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

To compare tolerance and sensitivity indices of sesame genotypes to water stress in Ahvaz (south-west of Iran) conditions, an experiment was conducted in Research Farm of Agricultural Sciences and Natural Resources University of Khuzestan, south-west of Iran, in summer 2018. The experimental design was split plot based on a randomized complete block design with four replicates. Experimental factors were three levels of irrigation (I1; fully irrigated, I2: changing altered irrigated and I3: fixed altered irrigated) in main plots and six sesame genotypes in subplots. The yield of studied genotypes showed a significant difference in different levels of irrigation. Genotype Shushtar produced the highest grain and oil yield and showed good performance in both normal and low irrigation conditions. The examined genotypes had significant differences in terms of Stress Sensitivity index (SSI), Tolerance Index (TI), Productivity Mean (PM), Harmonic Mean (HM), Yield Stability Index (YSI), Geometric Productivity Mean (GPM), Stress Tolerance Index (STI), Stress Damage Index (SDI), Modified Stress Tolerance for appropriate conditions (MSTI1), Modified Stress Tolerance for non-appropriate conditions (MSTI2), and Yield Reduction Index (YRI).  In general, the best indicator for evaluation of tolerance and susceptibility of sesame genotypes was stress tolerance index (STI). The most tolerant and sensitive genotypes were Shushtar and Halil genotypes, respectively.

In order to survey the efficacy of several pre-and post-emergence herbicides on weed control in the autumn cultivation of chickpeas, a split-plot experiment was conducted in a randomized complete block design with four replications in the Sararoud region during 2021–2022. The main plots contain two tillage systems (conventional tillage and no-tillage). The subplots include 12 herbicide treatments (Trifluralin, Trifluralin + Bethanal progress, Isoxaflutole, Isoxaflutole + Bethanal progress, Oxyfluorfen, Oxyfluorfen + Bethanal progress, Imazethapyr, Imazethapyr + Bethanal progress, Fluorochloridone, Fluorochloridone + Bethanal progress, Metribuzin, Metribuzin + Bethanal progress, and two controls (weed-free and weed-infested)). The maximum decline in weed dry weight was observed in tillage + Fluorochloridone, tillage + Isoxaflutole, tillage Oxyfluorfen, and no-tillage + Fluorochloridone at about 51%, 48%, 46%, and 45%, respectively. The greatest decrease in weed density is for tillage + Fluorochloridone and tillage + Oxyfluorfen + bethanal progress, tillage + Metribuzin + bethanal progress, tillage + Fluorochloridone + bethanal and tillage + Imazethapyr were registered with 47, 47, 43 and 40% reduction respectively. Conventional tillage reduced the density and dry weight of weeds, but this reduction was statistically significant for the dry weight of weeds. The highest yield of chickpea seeds in tillage + weeding, weeding, tillage + Trifluralin + bethanal progress, conventional tillage + Oxyfluorfen and no-tillage + Trifluralin + bethanal progress treatments are 846, 664, 528, 502 and 498 kg per hectare, respectively. The most effective herbicides in controlling weeds were Fluorochloridone, Isoxaflutole and Oxyfluorfen, and the highest yield of peas was recorded for Oxyfluorfen.

In order to investigate the effect of the growing day and plant density on some agronomic, morphophysiological and qualitative characteristics of the early-maturing line Soy-93-31 soybean, an experiment was conducted in the form of split plots in the form of a randomized complete block design in three replications. Two crop years 2017 and 2018 were implemented in Gorgan region. The first factor of growth days until harvest time includes five growth days (GDD) 2328, 2182, 1893, 1712 and 1499 resulting from the date of sowing (10, 24 June, 8, 12 July, 5 August) and the second factor is the distance between rows 24, 36 and 48 cm (42, 28 and 21 plants per square meter).in this experiment, grain yield, biological yield, number of pods per plant, number of seeds per pod, 1000 grain, oil yield, oil percentage and soybean fatty acids were measured. The results of this experiment showed that planting date and density had a significant effect on the percentage of soybean oil and fatty acids. The percentage of seed oil decreased with increasing planting time (delayed soybean) so that the highest percentage of soybean oil on 10 June and the lowest percentage of oil was obtained on 5 August. Also, based on the results of planting date and plant density had a significant effect on grain yield and grain yield components, the weight of 1000 soybeans decreased with delay in planting. With delay of sowing date in all densities, soybean grain yield decreased, so that the highest grain yield was observed on June 10 and the density of 42 plants per square meter (3760 kg.ha-1) and the lowest grain yield was observed. Soybean was obtained on August 5 and the density of 21 plants per square meter was (470 kg.ha-1). According to the results of this experiment, the planting date of 10 June and the density of 42 plants per square meter were the most desirable planting date and density to achieve maximum grain and oil yield.

To evaluate maize hybrids response to salinity stress, a factorial experiment was performed with three replications at the Ardabil Agricultural and Natural Resources Research and Education Center during 2020. The first factors were six maize hybrids (SC647, TWC647, SC704, SC705, SC706 and SC715), and the second factors were three levels of salinity stress (0, 100 and 200 mM NaCl). Electrophoretic analyses by using 8% slab polyacrylamide gels indicated that three, two and one isoforms for superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were observed, respectively, and for each isoform band the “density × area” scores onto gels were evaluated by MCID software as enzymatic activity. The applied salt stress reduced dry weight seedlings, but increased malondialdehyde (MDA), peroxide hydrogen (H2O2), and activity of SOD, POX and CAT isoforms. Significant correlations were observed between seedling dry weight and POX and CAT. The cluster analysis based Ward method was classified maize hybrids in two different groups. TWC647 hybrid with high biomass, high oxidative defense system and low MDA was salt-tolerance. The results indicated that salt-tolerance hybrids, which are associated with enhanced oxidative defense system.

Salinity stress is one of the main factors that limited crop production. Salt stress causes physiological effects by decreasing soil water potential. Azomite is an inorganic mineral that contains more than 60 forms of nutrients (macro and microelements). This material modifies and improves the soil, and the high ionic exchange capacity of this substance has resulted in some of it being used to reduce the effects of salinity stress. Mexican Parsley (Tagetes minuta) is a medicinal plant from Asteraceae family that used in the food and cosmetic industries. The purpose of this experiment was to investigate biochemical response and dry aerial biomass of Tagetes minuta under salinity stress and Azomite application.

A pot experiment was conducted at the research greenhouse of Ferdowsi University of Mashhad as factorial based on completely randomized design with three levels of salinity (0, 30 and 60 mM NaCl in irrigation water) and four levels of Azomite (0, 4, 8 and 12 g/kg soil) in three replications in 2018. The studied traits were included biochemical characteristics (RWC, Electrolyte leakage, chlorophyll a, chlorophyll b, carotenoid, total chlorophyll, antioxidant activity, total phenol, soluble carbohydrates, and proline) and dry biomass. Statistical analysis was performed using Minitab 17 software. The mean comparison was done by Bonferroni test at the 5% probability level. The figure drew by Microsoft Excel software.

The results of this experiment showed that the interaction effects of salinity and Azomite had a significant effect at a probability level of 1% on all of the studied traits. The highest amount of dry biomass (30.25 g.plant), RWC (74.2 %), chlorophyll a (7.5 mg.g-1FW), chlorophyll b (9.26 mg.g-1 FW), carotenoid (16.73 mg.g-1FW), total chlorophyll (33.39 mg.g-1FW) and essential oil content (0.46 %) were observed in treatment without salinity and 12 g/kg soil of Azomite. The highest amount of Electrolyte leakage (83.55 %), antioxidant activity (9727 %), Total phenol (95.10 mg.g-1FW), soluble carbohydrates (114.4 mg.g-1FW) and proline (0.12 µM/gDW) was observed on 60mM salinity and without the use of Azomite. NaCl stress can reduce nutrient uptake by the root of the plant and cause to decrease the growth of plants (Dry aerial biomass), RWC, Chlorophyll a, b, carotenoid and total chlorophyll and increase antioxidant activity, total phenol, soluble carbohydrates, and proline. Azomite in salinity stress increase water holding and inhibited the plants from Na uptake. Therefore it prevents plants from Na toxicity. The result of this study showed that the highest salinity level (60 mM NaCl) and application of Azomite especially at 12 g/kg soil level had the highest effect on ameliorating biomass and biochemical characteristics of the plant.

In order to study the effect of silicon foliar application and Nitrocara biofertilizer on some morpho-physiological traits of wheat under different irrigation regimes, an experiment was conducted as a factorial split-plot, during two cropping years in research farm of Islamic Azad University, Zabol Branch, Iran. Experimental treatments included water stress (irrigation regimes after water depletion of 50, 75, and 90% of field capacity) in the main plots and silicon acid foliar application at three levels of 0, 1 and 1.5 mM and Nitrocara biofertilizer in two levels of inoculation and non-inoculation (one liter per hectare as seed) in subplots were assessed. The results showed that the non-inoculate seeds with Nitrocara under 50% irrigation regime and seed inoculation under 75% irrigation regime in the second year of the experiment resulted in the highest wheat grain yield with an average of 1901.5 and 1892.3 g/m2, respectively. The highest total biomass was related to the inoculation of seeds with Nitrocara along with the use of 1 mM silicon in the second year of the experiment under irrigation regime of 50% moisture depletion (8793.3 g/m2). In general, under low irrigation conditions, the use of Nitrocara biofertilizer as well as silicon foliar application led to improved physiological parameters and increased growth and yield indices of wheat in Sistan climatic conditions.

Chia (Salvia hispanica L.), has achieved economic importance due to the products which are obtained from its leaves with antioxidant capacity and especially its seeds, because they contain omega 3. However, there is a lack of information on optimal agronomic management practices and especially the influence of water availability on its establishment and production. To evaluate the effect of various moisture regimes on some growth and physiological parameters of the medicinal plant of chia, a greenhouse experiment conducted at the university of Agriculture and natural Resources of Tehran, based on randomized complete blocks design with three replications.The treatments incorporate moist regimes that have been applied at 66, 57 and 43 and 35% Levels of soil Field capacity. Results demonstrated that diverce moisture regimes had a meaningful influence on most pre-examined parameters. Relative water content (RWC), the total biomass of plant, plant height, accessory branch, node number and the ultimate Leaf area decreased with increasing drought stress such that the lowest value of stated parameters is obtained in the 43% soil Field capacity. Also the highest value of ELI and root weighthad been obtained through 43% soil Field capacity. The lowest value of Fo and Fv/Fm was observed and affiliated with 66% and 43% soil Field capacity, respectively. Generally, concerning the decreasing trend of growth and physiological parameters of chia in response to drought stress and intolerance in severe water stress, it seems, in the growing stage, it needs to sufficient moisture to maintain the membrane function and Photosynthetic processes.

Pennyroyal (Mentha pulegium L.), Labiatae family, is widely used as a vegetable and medicinal herb. This plant commonly grows in the wet soils such as ditches, riversides and ponds. It is indigenous to the Central, Southern and Western Asia, North Africa, Ethiopia and the Canary Islands. It can also be found in Alborz, North and Northeast regions of Iran. The aerial parts of the plant are used as pharmaceutical and flavoring substances. The aim of this research was to find the best level of nitrogen fertilizer regime, harvesting time and plant density for pennyroyal plant in Rasht area.

This study was conducted as a split-plot experiment based on randomized complete block design with three replications in Faculty of Agriculture, University of Guilan. The main plots included two harvesting times, the subplots were four levels of Nitrogen fertilizer including control (without fertilizer), 50, 100 and 150 kg ha-1 Nitrogen and the sub-subplots were plant density at 3 levels; 10, 14 and 18 plants m-2.

The results showed that triple interaction of nitrogen, plant density and harvest time had significant effect on dry weight. The highest dry weight (1909 kg ha-1) were obtained by 150 kg ha-1 net nitrogen with the density of 18 plants per m2 for the first harvest. Moreover, 50 kg ha-1 nitrogen fertilizer treatment with 10 plants per m2 showed lowest amount of dry weight (396.66 kg ha-1) in the second harvest time. However, the interaction of nitrogen and planting density revealed significant effect on fresh yield and leaf area. The highest yield (8071 kg ha-1) was related to 150 kg ha-1 nitrogen treatment with the density of 18 plants m-2. About physiological traits, the results claimed that treatments significantly affected the essential oil percentage, total chlorophyll, total phenol, nitrogen and calcium elements. The highest essential oil content (2.66%) was exhibited by the treatment of 150 kg ha-1 nitrogen with plant density of 10 plants m-2. In addition, the essential oil yield was also influenced by the interaction effect of harvest time and planting density. The highest yield (25665/075 milliliters ha-1) was found by the plant density of 18 plants m-2 from the first harvesting time.

Finally, according to our results, the best treatment was first harvesting time, 150 kg ha-1 nitrogen with the density of 18 plants m-2, which can be recommended for the planting program of aromatic pennyroyal.

Maize is one of the important cereal crops in Iran. Moghan, in Ardabil province, is an appropriate region to grow it in the country. Redroot pigweed (Amaranthus retroflexus L.) is one of the major noxious weed in maize fields worldwide and also in Iran. To study the interference of effect of this weed on maize seed yield and its morphological characteristics, a factorial experiment based on randomized complete block design with three replications was carried out at the research field of Agricultural and Natural Resources Research Center of Ardabil (Moghan) in 2012. The experimental factors were maize plant densities with four levels (70000, 75000, 80000 and 85000 plant.ha-1) and redroot pigweed densities with four levels (0, 4, 8 and 12 plant/m per row). The results showed that increasing density of maize and redroot pigweed, grain yield, biological yield and chlorophyll content of maize leaves were significantly reduced. The highest grain yield (11.88 t.ha-1) at density corn of 80000 plants.ha-1 of maize under weed free condition and lowest grain yield (7.92 t.ha-1) at maize density of 75000 plants.ha-1 with the presence of the 12 plant/m per row of redroot pigweed. The highest biomass of redroot pigweed (497.8 g/m per row) was produced at density of 85000 plants.ha-1 of maize with the presence of the 12 plant/m per row of redroot pigweed. Generally, the results of this research showed that 80000 plants.ha-1 of maize resulted in highest control of redroot pigweed and grain yield.

Rapeseed is the most important edible oil source after soybean and palm in the world and is the most widely cultivated oilseed crop in Iran. The objective of this study was to adapt and test the ability of the AquaCrop model to simulate canola grain yield, biomass and soil water content. In this study, the dynamic simulation model AquaCrop for plant growth under conditions of limited water spring was used in climate Tabriz. The experimental design included four treatment I1, I2, I3 and I4 respectively regular watering of rape, 20, 35 and 50 percent less than its potential needs in four replicates in a randomized complete block design was carried out for two years 2010 and 2011. AquaCrop model using the measured data in 2010 calibration and validation data were measured in 2011. Based on found results, the AquaCrop model predicted the GY at maturity with a good precision and soil water simulated by AquaCrop tends to follow closely the trend in the measured data. In general, statistical indicators NRMSE and d for the final performance of the product (7.05%, 0.96), soil water content (16.03% and 0.77), respectively. Also Errors in the model’s evaluation such as average NRMSE statistics were for dynamic biomass in the calibration and validation process 29.31 and 20.38%. The overall results showed that AquaCrop is a valid model and can be used with a reliable degree of accuracy for optimizing canola grain yield production and water requirement in the region Karkag of Tabriz.

In order to assess the effects salicylic acid (SA) on corn, weeds, and some herbicide efficiency, a factorial experiment with two factor as randomized complete block (RCB) designed with three replications was conducted research field of university of Tabriz- Iran in 2015. The first factor 10 levels including 8 herbicide treatments (Bentason, Nicosulfuron, 2,4-D + MCPA, Bromoxynil + MCPA, Rimsulfuron, Nicosulfuron + Rimsulfuron, Mesotrion + S-metolacholor + Terbuthlazine, Udosulfuron + Foramsulfuron + Tincarbason), and 2 controls treatments (weed free and weed infest), and the second factor was SA with 2 levels (0 (distilled water), and 1 mM SA). Results show that SA can increase corn leaf area, and dry weight of leaf and stem. This increase was outstanding in herbicides that could successfully control weeds. SA in weed infested treatment, increased common lambesquraters (Chenopodium album L.) density and dry weight, as the main weed species observed in the field. So in presence of weeds, SA is more benefit for weeds. Nicosulfuron was weak in weed control, and SA application increased weeds density and dry weights. Bromoxynil + MCPA, Mesotrion + S-metolacholor + Terbuthlazine, and 2,4-D + MCPA were successful herbicides in reduction weeds density and dry weight, and their efficiency was not reduced in presence of SA. Therefore, in herbicide treatments with weak efficiency in weed control, usage of SA is more benefit for weeds. According to obtained results, applying SA is not recommended with weak efficiency herbicides in weed control.

In order to evaluate the effects of pigweed (Amaranthus retroflexusL.)on growth properties of cotton (gossypium hirsutum), this research was conducted in Agriculture and Natural Resources Research Center of Tehran province in 2014. Field trial was based on randomized complete block design with 9 treatments (consisting of three Amaranthus retroflexus emergency times coincide with cotton cultivation, two-leaves and four-leaves of cotton and three plant densities including (3, 6 and 12 Amaranthus retroflexus per square meter) in three replications. The results showed that all cotton quantity properties consisting of plant height, number of sympodia and monopodia, height and lenght of the first sympodia, leaf area index, leaf and stem biomass, number and weight of boll, and cotton yield in all treatments reduced compared to control treatment (cotton cultivation). The difference among treatments was significant in all traits except quality traits at the level of 1% so that emergence of pigweed coincide with cotton emergence by density of 12 plant pigweed, Morphological traits and cotton yield decreased. Due to the significant reduction in cotton yield in the presence of weed compared to conrol treatment,consideration of Amaranthus retroflexus time weeding is mandatory. Considering that the highest cotton yield reduction was related to plant density of 12 pigweed and coinciding germination of pigweed with cotton cultivation time, it is necessary weed control of pigweed from the beginning growth season and timely weeding at sowing time before formation of boll

During recent years, the adoption of soil biotechnology has received noticed for aiming to use the potential of helpful soil organisms to maximize crops instead of trying to improve soil. Today what encourages developed countries to produces and consume bio-fertilizers and bacteria are the environmental side effects caused by the inadvertently imbalanced consumption of chemical fertilizers. Bean is seventh major world food crop that is often affected by adverse environmental conditions such as drought, Despite beans economic importance, few studies have been done on the genetics and genetic resource assessment, Given the importance of water deficit, Thus, the objectives of this study attempted to identify the most appropriate fertilizer treatment for varieties of bean under water deficit stress on the greenhouse experiment by passing through several stages of sulfur and Thiobacillus bacteria application and reviewing the given results In order investigate the effect of Thiobacillus and Sulfur on photosynthetic pigments in different common bean (Phaseolus vulgaris) cultivars under water deficit, the greenhouse experiment was carried out in factorial form using a completely randomized design with three replicates at the greenhouse of Research Station of the Islamic Azad University, Tabriz Branch, Iran, during the 2016. The studied factors included: (A) cultivars of bean a1) white bean (Dorsa), a2) red bean (Akhtar) and a3) pinto bean (Sadri) in four stages of fertilizer (B), b1) control, b2) 300kg/ha sulfur, b3) Thiobacillus and b4) sulfur + Thiobacillus, Under three water deficit condition (C) c1) control, c2) No irrigation from flowering stage and c3) No irrigation from poding stage. In this study used from two flowerpot (8kg) for each treatments. The following plant growth parameters were measured when about 65-75% of pods were matured: No. pod, No. full pod, 100-grain weight, biomass, grain yield and harvest index. SAS software was used to check the normality of the data, analysis of variance, and means comparison. The mean of the treatments were compared using the Duncan’s test at p< 0.05. Results revealed that water deficit, especially No irrigation from flowering stage reduced harvest index, yield, biomass, 100 seed weight, number of pods and field pod but No irrigation from poding stage had fewer negative effect on measured traits. This decrease in most cases reduced negative effects of stress by applying the Thiobacillus especially with sulfur. Thiobacillus bacteria provided more suitable condition to improving bioactivities of soil and caused to increasing measured traits through absorbing nutrients by root in compared with control treatment. But whatever increased during the period of stress, subsequently the positive influence of the bacteria and sulfur was lower. In all of traits studied, control has the highest value and after that was stress at poding stage and flowering stage. Water deficit due to flowers loss and reduced number of pods and eventually reduced yield. Among the cultivars Dorsa had the less success to Resistance, and application Thiobacillus + sulfur could not make the most impact for Resistance to stress in this cultivar. Recent studies indicated that using Thiobacillus + sulfur also improving soil physiological structure and also increase available mineral nutrients to coexistent plant. All cultivars showed intense sensitivity to stress (especially during flowering stage) and we can by applying Thiobacillus + sulfur in soil help to increase solubility of minerals and their absorption ability for increased plants resistance to stress.

In order to study the effects of weed interference and mycorrhiza (Funn eliformis mosseae) on quantitative and qualitative characteristics of chickpea, the recent study was carried out in 2016-2017 at Agricultural Research Center of West Azarbayjan. The treatments included mycorrhiza symbiosis in two levels (with and without) and weeds competition in four levels (control, grass pea, chicory and grass pea) which were arranged as factorial plots based on randomized complete block design in three replications. The plant characteristics were studied in terms of number of nitrogen fixing nodules, seed protein, leaf temperature, percentage of colonization, biological yield and grain yield. In addition, dry matter production in chicory and grass pea were measured. The highest number of nodules per chickpea root (24.41) were obtained by using mycorrhiza and weeds (chicory and grass pea) while the lowest number of nodules per chickpea root (12.91) were observed in presence of weeds without mycorrhizal symbiosis which shows a significant difference between these two (89%). The results showed that the highest grain yield (915.6 Kg/ha) was achieved in control treatment (without weed plus using mycorrhiza) while the lowest belonged to the treatment without mycorrhiza and in presence of weeds (395.6 Kg/ha), which showed 131% difference between these two treatments. In general, using mycorrhiza as input led to increased number of nodules per root and improved the grain yield of chickpea under dry-land conditions.

This study was performed to investigate the effect of water deficit stress on the some activities antioxidant enzymes, photosynthetic pigments and forage yield of sorghum genotypes. This experiment was conducted to factorial based on completely randomized design with three replications in greenhouse of University of Mohaghegh Ardabili in 2013. Treatments consisted of irrigation at four levels (85, 65, 45 and 25% of field capacity) and three genotypes of forage sorghum (KFS2, KFS6, and KFS17). Catalase, peroxidase and polyphenol oxidase enzymes and soluble sugar content, proline and carotenoids, increased in severe stress (25% field capacity) and decreased chlorophyll a and chlorophyll b. KFS6 genotype had the highest chlorophyll a, chlorophyll b, and total chlorophyll, however, the maximum biomass, proline, soluble sugars, peroxidase and polyphenol oxidase activity and carotenoid were observed by KFS2 genotype. Also positive correlation were observed between the biomass production and carotenoid and chlorophyll content, proline, soluble sugar, catalase, peroxidase and negative correlation between biomass and polyphenol oxidase. Between photosynthetic indices, chlorophyll a, between adjustment indices, peroxidase activity had maximum contribution to prediction biomass. Also in KFS2 genotype except carotenoid and proline all traits had highest correlation with biomass. In general KFS2 genotypes introduced tolerant to water stress as compared with the other genotypes.

Planting of narrow leaf cover crops may have an important effect in reducing the use of herbicide. Cover crops, therefore, are an effective tools in the non-chemical weed management in sustainable agriculture. To evaluate the effect of cover crops on weeds control and essential oil yield of mint, a factorial experiment based on randomized complete blok design with three replications was conducted at the Research Field Mohagheghe Ardabili University, Iran, in 2015. First factor consisted of: spring wheat, spring barley, winter rye, winter wheat, winter barley, mixed winter rye winter barley and second factor consisted of: cutting mulch near ground, heading living mulch 20-30 cm. from ground and killing ground cover by herbicide. Also, two controls were: without cover crop and weeding without cover crop and without weeding, inside conducted experiments. The results showed that the main effect of cover crops management had significant effect on peppermint content and dry weight and density of weeds. Comparison of interaction effects showed that highest leaf oil yield in heading living mulch of winter wheat, undercutting spring barley and winter rye was (52g/h). On the average in three stages of sampling the percent biomass control of redroot pigweed andfield bindweed in undercutting mulch, heading living mulch, killing cover crops with herbicide were 38% and 66% and their density control were 44% and 70%, respectively.

Controling weeds at their critical periods of growth leads to low production costs and injurious effects of using chemical weed controling methods. In this experiment we studied the timinig effects of weed control (interference of weeds after 20, 40 and 60 days and complete control of weeds) and weed interference periods for 20, 40 and 60 days after planting and complete interference) on growth and yield of forage maize CV. 454. The experiment was conducted incomplete randomized blocks design with three replications at the Research Farm of Islamic Azad University of Tabriz Branch in 2013. According to the results, maintenaning the farm for 40 and 60 days under weed interference after 20 days prevented reduction of maize biomass, while weeds interference after 20 days, weed interference and controling weeds after 40 and 60 days resulted in 41.2%, 35%, 25% and 32.5% reduction of forage maize biomass, respectively. Reduction in fresh weight of corn and fresh weight of leaf and stem were also observed due to interference of weeds after 20 days. If weeds are controlled after 60 days, reduction of corn weight and fresh weight of stem will also results in reduction of biomass. Also, if weeds are controlled after 40 days, stem fresh weight of maize will result in biomass reduction. Corn traits were affected by weeds control treatments. Being affected by treatments of weeds interference after 20 days, weeds non-interference, controlling weeds after 40 and 60 days, the height of corn was reduced by 29.9%, 41.4%, 27.6% and 37.2%, respectively. The stem diameter demonstrated a significant reduction, although it was only affected by treatments of weeds interference and weeds control after 60 days. Based on the results of this study, it may be suggested that controling weeds during initial 20-60 days of maize growth would prevent the undesirable effect of weeds on growth, production and biomass production of maize and also results in production costs.

The Effect of different levels of nitrogen (control, 50 and 100 kg/ha) and phosphorus (control, 50 and 100 kg/ha) on the growth and production of wild rye species studied. Nitrogen Application of 100 kg/ha height, number of leaves, tiller, stem and leaf dry weight, 30/7, 63/4, 103, 82, 131, and 33.3 percent increased respectively. In this study, the height, number of leaves and tillers, stem dry weight and leaf dry weight by 20 kg of nitrogen fertilizer significant increase in stem dry weight caused. crop height, leaf number, tiller number, leaf dry weight and shoot dry weight of wild rye by application of 40 kg/ha phosphorus additive, 13/1, 25/3, 38/4, 29/7 and 47/6 percent , respectively increased. Leaf Area index treated with 112 percent increase in the application of 40 kg P ha and 100 kg N ha respectively. Maximum biomass per unit of 430 gr/m2 by application 20 and 40 kg/ha phosphorus with 100 kg/ha nitrogen was obtained.

To evaluate the effect of gamma rays on the seeds and amounts of nitrogen on growth and yield of chamomile (Chamomilla recutita synonym Matricaria chamomilla)، a factorial experiment was conducted based on randomized complete block design with three replications at the Research Farm of Agriculture College of Shahid-Beheshti. -Urmia in 2010. Treatments were gamma rays from cobalt-60 on chamomile seeds cv. ‘Bodegold’ (zero، four، eight، 12، 16، and 20 Gray) and different levels of nitrogen (zero، 50، 100، and 150 kg/ha، urea after appearance of the 4th leaf). The highest leaf dry weight per plant (12. 5 g) and per hectare (4194 kg/ha)، stem dry weight per plant (49 g) and biomass (19995 kg/ha) were obtained at 8 gray and 100، 100، 150، and 150 kg/ha of nitrogen. The highest dried flower yield at the second harvest (104 kg/ha) were obtained from 20 gray by 100 kg/ha nitrogen، and the yield of the third harvest (122 kg/ha) was from 20 gray of gamma irradiation. While، the highest flower yield at the first harvest (419 kg/ha) and total yield (533 kg/ha) were produced from 0 gray and 150 kg/ha nitrogen. Essential oil percent did not affected by treatments، but despite the significant interaction effect of gamma irradiation and nitrogen on the yield of essential oil، means comparison showed no significant differences among treatments. Yield of dried flower in the first harvest، had the greatest impact on the harvest index.