نشریه پژوهشهای زراعی ایران
سال چهاردهم شماره 1 (پیاپی 41، بهار 1395)

Recent evidences confirm that during the next few decades, many agroclimatic indices of Iran would be affected by global climate change. Koocheki et al. using two General Circulation Models showed that the mean annual temperature of the country will increase between 3.5-4.5°C while mean precipitation will reduce by 7-15% to 2050. It is well established that crop growth and development would drastically affect by the future global warming and its consequences because yield determining processes such as photosynthesis and crop phenology are directly related to temperature. On the other hands, the combined effects of CO2 enrichment and temperature rise on crop growth are complicated and should be studied using crop simulation models. Furthermore, adapting to climatic variability will have a substantially greater effect in reducing impacts than willing mitigation. However, such impacts on crop productivity at national scale and adaptive measures for future conditions are rarely studied in Iran. In this research crop development and yield of wheat, corn, chickpea and sugar beet were simulated for the target year of 2050 and the results are compared with the current yield as the baseline.
Future climatic variables were predicted using A1f (business as usual) scenario by GFDL general circulation model and the results were used as weather inputs in the SUCROS model which was previously validated against measured data of the four crops. To account for the effect of CO2 enrichment on crop growth the photosynthesis routine of the model was adopted for increased CO2 concentration using a scaling factor. Changes in developmental stages of each crop were estimated for the future conditions and the relation between duration of these stages and yield was determined. Predicted crop yields for the year 2050 were compared with the current potential yields considering some adaptation strategies.
Results indicated the average over the different regions, yield of wheat, corn, chickpea and sugar beet will be decreased by 18.6, 19.1, 6.6, and 20%, respectively. This decrease is mainly due to temperature rise and only 5.6% of the negative effects of temperature will be compensated by increased CO2 concentration. Regression analysis showed the yield of the studied crops will be reduced between 9 to 17% per 1°C increase in mean temperature during the growing season. For wheat and corn such a reduction would also be expected for the duration of the grain filling period. Based on these results, reduction of the total growing period (planting to maturity) as well as shortened grain filling period are the main causes of the predicted crops yield decline by the target year. On average up to 60% of the yield reduction over the country could be described by global warming and the pattern of the crops yield variation follows the same spatial pattern predicted for temperature rise in 2050. Therefore, adaptation strategies for the future climate should be designed to prevent the negative effects of increased temperature during the sensitive development stages. Simulation results obtained by SUCROS model showed that among different studied adaptation strategies, using new wheat cultivars with higher heat tolerance and changing planting dates are the most efficient management practices and drastically prevent yield reduction under defined future climate scenarios. Use of these readily implemented adaptation strategies is profitable based on the available resources by improving national wheat production compared to the same climatic scenarios without adaptation.
Despite of uncertainties in the predicted results of simulation models, the results of this research indicated that during the next few decades crop yields in different regions of Iran will be reduced due to climate change and more specifically temperature rise. This yield reduction could be more drastic under actual conditions where the effects of climate change will intensify due to biotic and abiotic stresses. However, these negative impacts could be avoided by using proper adaptation strategies.

Cold and freezing are the most important limiting factors on development of sensitive plants. When the ambient temperature deviates from optimal, physiological, and biochemical, metabolic and molecular changes will occur within plants. This is an effort of plants to maximize growth and developmental processes and to maintain cellular homeostasis during such adverse conditions. At the extremes of the natural temperature range of plant, the degree of physiological, cellular, metabolic and molecular dysfunction becomes so severe that it leads to death. Triazoles are the most potent groups of growth retardants with multiple effects. Plant growing with paclobutrazol generally has little effect on rates of net photosynthetic rate. However, because the compound reduces leaf area, net photosynthesis on a per plant basis is probably reduced. They have exhibited growth regulating, fungicidal, herbicidal, apicidal and antibacterial activities. More recently, it was found that triazole compounds are able to increase tolerance of plants to cold and freezing stress. Kochia (Kochia scoparia (L.) Schrad.), an out crossing species whose pollen move between plants in windy areas, has recently been considered as a forage or fodder crop in marginal lands. Steppuhn and Wall (1993) claimed that Kochia offers great potential as a crop that can be grown on saline soils, yielding fodder in quantities approaching that produced by alfalfa (Medicago sativa L.). Shamsutdinov et al. (1996) also reported more than 15 Mg ha-1 dry-matter production for Kochia under saline conditions and concluded that it is a good candidate for forage hay. Thus, the aim of the present study was to determine whether the triazole compounds could increase tolerance of kochia against freezing stress.
An experiment was carried out with hexaconazole and penconazole in 0, 10 and 20 mg.L-1 and freezing temperatures 0, -2, -4, -6 and -8 degree centigrade in factorial based on CRBD with three replications at research greenhouse of college of agriculture, Ferdowsi University of Mashhad in 2009. Plants were kept in natural condition until three weeks after planting, which in this stage they had three leaves, and then treated with fungicide. After 24 hours plants were frozen in thermo gradient freezer, in the dark. At first, the temperature of thermo gradient freezer was five degrees centigrade, and then temperature decreased two degree centigrade per hour. In order to make ice nucleation in plant at -3-degree centigrade ice nucleation active bacteria was sprayed. Plants were keeping an hour in each temperature treatment. In order to balance the ambient temperature, the plants are kept at the desired temperature for one hour and then the pots transport in a cold chamber at a temperature of 5 ± 2°C for 24 hours. The cell membrane stability was measured through electrolyte leakage (EL) and the lethal temperature 50 (LT50el) (according to El) also were determined in the youngest developed leaf from each plant. The electrolyte leakage in the solution was measured after 24 h of floating at room temperature using a conductivity meter. Total conductivity was obtained after keeping the flasks in an oven (75°C) for 90 minutes. Results were expressed as percentage of total conductivity. Survival percentage, plant height, dry weight and (LT50su) (according to survival) were determined after three weeks recovery in the natural condition. The data were analyzed statistically using a two-way ANOVA, applied to the various measured and calculated parameters, followed by a Duncan test for mean comparison between treatments at a 95 % confidence level by MSTAT-C program.
The results showed that increase of fungicide concentration by 10 and 20 mg.L-1 higher than control decreased electrolyte leakage but, electrolyte leakage build-up with decrease freezing temperature. Fungicide application increased -2 °C freezing tolerance in kochia. Increasing fungicide concentration in 10 and 20 mg.L-1 than control causes decreased LT50el from -5.9 to -7.2. Application of triazoles responsible of reduced electrolyte leakage but they did not effect on survival. The use of different concentrations of fungicides hexaconazole and penconazole of photosynthetic pigments in Kochia showed no significant effect. However, the concentration of chlorophyll a and b in the use of fungicides hexaconazole was more than penconazole.
Triazole application initially had a positive effect on the reduction of electrolyte leakage, but survival and re-growth did not affect. Generally, the use of Triazoles compounds prior to stresses such as cold, could expect the plants can tolerate oxidative stress, which usually occurs after cold stress.

A suitable planting date is an important management tool to determine the best match between phenological stages of plant growth with the environmental factors affecting them. Indigo is known for the natural blue colors obtained from the leaflets and branches of this herb. In addition to indigo dyes, it has been used medicinally to purify the liver, reduce inflammation and fever and to alleviate pain. Determining the proper sowing time for the sowing indigo plant is highly important that should be based on the climate of each region separately. The objective of this research was to determine the effect of sowing date on growth and biological yield of indigo plant in Shahrood region.
This experiment was carried out on randomized complete block design with three replications in the experimental field of the University of Shahrood, Iran, in 2011. Treatments were three planting dates (18 June, 3 and 18 July). Plant density was 50 plants per square meter. The distance between the plants on and between the rows was 10 and 20 cm, respectively. Sampling was conducted in six-stages (every 15 days) randomly in 0.25 m2. Equation 1 was used to calculate the growth rate.
CGR = (Equation 1) Y = (Equation 2)
In this equation, W1: dry weight in the first sampling, W2: dry weight in the second sampling, SA: sampling area (m-2), t1: first sampling time, t2: is the second sampling time. To do this, three parameters sigmoid function [Eq. 2], were fitted to dry matter accumulation variation during the season (Equation 2): In the equation 2: Y is the cumulative dry matter content at any time (x) of growing season, b: is the slope of increasing and xo is the time (in degree days) of reaching to 50% dry matter accumulation. Gaussian function parameter [Eq. 3] was fitted to the crop growth rate data variation: Y = (Equation 3) GDD (Equation 4)
In equation 3: Y value is crop growth rate at any time (x) of growing season, b: is the slope of increasing and x0 is the time of reaching plant to the maximum CGR. In this study, instead of day, we used growing degree days (GDD) according to Equation 4: In this equation Tmax: maximum daily temperature, Tmin: minimum daily temperature, Tb: temperature of the plant, which was considered to indigo 10.27 °C (6). Fitting equations and drawing diagrams were performed using Sigma Plot 10 version. Analysis of variance and correlation between traits were performed using SAS software and means were compared using LSD test at the 5% level.
Results showed that (Figure 2a and Table 2) the earliest planting date (18 June) increased total dry matter and crop growth rate about 4.41 and 3.59 folds compared to third planting date (18 July), respectively. In addition, the highest GDD was recorded for the first sowing date (18 June). The results showed that the fastest (38.34) and the lowest (12.37) growing rate was related to 18 June and 18 July planting dates, respectively (Table 3). Gupta (10) also stated that there was a significant correlation between sowing time and plant biological yield, as with delay in sowing date plant dry weight has been decreased. Mean comparison results showed that the lowest plant height was obtained at the early planting date (18 June) and the lowest of it was seen in the late planting date (18 July) (Figure 5 B). In the first planting date (18 June), biological yield increased 47.27% compared to the later planting date (18 July). In third sowing date biological yield decreased significantly than first and second planting dates (Figure 5 A). Zhelgazkov et al. (21) on Coriandrum sativum L. showed that the earliest cultivation increased the length of effective growth period and finally caused an increase in fruit and biological yield. The reason for reduction of biological yield in delayed cultivation in addition to shortening of growth season is related to coincidence of vegetative and reproduction period with summer heat which resulted in severe reduction in the stem height, leaf dry matter and finally decreasing biological yield. This result is in agreement with findings of Kacurik (14); he stated that the height, fresh and dry flowers of the chamomile was reduced with delay in planting date.
In this study, the highest plant height, leaf dry weight and biological yield, was observed in 18 June sowing date. According to our results may be both day long and especially temperatures during reproductive growth, flowering and maturity are the limiting factors in above ground biomass formation. Based on our results, sowing dates of 18 June was the best planting date for indigo plant in Shahrood region.

Water crisis as a main factor of agronomy limitation exists in all over the arid and semiarid regions such as Isfahan, province which is located in the central part of the Zayandehrud River Basin (ZRB). Due to the increase in the cultivated area of potato in Fareidan Region located in the west of Isfahan province, it will be necessary to use pressurized irrigation systems to achieve the highest irrigation application efficiency and water productivity.
The ZRB (41,500 km2) is a closed basin with no outlet to the sea. The research was conducted in the Fareidan region of Isfahan, which is located in the west part of the ZRB. The Rozveh Agricultural Research Station (32°, 58' N, 50°, 25' E) is located at the altitude of 2390 m above the sea level. This study was conducted as a randomized complete blocks design as a split strip plot layout with three replications and during two years (2007-2008). Three irrigation systems (Drip tape, Sprinkler and furrow) were considered as main plots, two planting methods (one - row planting and two-row planting) as split subplots and two potato cultivars (Marfuna and Agria) as split-split subplots. Production (Tuber-yield), the consumption water and cultivars reactions to common diseases were evaluated in different treatments. The soil of the experimental area, according to USDA Soil Taxonomy 1994 is of silty loamy. At the soil depth of 1m, soil salinity (1.1-2.0 dS m-1), water salinity (1.24 dS m-1), soil moisture at field capacity (23 Vol. %), and bulk density (BD = 1.44 g/cm3) at the field site were measured or experimentally obtained in the Isfahan Soil and Water Laboratory. The results were subjected to an ANOVA to analyze the effects of the treatments and their interactions. The data obtained were analyzed using the compound variance analysis and the averages of different treatments were separated using the Duncan multiple range test using the statistical software (SAS Institute, Inc., Cary, NC). The probability level of 0.05 (Duncan's test) also was selected.
An analysis of variance (ANOVA) was conducted on the irrigation systems and planting methods using PROC GLM (SAS 9.1, SAS institute Ltd., USA). Duncan’s multiple range tests at 0.05 probability level was used for paired mean comparison. The Results provided in two years show that the effect of irrigation systems × year (P≤0.05) and cultivars × year (P≤0.01) on (Tuber-yield), the consumption water and cultivars reactions to common diseases were found to be significant. There is no interaction between irrigation and planting methods, Variety × planting methods, Variety × irrigation, irrigation × Variety × planting methods and irrigation × Variety × planting methods × Year for (Tuber-yield), the consumption water and cultivate reactions to common diseases. On the contrary, the effects of the irrigation system treatments on the Tuber-yield and water productivity were significant (p≤0.05). The effects of variety on Tuber-yield and water productivity were not significantly (P≥0.05) detected.
Sprinkler irrigation method with 26152 kg ha-1 of production mean was preferred significantly to tape irrigation method with 23974 kg/ha of production mean. Tape irrigation leaded to the highest mean of WP equal to 4.69 kg m-3. Two years comparison of yield mean showed no significant difference between Agria and Marfuna potato cultivars. The two year comparison results of yield means using different planting methods indicated that one row planting method (24839 kg ha-1) was preferred significantly comparing to two row planting methods (22927 kg ha-1). Evaluation of tuber infection by ordinary scab and rhizoctonia showed that the highest mean of infection way observed in furrow method and the lowest one was observed in tape method of irrigation. Scab infection in furrow irrigation was 47% higher than sprinkler irrigation and 78% higher than tape irrigation.
During the three (2) years of the experiments with the three (3) irrigation treatments imposed on the potato crop, it was found that the drip type irrigation system, despite its lower yield than sprinkler irrigation, increased water productivity. A lowest pollution tuber to scab infection and rhizoctonia was determined by Drip type method. Thus, using this method, particularly in water restrictions on potato planting is required. The highest tuber yield was obtained in sprinkler irrigation, as well as from the point of view of the intensity and the infection rate of diseases on the tuber to Scab and rhizoctonia there was significant advantage compared to furrow irrigation. Therefore, in the lack of water restriction and the high speed wind can be used. The results showed that the one row planting method for all treatments is desirable therefore highly recommended for agricultural potato production.

Wheat (Triticum aestivum) is a cereal grain, originated from the levant region of the near east and Ethiopian highlands, currently cultivated worldwide. Light extinction coefficient K is a coefficient that represents the amount of light reduced by the plant. Light or radiation extinction coefficient is a concept that expresses the light penetration decrease into the canopy in the way the upper leaves of the canopy with less angles have lower amount of K in comparison with the horizontal leaves. Green et al., (2003) stated that nitrogen fertilizer increased light absorption by plant leaves; and affects the yield. The distribution patterns of nitrogen allocation in leaves are more exposed therefore photosynthesis rate per unit leaf area and canopy were optimized. Differences in canopy structure by the light extinction coefficient (k) of the Act Lambert - Beer is described, along LAI differing due to different species and genotypes which are important factors in absorption and light use efficiency. This experiment was performed to evaluate the maximum light absorption and light extinction coefficient in different levels of nitrogen usage and wheat cultivars.
An experiment was conducted during 2011-2012 on a research farm of Islamic Azad University, Isfahan Branch, located in Khatoon Abad Village (northern latitude of 320 and 40´ and eastern longitude of 510 and 48´ with altitude of 1555 m above sea level). A split plot layout within randomized complete block design was used with three replications. Main plots were consisted in four levels of N fertilizer (0, 50, 100 and 150 kg ha-1) from an urea source in main plots and different cultivars of wheat included Pishtaz, Sepahan and SW-486 in sub plots. Planting was performed on 14 November 2011 and at a density of 400 plants per square meter. In order to strengthen the land and required elements for plant regarding soil test and treatments based on the test plan, the amount of a third off chemical fertilizer of urea, 46 % Nitrogen was given to the plant and two third by the end of clawing the plot. In the period of growing in order to control brushes 2, 4, D herbicide and Fenitrothion insecticidal was used for countering the louse pest and other insects. In the laboratory, leaf area was measured using scanner and 4.Image 0.2 software program. To determine changes of growth indices, regression relations were used. Total dry matter, leaf area index, net assimilation rate, crop growth rate, light interception extinction were measured.
The results showed that the effects of N fertilizilation were significant on the maximum leaf area index, total dry matter and light interception percent were related to Pishtaz cultivar and 150 kg N ha-1 fertilizer treatment significantly resulted Maximum light interception percent, net assimilation rate, with other treatments. Effects of cultivar were significant on maximum light absorption. The Maximum absorption of light, crop growth rate, total dry matter was related to Pishtaz. The interaction between nitrogen and the harvest index was significant at the five percent level. The evidence showed that higher light interception in plants, is associated with the higher performance of plant. The increase of light interception promote the biological and economic performance.
The results showed that application of 150 kg nitrogen per hectare, with the highest level of leaf area index and higher light absorption caused higher extinction coefficient of light in the canopy. Nitrogen fertilizer consumption increased light absorption by leaves, therefore the light extinction coefficient consuming more nitrogen in the plant community. The Maximum absorption of light, crop growth rate, total dry matter was related to pishtaz. Scale of light extinction coefficient for fertilizer treatment control, 50, 100, 150 kg ha-1, was 0.4675, 0.4794, 0.4858 and 0.495, respectively and for Pishtaz, Sepahan and SW-486 cultivars 0.488, -0.4618 and -0.4504, respectively. The results indicated that the application of 150 kg nitrogen per hectare, provides the highest level of morphological characteristics of the plant for producing the highest level of dry matter. Nitrogen fertilizer increased with increasing total plant dry matter. Treatment of 150 kg N per hectare, with the highest plant height, leaf area index and light absorption led to the highest growth rate and resulted in the highest biological and grain yield. The results indicated that 150 kg nitrogen fertilizer treatment for Pishtaz under similar climatic conditions with the present study produces maximum amount of growth indicators.

Summer Savory (Satureja hortensis L.) is an annual, herbaceous plant belonging to the Labiatae family. This plant is most often used as a culinary herb, but it also has marked medicinal benefits, especially upon the whole digestive system. The most important components of S. hortensis include volatile oils, phenolic compounds, flavonoids and phenolic acids, tannins, mucus, resins, carotenoids and mineral components. Plant growth regulators are used to improve the quality and quantity of medicinal plant production. Salicylic Acid is one of this PGRs that involved in seed germination, photosynthesis, Stomatal opening and closure, Membrane Permeability, Ions Absorption and transmission and other growth processes. Polyamines are ubiquitous low-molecular-weight aliphatic amines that are involved in regulating plant growth processes. The most commonly found polyamines in higher plants, putrescine (Put), spermidine (Spd) and spermine (Spm) may be present in free, soluble conjugated and insoluble bound forms. It has been demonstrated that PAs are important for the normal course of diverse plant ontogeny processes such as cell division and elongation, organogenesis and somatic and zygotic embryogenesis.
This experiment was conducted in factorial based on a randomized complete block design with three replications in Karaj, Iran. Foliar spraying with SA (1, 2 and 3 mM.l) and Putrecine (50, 100, 150 and 200 mg l-1) was performed in thrice in Savory growth period. Spraying was performed at 21, 35 (Budding Phase) and 56 (flowering initiation phase) day after seed germination. In flowering stage, some morphological traits such as plant height, weight, yield, canopy diameter, stem diameter, leaf area, essential oil content and efficiency were measured.
Analysis of variance showed that the effects of salicylic acid and putrescine spraying on plant height, canopy diameter, stem diameter, number of axillary stems, foliage dry weight, foliage yield, flower dry weight, number of leaves, leaf dry weight, leaf yield, leaf area index (LAI), number of inflorescence, dry weight of inflorescence, total chlorophyll content, chlorophyll a and b content, essential oil content, yield and efficiency was significant (P This study revealed that foliar application of SA and putrescine significantly affected the morphological, physiological and biochemical traits of Satureja hortensis. Thus, it can be used as a plant growth regulator for yield and essential oil content improvement in field production of this plant.

Marigold (Calendula officinalis L.) is originated from North West Africa and Mediterranean area, is a medicinal plant used for several purposes. It is an annual herb or short-lived perennial from the Asteraceae family with yellow or orange flowers. The Marigold has been used as a traditional medicine and food dye, but is currently used as an anti-inflammatory and wound healer. It is grown for drug, obtained from the flowers. The flowers blossom during summer three or more times per year. The essential oil of yellow or orange petals of Calendula officinalis L. is one of the important yield components which is used for food and medicine. Moreover, the seed has an oil content of 5-20 %. Seed oil could be used as a binder in paints, coating and cosmetics.
Growth, development and production of medicinal plants, as well as other plants are affected by genetic and agronomic factors. Planting date and plant density are two most important factors that can affect yield and yield components. Planting date affects the quantity and quality of secondary metabolites of medicinal plants. The optimum sowing date and plant density can improve the light and temperature absorption and other factors during the growing season. The positive effects of optimal planting date and plant density has been described by a number of researchers. The Plant population is dependent on the plant characters, growth period, time and method of cultivation. Also, the suitable sowing date has advantages for maximum production. Early sowing in the spring causes weakly establishment of plant and late planting date shortens growth period and simultaneous flowering period due to high temperature in summer. In this study, the effects of plant density and planting date on physiological indices, quantity and quality of two varieties of spare and compact marigold has been evaluated.
In order to determine the effects of planting date and plant density on physiological indices, quantity and quality traits of two varieties of marigold (Calendula officinalis L.), a split-factorial experiment with three replications was carried out in agricultural research station in Arak (latitude: 34o 5' N; longitude: 29o 42' E; 1757 m altitude) in 2010 the growing season. Soil was silty-loamy with pH of 7.5 and EC of 0.8 Ds ms-1. The experimental factors included two planting dates (22 April and 2 May), four planting densities (26, 32, 41 and 57 plants/m2) and two varieties (sparse and compact petal). Thinning was performed 20 days after cultivation. Irrigation was carried out in 7 days intervals. For determination of growth indices, ten plants from each plot cut from crown and dried for 48 h in oven at 70°C and then weighted. The plant height, number of flowers per plant, leaf chlorophyll, leaf area index, total dry matter, seed yield, 1000 seed weight, essential oil and grain oil were measured. The extraction of the essential oil of the flower was performed using the Clevenger apparatus by steam distillation (1). Extraction of grain, oil was accomplished according to the soxhelet standard method. The data were analyzed using the statistical analysis system (SAS 9.1) and means were compared using Duncan test at P ≤ 0.05 probability.
Results showed that, planting date and plant density had significant effects on physiological indices, plant height, and number of flowers per plant, 1000 grain weight, chlorophyll index, oil percent and essential oil percentage of marigold. Late planting and decreasing plant density, reduced leaf area index (LAI), total dry weight (TDW) and crop growth rate (CGR) indices. The compact petal variety showed the highest growth indices compared with spare petal plants. On the other hand, early planting, high plant density and compact petal variety increased the growth and development of plants. The first planting date had higher leaf area index compared to second sowing date. It seems that first sowing date made adequate leaf area indices for light and radiation absorption for photosynthesis. Number of 57 plants per square meter in the first and second planting dates improved plant height by 25.1 % and 34.4 %, compared to 26 plants per square meter, respectively. It is noticeable that delay in planting date reduced the mention plant traits. The second planting date (2 May) with 57 plants per square meter in comparison to the first planting date (22 April) decreased chlorophyll index by 18.4%. The compact petal variation showed the highest number of flower and oil percent in comparison with sparse petal variety. The compact petal variety in the number of 57, 41, 32 and 26 plants densities increased essential oil percentage by 9.8, 6.8, 3.5 and 9.1 % compared to sparse petal, respectively. Martin and Deo (32) showed that the highest flower yield in Calendula officinalis L. was observed in 40 plants/m2 density and April 15 sowing date.
The present study showed that the best result for different traits with the exception of number of flower per plant achieved in the first sowing date (22 April) with a compact petal variety and 57 plants per square meter. Therefore, this treatment is suitable for marigold cropping in Arak situation and areas with similar climate and weather.

Sweet corn is the one of the most important types of corn. There is a high amount of sugar in the endosperm of sweet corn than dent corn. Baby corn is the ear of corn that is being harvested in the silking stage before the end of pollination. This crop has an interesting using methods as salad, conserve production and vegetative consumption. Both two sweet and baby corn is obtained from one plant in different growth stages and could be harvested from one corn hybrid. Best yield and quality of baby corn is obtained from sweet corn hybrids, because of high amounts of sugar in the grains and ears. Sweet corn and baby corn could be harvested at early dough stage (with about 30 % of humidity) and early silking stage before the pollination is completed, respectively. Plant density is the most important factor in growing corn, especially in sweet and baby corn. Khuzestan province is one of the main regions of corn production in Iran. In Khuzestan, forage and silage corn have the most production among the summer crops. Corn is planted in two planting date in Khuzestan: early spring and early summer. Spring corn planting produces little grain yield due to Simultaneity of silking stage with hot early summer days. Because of little production and little research about sweet and baby corn, this study was performed and designed.
In order to investigate the effects of plant density and harvesting method on sweet corn and baby corn yield, an experiment was performed during 2012-13, in research farm of Ramin Agriculture and Natural Resources University of Khuzestan, located in southwest of Iran. In this experiment, four plant densities (7, 9, 11 and 13 plants.m-2) and two harvesting methods (baby corn and sweet corn) were investigated in an RCB statistical design with four replications. The KSC 403 hybrid was used and investigated in the experiment, as a sweet corn hybrid. Statistical analysis was performed using SAS 9.1 through GlM procedure. Means of all treatments were comprised using least significant difference (LSD) at 5 % probability level.
The effects of plant density on yield components of baby corn was significant. Increasing the plant densities increased the ear number and percentage of non-standard ears. The Highest yield of ear without husk, standard and non-standard were obtained (2649.5, 766.97, and 3043.9 kg.ha-1, respectively) with 13 plants.m-2. In sweet corn, increasing plant density from 7 to 13 plants.m-2, decreased row per ear, grain per row and thousand grain weight. Highest grain yield (1232.5 kg ha-1) and green ear (12607.2 kg ha-1) of sweet corn were obtained with plant density of 9.m-2.
Analysis of correlation showed that in both baby and sweet corn, there were positive and significant correlations between yield and its components. There was the high number of non-standard ears in all experimental treatments. In sweet corn, the standard ear without husk yield has positive and significant correlation with all traits except the percentage of standard ear and sheathed ear weight. In addition, unsuitable climate conditions during silking stage reduced the yield of sweet corn through the high number of aborted florets. Yield of sweet corn yield showed negative and significant correlation with grain row per ear and grain per row. However, increasing the ear number.m-2 increased yield in higher plant densities up to 9 plant.m-2 density.
Generally, the baby corn had high yield with good quality in this region, but, standard ear percent of the baby corn of the hybrid KSC 403 was very low. On the other hand, sweet corn grain yield was low due to high air temperatures during pollination and maturity stages.

Since the use of chemical fertilizers causes environmental pollution and ecological damage, so application of biological fertilizers and selection the effective and compatible species in an special area, could be beneficial for sustainability of agroecosystems there. Nowadays, attention to the interrelation of plant-organism tended to interrelations between plant-organism-organism. Such nutritional relations, have ecological importance and important application in agriculture. The aim of this experiment was to evaluate the effect of chemical, organic and bio fertilizers on sorghum performance.
A field experiment was conducted in a randomized complete block design with three replications. The experimental treatments include three kinds of biofertilizers and their integrations and vermicompost and chemical fertilizer as follow: 1- mycorhhiza arbuscular (G.mosseae) vermicompost 2- mycorhhiza Nitroxine® (included bacteria Azospirillum sp. and Azotobacter sp.) 3- mycorhhiza arbuscular Rhizobium (Rhizobium sp.) 4-mycorhhiza arbuscular Chemical fertilizer NPK 5- mycorhhiza arbuscular 6-control. Mycorhhiza and chemical fertilizer were mixed with soil at the depth of 30 cm before planting. Seeds were inoculated with bio fertilizers and dried at shadow. First irrigation applied immediately after planting. In order to improve seedling emergence second irrigation was performed after 4 days and other irrigation was applied at regular intervals of 10 days. Studied traits were: height and percentage of root colonization, specific root length, seed yield, number of seeds in panicle, thousands seeds weight. To determine the specific root length (root length in a certain volume of soil) at the end of the growing season, plants in each plot were sampled. Then the length of root of each sample was determined.
The results showed that although the treatments did not affect the height of stem significantly, but they had significant effects on characteristics of root length colonization, specific root length, leaf area index, crop yield, number of seeds per panicle and thousand grains weight .The results demonstrated that the highest percent of root length colonization (82), specific root length (51.82 m root in 25 cm3 soil), leaf area index (5.47), seed yield (425.62 g.m-2), number of seeds in panicle (635) were obtained in mycorhhiza with Nitroxine® treatment. The highest weight of thousands seeds (29.26 g) was gained in simultaneous use of mycrhhoriza and vermicampost. On the basis of our results, the integration of mycrhhoriza with Nitroxine® is suggested as the best fertilizer treatment for sorghum.
The results showed that the application of mycorrhiza with nitroxin had the greatest effect on growth characteristics and yield of sorghum. It seems that whenever there was a source of nitrogen beside the mycorrhiza, the performance of sorghum was higher. Undoubtedly, application of bio and organic fertilizers specially in poor soils, have positive effects on soil physical and nutritional characteristics. On the other hand according to economical, environmental and social aspects, they are benefits and could be appropriate alternative for chemical fertilizers in future.

Drought stress is the most important factor limiting plant growth throughout the world so that the slowdown in drought is far more than other environmental stress (1). Following wheat, rice, maize, barley millet and sorghum, are the world's most important annual crops.
In order to evaluate the yield and yield components of millet genotypes and determine the most tolerant genotype based on indicators of drought tolerance a field experiment was conducted at the research farm of the Faculty of Agronomy of the University of Shahid Bahounar university of Kerman-Iran in 2012. The experiment was carried out as split plot based on the randomized complete block design with three replications. Main plots were dedicated to drought, water levels (50 and 100% field capacity) and in the subplots millet cultivars(including Common Millet: Pishahang cultivar, Rabor and Golbaf ecotypes and common promising lines P69, P101, as well as foxtail millet, Bastan cultivar and foxtail promising lines S79, S81, S85 lines) were planted. Irrigation levels was calculated based on the cumulative evaporation from class A evaporation pan. First irrigation was done after 50 mm evaporation and second was done after 100 mm evaporation. The irrigation method was conventional (flooding).
Analysis of variance showed significant difference for tiller number among the genotypes and stress reduced number of tillers. Foxtail millet such as Bastan cultivar, S79, S81 and S85 lines had the maximum number of tillers, while common millet genotypes including: Rabor ecotype and P69 had the lowest number of tillers in drought stress conditions.
Analysis of variance showed significant differences between genotypes in terms of plant height. Foxtail millet showed higher plant height than common millet, among the under studied genotypes, S85 line had the highest plant height whilst Golbaf and Rabor had the lowest plant height. Different irrigation regimes showed highly significant effect in plant height. Result indicated that there is no significant interaction of each millet genus by irrigation treatment in plant height, while foxtail and common millet showed significant difference in interaction by irrigation treatments.
Different genotypes had different number of branches. Among the genotypes in this experiment, the number of branches in Bastan was the highest and lowest was belonged to S85 line under drought stress, respectively. Effects of water stress also showed a significant decrease in the number of branches. Analysis of variance showed that the interaction of genotype by irrigation treatments on the number of branches was significant.
Drought caused a reduction in the number of panicle and the result showed there was no significant difference between genotypes. Among genotypes in this experiment, Rabor ecotype had the highest number of panicle in terms of stress and foxtail millet including: Bastan cultivar, S79, S81 and S85 had minimum number of panicle in drought stress conditions. Irrigation in genotype interaction was significant on a number of panicle.
Results showed that there was a significant difference between genotypes for harvest index. Among genotypes in this study, S79 and Golbaf genotypes had the lowest harvest index under drought stress. Drought stress effect on harvest index showed a significant decrease, also interaction effect was significant.
Analysis of variance showed significant differences between different genotypes of millet based on seed weight. Among genotypes in these experiments, Golbaf and Bastan had the highest seed weight while genotype, S79, S81 and S85 with no statistically significant difference had the lowest seed weight, respectively. There was no significant interaction between genotype by irrigation. Seed weight reduction due to drought stress has been reported in several studies (3). Analysis of variance showed a significant difference between millet genotypes about biological yield. Among genotypes in this study, genotype P101 showed highest biological yield in drought stress conditions but Rabor and S79, showed lowest biological yield in drought stress condition. Drought stress effect on biological yield showed a significant decrease. Genotype by irrigation interaction on biological yield was significant. Biological yield loss due to drought stress has been reported in several studies (2).
Mean productivity (MP), geometric mean productivity (GMP), stress tolerance index (STI) and performance index (YI), by a significant positive correlation with grain yield in stress and non-stress conditions were the best indicators for identification of superior varieties. Using mentioned Indices, a genotype with high yield potential was Golbaf as the most tolerant ecotypes to drought stress, S79 was more sensitive to drought than the other genotypes More details is described in the text as it is original.
Based on this experiment it can be concluded that at drought condition cultivation of common millet has advantage than foxtail millet. Among common millet genotypes Golbaf ecotype showed the highest yield potential and relative tolerance to drought stress. It can be introduced as a promising line in breeding programs for drought tolerance studies.

Salinity is one of the most important stress resulting depletion of vegetation in large areas of the world including some regions of Iran. Reduction of plant growth due to salinity occurs with a range of mechanisms, including low external water potential, ion toxicity and interfere with the uptake. Silicon (Si) is the second most abundant element in soil and could efficiently mitigate the effects of various biotic and abiotic stresses, such as drought, heavy metal toxicity and salinity on plants. Medicago scutellata is an important leguminous forage crop throughout the world that could increase soil nitrogen content via reduction of atmospheric nitrogen. To our knowledge, no study have examined the interaction of salinity and Si nutrition in Medicago scutellata or how the beneficial effects of Si in salt-stressed M. scutellata plants (if any) are exerted. Accordingly, the aim of the present study was to evaluate the effect of silicon nutrition on salt tolerance of Medicago scutellata.
Seeds of alfalfa (Medicago scutellata L.) were sterilized with a 2.5% sodium hypochlorite solution and were incubated in a moistened paper towel. Then, they germinated in the dark at 255  C for 48 h. Healthy seedlings of uniform sizes were selected for hydroponic culture (Hoagland solution) in a 10×15×15 cm plastic pots. A factorial experiment carried out based on a completely randomized design with two factors. The first factor was salinity, including 0 and 100 mM NaCl and the second was silicon nutrition, including 0, 0.75 and 1.5 m.M sodium silicate. The pH of the nutrient solution was adjusted daily at 6.4  0.2 and nutrient solution was refreshed weekly. During the experiment, maximum and minimum air temperatures were 30ºC and 21ºC respectively, and the mean relative humidity was 67%. Four weeks after exerting the treatments, plants were harvested and used for the assessment of growth parameters and chemical analyses.
Salinity led to a significant reduction in both the fresh and dry weights of the plants. On the contrary, the dry weight of the plants improved significantly under saline conditions when Si was added to the medium, especially 1.5 mM Si. Salt treatment increased the concentration Na and decreased the concentration K significantly in both shoots and roots; however, Na concentration, reduced and K concentration increased due to Si application in salt treated plants. Similarly, Fe content decreased in shoot of plants due to salinity, whereas Si nutrition increased Fe content in plants suffered from salinity. The activity of catalase declined and the amount of hydrogen peroxide increased in plants under salinity. Conversely, Si treatments, especially, at 1.5 mM could recover the activity of this enzyme and reduced hydrogen peroxide content. Salinity imposed significant reduction in the contents of chlorophylls, total carotenoids and xanthophylls and soluble proteins. The amount of hydrogen peroxide, lipid peroxidation as well as electrolyte leakage via plant leaves increased due to salt stress. In contrast, the contents of chlorophylls, carotenoids and xanthophylls, soluble proteins increased following Si application. Also, the amount of hydrogen peroxide and rate of lipid peroxidation and electrolyte leakage decreased in salt-treated plants by Si application. Silicon nutrition can recover the chlorophyll content and the amount of soluble proteins on Medicago scutellata plants under salinity, which suggests that it plays a role in the suppression of oxidative stress. Si application also improved the chlorophyll content of tomato and barley under salt stress (Al-aghabary et al., 2004). The data reported in the present study show new aspect of the beneficial effect of Si on plants grown under saline condition. The application of Si prevented Na accumulation and enhanced K content in Medicago scutellata plants. Reduced Na accumulation improves the plant ROS scavenging capacity through increased antioxidant enzyme activity (Al-aghabary et al., 2004 Hashemi et al., 2010), accompanied by reducing lipid peroxidation. Consequently, photosynthetic pigments increased and membranes functionality improved by Si in plants under salinity (Liang et al., 2005).
The results indicated that 1.5 mM silicon application alleviated harmful effects salinity, probably through declined Na enhanced K content that increased antioxidant enzyme activity and reduced reducing oxidative stress. Consequently, photosynthetic pigments increased and membranes functionality improved with plants under salinity. In this regards, Si application led to an increased salt tolerance of Medicago scutellata. Further, field experiments are necessary for confirmation of the results and expedience of economic cost.

Salinity is one of the most important factors limiting crop production in arid and semiarid regions of the world that affects crop yield. Salt tolerance of Brassica species are very complex due to genetic relationships. Because of low erucic acid (less than 2% of total fatty acids) and glucosinolates contents (less than 3 µmol g-1), oil of Canola has many consumers around the world. Because Canola have tolerance potential against toxicity of salinity and its minerals, its growth can be successful in saline condition. According to the recent ongoing drought and the need to use low quality irrigation water for crops such as Canola, aim of this experiment was to evaluate the effect of salinity on changes in carbon fixation process and photosynthetic pigments of three Canola genotypes under salinity as well as determine most salt tolerant genotype for use in saline regions.
An experiment was conducted in the greenhouse of Shahid Chamran University during 2007-2008 growing season in factorial test based on a completely randomized design with four replications. The first factor (genotype) included Hayola 401, RGS0003 and Shiraly and the second factor (salinity levels) had four levels of salinity (50, 100 and 150 mM NaCl) as well as distilled water as a control. Sources of salinity were NaCl and CaCl2 with equal ratio as most resembles to lower water quality resources in the region. Date and time of stress were considered four weeks after planting (four-leaf stage). A Stepped irrigation method using saline water was done every 12 days over three steps period. To perform this study 10 liters volume pots were used. Three pots per each treatment, and totally 144 pots were used. SAS (version 9.1), Excel and MSTAT-C software's was used for statistical analysis. The comparison of means was done by Duncan method.
The results showed that content of chlorophyll a, b and carotenoids in all three genotypes increased to 100 mM, while decreased at 150 mM. Health and invulnerability of main photosynthetic pigments at 100 mM NaCl, can be considered as an important reason for salt tolerance in the evaluated canola cultivars. Reducing the absorption of water due to stress caused by salinity reduced nutrient uptake. Toxicity of chlorine and sodium also leads to inhibition of plant growth and dry matter. Magnesium concentration raised with increasing salinity compared to control. It seems that the magnesium concentration in stomatal guard cells decreased osmotic potential and play a role in the biosynthesis of organic compounds such as glutamic acid. So, despite ABA-induced stomatal closure, the stomatal openings, even in small amounts remain photosynthesis activities. Probably, magnesium has a key role in the continuing photosynthesis of Canola under salinity. The leaf starch in the genotype Shiraly significantly increased to 150 mM salinity level. Reduction of starch in high levels of salt stress interferes with enzymes efficiency involved in the starch biosynthesis, such as starch synthase and ADP- glucose pyrophosphorylase. The trend of variation in stomatal conductance was similar to 50 mM in the early flowering, but a sharp decrease was observed at late flowering compare to control. When stress started on the four-leaf stage, the plant for some time kept stomatal conductance at maximum level, but continuation stress period led to close stomata. Thus, reducing the amount of leaf relative water content can be considered as the reason of different stomatal conductance among the different levels of salt stress. A significant positive correlation between relative water content and stomatal conductance confirms this results. On the other hand to avoid stress and better use of the limited amount of available water, the plants closed stomata to prevent more water loss.
It seems that genotype Shiraly using some mechanisms to avoid stress, such as maintaining relative water content, as well as increase the content of chlorophyll a and b up to 100 mM. Moreover, the concentration of magnesium up to 150 mM, has endured salinity.

Canola can be cultivated in large areas of the country due to its specific characteristics such as suitable composition of the fatty acids, its germination ability under low temperature, as well as its good compatibility with different climates. Canola is a high demanding crop in terms of fertilizers so that it uptakes considerable amount of nutrients from the soil during the growing season. Canola cultivation in poor soils or application of imbalanced fertilizers, especially nitrogen, can reduce qualitaty and quantity of final yield. On the other hand, salinity is known as one of the major limiting factors in canola production. Therefore, the aim of this study is the application of zeolite, selenium and silicon treatments to amend soil and increasing salinity tolerance in canola.
In order to study the effect of soil applied zeolite and foliar application of selenium and silicon on yield, yield components and some physiological traits of canola grown under salinity stress, a factorial experiment in randomized complete block design was conducted in Agriculture and Natural Resource Research Center in East Azerbaijan during 2011-2013 cropping seasons. Zeolite was applied at three levels (0, 5 and 10 ton ha-1) and foliar selenium and silicon were applied at three levels as well (each one zero, 2 and 4 g l-1). For this purpose, seedbed was prepared using plow and disk and then plot were designed. Canola seeds, cultivar Okapi, were sown in sandy loam soil with 4 dS.m-1 salinity at the depth of 2-3 cm. Irrigation was performed using local well based on 60% field capacity using the closed irrigation system. Potassium selentae and potassium silicate were used for selenium and silicon treatments. Treatments at rosette and stem elongation stages were sprayed on plants using a calibrated pressurized backpack sprayer. At flowering stage, photosynthesis rate was recorded. Then leaf samples were randomly collected to assay chlorophyll, relative water content, catalase, peroxidase and superoxide dismutase activity, as well as malondialdehyde, sodium and potassium content in the leaves. The samples were immediately frozen in liquid nitrogen and kept in -80° C freezer. At the end of the growing season, agronomic traits such as silique number, seed number on silique, 1000- grain weight, grain yield, biological yield and harvest index were recorded. Total oil percentage and fatty acids (oleic, linolenic and linoleic) percentage were measured.
The combined analysis of variance indicated that the effect of year was significant on all studied traits, except for silique number, grain number in silique, linoleic acid, chlorophyll content and peroxidase activity. In addition, the results showed that the main effect of zeolite, selenium and silicon were significant on all canola studied traits. However, relative water content and peroxidase activity were not affected by silicon application. Comparison of means indicated that triple interaction was significant at 1000- grain weight, grain yield, biological yield, chlorophyll content, photosynthesis rate, relative water content and antioxidant enzyme activity. Some traits such as 1000- grain weight, grain yield, biological yield, harvest index, oil percentage, linolenic percentage and superoxide dismutase activity as well as sodium content in leaves were found to be higher in the second year compared with the first year. Zeolite significantly increased silique number and grain number in silique. Furthermore, harvest index increased with the increase of zeolite level. According to the results, selenium increased silique number, grain number in silique and harvest index in canola plants. Silicon foliar application also significantly increased silique number, grain number in silique and harvest index. The highest chlorophyll contents, photosynthesis rate and relative water content were registered when zeolite was applied at 10% w: w and silicon and selenium were applied at 4 g per litter. Similarly, the highest peroxidase and superoxide dismutase activity was observed in this treatment. Finally, the highest grain yield (3009.92 kg ha-1) and biological yield (108778 kg ha-1) were obtained when 10% w: w zeolite was applied along with 4 g per liter selenium and 4 g per liter silicon In general, we concluded that application of zeolite, selenium and silicon could reduce adverse effects of salt stress and improve canola tolerance against salinity stress.
Among the applied treatments 10% w: w zeolite along with 4 g per liter selenium and 4 g per l liter silicon caused the best results in terms of canola grain yield.

Maize (Zea mays L.) which belongs to the Poaceae family is the third important cereal crop of the world after wheat and rice. Salinity is one of the major environmental factors limiting plant growth and productivity. Maize is sensitive to salinity. Planting method is a crucial factor for improving crop yield. Planting methods in saline and non-saline conditions are different. Kinetin is one of the cytokinins known to significantly improve the growth of crop plants grown under salinity. Indole acetic acid (IAA) is also known to play a significant role in plant tolerance to salt stress. However, little information appears to be available on the relationship between salinity tolerance and auxin or cytokinins levels in plants. In this respect, the objective of this study was to study the effects of foliar applications of cytokinin and auxin hormones on yield and yield components of grain maize under different planting patterns in saline conditions.
The experiment was carried out at Bushehr Agricultural and Natural Resources Research Center, Dashtestan station with 29° 16´ E latitude and 51° 31´ N, longitude and 70 m above the see surface during the 2013 growing season. Dashtestan region is a warm-arid region with 250 mm precipitation per year. The field plowed by April 2013 and then prepared and sowed by August 2013. There were five rows with 75 cm distance. The experiment was conducted as a split-plot factorial design based on complete randomized blocks with three replications. Planting pattern (ridge planting, double rows of planting on a ridge in zigzag form and furrow planting) as the main factor and time of cytokinin (0 as a control, V5- V6 stage and V8- V10 stage) and auxin (0 as a control, silking stage, two weeks after silking stage) foliar-applied was considered in a factorial. Cytokinin (Benzyl Adenine, Merck) and Auxin (Indole-3-Butiric Acid, Merck) were sprayed on the entire plant in the evening with concentration of 50 and 10 g. l-1, respectively. All morphological and yield component traits measured on 10 randomly selected plants of each plot. Yield was measured in 9 m2 for each treatment. Data analyzed using the SAS (Ver.9.1) and comparing of the means was conducted using Duncan’s multiple range test.
Results showed that the planting pattern had a significant effect on plant height, ear (cob) length, ear diameter, kernel row number, per ear, kernel number per row, 1000- kernel weight, biological yield, grain yield and harvest index. The highest and the lowest yield obtained through furrow planting and conventional planting, respectively. Applying furrow planting, resulted in water use improvement and reducing side effects of saline soils
Cytokinin application in V8- V10 stage produced the highest plant height and row number per ear and the highest 1000- kernel weight and harvest index was belong to the application of cytokinin in V8- V10 stage. The maximum kernel number per row was obtained without cytokinin.
Auxin effect on 1000- kernel weight, biological yield, grain yield and harvest index were significant (p≤0.01). The highest grain yield by a mean of 6.57 tons.ha-1 produced by time of auxin foliar-applied in the silking stage. It has been found that both auxin and cytokinin may have a role in mediating cell division in the endosperm during the grain-filling stage. Therefore, these hormones might regulate the grain capacity (sink size) for the accumulation of carbohydrates. It has been found that IAA actively participated in the mobilization and accumulation of carbohydrates in seeds. Auxin and cytokinins hormones are also thought to be involved in regulating the sink strength either by mediating the division and enlargement of endosperm cells or by controlling the import of assimilates to the sink.
The results indicated that the foliar application of cytokinine and auxin hormones counteracted some of the salt induced adverse effects and improved the maize yield .Due to its effect on diminishing salt aggregation in relation to ridge planting, furrow planting, prepare semi saline and saline areas for growing crops. It is concluded that furrow planting with CK application in V8- V10 stage (50 g. l-1) and IBA in silking stage (10 g. l-1) reduced the effects of salinity on plant and produced the highest grain yield.

Maize (Zea mays) is a cereal crop that is grown widely throughout the world in a range of agroecological environments. .Its value as a cost-effective ruminant feed is one of the main reasons that farmers grow it. However, lack of nutrients such as N and P, are the principal obstacles - to crop production under low input agricultural systems leading to dependency on chemical fertilizers. Long-term use of chemical fertilizers destroy soil physicochemical properties and it reduced permeability which restricts root growth, nutrient uptake and plant production. Therefore, the use of organic fertilizers can help to enrich the soil root zone As a result growth and yield will improve.
In order to study the effects of different levels of vermicompost and foliar application of tea compost on growth characteristics of the hybrid maize genotype 713, a greenhouse experiment was conducted as a factorial experiment in randomized complete block design with three replications at the Vali-e-Asr University of Rafsanjan, during 2013. Treatments were included vermicompost (0, 5%, 10%, 15%, 20%, 25% and 30% pot weight) and tea composts (foliar application, non-foliar application). Measured traits were included root dry weight, root volume, leaf dry weight, stem dry weight, macro nutrient concentration (N and P) and micro nutrient concentration (Zn, Mn, Fe and Cu). All the data were subjected to the statistical analysis (two-way ANOVA) using SAS software (SAS 9.1.3). Differences between the treatments were performed by Duncan’s multiple range test (DMRT) at 1% confidence interval.
Results indicated that leaf and stem dry weight affected by the application of vermicompost and tea compost. However, the interaction effects had no significant effects on the leaf and stem dry weight. Application of tea compost increased 20% and 50% leaf dry weight and stem dry weight of corn compared to non- foliar application, respectively. The highest leaf dry weight and stem dry weight observed at 25% pot weight vermi compost, and lowest leaf and stem dry weight observed in control. Root volume and root dry weight affected by the interaction effects of vermi compost and tea composts. The highest root dry weight and root volume observed in 30% weight in non-foliar application condition. The highest root dry weight and root volume observed in 15% pot weight in tea compost application condition. It is also resulted that Fe concentration of shoot had affected by the application of tea compost, and using vermi compost affected the concentration of Zn, Fe and N in shoot. Application of tea compost increased 15% Fe concentration of shoot compared to non- foliar application. Using vermi compost of 30, 30 and 15% per pot weight increased concentration of Fe, N and Zn of corn shoot, respectively.
Result indicated that Mn, Cu and P concentration of corn shoot affected by interaction effects of vermicompost tea compost. It is also resulted that the highest concentration of Mn, and Cu observed in 15% pot weight in tea compost application condition and the highest concentration of P observed in 5% pot weight in tea compost application.
Nutrient contents of vermicompost and tea compost are comparable with other organic fertilizers. Totally, it seems that using tea compost foliar application due to bioavailability nutrient could decrease the amount of vermicompost application.

Human always has looked for improving food production through increasing crops yield. In this path, weeds through competition with crop for environmental factors and inputs have reduced the quantity and quality of crop products. Competition for nitrogen absorption not only is the most common form of intra-specific competition amongst crop plants, but also is the most popular form of inter-specific competition in the system of weed-crop interference. Therefore, understanding the method of nitrogen absorption and its allocation in competing plants, will be a key tool to improve weed management strategies.
In order to study the effect of sowing method and nitrogen rate on the growth pattern of onion under interference with purple nutsedge, a factorial experiment based on a randomized complete block design was conducted with three replications at the Research Greenhouse of University of Birjand in 2013. The first factor included three sowing methods of onion (seed sowing, onion set and transplanting) and the second factor consisted of three levels of nitrogen (50, 100 and 150 kg N ha-1, equivalent of 25, 50 and 75 mg N kg-1 soil) that urea fertilizer with a purity of 46% was used for this purpose.
The results of the analysis of variance showed that nitrogen levels had significant effects on plant height, leaf area index as well as aboveground and bulb dry weights. Furthermore, sowing methods revealed significant effects on plant height, leaf number, leaf area index as well as aboveground and bulb dry weights. Moreover, the interaction between sowing methods and levels of nitrogen had a significant effect on plant height, leaf area index and aboveground dry weight, while it had no significant effect on leaf number and bulb dry weight. The results of the comparisons of the means of onion planting methods and nitrogen levels interactions confirmed that the superiority of the influence of onion set were planted method and high level of nitrogen in plant height trait, so that the maximum plant height was obtained where onion set methods and high nitrogen levels were applied during the growing season. In addition, the lowest plant height during the growing season was observed where the direct seed sowing method and 150 kg N ha-1 were used. The lowest leaf number during the growing season were obtained from direct seed sowing method and the leaf number per plant in this method of planting was 4.33 and 4.66 at eight and ten weeks after planting, respectively. The greatest number of onion leaves was produced in onion set planting method and the leaf number per plant in this method was 12.66 and 13.44 at eight and ten weeks after planting, respectively. The highest leaf area index of onion plants during the growing season was observed under onion set planting method and high levels of nitrogen, while the lowest value of this trait was obtained from direct seed planting method. During the growing season, the maximum shoot dry weight of onions was observed where the onion set planting method and high levels of nitrogen were employed. At eight and ten weeks after planting, the maximum amount of this trait was obtained from 100 kg N ha-1 that was about 4.335 and 5.565 gr plant1, respectively.
Onion growth pattern under interfering with purple nutsedge demonstrated that the highest and lowest growth of onion plants were obtained where onion sets and seed sowing planting methods were employed, respectively. Moreover, changes of growth characteristics of onion under different levels of nitrogen fertilizer and interference conditions illustrated that the maximum and minimum amount of onions growth were obtained at 100 and 50 kg N ha-1, respectively. In conclusion, the superiority of applying the onion set planting method and 100 kg N ha-1 improved onion growth where it competes with purple nutsedge. Thus, in order to minimize the yield damage due to purple nutsedge presence, application of 100 kg N ha-1 and using the onion set planting method can be recommended as the most appropriate treatment in the management of infected farms with purple nutsedge. However, this study was conducted under greenhouse conditions and there is no doubt that the study should be repeated in the field to verify these results.