جستجوی مقالات مرتبط با کلیدواژه "nutrient elements" در نشریات گروه "زراعت"

In order to increase the quantity and quality of plant production in sustainable agriculture system, the co-application of organic and inorganic (chemical) fertilizers are in great importance. The co-application of organic and chemical fertilizers could potentially increase both plant growth and crop yield by improving the soil quality properties and enhancing the uptake of plant nutrients. In this approach, a proportion of needed plant nutrients is supplied by the chemical fertilizers and the rest is provided by organic fertilizers. Meanwhile, in this study the co-application of the organic i.e leonardite, vermicompost and black soils and their extracted humic acid and the inorganic fertilizers were studied. The main objective of this study was to investigate the effect of co-application of some organic amendments and chemical fertilizer on yield, yield components and concentration of some nutrients in green pepper.

To investigate the effect of co-application of some organic amendments on the yield and yield components of green pepper, a split-plot design over randomized completely design in three replications at pot-experiment level was conducted in 2019 growing season. In this experiment, the main factors include three types of organic amendments (leonardite, vermicompost and black soil) and sub-factors were 14 levels including (control, chemical fertilizer treatment (NPK) according to soil test, leonardite in three levels (2.6, 5.2 and 7.8 ton ha-1), extracted humic acid from leonardite in three levels (2.6, 5.2 and 7.8 kg ha-1), leonardite at the level of 2.6 (ton ha-1) with 75 % of needed chemical fertilizer (NPK), leonardite at the level 5.2 (ton ha-1) with 50 % of needed chemical fertilizer, leonardite at the level of 7.8 (ton ha-1) with 25 % of needed chemical fertilizer, extracted humic acid from leonardite at the level of 2.6 (kg ha-1) with 75 % of needed chemical fertilizer, humic acid extracted of leonardite at the level of 5.2 (kg ha-1) with 50 % of needed chemical fertilizer and the humic acid extracted of leonardite at the level of 7.8 (kg ha-1) with 25 % of needed chemical fertilizer were considered. Furthermore, all sub-surfaces for vermicompost and black soil treatments were similar to those for leonardite treatment.

The results indicated that co-application of organic amendments and chemical fertilizers and its interaction effect had significant effects on yield, yield components and concentration of nitrogen, phosphorous and potassium of green pepper fruit. Application of extracted humic acid from leonardite (2.6 kg ha-1) with 75 % of NPK was able to increase yield of pepper, plant height, leaf area and total leaf chlorophyll 6, 1.7, 2.3 and 2.7 time compared to the control. Also, the highest amount of nitrogen, phosphorus and potassium of green pepper fruit increased by 7, 2.8 and 2.9 times in the above treatments compared to the control, respectively.

The co-application of organic fertilizers and/or extracted humic acid with chemical fertilizer increase the concentration of high elements such as nitrogen, phosphorus and potassium in green pepper fruit as well as vegetative traits such as plant dry weight, plant height, chlorophyll content and leaf area in green pepper. In fact, leonardite and extracted humic acid due to the increased root uptake and the chelating ability of the element, will make these elements more available to the plant. In general, the combined application of humic acid and chemical fertilizers (NPK) due to the richness of nutrients required for plant growth of green pepper compared to the control treatment.

Soil contamination with heavy metals is one of the most serious problems in the agricultural environments. Due to excessive injudicious and unregulated use of agrochemicals such as pesticides, bactericides and fungicides, which contain Cu as an active component, contamination of agricultural soils with Cu is often occurred. In many plant species, excess copper (Cu) toxicity is an important disorder that limits uptake and accumulation of mineral nutrients. The root system of crops in contact with the roots of neighbor plants (crop or weed) has different characteristics in terms of heavy metals adsorption compared to the pure stand of crops. The position of the roots of heavy metal accumulator weeds may affect the absorption of such metals by adjacent crops in infected conditions. The heavy metal accumulator weeds by reducing or evacuating metals from the rhizosphere of the adjacent plants, cause the plants to be immune to the toxicity of metals. Biomass reduction is a dominant effect of copper toxicity in plants. Application of high copper doses (50 and 75 µM) in nutrient solution, decreased the dry weight of common bean plants in comparison with control. Contamination of soil can affect ecological interactions between plants such as the weed-crop competition. Positive plant-plant interactions are expected to be especially beneficial under high abiotic stresses and therefore, the facilitation effects could be enhanced by increasing stress intensity. Weeds possess the ability to accumulate heavy metal and nutrients, in comparison with crops. The role of nurse plants in facilitating plant community has been applied in severe conditions. Metal hyper-accumulator plants have a positive effect on co-occurring species in met al-rich soils. Redroot pigweed (Amaranthus retroflexus L.) is a serious weed, which affects common bean production. Amaranthus retroflexus and Amaranthus spinosus are known as metal accumulators. We hypothesized that in contaminated fields, the effects of heavy metals on crop growth may be modified by the presence of a metal accumulator weed such as redroot pigweed.

To investigate copper uptake and accumulation of mineral nutrients by common bean in association with redroot pigweed under excessive copper conditions, a factorial experiment based on a completely randomized design with four replications was carried out in a research greenhouse of Bu-Ali Sina University in 2016. Experimental factors were three Cu doses of 1 (control), 25 and 50µM CuSO4 and five replacement intercropping ratios of bean (B) and redroot pigweed (P) (1B: 0P, 0.75B: 0.25P, 0.5B: 0.5P, 0.25B: 0.75P, 0B:1P). The experiment was carried out in a hydroponic condition. 15 days after seedling establishment, the seedlings of both plants were transferred to the hydroponic conditions with a Hoagland solution, and Cu doses were applied in the Hoagland solution. 30 days after growing the plants in above condition, biomass dry weight and concentration of Cu, K, P and Mg in the leaves and roots of both plants as well as copper translocation factor were determined.

The results showed that under three doses of copper, the highest concentration of copper in bean was obtained in sole crops, and with increasing replacement intercropping ratios of pigweed, the copper concentration was decreased in bean. In pigweed, the highest concentration of copper was observed in 0.75B: 0.25P proportion. At 1µM CuSO4, potassium concentration in the roots and the leaves of bean in 0.25B: 0.75P proportion, was decreased by 7 percentage in comparison with that of the sole crops, and at 25 µM CuSO4, by 10 percentage and at 50 µM CuSO4, by 15 percentage were increased compared to the sole crops, respectively. At 25 µM CuSO4, phosphorus and magnesium concentration in the roots of bean in 0.25B: 0.75P proportion was increased by 17 and 18 percentage, and at 50 µM CuSO4, by 21 and 26 percentage, respectively in comparison with the sole crops, respectively. Association of pigweed to the bean, decreased Cu pollution in bean plants, which could be related to the balance of nutrient elements uptake by bean under excessive copper conditions. Under excessive copper conditions, the higher copper uptake by pigweed, improved the growth of bean.

The results of this study showed the facilitative effects of pigweed plant in decreasing the Cu toxicity stress effects to the bean and indicated that pigweed could be as a potential Cu accumulator to improve bean plant growth under the Cu stress. Here we showed that the presence of some heavy met al accumulator plants such as pigweed in common bean farms, might be a useful practice in contaminated soils. In addition, these facilitation effects of such weeds, emphasize ecological management of weeds rather than weed eradication.

Salinity stress is one of the factors reducing yield and production in crops, horticulture and medicinal plants in the world. One of the suitable solutions for improving salinity tolerance in horticultural products is the use of arbuscular mycorrhiza. They have the stimulant effect of plant growth. They increase resistance to drought stress, salinity, pathogenic agents, soil contamination and heavy metals by increasing the absorption of nutrients such as phosphorus, nitrogen and some elements of low consumption, increasing water absorption and production of hormones.

In order to evaluate the effect of mycorrhizal fungi on morphophysiological and biochemical characteristics of Mexican marigold (Tagetes minuta) under salinity stress, a pot factorial experiment based on completely randomized design with three replications was performed in the horticulture greenhouse of Agriculture Faculty, Ferdowsi University of Mashhad in 2017. The first factor using mycorrhizal fungi at three levels (without inoculation, Rhizophagus intradices and Funnetiformis mosseae) and the second factor included four levels of irrigation with salinity water (0, 40, 80 and 120 mM NaCl. The inoculum of mycorrhiza was mixed before planting the seedlings. Afterwards, the seedlings were transferred to the pot. Saline treatment was started at the four-leaf stage and performed three days a week. Saline treatment was done forty days. Measurement of the traits was performed forty days after beginning stress on the plant. The plant height, number of lateral branches, number of nodes, stem diameter were measured. Also, at the end of the experiment, nitrogen, sodium, potassium, magnesium, iron, phosphorus, manganese, zinc, calcium and chlorine were measured.

The results showed that all of the growth characteristics significantly decreased under salinity and application of mycorrhiza cause to adjustment harmful effects of salinity and tolerance of plant to salinity. The highest nodule number (12.89), stem diameter (7.49 mm), height (65.75 cm) and lateral branches number (23.33) were obtained at the treatment without salinity with using mycorrhizal fungus Rhizophagus intradices. Salinity increased the amount of phosphorus, calcium, sodium, chlorine and nitrogen in the leaf and decreased the amount of potassium, manganese, zinc and leaf iron. The highest amount of phosphorus of leaf (8.5 mg / g of leaf dry weight) was observed in the highest salinity stress and application of Funnetiformis mosseae, the highest sodium content (12.33 mg/g leaf dry weight) and chlorine (63.09 mg Kg dry weight of leaves) was observed in 120 mM salinity without mycorrhizal. However, the highest amount of potassium (6.23 mg /g leaf dry weight) was observed in the treatment without salinity and without mycorrhizal application, the highest amount of manganese (143.91 mg/kg dry weight) in 40 mM salinity and application of Funnetiformis mosseae and the highest amount of zinc (7.12 mg/kg dry leaf) were recorded in salt free treatment and application of Funnetiformis mosseae. Salinity stress reduces cell growth through restrictions on the absorption of nutrients, plant nutrient deficiency and toxicity of food elements. In addition, salt stress reduces the production of carbohydrates and thus reduces the growth of various plant components. The higher the salt concentration, the more significant the growth is. Mycorrhizal plants have better growth compared to non-microscopic plants in soil salinity conditions. Mycorrhiza fungus stimulates plant growth by increasing the absorption of nutrients such as phosphorus, nitrogen, and some elements of low consumption, increasing water absorption and production of plant hormones and increasing plant resistance under stress conditions.

The results showed that all vegetative traits reduced due to salt stress and mycorrhizal application reduce the harmful effects of salinity and increase the resistance of the plant to salinity. Mycorrhizal has an irritating effect on plant growth. Increases plant resistance to salinity by increasing the absorption of nutrients such as phosphorus, nitrogen and some elements of low consumption, increasing water absorption and production of plant hormones. According to the results of this study, the use of mycorrhizal is an appropriate strategy to increase the resistance to salinity in plants.

Oil of linseed are used in various industries. linseed seeds contain bioactive components which reduce formation of cancerous colonies. Drought is one of the factors that reduces the crop production in most part of the world. These days several techniques are used in order to increasing plants tolerance to drought. One of these methods is seed pretreatment with plant growth promoting bacteria. These bacteria through mechanisms such as phosphate and potassium dissolution, nitrogen fixation, production of siderophore and growth regulators, production of hydrolytic enzymes and exopolysacharides increase tolerance and yield of crops under stressful conditions. Since water deficit is one of the main limiting factor of production in Iran and the use of chemical fertilizers caused much environmental pollution, so this study was conducted to investigate the effect of bio fertilizers as plant growth promoting bacteria on linseed under water deficit condition.

This study was carried out in split plot experiment based on randomized complete block design with three replications in 2015 at the research farm of Shahrekord university. Factors were irrigation in three levels (full irrigation, 75 and 50 percentage of full irrigation) and bacteria in seven levels (control, Bacillus sp strain1, Bacillus sp strain2, Bacillus amyloliquefaciens, Azotobacter Chroococcum, Pseudomonas putida and Azospirillium lipoferum). Applying of stress began from stem elongation. In ripening stage, grain yield and amount of P, Fe and Zn nutrients in grain were measured. After crop harvesting EC, pH, P, Fe and Zn of soil also were measured. Analysis of variance and correlation between traits used by SAS software, means comparison by LSD and interaction were carried out by slicing.

Interaction of irrigation and bacterial inoculation on grain yield, P percentage and concentrations of Fe and Zn in grain and soil EC were significant. Bacterial treatments in three irrigation levels showed the highest grain yield, P percentage in grain, concentrations of Fe and Zn in grain and soil EC while control treatments showed the lowest amount. Amount of nutrients in soil increased by increasing stress levels. Also, bacterial treatments had the lowest nutrients of soil in comparison with control treatment. Among bacterial treatments Bacillus sp strain1, Bacillus amyloliquefaciens and Azotobacter Chroococcum were more effective while Azospirillium lipoferum was not. Significant negative correlation between P percentage in grain and concentrations of Fe and Zn in grain with concentrations of P, Fe and Zn in soil was observed.

The use of plant growth promoting bacteria by increasing nutrients absorption from soil can increase grain yield. In fact, growth promoting bacteria by absorbing soil nutrients and contributing their absorption by plant may reduce the amount of soil nutrients.

 In a sustainable agricultural system, the utilization of organic matters such as humic acid had the minimum damage to the environment and with its hormonal like activity; it can absorb water, mineral nutrients, and ultimately increase crop yields. To investigate the effect of humic acid on quantitative yield and some qualitative characteristics of sunflower (Var. Farrokh Hybrid) under drought stress, a split-plot experiment was conducted in a randomized complete block design with three replications at Shahroud Agricultural Research Center, Shahroud, Iran. Treatments were three levels of drought stress: control (irrigation by 100% water requirement), mild stress (irrigation by80% water requirement) and high tension (irrigation by 60% water requirement) as the main plots and five levels of humic acid: control (no humic acid), two concentrations of foliar application (1.5 and 3 gr/ liter of water), two levels of field application (15 and 30 kg/ha) as a subplots. Results showed that drought stress reduced grain yield (45.5%), 1000-seed weight (26.7%), head (23.3%) and stem diameters (25.9%), biological yield (44.6%), seed phosphorus (16.2%), and leaf chlorophyll “b” (50.7%) and carotenoids (29.8%). Foliar and soil applied humic acid had significant effects on plant height, head diameter, grain yield, biological yield, chlorophyll “a,” and P and K percentages in seeds and increased them. According to the results, it can be concluded that the application of humic acid can reduce the effects of drought stress on sunflower. At first, the application of 30 kg/h of humic acid and next, 1.5 gr humic acid /liter of water had the highest efficiency in improving the sunflower yield under water stress conditions.

Severe water shortage is one of the major challenges of agricultural sector in arid and semi-arid region. Optimal use of water resources, along with improving the efficiency of nutrient elements under drought conditions, will increase or stabilize crop yield. Forage production using plant species with low water requirement and adapted to low quality waters is a sustainable strategy for fodder production in dry areas. Blue panic grass (Panicum antidotale Retz.) is a halophytic crop plant, which is water productive and adapted to tropical conditions. This study was carried out to investigate the effects of drought stress, nitrogen and potassium on some physiological characteristics and dry matter yield of blue panic grass in Birjand, South-Khorasan province of Iran.
  This study was conducted as a split-factorial experiment with three replications using a randomized complete block design at the Research Field of Islamic Azad University of Birjand. Irrigation was considered as the main factor at three levels based on cumulative evaporation from evaporation pan class A (70, 140 and 210 mm), nitrogen fertilizer was applied in three levels based on soil test including zero, 50% (100 kg ha-1) and 100% (200 kg ha-1) of recommended N. Potassium was applied in two levels (zero and 100 kg ha-1). Blue panic grass is perennial and in the first year, most of the photosynthetic assimilate are being used for the establishment of the plant; Hence, treatments were imposed in the second year of the experiment. During the growing season, radiation use efficiency and water use efficiency calculated three times during the growing season. Dry matter accumulation was measured at the final harvest. In addition, nitrogen use efficiency and agronomic nitrogen efficiency were calculated based on the consumed nitrogen fertilizer during the growing season and total dry matter harvested during the growing season.
  Results showed that under water stress conditions the radiation use efficiency decreased, while, water use efficiency increased. We concluded that providing enough water and nutrients can increase dry matter production and radiation use efficiency. Application of nitrogen and potassium fertilizers under severe water stress conditions led to an increasing water use efficiency. Application of higher levels of nitrogen reduced nitrogen use efficiency.
  Blue panic grass showed good performance under water stress conditions. Results indicated that application of nitrogen and potassium fertilizers under water stress conditions could mitigate the adverse effects of drought stress and increase nitrogen and water use efficiency.

Excessive application of chemical fertilizers can lead to poor soil and groundwater quality and severe nutritional disturbances on the land and environmental damage. In recent years, increasing concern about the production of healthy food and the emphasis on maintaining fertility and soil quality have led to more attention to maintaining and increasing soil organic matter through appropriate management practices. Management of crop residues can play pivotal role in improving soil productivity and quality as well as crop yield through its effects on soil physical, chemical and biological properties. Soil quality, generally, indicates the ability of the soil to function as an ecosystem by preserving fertility, environmental quality and enhancing the health of plants and creatures which is always under the influence of management operations. Hence, soil quality assessment methods allow quantitative biological, chemical and physical responses of soil to be compared to different management practices. Soil quality assessment is a very complicated process due to the different soil properties in different management conditions. To investigate the effect of various managements of wheat and sugar beet residues on some chemical and biological properties of soil, two distinct experiments were carried out in a completely randomized design with three replications. Treatments of first experiment included control (CW), wheat residues retained on soil surface (W), wheat residues incorporated into soil with plowing (PW), wheat residues incorporated into soil with plowing plus urea fertilizer (PFW), wheat residues burnt (BW) and wheat residues burnt is followed by incorporating into soil with plowing (PBW). Treatments of second experiment were including control (CS), sugar beet residues retained on soil surface (S), sugar beet residues incorporated into soil with plowing (PS) and sugar beet residues incorporated into soil with plowing plus urea fertilizer (PFS). In W and S treatments, the remained plants were distributed uniformly throughout the plot. In PW and PS treatments, the remained plants were mixed with soil by plowing to a depth of 30 cm. In PFW and PFS treatments, plant residues with urea fertilizer (4 tons per hectare) were added to soil surface and then plowed. In BW treatment, wheat plant residues were distributed uniformly in plot and then the burning was performed manually. In BPW treatment, plant residues were mixed with soil after burning by plowing. After applying the experimental treatments, all plots were irrigated in the same way. Irrigation intervals were applied to the plots similar to the adjacent plots and were irrigated regularly during the experiment period. After 6 months of application of the treatments, sampling of the treatments was carried out using a systematic method, consisting of plowing depth (0 to 25 centimeters of soil). Results showed that various managements of wheat and sugar beet residues caused significant changes in studied chemical (except pH) and biological properties. All management methods, except retention of residues on soil surface (C and S treatments), increased organic carbon, total nitrogen, available phosphorus and potassium compared with the control treatment. Generally, in both crop residues, the greatest content of organic carbon, total nitrogen and available potassium were related to incorporating residues into soil with plowing plus urea fertilizer (PFW and PFS treatments). Also, the highest content of available phosphorus was related to PBW and PFS treatments in wheat and sugar beet residues management, respectively. In the case of basal microbial respiration and microbial biomass carbon, the most effective managements were residues incorporation into soil with plowing (PW and PS treatments) and then residues incorporation into soil with plowing plus urea fertilizer (PFW and PFS treatments). In this study, although residues burning (BW and PBW treatments) improved nutrient content, microbial respiration and microbial biomass carbon compared with the control treatment, they were less effective than PW and PFW treatments. According to the results, in both wheat and sugar beet residues, the most appropriate managements to improve the soil quality indicators were to incorporate the residues into soil with plowing plus urea fertilizer, as well as only incorporating the residues into soil with plowing. The results showed that the use of a minimum set of properties affecting soil quality or MDS can determine the soil quality with reasonable accuracy and cost and time less in the studied soil.

In order to study the effects of drought stress and foliar application of iron oxide nanoparticles on sesame plants, a field experiment was laid in Faculty of Agriculture, University of Shahrood in 2014. The design of experiment was in split plot with blocks completely randomized in three replicates. Drought stress, W1=7, W2=12 and W3=17 irrigation time, were randomized in main plots with four concentrations of foliar application of iron oxide nanoparticles, F1 = 0, F2 = 0.5, F3 = 1 and F4 = 1.5 kg at 1000 l water, in sub-plots. Results showed that the interaction between drought stress andiron oxide nanoparticles had significant effect on grain yield, biomass, leafstomatal conductance, chlorophyll "b" and carotenoids content in leaves, and seed nitrogen. The results indicated that the highest grain yield and biomass were obtained at W1F3, stomatal conductance at W1F2, chlorophyll "b" at W1F4, carotenoids at W2F3 and seed nitrogen at the W3F3 treatments. Moreover, the number of branches per plant and the concentration of potassium in seeds were significantly affected by both treatments. However, phosphorus in seeds, and potassium and phosphorous in leaves remained unchanged under treatments. Number of seeds and seed weight per capsule decreased about 12.3 and 27.7%, respectively by worsening the drought condition from W1 to W3. In general, it can be stated that in the drought stress condition, foliar application of iron oxide nanoparticles about 1 kg per thousand liters of water improves the physiological characteristics of sesame and grain yield.

Deficiency of soil nutrient elements is one of the most important restricting factors of crop production. Hence, management of nutrition is necessary for optimizing of plant growth, yield increment and sustainability of crop production. In order to evaluate growth stages and some quantitative indices in winter rapeseed (Brassica napus L.) cultivars as affected by micronutrient fertilizers, a field experiment was performed in 2010-2011 cropping seasons as a split plot arranged in randomized complete block design with three replications in Arak, Iran. Eight micronutrient fertilizers (Zero as control, Fe, Zn, Mn, Fe + Zn, Fe + Mn, Zn + Mn, Fe + Zn + Mn) and four rapeseed cultivars (Zarfam, Okapi, Modena and Licord) were randomized in main plots and subplots, respectively. The result showed that, Okapi cultivar had the highest grain yield under no fertilization treatment (4194 kg/ha) and Zn + Mn (4011 kg/ha) treatments, respectively. Licord cultivar produced the highest grain yield (3998 kg/ha) at Mn treatment, but there were no significant differences between fertilizer levels. Okapi variety showed the highest biological yield as affected by Fe + Zn (13666 kg/ha), Zn + Mn (13221 kg/ha) and control (12944 kg/ha) treatments, respectively. In this experiment, the interaction between Licord Mn, Licord (Fe + Zn + Mn) and Okapi (Fe + Zn + Mn) had the highest harvest index (35.46, 34.77 and 32.23 percent), respectively. In addition, the interaction between Licord (Fe + Zn + Mn) showed the highest silique number (369.86) per plant. In general, seed yield and its component in rapeseed varieties showed different responses to micronutrient fertilizers. According to the results of this experiment, cultivation of Okapi and Licord varieties and application of Mn and Mn + Zn fertilizers cased to enhance seed yield of canola in Arak climatic conditions.

To investigate the combined effects of arbuscular mycorrhizae fungus and salicylic acid on nutrient uptake and distribution of Abareqi Pistachio seedlings under drought stress, an experiment was conducted using a completely randomized design with two mycorrhizae treatments (with or without mycorrhiza), three salicylic acid levels (0, 0.5, 1mM) and four drought stress levels (irrigation with 1, 3, 6 and 10 days intervals). The results indicated that drought strees increased total and shoot K, Fe, Zn, Cu and shoot Mn significantly but it decreased root K and Mn and shoot P. Mycorrhizal application increased total and shoot K, P, Fe, Zn and Cu but reduced root Fe and root and shoot Mn. Salicylic acid application increased total and shoot k but reduced root K, Cu and Mn and total and root Fe and Zn. Mycorrhizal symbiosis had the main role in elements uptake and distribution of K and P while salicylic acid application had a little effect on elements absorption and movement. The maximum amount of shoot K was obtained with mycorrhizae and salicylic acid at 1mM concentration. With respect to the role of K and P in drought resistance, it could be concluded that the use of mycorrhiza alone and in combination with salicylic acid, in part, played a positive role in drought tolerance of Abareqi pistachio seedlings.

In order to investigate the effect of different levels of nutrient solution concentration and times and frequencies of foliar applications on dry weight, nitrogen, phosphorus and potassium concentrations of leaf and corm of saffron, a pot experiment was conducted as a completely randomized design with factorial arrangement and three replications under open door conditions in research garden of ferdowsi university, faculty of agriculture. The experimental treatments were included 4 levels of solution concentration (0, 4, 8 and 12 per 1000) and 7 levels of time and frequency of foliar applications (F1: foliar application on th February, F2: foliar application on 18th February, F3: foliar application on 5th March, F4: foliar applications on 3th and 18th February, F5: foliar applications on 3th February and 5th March, F6: foliar applications on 18th February and 5th March, F7: foliar applications on 3th and 18th February and 5th March). Results of variance analysis showed that fresh and dry weight of corm and leaf were not influenced by concentration, time and frequency of foliar applications. Also, comparison of nitrogen, phosphorus and potassium concentrations of leaf and corm showed that there was no significant difference between levels of foliar treatments and control. Therefore, it seems that due attention to pattern of leaf and low nutrient demand of saffron, foliar applications in different levels of nutrient solution concentrations and times and frequencies of foliar applications could not increase vegetative growth and consequently, could not improve the growth and nutritional properties of saffron corms.

Vermicompost can improve physicochemical traits of soil having desirable effect on plant growth and development due to its structural traits and having macro and micro nutrients، plant growth regulators and favorable microorganisms. In order to investigate the effect of interactions between ratios of vermicompost and saline stress on some morphological، physiological and biochemical traits of Phaseolus vulgaris L. cv. Light Red Kidney cultivar، an experiment was conducted in randomized complete block design with three replications at the Research Greenhouse، Faculty of Agriculture، Ferdowsi University of Mashhad، in 2010. The treatment levels were considered including five volumetric ratios of vermicompost and sand (0:100; 10:90; 25:75; 50:50 and 75:25) and four saline levels including 0. 00 (control)، 30، 60، 90 and 120 mM NaCl. Bean seeds were cultured in plastic pots، the seedlings being sampled 28 days later. The results showed that vermicompost under stress and without stress had significant effect (P≤ 0. 01) on all traits including ratio of leaf area/root area، root/shoot ratio، membrane stability index، relative water content، amounts of sodium، potassium and calcium found in leaf and root tissues. In this experiment، vermicompost caused increase in potassium and calcium intake and decrease in sodium intake، in saline stress، due to its structural traits and the materials it. Therefore، it seems that vermicompost can ameliorate undesirable effects of salinity on bean seedlings.

In the first phase of this research, adaptability of winter rapeseed (Brassica napus L.) varieties was investigated to select high yielding rapeseed cultivars. Accordingly, two field experiments were performed in a randomized complete block design with 15 winter rapeseed varieties in three replications from 2006 to 2008 cropping seasons at experimental field of Agricultural and Natural Resources Research Center of Markazi Province, in Arak, Iran. Results showed that Licord, Modena and Okapi varieties had superiority to other cultivars, respectively. At the second phase of this research, also, two field experiments were carried out from 2008 to 2010 cropping seasons at the same site, in order to evaluate the effects of nitrogen sources on seed yield and content of macro elements in seed of selected high yielding rapeseed varieties. Experimental design was a factorial arrangement based on randomized complete block with three replications. Three rapeseed varieties (V1=Okapi, V2=Modena and V3=Licord) and three sources of nitrogen based on 150 kgN/ha (N1=Compost of Azolla, N2=50% Compost of Azolla plus 50% Urea and N3=Urea) comprised the experimental factors. Results showed that Licord variety had the highest seed yield and seed content of Sulphur. Integrated nutrition system showed superiority to other treatments for seed yield and seed content of macro nutrients such as nitrogen, phosphorus and Sulphur. But, the greatest seed potassium content was observed in N1 treatment. Results showed that integrated application of nitrogen sources increased yield and seed macro nutrients content.