese, iron, and copper) applied three times. Then, leaf samples (both 5–6-month-old leaves and new leaves) and fruits were collected and transported to the laboratory for analysis. This analysis included measurements of number of new leaves, leaf area (average surface area per tree leaf), yield, fruit length and diameter, and the concentration of specific macro- and microelements in the leaves.

The results revealed an inverse relationship between the average number of new leaves per tree and the severity of decay. Treatment-4 displayed a 1.5-fold increase in new leaves compared to the control (treatment-1). Additionally, the number of final shoots (spring and summer regrowth) was 191 in the treatment-4 and 76 in the control treatment. In the treatment-4, the mean leaf area was 41.8 cm2, compared to 29.4 cm2 in the control treatment, demonstrating an increase of 42.20%.  Statistical comparisons of other responses also indicated a significant increase in treatment-4 compared to the others. Treatment-4 also exhibited the greatest improvements in fruit size. Fruit diameter and length increased by 35.5% and 33.9%, respectively, compared to the control. Treatment-4 resulted in the largest average leaf area (41.8 cm²) compared to the control (29.4 cm²). Fruit yield followed a similar trend, the lowest fruit yield (22.9 kg/tree) being observed in the control treatment. Conversely, treatment-4 (optimal irrigation management with shading and mulch) achieved the highest fruit yield (50.2 kg/tree), representing a significant increase of 119.2%, 45.9%, 52.5%, 2,100.0%, 95.3%, and 77.4% compared to control, treatment-2, treatment-3, treatment-5, treatment-6, and treatment-7, respectively. Treatment-4 also demonstrated the highest concentrations of zinc, manganese, and iron in the fruits. These elements increased by 1.50, 1.52, and 1.65 times, respectively, compared to the control. The results overwhelmingly favored treatment-4 compared to the control and other treatments. This superiority likely stems from the combined effects of shade mesh and mulch, which are unique to treatment-4. Shade mesh not only provides shade but also reduces radiation intensity, ultimately minimizing heat stress, sunburn, and water loss through evaporation and transpiration from the tree's foliage. Beneficial effects of Treatment-4 go beyond shade and mulch by ensuring optimal plant nutrition based on soil tests, addressing a crucial factor in citrus health. Inadequate nutrition can contribute to tree decline. By providing the necessary macro and micronutrients and adjusting environmental conditions like temperature and humidity, particularly around the roots, we can minimize disruptions in nutrient uptake and promote overall tree health.

Given the warm climatic conditions of Jiroft at Kerman's southern region, citrus decline arises from a combination of biotic and abiotic stresses. Consequently, solutions targeting either biotic or abiotic constraints are unlikely to provide a sustainable solution to the citrus decline question. An integrated approach, incorporating optimal irrigation and combined nutrient management, was found to be more effective. Therefore, implementing optimal irrigation and combined nutrition management, using plant mulch in the shaded area of the trees, and employing netting as a shade was proven to be a suitable solution to the citrus decline in the Jiroft at southern region of Kerman province, Iran.