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

 Cotton (Gossypim hirsutum L.) has a special position as one of the most important crops in the country. Considering that salinity stress is one of the most important stresses, it threatens cotton production in arid and semi-arid regions of the country and the world, it is possible to reduce the adverse effects of salinity stress through application of organic fertilizers (manure and humic acid). In addition, Organic inputs can guarantee both agricultural production and nature conservation. The current approach is to employ the organic compounds like manure and humic acid (that are cost-effective and eco-friendly) as an appropriate substitute for chemical fertilizers.

This study was carried out to assess the effect of manure and humic acid application on some elements accumulation and ions concentrations in cotton (Gossypim hirsutum L.) (cotton leaves) under salinity stress. The experiment was conducted as a factorial split plot in the form of a randomized complete block design (RCBD) with four replications in the 2019-2020 cropping year in Beshravieh city in South Khorasan. The main plot included different levels of irrigation water salinity at three levels (2.5, 5.5 and 8.5 ds.m-1) and sub-plots consisted of a factorial combination of manure at two levels (0 and 20 t/h) and humic acid at two levels (0 and 200 gr/ 100 kg of seeds as priming). In order to measure the concentration of sodium (Na) and potassium (K) elements, it was done using a flame photometer and chlorine concentration based on the method provided by Johnson and Ulrich (1995).  In order to assess the cotton yield, the yield of two consecutive harvests were added together and was considered as the seed cotton yield of each experimental unit.

The results of the present study illustrated that the salinity stress increased Na+ and Cl- concentration in cotton leaves and consequently decreased K+ concentration. The increase of salinity stress from 2.5 to 5.5 and 8.5 dSm-1 caused a significant decrease in seed cotton yield. Manure application treatment increased Na+ (13.45%), K+ (2.67%), Cl- (18.30%) concentration in the leaves and seed cotton yield (13/90 %) compared to the no use of manure. Humic acid application treatment decreased Na+ (3.08%), Cl- (9.78%) concentration and increased K+ concentration (4.17%) and cotton yield (9/15 %) and improved the growth conditions compared to the treatment of no use of humic acid. The application of manure (before planting) and humic acid (as priming treatment) increased the seed cotton yield by improving the accumulation of beneficial elements in the leaves under salinity stress conditions.

Based on the results of this experiment, it can be concluded that the application of manure and humic acid (priming) moderated the negative effects of salinity stress on seed cotton yield. In addition, manure and humic acid can be used as an effective and alternative fertilizer in order to reduce the consumption of chemical fertilizers and salinity stress in hot and dry climates. Therefore, manure and humic acid (organic fertilizers) are recommended to be applied under (environmental stresses) salinity stress conditions to mitigate the effects of salt stress and obtain a higher seed cotton yield.

This study was performed to evaluate the effect of Rahnella aquatilis and Burkholderia cepacia bacteria on yield, yield components, and uptake of potassium and zinc elements in rice (Oryza sativa L.).

The experiment was conducted as a split-plot in a randomized complete block design with three replications in 2022. Treatments included two levels of chemical fertilizer (100 and 75% of chemical fertilizer consumption based on the soil test results as optimal and reduced fertilizer levels, respectively) and four inoculation treatments (separate inoculation of R. aquatilis, B. cepacia, a co-inoculation (R.aquatilis+B.cepacia) and control (non-inoculation)).

The results indicated that there was no significant difference between the optimal and reduced fertilizer levels in all the studied traits. The separate inoculation of R. aquatilis, B.cepacia and their co-inoculation increased the panicle length (from 5.88 to 11.3%), the number of total tillers in hill-1 (from 19.4 to 29.1%), the total number of grains in panicle-1 (from 22.8 to 46.5%), paddy yield (from 22.8 to 44.3%), biological yield (from 20.3 to 33.6%), 1000-seed weight (from 2.4 to 8.8%), potassium uptake in grain (from 6.0 to 41.4%) and in above-ground biomass (from 38.4 to 65.4%), zinc uptake in grain (from 6.29 to 40.9%) and in above-ground biomass (29.4 to 54.6%) as compared with the control (non-inoculation).

The application of plant growth-promoting rhizobacteria in combination (as the best inoculation treatment) reduced chemical fertilizers consumption without a significant reduction in the paddy yield, indicating the importance of these rhizobacteria for achieving sustainable agriculture goals.

The present experiment was conducted to investigate the effect of tillage, organic fertilizers and mycorrhiza on quantitative traits and nutrient uptake in maize. The experiment was performed as a split plot with 4 replications in a randomized complete block design in August of the crop year 2017 and 2018 in Ivan city in Ilam province. Tillage at 3 levels (no tillage, tillage to a depth of 10 cm and tillage to a depth of 30 cm), organic fertilizer at 3 levels (no use, vermicompost 30 tons per hectare and bovine manure 30 tons per hectare) and mycorrhizal fungus Glomus mosseae and it was by soil inoculation method (consumption and non-consumption). In a minimal tillage system, seed yield was 7053.2 kg ha-1, an increase of 21% compared to the least amount of tillage-free treatment. In the minimum tillage system and the consumption of cow manure, the highest grain yield was obtained in the amount of 8198.2 kg ha-1. The interaction of mycorrhizae and tillage on grain yield was significant. In the case of minimal tillage and mycorrhizae, the maximum grain yield was707.1 kg ha-1, which was significantly different from the treatment without tillage and deep in both mycorrhizal and non-amycorrhizal states. According to the results obtained in this study, it was found that soil application at least relative to the deep system has increased plant yield.

Potato (Solanum tubersum) is an important economic crop in the world. In order to investigate the effect of potassium (Potabarvar Bioferrtilizer) and Phosphorus (Barvar 2 Biofertilizer) biofertilizers on the yield and quality of two families of true potato seeds, including Fanta free pollinators and Savalan × Agria hybrids, an experiment was conducted in the form of a completely randomized block design with 8 treatments and three repetitions were done. The results showed that the use of Potabarvar Bioferrtilizer and Barvar 2 Biofertilizer affected plant height, leaf area and the dry matter percentage of tuber and leaf and led to an increase in yield compared to the control plants and the application of a mixture of biological fertilizers at the probability level of 1%. So that the highest yield in the treatment of Potabarvar biofertilizer was obtained on the free-pollinating Fanta family. Also, the application of these fertilizers led to an increase in the leaf chlorophyll index at the five percent probability level. The use of these biofertilizers led to an increase in the concentration of potassium, nitrogen and phosphorus elements in the plant at the level of 1% probability. The application of these fertilizers had a greater effect on the free-pollinating Fanta family. Also, the application of the mixture of these biofertilizers did not lead to an increase in the desired indicators.

To investigate the effect of zinc and potassium application on some morphological traits and yield of wheat (Triticum aestivum L.) under drought stress, a split-factorial layout based on a randomized complete block design (RCBD) with three replicates were carried out at the experimental farm of the Research, Education and Extension Center of Agriculture and Natural Resources of Hamadan during 2017-2018. The main plot included irrigation levels (normal and water stress) and the subplot included two factors of foliar application of potassium (K) and zinc (Zn) fertilizers. Potassium fertilizer from K2O source (40%) including 2 L/ha at three levels; I) without fertilizer (control sample), II) leaf spray at the beginning of booting, III) leaf spray after pollination, and zinc fertilizer from water-soluble zinc source (10%) including four liters per ha in three levels; I) without fertilizer (control sample), II) leaf spray at the beginning of booting, III) leaf spray was used after pollination. The results of the analysis of variance showed a significant difference between treatments in all studied traits. Significant differences in all of the traits were observed under stress and normal irrigation. Co-application of potassium and zinc fertilizers compared to the control increased grain yield (4.5%) and RWC (5.8%) evaluated morphological indices under stress conditions.To investigat

To study the effect of irrigation water salinity on physiological characteristics and the concentration of leaf elements of different accession of melons a split-plot experiment was designed based on RCBD with 3 replicates on two accessions, tolerant (Sooski and Diamond) and two accessions sensitive (Daregazi and Zard Ivanaki) and two salinity levels (tap water  2.3 ds/m (control) and 8 ds/m) according to the salinity of wells) in the field of Isfahan research station in 2016-2017. The results showed that with increasing salinity, the chlorophyll index decreased in all sensitive and tolerant accessions 21 and 16% respectivly. Photosynthesis and stomatal conductance showed the highest and lowest reduction in the Zard Ivanaki and Diamond accessions,62 and 19% respectively in comparison to the control. Stomata conductance was lowest in Zard Ivanaki (0.05) and highest in Diamond (0.39). CO2 substomatal was reduced by 44%, 26%, and 11%, respectively, in the Zard Ivanaki, Sooski and Diamond accessions. Photosynthetic water use efficiency did not have a significant effect with increasing salinity in all accessions. The amount of Na and Cl increased in the Daregazi and Zard Ivanaki accessions compared to the control, and K showed the lowest decrease by 26% in the Diamond accession. The highest reduction K/Na ratio was observed in Daregazi by 71%. The amount of P decreased in all of the accessions, except for the Daregazi, Overall, the results showed that by applying salt stress, photosynthetic parameters, K and P elements decreased, and Na and Cl increased, and this decrease was lowest in Diamonds and highest in Zard Ivanaki. Diamond resistant mass has a higher tolerance to salinity compared to sensitive cultivar through defense mechanism by restricting the uptake or transfer of sodium to aerial parts and also maintaining a good level of potassium and can be used as a tolerant cultivar under salinity conditions.

In order to investigate the possibility of improvement of yield, yield components and the concentration of some nutrients in rice leaves (Tarom variety) by using rice straw and its biochar, a factorial experiment was conducted in the form of a randomized complete block design in nine treatments and three replications in the farm of Sari Agricultural Sciences and Natural Resources University, Sari, north of Iran, in 2021. The first factor was rice straw (S) at three levels of zero, 2 and 4 tons/ha and the second factor was rice straw biochar (B) at three levels of zero, 1 and 2 tons/ha. The maximum concentration of potassium (1.22%), nitrogen (4.73%) and iron (208 mg/kg) in the flag leaf was observed when rice was grown in the high levels of rice straw and particularly its biochar. Also, the concentration of silicon, manganese and zinc in the flag leaf increased with the increase in the levels of rice straw and its biochar. By increasing the use of rice straw and its biochar, the number of tillers, plant height, panicle length, weight of 1000 seeds and the number of filled seeds increased significantly. The combined use of rice straw and its biochar increased the rice grain yield, indicating a 1.78 times increase in the treatment of 2 tons/ha of rice straw biochar + 4 tons/ha of rice straw (S2B2) compared to the control. Therefore, it can be concluded that the application of 2 tons/ha of biochar and 4 tons/ha of rice straw can lead to the maximum grain yield by increasing the concentration of nutrients in the flag leaf and improving the growth and yield components of rice.

Drought is one of the major factors limiting productivity in agriculture and nutrition management, including the use of potash fertilizers, plays an important role in plant resistance to drought. In order to evaluate the quantitative and qualitative characteristics of forage amaranth in comparison with forage millet, a split factorial experiment was designed and conducted in a randomized complete block design with three replications in 2016 and 2017 in Saadatshahr region of Fars province. In this experiment, three irrigation intervals (5, 10 and 15 days) were used as the main factor, potassium fertilizer (50, 100 and 150 kg.ha-1) and forage plants (amaranth and millet) as sub-plots. The results of mean comparison of two-year combined analysis showed that amaranth had significantly more height, stem diameter, inflorescence length, number of leaves per plant, dry forage yield, ash percentage, crude protein and carbohydrate content than millet. Increasing the irrigation interval reduced the height, stem diameter, inflorescence length, number of leaves per plant, 1000-seed weight, percentage of crude fiber, dry matter yield, ash percentage, and soluble carbohydrates. By increasing potassium fertilizer level, plant height, stem diameter, inflorescence length, number of leaves per plant, percentage of crude fiber, dry forage yield, ash percentage, crude protein percentage, ADF percentage and NDF percentage in the plant decreased. In general, it can be concluded that amaranth plant has higher yield and drought tolerance than millet and the application of 150 kg.ha-1 of potassium fertilizer can be recommended to achieve higher yield.

Natural biostimulants such as seaweed and humic acid may have positive effects on germination. Seaweed extract comprises high and low consumption elements, amino acids, plant growth regulators, and vitamins which increase root absorption and improve the quality and compounds of antioxidants. Humic acid is a mixture of sources such as soil, humus, oxidized lignite, coal and etc. Nutrients are essential for the growth and development of plants which are consumed in lower amounts. This current study was conducted to investigate the effects of biostimulants of seaweed and humic acid and some nutrients on seeding and other related traits in soybean. The current study showed that biostimulants of seaweed extract and humic acid and some nutrients had positive effects on germination.

Drought, being the most common abiotic stress, is a major factor in crop yields as it limits crop production on a global basis. To evaluate the effects of foliar application with potassium (K) and zinc (Zn) in the pollination stage on morphological and physiological characteristics of wheat under water stress conditions, a split-factorial layout based on a randomized complete block design (RCBD) with three replicates have been carried out at the experimental farm of the Research, Education and Extension Center of Agriculture and Natural Resources of Hamadan during 2017-2018. The main plot includes irrigation levels (normal and water stress) and the subplot, two factors of foliar application of potassium (K) and zinc (Zn) fertilizers. Potassium fertilizer from K2O source (40%) includes 2 liters per ha at three levels; I) without fertilizer (the control), II) leaf spray at the beginning of booting, and III) leaf spray after pollination. Also, zinc fertilizer from water-soluble zinc source (10%) includes four liters per ha in three levels: I) without fertilizer (the control), II) leaf spray at the beginning of booting, and III) the use of leaf spray after pollination. The results of the analysis of variance show a significant difference between treatments in all studied traits. Significant differences in all of the traits are observed under stress and normal irrigation. Co-application of potassium (K) and zinc (Zn) fertilizers, compared to the control, has increased evaluated morphological indices of HI (21%), grain yield (52%), total yield (29%), and TKW (25%) under stress conditions. Therefore, according to the results, the use of K and Zn fertilizers as a foliar application at the beginning of booting reduces the harmful effects of drought stress on the plant, increasing the yield and morphological characteristics of wheat.

Chickpea is known as a plant with high nutritional and economic value; however, it is sensitive to salinity stress. Nowadays, a lot of research has been done to identify cultivars tolerant to salinity stress in chickpeas to increase their yield in saline soils. In general, due to the economic value of chickpeas, including chickpea as an important and useful food for humans, the need to grow chickpeas in areas that are less stable and obtained for resources, soil and cultivars of salt-resistant chickpeas selection of salt-resistant cultivars is needed. Results In the present study, 72 cable-type chickpea genotypes were selected and studied in terms of tolerance to salinity stress.

In this study, seeds of 72 chickpea genotypes were prepared from the seed bank of the Plant Science Research Institute of Ferdowsi University of Mashhad and cultivated in a greenhouse under hydroponic conditions. The study was conducted in a completely randomized design with three replications at salinity stress of 12dSm-1sodium chloride (NaCl) one week after grow. Four weeks after stress, different characteristics were examined.

The results showed that 53 genotypes (equivalent to 74%) were in the range of survival of more than 76% and most of them had 100% survival. Also, none of the genotypes survived less than 25%. Most genotypes were in the vegetative stage at harvest time and only MCC1299, MCC1254, MCC1134, MCC1058 and MCC1037 genotypes were in the flowering stage and had a survival range of more than 75%. As the survival percentage increased, the number of lateral branches increased. Leaf survival percentage in the survival range of 75-51% showed the highest value of this index (76.78%). The highest amount of sodium (11.09 mg. g-1. DW-1) was observed in the survival range of 75-51%. But the amount of potassium showed an insignificant decrease with increasing survival percentage. With an increasing survival percentage, the amount of dry weight increased significantly and increased from 50-26 to 75-51 and 100-76% by 1.6 and 1.8 times, respectively. The results of cluster analysis showed the relative superiority of the forth group genotypes including MCC1058, MCC1291 and MCC1296 in most of the studied traits.

In general, the results indicate that the genotypes belonging to the fourth group are more suitable to use their superior traits in tolerance to salinity stress.

Tritipyrum lines are obtained from a cross between durum wheat and Thinopyrum bessarabicum (2n=2x=EbEb) and its tolerance to salinity has been reported. Tritipyrum (2n=6x=42, AABBEbEb) is the third new man-made grain after triticale and tritordium, and needs further studies until release as a commercial cultivar. Therefore, this study was designed to investigate the effect of salinity stress on the amount of sodium and potassium in roots and leaves, the ratio of potassium to sodium in roots and leaves, the amount of soluble protein, soluble sugar and proline in a number of primary and combined tritipyrum lines.

In this study, 13 promising of primary and combined tritipyrum lines were tested in a factorial experiment based on completely randomized design with 3 replications. The first factor includes salinity levels (0, 80, 160 and 240 mM of sodium chloride salt) and the second factor includes 13 promising of primary and combined tritipyrum lines and 2 bread wheat varieties of Alvand and Qods (tolerant and sensitive to salinity, respectively). Measurement of sodium and potassium elements of leaves and roots was performed one month after salinity stress and the amount of proline, leaf soluble protein and leaf soluble sugars were also measured.

The results showed that with increasing salinity stress, root potassium decreased but root and leaf sodium increased. Levels of proline and soluble sugars also increased with increasing salt concentration. At 240 mM salinity stress, the highest amount of leaf potassium belonged to Ka/b and La(4B/4D)*b lines and the lowest amount of it belonged to Az/b, (Cr/b)(Ka/b)F3 lines and the Qods variety. The highest ratio of leaf potassium to sodium was belonged to (Cr/b)(Ma/b)F3, La(4B/4D)*b and St/b lines and therefore these lines are more tolerant to salinity stress. At 240 mM salinity stress, the highest leaf protein belongs to the Az/b line and the lowest value belongs to the (Cr/b)(Ma/b)F3 line. In both stress and non-stress conditions, the highest genetic variance belonged to leaf protein and the amount of this variance in stress conditions was much higher than non-stress conditions. The environmental variance of root and leaf sodium and leaf potassium traits was higher in salinity stress conditions than in non-stress conditions, which indicates that it will be more difficult to evaluate genotypes for stress traits under stress conditions. Phenotypic variance of root and leaf sodium and leaf potassium as well as leaf protein in salinity stress conditions was higher than non-stress conditions, i.e. the above traits are not suitable for selection. The highest general heritability in normal conditions belonged to proline and in stress conditions belonged to leaf soluble sugar. Under normal conditions, the most significant negative correlation was between root sodium and leaf sodium. There is also a significant positive correlation between leaf protein and soluble sugar. Under stress conditions, there is a significant correlation between leaf sodium and root sodium and also between leaf potassium and proline. There is a significant negative correlation between leaf proline and sodium and the root and leaf potassium to sodium ratio has a significant positive correlation with the amount of proline. The studied genotypes categorized in 3 groups under stress conditions and 4 groups under stress conditions using cluster analysis.

Based on the ratio of potassium to sodium in plant tissues, which is one of the important index for the identification of salinity-tolerant species, we can introduced (Cr/b)(Ma/b)F3 and La(4B/4D)*b and St/b lines as salinity tolerant lines. On the other hand, according to the results, the crossing of genotypes with maximum genetic distances can be used to hybridization and produce more tolerant hybrids in breeding programs.

Sugar beet is one of the most important industrial plants that is grown in various climates. Crop nutrition management is one of the most important factors in increasing the yield and quality of sugar beet crop. In the proper nutrition of the crop, every element should be available to the plant enough, because in the case of nutritional imbalance, adding a number of nutrients in addition to reducing yield, also disrupts plant growth and ultimately leads to a slight reduction. And the quality of the product will be.

This research was conducted in the year 2019 as a split plot based on a randomized complete block design with three replications in two regions of West Azerbaijan province, Khoy and Naghadeh counties. Nitrogen factor at four levels as N1 (fifty percent at planting and fifty percent at 6-8 leaf stage), N2 (fifty percent at planting and fifty percent at 8-12 leaf stage), N3 (1.5 times N1) and N4 (1.5 times N2) in main and boron plots in four levels B1 non-use, B2 soil use, B3 as foliar application in two stages of 6-8 leaves and 8-12 leaves and B4 as foliar application in two stages of 8 and 16-20 leaves in the subplot.

The results showed that in all four levels of nitrogen, root boron accumulated at the B4 level and reached its highest level and the minimum root boron was obtained from plants treated in B1 (control treatment). The highest efficiency of boron treatment in increasing root boron observed in N1. Root yield also increased due to increasing amounts of nitrogen and boron. Application of nitrogen at higher levels resulted in an increase in sodium, potassium, α-amino nitrogen and consequently molasses sugar, which with the increase of root impurities, the percentage of root sugar also decreased. Technological yield of sugar is also dependent on root impurities, which decreased with increasing impurity of technological yield, so that the effect of B4 on increasing the technological performance of sugar was more pronounced in N1 and the highest technological yield of sugar was obtained in N1B4. The coefficient of reduction of sugar productivity in all four levels of nitrogen in Khoy was lower compared to Nagadeh, so that at least it belonged to N3 plants in Khoy.

In general, the results showed that the application of nitrogen at higher levels resulted in increased sodium, potassium, harmful nitrogen and molasses sugar and reduced technological performance of sugar and with increasing boron treatment more sugar was stored in the root and consequently root yield increased.

In order to investigate the application of superabsorbent polymer and potassium sulfate under deficit irrigation condition on quantitative and qualitative yield of sesame, a factorial experiment in a randomized complete block design with three replications was conducted in the research farm of Birjand University in 2018. Experimental factors include three levels of irrigation (full irrigation, irrigation up to 50% of flowering and irrigation up to 50% of capsule emergence), three levels of potassium fertilizer (non-use, application based on fertilizer recommendation and 1.5 times fertilizer recommendation) and two levels of superabsorbent (Zero and 100 kg.ha-1). With stopping irrigation, grain yield, biological yield, harvest index, oil percentage, oil yield and protein percentage decreased but leaf potassium percentage increased. The highest grain yield was under normal irrigation conditions (2342 kg.ha-1) and the lowest was under irrigation conditions at flowering stage (668 kg.ha-1). The interaction effect of irrigation in superabsorbent on grain yield, harvest index, oil percentage and oil yield was significant. Consumption of superabsorbent reduced the negative effects of stress and improved traits. Also, potassium consumption in soil was associated with increased potassium accumulation in leaves. The simultaneous use of superabsorbent and potassium sulfate did not have a significant effect on growth and yield, but the use of potassium fertilizer due to the modification of drought stress and superabsorbent due to its role in reducing the effects of water shortage and improving drought stress tolerance is recommended to maintain yield.

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

Drought stress is one of the most important factors that limiting the growth and yield of plants. In recent years the use of various methods to reduce its negative effects has been considered by many researchers. This experiment was performed as a split plot in the form of randomized complete blocks with four replications in two years. The effect of foliar application of different ratios of magnesium and potassium on the morphological, biochemical and functional characteristics of maize (single cross cultivar 704) in different irrigation cycles (50, 75 and 100 mm evaporation from Class A evaporation pan) was evaluated. The results of analysis of variance showed that the interaction of irrigation and magnesium to potassium ratio on the characteristics of height, stem diameter, ear length, number of seeds per ear, potassium uptake, magnesium uptake, chlorophyll a, chlorophyll b, total chlorophyll, Carotenoids, proline, biological yield, grain yield and harvest index had a statistically significant effect. The results of the study of the effect of potassium and magnesium on morphological and biochemical changes in drought tolerance in maize (Single Cross 704 cultivar) showed that consumption of these elements significantly increased plant height, stem diameter, ear length, number of seeds per ear, uptake rate Potassium, magnesium uptake, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, proline, biological yield, grain yield and harvest index in water deficit conditions; So that the highest value of these traits in evapotranspiration conditions was 50 mm from the evapotranspiration pan and application of 200 kg of magnesium sulfate/ 300 kg of potassium sulfate. Also, foliar application of different concentrations of potassium sulfate and magnesium sulfate by increasing the uptake of potassium and magnesium, preserving leaf chlorophyll, resulting in more effective photosynthesis as well as increasing the concentration of proline in plant leaves, moderate the negative effects of water deficiency and corn tolerance to conditions. Improve water shortage.

Fertilizer management is one of the most important managements to improve production and also to minimize its harmful effects on the environment. The aim of this study was to investigate the effect of optimal and conventional application of nitrogen (N), phosphorus (P) and potassium (K) on the yield of low-yielding (Deylamani and Hashemi) and high-yielding (Fajr and Shirodi) rice varieties. The experiment was conducted as a split plot in a randomized complete block design three replications at a research farms of Sari University of Agricultural Sciences and Natural Resources in 2019. In the absence of any of N, K and P fertilizers, yield of Shiroodi cultivar was 5458, 8399 and 9926 kg ha-1, respectively, and yield of Fajr cultivar was 4894, 7364 and 8903 kg ha-1, respectively. In low-yield cultivars, in the absence of any of N, K and P fertilizers, yield in Hashemi cultivar was 2969, 5134 and 4925 kg ha-1, respectively, and yield in Deylamani cultivar was 3028, 5408 and 5384 kg ha-1, respectively. Optimal application of N, P and K fertilizers caused a significant increase of 82, 65, 55 and 34% of yield in Shiroodi, Fajr, Hashemi Tarom and local Tarom cultivars, respectively, compared with the current application of these three nutrients. The results showed that a suboptimal application of nitrogen, phosphorus and potassium fertilizers is a main limiting factor for rice production, and improving the amount and split application of these fertilizers simultaneously can increase yield by 59% compared to their current application in the region.

Date palm (Phoenix dactylifera L.) is an important fruit crop in arid and semi-arid regions of the world. Today, the development of tissue culture propagation methods has enabled date palm to be rapidly propagated on a large scale. The production of genetically uniform and stable in vitro date palms has a critical importance. Low levels of fruit set and supernumerary carpels were detected in many date palm trees produced by tissue culture, especially in Barhee cultivar which leads to economic losses to gardeners. One of the best tools for date palm reproductive potential studies is the direct application of nutrient elements on inflorescences and fruits. Nutrients, such as boron and potassium on dates yield and fruit quality seems to play an important role in achieving satisfactory fruit set and fruit quality. This study was conducted to investigate the effects of boron and potassium spray on improving the fruit set of tissue culture- derived date palm cv. Barhee in grove of Date Palm and Tropical Fruit Research Center Ahvaz city.

The experiment was conducted in a randomized complete block design with 9 treatments of bunches spraying with nutrients and 3 replications for two years (2018-2019) and each tree was considered as an experimental unit. Experimental treatments included spraying with boric acid at 0.5 and 1% , potassium sulfate at 2 and 3% as individual application or in a combination between boric acid and potassium sulfate concentrations treatments and control (distilled water). All treatments were replicated three times: 2 hours before pollination, 2 and 5 days after pollination. In 5th weeks after pollination, fruit set percentage, parthenocarpic fruits percentage and flower and fruit drop percentage were recorded.

Analysis of variance showed that that bunches spraying with potassium and boron significantly increased fruit set, yield and fruit physical characteristics i.e. weight, volume, length and diameter of fruit and TSS (%) compared with the control treatment. Among the different treatments, potassium sulfate at 2% was more effective in improving fruit set and reducing parthenocarpic fruits (seedless) than other treatments. Increasing fruit yield due to boron or potassium may be attributed to their effect an increasing fruit set. Increasing fruit set due to boron may be attributed to its role in maintaining high pollen viability, germination, and pollen tube elongation. Applying the potassium element has a role in controlling cell water content and carbohydrates biosynthesis and mobilization in plant tissues, consequently, carbohydrates play a serious role in fruit set and retention.

Boron and potassium nutrients play an important role in fruit set, fruit retention and development and cause efficient yield and quality improvement. Our results revealed that spraying Barhee date palm inflorescences with boric acid and potassium sulfate as individual had a positive effect on fruit set, yield and fruit quality.

A two-year field experiment was conducted in flooded rice fields of Islamic Azad University, Astara Branch in 2018-2019. Experiments in the form of randomized complete blocks in two places (in saline and normal soils) and experimental treatments including inoculation with plant growth-promoting microorganisms at five levels (Pseudomonas putida; Pseudomonas fluorescent; Arbuscular mycorrhiza; P. putida + P. fluorescent + mycorrhiza; as well as a non-inoculation treatment as a control). The results of the combined analysis showed that the effect of microorganisms and soil salinity on sodium (Na+) and potassium (K+) concentrations of roots, stems, young and old leaves, and yield and yield components were significant. Soil salinity increased Na+ concentrations in roots, stems, young and old leaves, while microorganisms significantly decreased Na+ concentrations in all organs except roots and increased K+ concentrations in them, especially in young leaves. Also, microorganisms increased rice grain yield in normal soil by 34% -25% in the first year and 67% -21% in the second year and in saline soil by 45% -22% in the first year and 67% -45% in the second year compared to the treatment. Witnesses increased. Among microorganisms, except P. putida, other microorganisms showed significant superiority over control in most of the measured traits. In general, P. fluorescens + AM fungi + P.putida inoculation is recommended for rice cultivation in saline soils of northern Iran.