116 research outputs found

    Effect of Salt Stress on Grain Reserve Composition in Ten Durum Wheat Cultivars

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    Saline soils are defined as those that contain sufficient soluble salts in the root zone to impair plant growth. Wheat is one of the three major cereals dominating world agriculture to date. Durum wheat is the hardest wheat and the concept of durum wheat quality is complex and confusing. Quality factors such as protein content, gluten strength and color have different priorities in various durum wheat markets. Changes in the grain quality of ten durum wheat cultivars under salt stress studied at the greenhouse condition. A factorial experiment was carried out based on completely randomized design with three replications. Treatments were salinity including 0, 60 and 120 mM and ten durum wheat cultivars (Boomer, PGS, 71135, 61130,605, C1351, KND, KDM, Haurani and G1252). Biochemical grain reserves such total protein and carbohydrate content, gluten, phosphorous and beta carotene were measured. Results showed that interaction of salt and cultivars was significant for all studied traits except of beta-carotene. At this experiment, gluten content changed very little with salinity levels. Cultivar 71135 at all salinity levels had the highest gluten content. With increasing of salt severity, the content of protein and carbohydrate decreased and content of phosphorous increased compared with control. In 60 mM salinity, cultivars 61130 and 71135, in 120 mM, 71135 and KDM and in control, 61130 and PGS respectively, had the highest and lowest content of protein. Cultivars 71135 and 61130 had the highest and PGS had the lowest phosphorous content in control. At 60 mM, cultivars 71135 and PGS respectively, had the highest and lowest phosphorous content. At 120mM, 71135 and Haurani respectively, had the highest and lowest phosphorous content. In three salt levels, cultivar 71135 was determined as the most tolerant cultivar according to content of grain reserve composition results

    The Effect of Osmo and Hormone Priming on Germination and Seed Reserve Utilization of Millet Seeds under Drought Stress

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    The objective of this research was to evaluate the effect of seed priming with osmo and hormone priming on growth and seed reserve utilization of millet seeds under drought stress. Treatments were combinations of 4 levels of drought stress (0, -4, -8 and -12 bar) and 3 levels of seed priming and control with 3 replications. Results showed that with increase in drought stress, germination components such as germination percentage, germination index, mean time to germination, normal seedling percentage, seedling length, seedling dry weight, weight of utilized (mobilized) seed and seed reserve utilization efficiency decreased, but seed priming showed lower reduction. The highest germination characteristics and seed reserve utilization was obtained by priming in control conditions. It is concluded that priming results in improvement in germination components of millet in drought stress conditions

    Effect of Planting Pattern on Radiation Use Efficiency, Yield and Yield Components of Sunflower

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    In order to determinate suitable planting pattern of sunflower, a field experiment was done in research field of university of Mohaghegh Ardabili in 2009. Factorial experiment was done based on randomized completely block design with three replication and two factor includes cultivars with three levels (Armavirusky, Azargol and Progress) and planting pattern with three levels (75*16.5, 60*20.5 and 45*27.5) with constant density (8 plant.m-2). Results of study showed that planting pattern effect was significant on head diameter and radiation use efficiency but have no significantly effect on yield and yield components. Cultivar effect was significant on yield and yield components but has no significantly on head diameter and radiation use efficiency. Among the cultivars studied, the highest grain yield (3616 kg.ha-1) belonging to Azargol cultivar and lowest grain yield (3131 kg.ha-1) belong to Progress cultivar. Therefore, it is better that according to exist facilities and machinery suitable planting pattern shall be selected and in the study area Azargol cultivar being planted

    Efficacy of syringe irrigation, RinsEndo and passive ultrasonic irrigation in removing debris from irregularities in root canals with different apical sizes.

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    ZIEL Vergleich der Effektivität der Debrisentfernung aus simulierten Wurzelkanalunregelmäßigkeiten bei unterschiedlicher apikaler Präparationsgröße mithilfe von Handspülung, Ultraschallspülung und RinsEndo. MATERIAL UND METHODE Dafür wurden 30 extrahierte einwurzelige humane Prämolaren randomisiert in 3 Gruppen (n=10) aufgeteilt. Im Anschluss wurden die Wurzelkanäle mit FlexMaster (VDW, München) entsprechend ihrer Gruppenzuteilung aufbereitet: Gruppe A 02/30, Gruppe B 02/40 und Gruppe C 02/50. Die Zähne wurden dann längs gespalten. Um nicht instrumentierte Wurzelkanalbereiche zu simulieren, wurde in der einen Zahnhälfte eine Rille 2-6 mm vom Apex entfernt angelegt, in der anderen Zahnhälfte wurden drei Gruben im Abstand von 2, 4 und 6 mm vom Apex präpariert. Die Gruben und Rillen wurden mit künstlichem Debris befüllt, die Zahnhälften anschließend reponiert. Alle Versuchsgruppen wurden den drei folgenden Spülmethoden mit 30 ml NaOCl (1%) unterzogen: Gruppe 1: Handspülung (Nadelgröße 30), Gruppe 2: RinsEndo und Gruppe 3: Ultraschallspülung. Vor und nach jeder Spülung wurden digitale Fotos mit 30facher Vergrößerung angefertigt. Die Menge des verbliebenen Debris wurde mithilfe eines 4-Punkte Scoresystems bewertet. Die Daten wurden mit einer nichtparametrischen Kovarianzanalyse ausgewertet und ein Paarvergleich adjustiert für multiples Testen nach Tukey (p=0,5) durchgeführt. ERGEBNISSE Die Ultraschallspülung zeigte eine signifikant bessere Debrisentfernung aus den künstlich angelegten Gruben und Rillen als Handspülung bzw. Spülung mit RinsEndo unabhängig von der Aufbereitungsgröße der Wurzelkanäle. Nur in Gruppe A (02/30) unterschied sich die Spülwirkung von Ultraschall und RinsEndo nicht signifikant (p=0,99). RinsEndo zeigte in allen Versuchsgruppen eine signifikant bessere Spülwirkung als die Handspülung (p=0,001)

    Evaluation of Drought Tolerance Indices and their Relationship whit Grain Yield in Wheat Cultivars

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    To illustrate the effect of drought stress on grain yield of 8 wheat cultivars and evaluation of drought tolerance and susceptible ones, two trials were established using randomized complete block design with three replications at research field of University of Mohaghegh Ardabili, Iran. In the first trail, drought was aplplied and irrigation was done once in order to seed germination, but in the second trail, regional normal irrigation regime was used. Wheat cultivars were Azar2, Agostave, Phinican, Sardari, Soysonz, Gaspard, Gascogen, and MV17. Results showed that according to the Fernandz grouping, Azer 2 was suitable for both stress and non stress conditions. MV17, Gascogen and Gaspard were recommended for optimum environment. Sardari cultivar was identified suitable for severe stress environment. Finican, Soysonze and Agostave cultivars had few grain yields in both stress and non stress conditions

    Simulating Photosynthesis, Respiration and Dry Matter Production in Annual Crops

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    Crop simulation model, mathematical exhibition of physiological different process of crop growth and development and its response to environmental factors. Then the aim of  this study is to provide a computer model for simulating photosynthetic, respiration and dry matter production in annuls crop. In this model daily gross canopy photosynthetic rate is a fraction of the maximum photosynthetic rate of a fully developed canopy at light saturation. For calculation of that, leaf area index based on the relative length of the four different crop development stage is calculated. Leaf area index, minimum and maximum daily temperature and daily radiation as model inputs were considered. After calculating gross photosynthetic rate, growth and maintenance respiration waste minus its and daily dry matter is calculated based on conversion efficiency coefficient. Sunflower data is used for testing of model. Regression of simulated over observed dry matter yield and leaf area index showed a good correspondence between predicted and observed dry matter yield and leaf area index. R2  for both  dry matter yield and leaf area index were more than 0.95 suggesting that the model was successful in growth and yield crop

    Modeling Growth and Yield of Sunflower (Helianthus annus L.)

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    Sunflower (Helianthus annus L.) is one of the most important oil seed crops in Iran. In spite of very progressing in production mechanization and varieties breeding, weather is still one of the most important determining factors for growth and production crops. Under optimal water and nutrient supply, radiation and temperature are two important factors for determining of production and dry matter accumulation. Quantification of the effect of radiation and effect of temperature on growth and yield of sunflower is important in selecting this crop for different agro-climatic situation. Environmental limitations in production at each regional can be evaluated using a crop simulation model and prolong weather data. The model operates simulation daily and it has four segments include simulation of leaf area index, light interception, dry matter production and seed yield. For testing model, the capability of the model was determined to predicting of leaf area index and accumulated dry matter production. Paired data of observed and simulated for both leaf area index and accumulated dry matter were tested by t test. Between paired data were not significant (α =0.05). Also linear regression between observed and simulated values for leaf area index and accumulated dry matter explained more than 95% of variability

    A Very Simple Model For Simulating Sugar Beet Yield For Potantial Production

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     Sugar beet is one of the most important crops in Iran. The potential yield and its limitations can be estimated using a simple model and long-term weather information. The present study was aimed to develop a very simple model for sugar beet. this model is a dynamic and mechanistic simulation model to simulate sugar beet growth and sugar accumulation for potential production condition. Therefore when the water is not a limiting factor for plant growth, maximizing intercepting solar radiation during growth season has major important. Because in this condition, solar radiation is a limiting factor for plant growth. Therefore selecting suitable planting date is important. Crop simulation models help us to determine planting date and to asses risk production. The model uses a few relationships to define leaf area development as a function of accumulated thermal time units. Biomass accumulation was simulated as a function of fraction of photosynthetically active radiation interception and radiation use efficiency. The growth of root is dependent on the biomass accumulation. The model uses a daily time step and readily available maximum and minimum temperatures and solar radiation. The model was tested for different planting dates at Ardabil in Iran. The model performed satisfactory in predicting the leaf area index and root biomass of sugarbeet as influenced by potential production condition. The simulated average root yield and leaf area index and its range were similar to observed root yield and leaf area index (root mean square error for root yield and leaf area index were equal to 3.97 t ha-1 and 1.3 respectively)

    Investigation of Correlation between Traits and Path Analysis of Corn (Zea mays L.) Grain Yield at the Climate of Ardabil Region (Northwest Iran)

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    In order to study correlation between some traits and yield components of corn and to determine the most effective factors on its yield, an experiment was conducted at the agricultural research farm of university of Mohaghegh Ardabili in 2007. The experiment was conducted as a split plot in a randomized complete block design with four replications. Main plots were allocated at three levels to different planting dates (10, 20 May and 30 June) and subplots were allocated at the different levels of nitrogen fertilizer (0, 75, 150, 225 Kg N ha-1). The utilized corn seed was SC 404 hybrid. Sequential path analysis was used for evaluation of relationships between yield and yield attributes and to eliminate less important variables by using SPSS. Results showed that kernel per ear has the most correlation (r = 0.53) with grain yield. The grain yield and kernel per ear indicated negative and significant correlation with grain thickness (r = -0.33 and r = -0.52 respectively). The correlation between grain protein and thickness was negative and significant, too (r = -0.52). Results obtained from path analysis revealed that kernel per ear has more importance for selecting corn cultivars with high yield among different traits. Kernel per row and grain length had an effect on grain yield. Thus, these two traits can be attend in breeding programs and also be effective as a potential traits in improving desired corn cultivars
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