Mohammad Hosein Najafi Mood; Ali Shahidi; Abbas Khashei Siuki
Abstract
In order to determine the best water- salt-quantitative parameters (number of bolls per square meter, boll weight, plant height, lint percentage) of cotton cultivars Varamin and Khordad, a research project examined the impact of salinity and irrigation water levels on yield and yield components of these ...
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In order to determine the best water- salt-quantitative parameters (number of bolls per square meter, boll weight, plant height, lint percentage) of cotton cultivars Varamin and Khordad, a research project examined the impact of salinity and irrigation water levels on yield and yield components of these two cultivars cotton in Birjand climatic conditions. The statistical design was a factorial randomized block split under climatic dry conditions with three levels of salinity and four levels of irrigation water. Sowing was done using basin method with dimensions of 4 x 5 meter on 28 April. Simple linear, Cobb-Douglas, quadratic and transcendental functions were used for this research. First, the results of functions coefficients tables and F value showed that all functions mentioned above were able to provide a determinant and significant estimation of the parameters the number of bolls per square meter, boll weight and plant height. Moreover, coefficients of determination of the plotted regression lines and the t-student statistic in regression line between the measured and predicted values confirmed the above results. So, the next step was to rank and identify the best function among them. To achieve this, five statistical parameters including root of the mean square error, coefficient of determination, modeling efficiency, the maximum error and coefficient of residual was used.The results obtained with both cotton cultivars of Varamin and Khordad showed that for the parameter of boll weight the quadratic function with a coefficient of determination of 80 and 89%,, respectively, and for the parameters of number of bolls per square meter and plant height transcendental functions with determination coefficients of 98, 95, 99 and 90% were able to be introduced as the superior functions amongst all others in the climatic area of Birjand. Additionally, none of the studied functions not able to provide an acceptable estimation of the lint percentage, because F value which showed the significant estimation of the studied parameters was not significant for the above mentioned parameter.
Majid Abdoli; Mohsen Saeidi; Saeid Jalali-Honarmand; Siroos Mansourifar; Mohammad Eghbal Ghobadi
Abstract
Among different cereal crops, wheat has the most cultivation areas and yield in the world. Also, wheat is the major crops grown in arid and semi-arid regions. The occurrence of drought stress during grain filling is the prominent and inevitable characteristic of these areas. The objectives of this research ...
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Among different cereal crops, wheat has the most cultivation areas and yield in the world. Also, wheat is the major crops grown in arid and semi-arid regions. The occurrence of drought stress during grain filling is the prominent and inevitable characteristic of these areas. The objectives of this research were to determine the effect of water deficiency and the role of current and storage sources of assimilates on grain filling, grain yield and carbohydrates remobilization. Therefore, an experiment was carried out in a split-plot factorial arranged in a randomized complete block design with three replications during 2010-2011 cropping season at the Research Farm of Razi University in Iran. The main factor was the irrigation treatments including control or non-stressed treatment (irrigating plants at all growing stages based on crop water requirement and climatic conditions) and water deficit stress (irrigation termination after anthesis). The combination of eight wheat cultivars including Bahar, Parsi, Pishtaz, Pishgam, Chamran, Zarin, Sivand, Marvdasht and one line DN-11 along with the photosynthetic sources limiting treatments including control (no limitation of photosynthetic sources), defoliation of the flag leaf, defoliation of all leaves except the flag leaf), de-awning and shading over the ear were considered as the sub plots. The results showed that post-anthesis water deficiency significantly decreased grain yield (22.2%) and removal of photosynthetic sources reduced grain yield through reducing the grain weight. In this case the role of spike photosynthesis in grain filling (35.4%) was greater than the flag leaf and lower leaves roles (18.6 and 18.5%, respectively) and awns had the lowest role in grain filling (3.3%). Under removing of assimilate sources, remobilization of stored material from the different parts of stem internodes was increased, suggesting the compensatory role of them in yield loss prevention. Water deficit stress could not increase the remobilization efficiency, but in terms of mentioned traits, there were differences amongst cultivars and different removing photosynthetic sources. In both control and water deficiency stresses treatments, the amounts of remobilization from different parts of stem and spike to the growing grains were similar. Under well watered condition, the grain yield increased due to higher photosynthesis rate compared to water deficiency stress conditions.
Ali Hamed; GholamAbbas Akbari; Nayer Azam Khosh Kholgh Sima; Amir Hosein Shirani Rad; Hamid Jabbari; S. Ali Tabatabaee
Abstract
In order to evaluate the agronomic characteristics and some physiological traits of canola varieties under drought conditions, separate experiments were carried out at the Research Field of Yazd Agricultural and Natural Resources Research Center in 2011-2012. Each experiment was conducted in a randomized ...
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In order to evaluate the agronomic characteristics and some physiological traits of canola varieties under drought conditions, separate experiments were carried out at the Research Field of Yazd Agricultural and Natural Resources Research Center in 2011-2012. Each experiment was conducted in a randomized complete block design with three replications. In the first experiment (control) that was conducted under optimal irrigation, plants were irrigated based on 80 mm evaporation from pan class A at all stages of plant growth, in the second experiment, drought stress was applied at stem elongation up to maturity stage, in the third experiment, drought stress was performed at flowering up to maturity stage and in the fourth experiment, drought stress was performed at silique formation up to the end of maturity stage using three canola varieties including GKH2005, Opera and Okapi. The results of combined analysis showed that withholding irrigation started at stem elongation, flowering stage and silique formation reduced the silique number in the main stem by 44, 34 and 9 %, silique number per branches by 60, 34 and 17 %, seed number in silique per main stem by 62, 35 and 5 %, seed number in silique per branches by 73, 46 and 11 %, 1000- seed weight by 19, 28 and 26 % and seed yield by 62, 51 and 27 %, compared with the control conditions, respectively. The greatest grain yield was obtained from the control experiment as 3110 kg/ha and followed by withholding irrigation from silique formation, flowering stage and stem elongation with corresponding values of 2510, 1773 and 1450 kg/ha, respectively. Drought stress reduced the stomatal conductivity, relative water content (RWC) and cell membrane stability, whereas SPAD value was higher under drought conditions as compared with the control experiment. Under drought stress among studied cultivars, GKH had the maximum silique number, seed number in silique and seed yield due to the least electrolyte leakage percentage, higher stomatal conductivity and relative water content (RWC). The overall results of the experiments showed that withholding irrigation from silique formation owing to the reduction in irrigation frequency and efficient use of it in summer crops irrigation accompanied with the employment of drought tolerant varieties can be effective in increasing productivity and canola cultivation areas in arid and semi-arid regions.
Masoomeh Hatamvand; Tahereh Hasanloo; Fatemeh Dehghan Nayeri; Amir Hosein Shiranirad; S. Ali Tabatabaei; S. Mohammad Hosseini
Abstract
Drought is one of the major environmental factors limiting crop production in the world. In order to evaluate some physiological and biochemical traits of rapeseed varieties (Brassica napus L.) under drought stress, a field experiment was conducted as a split plot, arranged in a Randomized Complete Block ...
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Drought is one of the major environmental factors limiting crop production in the world. In order to evaluate some physiological and biochemical traits of rapeseed varieties (Brassica napus L.) under drought stress, a field experiment was conducted as a split plot, arranged in a Randomized Complete Block Design (CRBD) with three replications at the end of flowering to seed filling (26 days). The main factor was drought stress in two levels including stress and control (160 and 80 mm evaporation from pan, respectively) and the sub-factor was cultivar at three levels including (1) Billy, (2) Adriana and (3) Tassilo. Relative water content, stomatal conductance, proline and total sugar content were measured 7, 12 and 26 days after the cessation of irrigation. The results showed drought stress at flowering stage (7 days after stress) reduced the relative water content, stomatal conductance and increased total sugar and proline content. Stress at pod setting stage (12 days after stress) and seed filling (26 days after stress) reduced the relative water content and stomatal conductance and increased proline and total sugar content. Seed yield and its components were measured after plant maturity. Stress at flowering stage reduced seed yield and its components but reductions in seed weight were not significant. The highest and lowest seed yield was observed in Adriana in control treatments (2814 kg.h-1) and in Tassilo in stress conditions (994.4 kg.h-1), respectively. According to the results, Adriana showed a better performance under drought stress than other cultivars. Thus, cultivation of this cultivar is recommended in arid areas.
Mohammad Zabet; Sadegh Bahamin; Sadegh Ghoreishi; Hosein Sadeghi; S. Gholamreza Moosavi
Abstract
Water shortage is the most important limiting factor for achieving potential yield of crops, especially in arid and semiarid regions. Nitrogen is also amongst the most important factors that limit agricultural production. In order to study the effects of deficit irrigation and fertilizer on forage yield ...
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Water shortage is the most important limiting factor for achieving potential yield of crops, especially in arid and semiarid regions. Nitrogen is also amongst the most important factors that limit agricultural production. In order to study the effects of deficit irrigation and fertilizer on forage yield as well as aboveground dry and fresh weight of forage millet (Notrifid), a split plot experiment based on randomized complete block design was conducted with three replications in the Research Field of the Islamic Azad University of Birjand in 2006. Irrigation levels (50 and 100 percent of the plant required water) and nitrogen fertilizer levels (0, 75, 150 and 225 kg N ha-1), were considered as the main and sub plots, respectively. Analysis of variance showed that both irrigation and nitrogen had a significant effect on dry and fresh weight of leaves and stems as well as forage yield of millet in the sum of the two harvesting stages. The interaction of experimental treatments, however, was not significant in any of these traits. By reducing irrigation, the sum of forage yield decreased from 40.72 to 24.92 t ha-1 and the hay yield also decreased from 8.94 to 5.34 t ha-1. Increasing nitrogen usage up to 225 kg N ha-1 enhanced the total fresh and dry yield for about 79.8 and 81.2%, respectively, compared to the control treatment (0 nitrogen). In general it can be concluded that irrigation and nitrogen are the two effective factors determining the forage yield of millet.
Jafar Nabati; Mohammad Kafi; Saeid Khaninejad; Ali Masoumi; Mohammad Zare Mehrjerdi
Abstract
Sustainable production of crops in arid and semiarid regions of Iran is under threat of salinity stress. Therefore, cultivated crops should be compatible with salinity in these regions and also provide proper yield productivity. In order to investigate the forage quality of five different kochia ecotypes ...
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Sustainable production of crops in arid and semiarid regions of Iran is under threat of salinity stress. Therefore, cultivated crops should be compatible with salinity in these regions and also provide proper yield productivity. In order to investigate the forage quality of five different kochia ecotypes in response to different levels of salinity, an experiment was performed in a split plot arrangement based on randomized complete block design with three replications. Saline waters (5.2 and 16.5 dS m-1) and five kochia ecotypes (Birjand, Urmia, Borujerd, Esfahan and Sabzevar) were considered as main and sub plots, respectively. Results showed that dry matter digestibility of leaves, stems, and total dry matter were enhanced by increasing salinity. There was no significant difference in dry matter digestibility among ecotypes, while stem dry matter digestibility of Sabzevar ecotype, total dry matter digestibility and digestible dry matter of Urmia ecotype were the highest amongst ecotypes. Increased salinity level enhanced the total digestible organic matter. Digestive value of leaves and stems was enhanced by increasing salinity, but the total digestive value was reduced by increasing salinity. Salinity stress reduced the enhancement of crude protein content of organs and whole plant. Overall, kochia forage quality traits are comparable with other common forage crops.
Negin Asadipoor; Adel Sepehry; S. Ali Hossaini
Abstract
Salinity stress is regarded as one of the most important factors limiting plant growth and agricultural products, particularly in arid and semi-arid regions. Regardless to increment in salinity lands and shortage in desirable soils for cultivation in country, recognition of range plants that are salt ...
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Salinity stress is regarded as one of the most important factors limiting plant growth and agricultural products, particularly in arid and semi-arid regions. Regardless to increment in salinity lands and shortage in desirable soils for cultivation in country, recognition of range plants that are salt tolerant is very important. In many plant species sensitivity to NaCl is known to vary amongst growth stages. The purpose of this study was to determine the effect of different salinity levels on some growth indices (including shoot length, root length, shoot dry mass and number of seeds), in three species of M. scutellata, M. polymorpha and M. rigidula. The experiment was conducted as a factorial based on completely randomized design with 4 replications and six salinity levels (0, 5, 10, 15, 20 and 25 dS.m-1). The results showed that salt stress had a significant effect on estimated parameters and shoot length, root length, seed number and dry weight were reduced by increasing salinity level. Comparison of the means showed that M. scutellatawas the best species amongst all based on the studied characteristics. Results suggest that M. scutellata could be identified as a successful cultivar in breeding programs under saline conditions.
S. Fazel Fazeli Kakhki; Ahmad Nezami; Mehdi Parsa; Mohammad Kafi
Abstract
Germination and seedling growth is important for plants establishment under saline conditions. So choosing the plants that have rapid and uniform germination under saline conditions may help initial establishment and seedling growth. In order to assess the response of sesame ecotypes to salinity, a factorial ...
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Germination and seedling growth is important for plants establishment under saline conditions. So choosing the plants that have rapid and uniform germination under saline conditions may help initial establishment and seedling growth. In order to assess the response of sesame ecotypes to salinity, a factorial experiment based on completely randomized design was conducted with three replications under laboratory conditions. The first factor was five sesame ecotypes (MSC3, MSC6, MSC7, MSC12 and MSC14) and the second factor consisted of 11 salinity levels (1, 3, 6, 9, 11.4, 14.5, 16.4, 19.6, 21.1, 23.1, and 25.1 dS.m-1) that was provided from water wells in the region with electrical conductivities of 2.5, 10 and 23 dS.m-1 and then treatments were achieved by diluting or concentrating these saline solutions. The results showed that germination was decreased by increasing salinity, so that there was very low germination in the salinity level of 23.1 dS.m-1 and no germination was observed in the salinity of 25.1 dS.m-1. Salinity had significant effects on components of final germination percentage (FGP), germination rate (GR), germination uniformity (GU), time to reach 50% germination (T50), germination energy (GE ), seedling vigor index (SVI), length of shoot and root to shoot dry weight ratio (R / S). With increasing salinity levels, however, these components were not equally affected. In salinity of 3 dS.m-1, the indices related to seedling growth was higher than the control and other treatments, and FGP, GU, GE and SVI indices were 8, 5, 10 and 66% higher than the control treatment, respectively. The highest correlation of FGP was observed with GE (0.98**) and GR (0.83**), which indicates that sesame ecotypes seeds with high germination energy will have increased amount of FGP. In high salinity conditions (23.1 dS.m-1), the maximum and minimum amount of FGP, GR and GE were observed in MSC6 and MSC12 ecotypes, respectively. MSC6 and MSC7 compared with other ecotypes had a higher SVI index. It seems that MSC6 ecotype had a greater tolerance range than other ecotypes under conditions of this experiment.
Rana Naderi Zarnaghi; Mahmood Toorchi
Abstract
Agricultural productivity is severely affected by soil salinity, and the damaging effects of salt accumulation in agricultural soils have influenced ancient and modern civilizations.A split plot experiment was carried out to study the effect of salinity stress on morphological and physiological characteristics ...
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Agricultural productivity is severely affected by soil salinity, and the damaging effects of salt accumulation in agricultural soils have influenced ancient and modern civilizations.A split plot experiment was carried out to study the effect of salinity stress on morphological and physiological characteristics of several rapeseed genotypes. Three salinity levels (0, 150 and 300 mM NaCl) and 12 spring type rapeseed genotypes, were considered as the main and sub factors, respectively. Morphological parameters of shoot height, root length, root and shoot fresh weight, root and shoot dry weight, 100-seed weight, seed yield, osmotic potential, leaf water potential, leaf proline, Na+ content of leaf, K+content of leaf and leaves K+/Na+ ratio in rapeseed genotypes were studied. Analysis of variance showed highly significant differences between the studied genotypes in all traits. The methods of UPGMA were used to cluster analysis for grouping on the studied traits. Cluster analysis were classified the genotypes into two groups in which Heros and Comet were belong to the cluster with low mean with respect to all the traits. Therefore, these genotypes could be crossed with tolerant genotypes, Amica and Comet, for providing a genetic maps and QTL analysis. Furthermore, identification of tolerant and sensitive genotypes to salinity may provide a basis for molecular studies aiming to achieve a proper understanding of the mechanism of canola tolerance to salinity stress and involved genes in this process.
Seyed Ahmad Sadat Noori; S.M. Mahdi Mortazavian; Mohsen Ebrahimi; Maryam Ashrafijou; Elnaz Hosseinzadeh
Abstract
After it is confirmed that laser beam may affect plant traits, nowadays this physical factor is widely used as a suitable abiotic stimulator in scientific research studies. In the current investigation, the influence of three laser irradiation levels (red, Infra-red and Nd:YAG) at two different dosages ...
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After it is confirmed that laser beam may affect plant traits, nowadays this physical factor is widely used as a suitable abiotic stimulator in scientific research studies. In the current investigation, the influence of three laser irradiation levels (red, Infra-red and Nd:YAG) at two different dosages (one and two times laser radiation for 18 seconds each time) on germination traits and yield of canola (Brassica napus L.) was studied under different NaCl concentrations (0, 100, 200 and 300 mM NaCl). The study was conducted as a factorial experiment based on completely randomized design with three replications in 2009. Final germination percentage (FGP), mean time for germination (MTG) and mean daily germination (MDG) and final yield were recorded. All germinations and yield significantly increased with irradiation by laser beam. Non-irradiated seeds were considered as the control treatment. Study results showed significant diffrences between irradiated seeds and control ones in terms of germination characteristics and plant yield. The Nd:YAG laser irradiation had the highest effect on the germination characters and yield compared to the red and infrared laser at either dosages and averagely twice application of laser irradiations caused a significantly higher germanations and yield compared to one application. Results indicate the positive impact of laser beam irradiation for canola tolerance to salinity.
Babak Motesharezadeh; Leila Aghaei; Gholam Reza Savaghebi
Abstract
In recent years a major part of agricultural lands has been contaminated with heavy metals as a result of industrial activities,ore mining, smelting, irrigation with sewage and fertilization which has reduced soil quality and plant products health. This study was conducted to investigate some plant responses ...
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In recent years a major part of agricultural lands has been contaminated with heavy metals as a result of industrial activities,ore mining, smelting, irrigation with sewage and fertilization which has reduced soil quality and plant products health. This study was conducted to investigate some plant responses of two bean cultivars (Khomein and the G01437) to cadmium and lead in a calcareous soil under greenhouse conditions. In a factorial experiment based on completely randomized design, cadmium in the form of cadmium nitrate four levels of zero, 20, 40 and 80 mg/ kg soil and lead as lead nitrate in zero, 50, 100 and 200 mg/ kg levels were added to pots. Then seeds of the two mentioned bean cultivars were planted. Plants dry weight, concentration and uptake amounts of cadmium and lead in shoots and roots were determined after harvesting. Analysis of variance showed that main and interaction effects of cadmium and lead were significant on dry weight of roots and shoots (p<0.01). The effects of treatments on the uptake responses, however, were varied. Plant cultivars had a significant effect on cadmium and lead uptake in shoots and roots. Shoots cadmium uptake in Khomein cultivar was greater than G01437, while Cadmium uptake in the roots was greater in G01437 than in Khomein. The greatest uptake of cadmium in the shoots was observed in the zero lead + 80 cadmium treatment in Khomein (9.40 micro g per pot) and its lowest amount was obtained from 50 lead + zero cadmium treatment in G01437 (1.27 micro g per pot).Translocation factor (TF) of cadmium and lead and BRS index was decreased by increasing the cadmium and lead concentrations in soil.
Shahrbano Taherabadi; Mehdi Parsa; Ahmad Nezami
Abstract
Recent research studies show that the foliar application of methanol increases the growth of C₃ crops in arid regions. An experiment was carried out in a split plot based on randomized complete block design with three replications at the Research Station of Faculty of Agriculture, Ferdowsi University ...
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Recent research studies show that the foliar application of methanol increases the growth of C₃ crops in arid regions. An experiment was carried out in a split plot based on randomized complete block design with three replications at the Research Station of Faculty of Agriculture, Ferdowsi University of Mashhad in spring 2010. Three irrigation levels (100, 75 and 50 percent of water requirement) and four foliar application levels of methanol (0, 20, 40 and 60 volumetric percent) formed the main and sub plots, respectively. Methanol was sprayed on chickpea shoots after pod stage in 3 times with a 10- day interval. Theresult showed that the effects of foliar application of methanol on physiological traits were significant. So that spraying of 60 volumetric percent of methanol affected physiological traits greater than other treatments and caused increasing in dry matter, leaf area index and crop growth rate while had no effect on relative growth rate. In drought stress treatment, leaf area index, cumulative dry weight and crop growth rate, relative growth rate were in their maximum amounts under adequate moisture treatment (control) compared with the drought stress conditions due to continued vegetative growth in control plants. In this experiment, the differences observed in the amount of dry matter accumulation and crop growth rate are mainly due to decreased leaf area index under drought stress conditions.
Seyedeh Farahnaz Talebi; S. Najm Aldin Mortazavi; Yavar Sharafi
Abstract
In order to evaluate different NaCl concentrations on some morpho-physiological specifications of Zinnia elegans,an experiment based on randomized complete block design with three replications was conducted by adding NaCl of 0, 20, 50 and 75 mM with electrical conductivity of 1, 3.1, 6 and 9.3 dS.m-1, ...
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In order to evaluate different NaCl concentrations on some morpho-physiological specifications of Zinnia elegans,an experiment based on randomized complete block design with three replications was conducted by adding NaCl of 0, 20, 50 and 75 mM with electrical conductivity of 1, 3.1, 6 and 9.3 dS.m-1, respectively. Results showed that increasing NaCl concentration over 50 mM significantly decreases the leaf number, leaf area, root length, shoot and root fresh and dry weight, and chlorophyll content. In this research, increasing salinity enhanced catalase and peroxidase activities, while catalase showed greater activity than peroxidase. So, because Zinnia elegans flowers are resistant to salinity, salinity levels above the 6 mS cm-1 can reduce plant growth and development.
