Pomology
Sh. Sorori; A. Asgharzade; A. Marjani; M. Samadi
Abstract
Introduction Drought is one of the most important environmental stresses. It limits crop production in the world and has adverse impacts on growth of plants and their metabolic processes. By changing some of the metabolic processes, drought stress changes the behaviour of plants and, eventually, ...
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Introduction Drought is one of the most important environmental stresses. It limits crop production in the world and has adverse impacts on growth of plants and their metabolic processes. By changing some of the metabolic processes, drought stress changes the behaviour of plants and, eventually, makes them resistant to some stresses. Given the water crisis in Iran, and since most of the available water is used in the agriculture sector, there is a need to change the current cropping pattern. The substitution of low-water-use for high-water-use plants could be an important water management strategy. Every physiological and biochemical factor involved in water conservation in plants is an effective factor in introducing tolerant varieties.Materials and MethodsThe required chemicals ( 80% acetone, 95% ethanol, ninhydrin, glacial acetic acid, benzene, proline, pure glucose, anthrone, sulfuric acid, potassium phosphate, polyvinylpyrrolidone [PVP], EDTA, hydrogen peroxide and guaiacol) were purchased from the Merck Company. This study was carried out in the spring and summer of 2019 in the Research Greenhouse of Islamic Azad University of Bojnourd. The rooted cuttings of 18 dominant grape varieties in the region (Kolahdari, KajAngoor, Fakhri, sefid Beryan, Divaneh, Sahebi, La’l, Siyah, Shiregi, Garmeh, Khalili, SanjariKajAngoor, Keshmeshi, Ghareghat, Maskeh, Asgari, Flame Seedless and White Seedless) were planted in plastic pots with a diameter of 35 cm and a height of 40 cm. The soil was a mixture of blown sand, leaf litter, and garden soil in the 1:1:1 ratio. Before the experiment, all pots were irrigated to reach field capacity.The factorial experiment was conducted using completely randomized design with three replications. The first factor was irrigation cessation (15-day drought stress) and control (irrigation to field capacity level). The second factor was variety (18 varieties).To apply the stress condition, irrigation cessation continued until leaf wilting signs were appeared. Based on previous experience, the duration of tolerance to drought stress was approximately 2 weeks. During the experiment, the minimum and maximum greenhouse temperatures were, respectively, 18.5 °C and 34 °C and natural light was used.Results and Discussion The results of analysis variance showed that drought stress significantly increased the amount of electrolyte leakage (6.29), and activities of peroxidase (0.056 katal per ml) and catalase (0.92 katal per ml). It also decreased leaf relative water content (61.95%), relative chlorophyll content (16.85) and contents of chlorophyll a (3.45 mg/g), chlorophyll b (1.12 mg/g) and carotenoids (2.84 mg/g).Grape varieties respond differently to drought stress and, in general, water scarcity reduces their leaf RWC and chlorophyll contents. According to Schutz and Fangmier (2001), a decrease in chlorophyll content under stress conditions is because of an increase in the production of oxygen radicals in the cell. These free radicals can cause peroxidation and decomposition of the pigments. The intensity and greenness of the leaves reduce with decreasing the chlorophyll concentration and accelerating the process of aging.Reduced greenness of the leaves under long-term stress conditions may be partially due to reduced nitrogen flow into the tissues and changing activities of such enzymes as nitrate reductase. Since nitrogen is a constituent of a chlorophyll molecule, its deficiency in plants may slow down the formation of chlorophyll. Lawlor and Cornic (2002) showed the effectiveness of carotenoid, as an auxiliary pigment, in protecting thylakoid membranes and preventing chlorophyll photo-oxidation. Drought stress increases the activity of the peroxidase and catalase enzymes in both drought-sensitive and -resistant varieties; however, the activity of antioxidative enzymes is significantly higher in the stress-resistant varieties.The studied cultivars were divided into the three groups include of tolerant (White Seedless, Garmeh, Maskeh, Flame Seedless, Fakhri, Khalili and Divaneh), semi-susceptible (Kolahdari, Sefid Beryan, Sahebi, Laal, Shiregi, Kaj Angoor Sanjari and Asgari) and sensitive (Siah, Ghare-Ghat, Kaj Angoor Sanjari and Keshmeshi) cultivars to drought stress. Among the studied cultivars, White Seedless had the highest levels of relative leaf water (77.81%), relative chlorophyll content (28.62), carotenoids (4.81 mg/g) and the lowest amount of electrolyte leakage (31.5) and Garmeh the highest chlorophyll a (6.64 mg/g) and chlorophyll b (2.12 mg/g) contents and peroxidase (0.0618 katal per ml) and catalase activities (0.959 katal per ml).Conclusion The grape plant adaptation to drought stress is the result of changes in many morphological, physiological, and biochemical mechanisms, which cause changes in the rate of electrolyte leakage, leaf RWC, proline content, soluble solids, speed of photosynthesis, enzymatic activities, etc. The results showed that the white seedless variety had the highest leaf RWC, relative chlorophyll content, carotenoid content, and the lowest electrolyte leakage. Besides, Garmeh variety with the highest chlorophyll a and b, peroxidase, and catalase contents is amongst the most resistant varieties.
Pomology
M. Janali nejad; H. Afshari; B. Alizadeh; O. Ghasemi
Abstract
Introduction: Environmental stresses are the most important factors that reduce agricultural yield all over the world. The water stress especially in flowering damages yield and yield quality, however, some studies showed that sometimes it does not have any harmful effect on yield. For instance, some ...
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Introduction: Environmental stresses are the most important factors that reduce agricultural yield all over the world. The water stress especially in flowering damages yield and yield quality, however, some studies showed that sometimes it does not have any harmful effect on yield. For instance, some studies approved that deficit irrigation improves sugar content and then fruit quality. Therefore, in order to evaluate the effects of potassium sulfate, vermicompost and water stress on yield and quality of four years old nectarine (CV Red gold), an experimental study was carried out on a garden which covers 5000 m2 in Eslamdeh (Sari) during 2015 to 2016.
Materials and Methods: A split-split plot experiment based on complete randomized block design (RCBD) with 18 treatments in three replications (totally 54 treatments (trees)) was used in this study. Some complex soil samples were gathered individually from 0-30 and 30-60 cm to determine macro and micro fertilizer demand and were analyzed to determine physicochemical characteristics. Two levels of tree water requirement (50% and 100%) as the main plot, vermicompost in three levels (0, 5 and 10 kg per tree) as subplot, and three levels of potassium sulfate, (0, 200 and 400 g per tree) as sub-sub plothad been applied. The rest fertilizer demand was recommended based on soil analysis. vermicompost, potassium sulfate and other essential fertilizers were applied in late winter and then aeration or digging was carried out. The fruit was picked after ripening and was weighed. Diameter, height and mass weight were measured. Soluble solids, the total sugar content of fruit was measured based on pH-meter, refractometer and Arnon methods. Potassium and chlorophyll were measured by flame photometer and chlorophyll meter.
Results and Discussion: The results showed that the effects of different levels of applied treatments were not significant on fruit pH. In addition, effects of different levels of potassium sulfate on TSS, leaf chlorophyll, potassium sulfate levels of leaf, fruit weight and yield, fruit height, and flesh weight, single fruit weight were all significant at 1 % level. The results also showed that levels of vermicompost on K level of leaf and fruit yield was significant at 1% level, and on fruit weight at 5% level. Effects of other treatments were not significant on other studied traits. Results of mean comparison showed that fruit crop was increased with an increase in vermicompost application. The minimum yield (41.44 kg/fruit) obtained from control and application of 10 and 20 kg/h vermicompost resulted in 58.33 and 60.61 kg/h, respectively. Application of potassium sulfate also showed to be effective on fruit yield. The minimum yield obtained from control, applying 200, 400 g of potassium sulfate, resulted in 54.89 and 61.33 kg/tree. Furthermore, potassium sulfate levels resulted in TSS enhancement. The minimum obtained from control plot (8.083) and maximum obtained from 8.864 and 9.612 with applying 200, 400 g of potassium sulfate, respectively. Potassium application also resulted in fruit level volume. The minimum level observed at control plot (116.2), applying 200, 400 g of potassium sulfate, resulted in 131.5 and 141.3 kg/tree. The interaction effects of different levels of potassium sulfate, vermicompost and irrigation showed that maximum fruit yield obtained from 400 g/K, 10 kg of vermicompost and applying 100% tree water requirement with yield of 70.66 g which was not statistically different with triple interaction of 400 g/K, 10 kg of vermicompost and applying 50% of tree water requirement.
Conclusion: In the current research, the effects of the use of potassium sulfate and vermicompost on maintaining plant balance and fruit quality and also decreasing water use in stress conditions were studied. Results showed that the use of potassium sulfate along with vermicomposts had a significant effect of improving morphological and physiological characteristics of nectarine. Furthermore, they increased nutrition availability for the crop and then increased yield and fruit quality. The following conclusion to be drawn is that fruit was increased with an increase in vermicompost application. Application of potassium sulfate also showed to be effective on fruit yield and TSS enhancement. The interaction effects of different levels of potassium sulfate, vermicompost and irrigation showed that maximum fruit yield obtained from 400 g/K, 10 kg of organic matter and applying 100% tree water requirement with yield of 70.66 g which was not statistically different with triple interaction of 400 g/K, 10 kg of vermicompost and applying 50 % tree water requirement.
H. Farhadi; M.M. Sharifani; M. Alizadeh; H. Hokmabadi; Sasan Aliniaeifard
Abstract
Introduction: Agriculture of Iran is known worldwide for its pistachio (Pistacia vera L.) and is one of the most important non-oil exports. Therefore, attempts to improve the yield can be one of the primary goals in the pistachio industry in Iran. Due to the drought problem in Iran, increasing the cultivation ...
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Introduction: Agriculture of Iran is known worldwide for its pistachio (Pistacia vera L.) and is one of the most important non-oil exports. Therefore, attempts to improve the yield can be one of the primary goals in the pistachio industry in Iran. Due to the drought problem in Iran, increasing the cultivation area to increase production may not be a good option. Therefore, the purpose of this study was to compare the drought tolerance of different pistachio seedlings from open pollination and pollinated with domestic species pollen and controlled crosses using integerrima pollen in order to find the most tolerant genotypes.
Materials and Methods:
The first step: Controlled pollination and hybrid seed production In order to produce hybrid seeds, a controlled pollination using integerrima pollen grains at Razavi Pistachio Research Institute was conducted for five cultivars; Ahmad Aghaei, Akbari, Sorkheh Hosseini, Garmeh and Fandoghi. Each replication had a tree and from each tree, seven branches were selected that had at least three to four flower buds and four branches from it for controlled pollination, two branches for open pollination and a branch was considered for negative control. Before the flower clusters were fully opened, 70% alcohol was sprayed on the branches to prevent the possibility of unwanted pollen. In order to ensure controlled pollination, in the bud swelling stage, the branches were isolated by double-layered bags measuring 30 × 45 cm. Pollen was collected from the Arzooieh area of Kerman province to select the male parent of integerrima. Then, a combination of flour and integerrima pollen (1:1 ratio) was injected into the insulating bags and pollination was performed. In late summer, hybrid seeds were harvested.
The second stage: Drought resistance test of hybrids obtained from first step The experiment was conducted as factorial based on a Completely Randomized Design with four replications at the research greenhouse located in Gorgan University of Agricultural Sciences and Natural Resources during 2019-2020. The treatments were consisted of ten pistachio genotypes; Ahmad Aghaei, Akbari, Sorkheh Hosseini, Garmeh, Fandoghi and (hybrids between integerrima as the pollinizer and genotypes of Ahmad Aghaie, Akbari, Sorkheh Hosseini, Garmeh and Fandoghi were applied as the maternal parent and three levels of drought including control (field capacity), mild stress (65% of field capacity) and severe stress (30% of field capacity) were applied on 3 months old seedlings for 84 days. Seeds obtained from free and controlled pollination were planted in pots with a diameter of 33 cm and a height of 35 cm on April 6, 2017. Three seeds were planted in each experimental unit, and after planting and ensuring establishment, the number of plants in the pot was reduced to the final level of one in each pot. Each replication was consisted of four experimental units or four pots, and each pot was contained a plant. At the end of the experiment, growth and physiological parameters were measured. Statistical analysis of the results was performed using SAS 9.1 software.
Results and Discussion: Results of statistical analysis showed drought stress had a significant effect on leaf number, stem length, root length, leaf relative water content, electrolyte leakage, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, and leaf and root proline content. With increasing drought levels, all traits except root length, electrolyte leakage and proline content were reduced in comparison with control. Sorkheh Hosseini × integerrima, Ahmad Aghaei × integerrima, Akbari × integerrima interactions and genotypes of fandoghi and fandoghi × integerrima interaction were superior in the most of traits by drought, respectively. Based on the results it seems hybrids of Sorkhe Hosseini × integerrima, Ahmad Aghaei × integerrima and Akbari× integerrima crosses will be used as genotypes with dry-tolerant genes to modify cultivars in arid regions.
M.R. Naroui Rad; B. Bakhshi; J. Kohpalekani Abbasi; A. Ghasemi; M. Fazeli Rostampoor
Abstract
Introduction: In Iran, there are various melon populations due to properties of cross pollination, which are mostly cultivated in the desert, so it is important to identify populations and study their response to low irrigation conditions and their selection. Sistan is one of the most important melon ...
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Introduction: In Iran, there are various melon populations due to properties of cross pollination, which are mostly cultivated in the desert, so it is important to identify populations and study their response to low irrigation conditions and their selection. Sistan is one of the most important melon production areas in the country. Every year, in the optimal water conditions of the region, cultivation area reaches nearly to 6,000 hectares, but the area under cultivation is affected by fluctuations in the Hirmand River. Its famous melons in the region include Sefidak, Firoozi and Helmendi, which are very popular among farmers in terms of taste. The amount of rainfall in this region is very small and the agriculture of the region is affected by the fluctuations of Hirmand River and these fluctuations cause damage to agricultural producers, but recognizing the best and most suitable genotypes can help a lot to melon production. Variation and selection are the important elements of the breeding program and the selection by the breeder requires a good variation in the population. In Iran, the largest producer of melons is province of Khorasan Razavi, with 48.7 percent of the production in country, and province of Sistan and Baluchistan with the 5.62 percent is in the fifth rank. Therefore, in this regard, it is necessary to consider the desirable populations and cultivars in terms of production and yield. The quality of soil and the limitation of water resources, especially in recent decades, have intensified the world's agriculture. In the most parts of Iran, especially in Sistan, due to recent drought, identification of resources and cultivars with the potential of optimal production is important. Therefore, the present study was conducted to evaluate the populations of melons and their response to different irrigation regimes.
Materials and Methods: In this study, the populations of the gene bank (34 population), mostly from the central and eastern regions of the Iran, along with two local sefidak and suski, which were relatively tolerant and sensitive, respectively to drought stress were cultivated in a simple square lattice design with 2 replications for comparison under normal and drought stress conditions. Under water deficit conditions, irrigation was carried out at water depletion of 75% and for normal irrigation with 50% water depletion from the field capacity. Soil moisture monitoring was carried out using a TDR device. Some morphological and physiological traits such as yield, number of fruits per plant, average fruit weight, fruit length and width, plant length, hole diameter, chlorophyll content, canopy temperature, relative water content were measured
Results and Discussion: Based on the results of combined analysis of variance, there was a significant difference between the populations for all traits except for the number of fruits per plant. The effect of the environment was significant only for the traits of soluble solids, single plant yield, canopy temperature and days to maturity also the interaction of the population with the environment was significant only for plant length, canopy temperature and root length, which indicated a different population reaction in relation to these traits under two conditions of normal and moisture stress. The results of the mean comparison of the traits showed that in normal conditions, the highest number of fruits belonged to numbers 1, 2, 6, 7 and 8, which had no significant difference with the check number 36. The results of analysis of factor in moisture stress condition showed that the first four factors justify nearly 70% of the variation among the traits. Therefore, the positive values of the first factor can be effective for selection of genotypes with a high yield and high fruit weight. However, the second factor with negative values of canopy temperature and positive values of leaf relative water content is effective in determining the high tolerance genotypes to moisture stress conditions.
Conclusion: Under normal and stress conditions, population number 23 had acceptable yields. The traits of fruit weight and size, flesh diameter and fruit length and width are among the traits that should be considered by the breeders according to their relationship with the yield. Genotypes with high root length had high tolerance to water deficit condition. In general, under stress conditions, more soluble solids were observed in the populations.
Bahareh parsamotlagh; Parviz Rezvani Moghaddam; Reza Ghorbani; Zabihollah Azami Sardooei
Abstract
Introduction: Roselle (Hibiscus sabdarjffaL.) is an annual or biennial plant cultivated in arid and semiarid regions. This plant is grown in parts of Africa, Asia, America and Australia. This plant is ecologically short day, self-pollinated and sensitive to cold and freezing stress. Studies conducted ...
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Introduction: Roselle (Hibiscus sabdarjffaL.) is an annual or biennial plant cultivated in arid and semiarid regions. This plant is grown in parts of Africa, Asia, America and Australia. This plant is ecologically short day, self-pollinated and sensitive to cold and freezing stress. Studies conducted on the medicinal plants in natural ecosystems suggested that using sustainable agriculture system provides the best conditions for the production of these plants, leading to maximum qualitative and quantitative yield in such conditions. In order to analyze the growth indices, leaf area index (LAI) and total dry matter (TDM) is required. Other indices were calculated from LAI and TDM. Considering the importance ofuses andresistant to droughtstress of roselle, this plant cultivate in provinces of Kerman and Fars recently. In order to evaluate the effect of organic, chemical and biological fertilizers on thermal requirements, developmental stages and some of physiological indices of roselle by irrigation levels, was conducted in Jiroft area.
Materials and Methods: In orderto evaluate the effect of organic, chemical and biological fertilizers on thermal requirements, developmental stages and some of physiological indices of roselle by irrigation levels, an experiment was conducted at Agricultural Research Farm Jiroft of Universityin2013-2014 growing season. Theexperiment was conducted as strip plot based on a randomized complete blocks design with three replications. Three irrigation regimes (100%, 80% and 60% of crop waterrequirement) were assigned ashorizontal factor and four fertilizer resources (mycorrhiza, vermicompost, cow manure and chemical fertilizer (NPK)) were allocated as vertical factor. Plant water requirement was calculated by using salinity parameters (sensitivity coefficient, salinity threshold and gradient of yield reduction), plant characteristics (height and the maximum depth of root), vegetation coefficients (first, middle and end of growth season), characteristics and duration of growth period with AGWAT software. Then, treatments of 80% and 60% of plant water requirements were determined and irrigation water per irrigation period was recorded by the water meter. As drip irrigation system with 0.001 Sq. M. were independently used for each treatment.Traits such as LAI, TDM, LAD, CGR and RGR indices and dry sepal yield were measured. All data were subjected to analysis of variance (ANOVA) using SAS 9.3 software. When F test indicated statistical significance at P< 0.01 or P < 0.05, the least significant difference (LSD) was used to separate the means.Figure drawing was done with Excel andSigmaplot Ver. 12.5
.
Results and Discussion: The results indicated that roselle is short-day plant and its flowering is stimulated by nearing the short days. Fertilizer resources and irrigation water levels had not significant effect on flowering of plant. Also fertilizer resources and irrigation water levels had significant effect on LAI and TDM. The highest LAD value was found in the cow manure and vermicompost treatments. The highest CGR value was obtained from 100%, 80% and 60% respectively. Growth reduction between irrigation levels 100% and 80% was not significant. Slope decline between irrigation levels (i.e., 100% and 80%) was similar. Slope decline in control and mycorrhizal morethan vermicompost, cow manure and chemical fertilizer. Similar results also reported by Gendy et al., (2012) and Samiran et al., (2010). The results showed that the interaction of Fertilizer resource and levels irrigations on the sepal yield was significant. Sepal yield at all three levels of irrigation showed increase in the plants treated with cow manure, vermicompost and chemical compared with mycorrhizal and control treatment. The highest sepal yield (1217 kg.ha-1) was obtainedfrom100% crop water requirement cow manure treatment and the lowest sepal yield (493 kg.ha-1) was obtained at 60% crop water requirement control treatments.
Conclusion: It seems that among the different fertilizer resources, cow manure and vermicompost have a greater impact on soil water holding compared to other sources of fertilizers (mycorrhiza and chemical fertilizer) by increasing soil organic matter. The results of Growth indices analysis, growth degree days and phenology assessment indicated that the most leaf area index and dry matter was observed at flowering stage and the beginning of flowering rosellewas under the influence of photoperiod. Due to soil and climatic conditions of the study area, using cow manure or vermicompost with 80% of the irrigation water requirement, roselle plant seems appropriate.
seyyed mousa mousavi; mehrangiz chehrazi; Esmaeil Khaleghi
Abstract
Introduction: With regard to decrease of precipitation and poor distribution of rainfall during the dry phenomenon of urban, green spaces face problems. In fact, one of the most important environmental stress is drought stress at different stages of plant growth such as seed germination, seedling establishment ...
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Introduction: With regard to decrease of precipitation and poor distribution of rainfall during the dry phenomenon of urban, green spaces face problems. In fact, one of the most important environmental stress is drought stress at different stages of plant growth such as seed germination, seedling establishment and crop production. The effect of drought stress, plants photochemical activity ceased Calvin cycle enzymes and chlorophyll content also varies in the process of photosynthesis under drought stress. Under drought stress, reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), superoxide radicals (O2 • -) and hydroxide (OH •) increase their accumulation in cells that can lead to oxidative stress. To neutralize ROS, antioxidant enzymes systems in plant such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) are active. The response of antioxidants depends on the lack of water, the intensity of the stress and the type of plant species. Also, it is well known that photosynthetic systems in higher plants are most sensitive to drought stress. Indeed, drought is one of the factors affecting photosynthesis and chlorophyll content. Some of researchers reported that chlorophyll might estimate influence of environmental stress on growth because these parameters were closely correlated with the rate of carbon exchange. The aim of this study was an investigation of effect of water deficit different levels on antioxidant system and lipid peroxidation in two species of marigold. Therefore, an experiment was carried out as factorial in a randomized complete block design with three replication at Shahid Chamran University of Ahvaz in 2014 year.
Materials and methods: Experimental treatments were irrigation with three levels: 100% ETcrop (no stress), 75% ETcrop (moderate stress) and 50% ETcrop (severe stress) and two species of marigold (African and French). Catalase activity decreased absorption at a wavelength of 240 nm through catabolizing on the basis of H2O2 according to Beers and Sizer (1952). Peroxidase activity decreased absorption at a wavelength of 470 nm that was measured by using Hemeda and Kelin (1990). Ascorbate peroxidase enzyme extracted from leaf based on defects in the wavelength of 290 nm that was measured by Nakano and Asada (1987). The final product of membrane lipid peroxidation malondialdehyde concentration as the reaction thiobarbituric acid (TBA) was measured. Also, chlorophyll a, b and total chlorophyll were calculated by Arnon’s equations and chlorophyll content index (C.C.I) was measured by chlorophyll content meter (SPAD-502).
Results and discussion: Results of analysis of variance showed that irrigation treatment had significant effect on chlorophyll a, total chlorophyll (Chl a+b), chlorophyll content index and catalase peroxidase, ascorbate peroxidase enzymes activity and malondialdehyde while there was not significantly difference between two species of marigold on any of the measured biochemical characteristics. Also, results revealed that amount of leaf chlorophyll a and total chlorophyll (chl a+b) were reduced by increasing water deficit. In fact, amount of total chlorophyll, chlorophyll a, b and chlorophyll content index were higher in plants that were received 100% ETcrop than 75 and 50% ETcrop. ,The results of enzyme activity were similar to total chlorophyll and chlorophyll a and b. Amount of decreased chlorophyll a and total chlorophyll in plants were received 50% ETcrop were 24% and 47.46%, compared with 100% ETcrop, respectively.
Conclusion: Result showed that different levels of irrigation were significantly different at 5% level on catalase, peroxidase, ascorbate peroxidase enzymes activity and malondialdehyde concentration. Catalase, peroxidase, ascorbate peroxidase enzymes activity and malondialdehyde concentration were increased by reducing the amount of irrigation while there were no different between two species of marigold and interaction between species and irrigation was not effective on measured indexes.
mahdi yaghoobi; mahdi parsa; Ali Gazanchian; hamidreza khazaie
Abstract
Introduction: Lack of water resources is one of the most problems ofincreasing urban green spaces. Over the last threedecades, turfgrass and lawn researches have put significant effort into developing and evaluating turf species that have good drought resistance. As water conservation becomes an important ...
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Introduction: Lack of water resources is one of the most problems ofincreasing urban green spaces. Over the last threedecades, turfgrass and lawn researches have put significant effort into developing and evaluating turf species that have good drought resistance. As water conservation becomes an important issue, considerable interest is increasing in identifying grasses that require less water. Plants with good drought resistance are those that are able to survive stress by means of drought avoidance, drought tolerance at leaf water potentials, or both. The efficient use of water is made possible by understanding the effects of irrigation water on crop development and yield. Drought affects the visual quality, growth rate and evapotranspiration. Researchers reported that turfgrass subjected to drought conditions for short periods could sustain a fairly good appearance by irrigation about half of its consumptive use whenever soil moisture level falls to near permanent wilting point. Drought stress caused decrease in RWC and visual quality of many grass cultivars. In drought conditions resistance grass showed increase in proline content on their leaves. Therefore the use of native grasses with high-strength instead of grass imported with low-resistance is one way to increase green space and reduce costs. The purpose of this study was comparednative grasses with commercial grass cultivars.
Materials and Methods: This study was to evaluate the yield and resistance of native grasses to drought stress in 2014. This experiment was conducted in Khorasan Agricultural Research Center. NativeAgropyron grass species includedAgropyronelangatum, A. desertrum, A. cristatum and commercial cultivarwassuper sport and third level of stress, including severe stress (45% FC), moderate stress (65% FC) and control (85% field capacity) were experimental treatments. Plants were cultured in PVC containers measuring 9 cm in diameter and 60 cm deep under greenhouse condition. Soil was mixture of 70% loam soil, 20% pit mass and 10% sand. Greenhouse air temperature was maintained between 22 and 28 centigrade degree. All plants were maintained under well watered conditions for 45 days before drought stress. This experiment was designed in factorial experiment based on completely random with fourreplicates. After the stress treatment parameters such as length and width of leaves, chlorophyll a, chlorophyll b and total chlorophyll content, visual quality, electrolyte leakage, RWC and proline content of leaves were measured. Length and width of leaves were measured with ruler. Proline content, RWC percent, chlorophyll a, chlorophyll b and total chlorophyll content of leaf, visual quality and leaf electrolyte leakage weremeasured with standard protocols. Analysis of the data by statistical software JMP 8 and graphs with Excel 2010 was drawn.
Results and Discussion: Result of the experiment showed that those native species have different response to soil moisture stress conditions. The highest and lowest lengths of leaf were observed under45% field capacity in A. elangatum and super sport grass, respectively. The results showed that width of leaves of A. elangatum increase and then decrease in super sport. Under drought stress conditions A. desertrum has best visual quality with 6.07 score. Highest chlorophyll a and total chlorophyll were observed in A. elangatum. The lowest electrolyte leakage under drought stress was obtained from A. elangatum with 17.91 percent. RWC content in the native A. elangatum increased to 82.12 compared with super sport (control). A. elangatum under drought stress showed highest proline content and commercial cultivar (super sport) indicated lowest proline content at 45% field capacity irrigation. Selahvarzi and et al. (2009) found that visual quality of tall fescue decrease in drought stress. In drought stress, RWC percent decrease in grass species. Proline content was increasedupondrought stress inLoliumperenecool season grass. Many studies on native cultivar indicated that native turfgrass cultivar have more resistance to drought stress compared with exotic turfgrass cultivars.
Conclusions: According to the results, we said native grass species under drought stress conditions have better quality compared with imported grass cultivar such as Super sport. Visual quality in native grass was suitable for use in urban landscape, that visual quality show little change in drought stress and leaves were fresh in this conditions. The best visual quality of two native species A. elongatum and A. desertrum was observed under 65% field capacity. Nativegrass cultivars were more resistance than imported grass cultivars. This study showed that native grass such asA. elongatum and A. desertrumhas low cost to use and these turfgrass need to lower water irrigation than commercial grass Super sport. Then two species can be introduced as low-input cultivars.
Nasser Abbaspour; Lavin Babaei; Alireza Farrokhzad
Abstract
Introduction: Water stress is considered as a main environmental factor limiting crop growth and yield, including grape in Mediterranean areas.Selection for drought-tolerantvarieties is possible through investigation of their performance under stress conditions. The estimation of physiological characteristics ...
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Introduction: Water stress is considered as a main environmental factor limiting crop growth and yield, including grape in Mediterranean areas.Selection for drought-tolerantvarieties is possible through investigation of their performance under stress conditions. The estimation of physiological characteristics as reliable indices can be used as a tool to select tolerant plants. For this reason, varieties and genotypes of one plant species are usually investigated through physiological characteristics and its relation to drought tolerance. Investigation of the effects of water stress on some growth and physiological characteristics in grape plants has revealed that plant height, number of leaves and nodes, leaf area and the percentage of dry weightdecreased under increasing drought stress. Salicylic Acid is a naturally occurring plant hormone whichinfluences various morphological and physiological functions in plant. It can act as an important signaling molecule and has diverse effects on biotic and abiotic stresses tolerance capacity.
Materials and Methods: In this research, two-yearold grapesplanted in plastic pots containingingredients of humus, soil and sand (1:2:1) were used. The experiment was conducted using a factorial based on randomized complete block design with three factors including irrigation periods (every 5, 10 and 15 days), salicylic acid concentrations (0, 1 and 2 mM) and grape cultivars (Rasheh andBidanesefid) with 3 replications in thegreenhouse of faculty of agricultureinUrmia University. Plant height, stem diameter and leaf area and chlorophyll indicesweremeasuredby usingruler, digital caliper (Model22855 NO: Z), leaf Area Meter (ModelAM200) and SPAD-502 chlorophyll meter (Minolta Crop, Japan),respectively. In order to determine proline content, malondialdehyde (MDA), total protein and total soluble sugars, spectrophotometric methods [51,25,6and28] were utilized,respectively.
Results and Discussion: Based on comparing the averages related to the interaction of various levels of drought and salicylic acid, increasing watering intervals resulted in significant decrease in parameters of plant height, stem diameter, leaf area, leaf number and chlorophyll index,and increase inproline content, malondialdehyde, total protein and total soluble sugars.Furthermore, according to the obtained results, plant height, stem diameter, leaf number, chlorophyll index, accumulation of prolineandtotal protein in grape cv. Rashehwere higher than Bidanesefidone.Drought effected the mitotic division, andelongation and expansion of cells, leading to reduced growth and crop yield. It was concluded that plant height, stem diameter, and leaf area decreased noticeably byincreasing water stress. The reduction in plant height could be attributed to decline in the cell enlargement and higher rate ofleaf senescence in the plant under water stress. The reduction in leaf number under severe water deficit was partially due to leaf senescence. Reduction inthe number of leaves could be a response by plants to minimize the transpiration surface. Sorghum plants have also been reported to have a similarbehaviorthroughwhichthey conserve water by reducing the number of leaves. When exposed to chronic water deficit, they showed an initial decrease in the daily increment of leaf area and eventually a decrease due to accelerated senescence. Dropping of the leaves during severe stress markedly reduces the evaporative surface and allows the plant to conserve water.It is well known that proline contents in leaves of many plants are enhanced by several stresses including drought stress. The efficiency of exogenous SA depends on multiple causes such as the species, developmental stage of the plant, manner of application and concentration of SA.Plant height, stem diameter, leaf number, leaf area, leaf total soluble sugar and chlorophyll index increased by applying 2 mM salicylic acid comparedwith 0 and 1 mM doses. The findings of this study showed that salicylic acid was able to enhance the tolerant capacity of the grape plant to the drought stress. According to theobtained results, Rashehcultivar showed a greater resistance to drought stress. Salicylic acid prohibits auxin and cytokinin loss in plants and thus enhances cell division and plant growth. Salicylic acid maintainsphotosynthetic aspects like chlorophyll content at proper level and thus helps plants to grow and developwell. In this study, the drought stress increased the amount of MDA.MDA and other aldehydes in the dry conditions are the result ofactive oxygen species (ROS) such as super oxide radical, peroxide, hydrogen and radical hydroxide, whichareproduced underoxidative stress conditions. The species of active oxygen leads to lipids' per oxidation as a result of injury or damage to the cellular membrane, especially chloroplast membrane.Salicylic acid increases the activity of antioxidant enzymes such as CAT, POD and SOD which in turn protect plants against ROS generation and lipid peroxidation. Salicylic acid treatment also providesa considerable protection from the enzyme nitrate reductase, thereby maintaining the level of diverse proteins in leaves.Mohammadkhani and Heidari (48) found that the initial increase in total soluble proteins during drought stress was due to the expression of new stress proteins.
ramin mahdavi; madhi parsa; ali gazanchian; hamidreza khazaie
Abstract
Introduction: Over the last three decades, turfgrass breeders have put significant effort into breeding and developing turf species that have good drought resistance. As water conservation becomes an important issue, an interest is increasing in identifying grasses that require less water. Lack of water ...
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Introduction: Over the last three decades, turfgrass breeders have put significant effort into breeding and developing turf species that have good drought resistance. As water conservation becomes an important issue, an interest is increasing in identifying grasses that require less water. Lack of water resources is most problems to increasing urban green spaces. Plants with good drought resistance are those that are able to survive stress by means of drought avoidance, drought tolerance at leaf water potentials, or both. The efficient use of water is made possible by understanding the effects of soil moisture water on crop development and yield. Drought affects the visual quality, growth rate and evapotranspiration. Researchers reported that turfgrass subjected to drought conditions for short periods could sustain a fairly good appearance by soil moisture about half of its consumptive use whenever soil moisture level falls to near permanent wilting point. Drought stress caused decrease in RWC and visual quality of many grass cultivars. In drought conditions resistance grass showed increase in proline content on their leaves. Therefore the use of native grasses with high-strength instead of imported grass with low-resistance is one way to increase landscape areas and reduce costs. The purpose of this study was to be compared native grasses with commercial grass cultivar “Super sport”.
Materials and Methods: The objective of this study was to evaluate the effect of soil moisture stress levels included 85% (control), 65% and 45% of field capacity on native species Brumos tomentellus, Festuca rubra and F. arundinacea and commercial cultivars Super sport (control) under greenhouse conditions. Plants were cultured in PVC containers measuring 9 cm in diameter and 60 cm deep. Soil was mixture of 70% loam soil, 20% pit mass and 10% sand. Greenhouse air temperature was maintained between 22 and 28 centigrade degree. All plants were maintained under well watered conditions for 45 day before drought stress. This experiment was conducted as factorial experiment based on completely random design with four replications. Measured parameters were length and width of leaves, chlorophyll a, chlorophyll b and total chlorophyll content, visual quality, electrolyte leakage, RWC and proline content of leaves. Length and width of leaves measured with ruler. Proline content, RWC percent, chlorophyll a, chlorophyll b and total chlorophyll content of leaf, visual quality and leaf electrolyte leakage was measured with standard protocols. Analysis of the data by statistical software JMP 8 and graphs with Excel 2010 was drawn.
Results and Discussion: Result of the experiment showed those native species have different response to soil moisture stress conditions. The highest and lowest length of leaves were observed in 65% field capacity in F. arundinacea and super sport grass, respectively. The results showed that width of leaves of B. tomentellus increased and decreased in super sport. Under soil moisture stress conditions, F. arundinacea has best visual quality with 7.66 score. Highest chlorophyll a and total chlorophyll were observed in tall fescue grass. The lowest electrolyte leakage under drought stress was obtained from F. rubra with 25.66 percent. RWC content in the native F. arundinacea increased to 77.80 compared with super sport (control). B. tomentellus under soil moisture stress showed the highest proline content and commercial cultivar (super sport) indicate lowest proline content at 45% field capacity. Selahvarzi and et al. (2009) found that visual quality of tall fescue decrease in drought stress. In drought stress RWC percent decrease in grass species. Proline content was increased in drought stress at Lolium perene cool season grass. Much studies on native cultivar indicated that native turfgrass cultivar have more resistance to drought stress compared with exotic turfgrass cultivars.
Conclusions: According to the results, we said native grass species under drought stress conditions have better quality compared with imported grass cultivar Super sport. Visual quality in native grass were suitable for use in urban landscape, that visual quality showed little change in soil moisture stress and leaves were fresh in this conditions. Native grass cultivars were more resistance than imported grass cultivar. This study showed that native grass such as F. arundinacea and F. rubra has low cost to use and these turfgrass need to lower water soil moisture than commercial grass Super sport.
Sarah Bakhtari; Gholam Reza Khajoei Nejad; Ghasem Mohamadi Nejad; Rooholla Moradi
Abstract
Introduction: Medicinal plants play major roles in human health. . Cumin (Cuminum cyminum L.) is an annual plant that commonly cultivated in arid and semiarid regions of Iran. The crop has a wide range of uses including medicinal, cosmetic and food industry. Cumin occupies about 26% of the total area ...
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Introduction: Medicinal plants play major roles in human health. . Cumin (Cuminum cyminum L.) is an annual plant that commonly cultivated in arid and semiarid regions of Iran. The crop has a wide range of uses including medicinal, cosmetic and food industry. Cumin occupies about 26% of the total area devoted to medicinal plants in Iran. However, cumin is seriously affected by the Fusarium wilt and blight diseases. The diseases usually increase under warm and wet conditions. It was demonstrated that the peak of the disease incidence is occurring at the flowering stage and irrigation cutoff at this time may be reduced the diseases density.
Materials and methods: In order to evaluate the effects of irrigation cutoff in flowering stage and foliar application of spermidine on some characteristics of various ecotype of cumin, an experiment was conducted in a split-split-plot arrangement in randomized complete block design with three replications at the research farm of Shahid Bahonar University of Kerman at 2014. The experimental treatments were irrigation in two levels (complete irrigation and cutoff the irrigation in flowering stage) assigned to main plots, foliar application of spermidine in three levels (0, 1 and 2 Mm) as a subplot and cumin ecotypes in three levels (Kerman, Khorasan and Esfahan) that was randomized in sub-subplot. Plots size under the trial was 4 m × 3 m so as to get 50 cm inter row spacing in six rows. The ideal density of the crops was considered as 120 plant m-2. As soon as the seeds were sown, irrigation was applied every 10 days. Foliar application of spermidine was done at three stages (after thinning, before flowering stage and in the middle of flowering stage). No herbicides and chemical fertilizers were applied during the expriments.
Results and discussion: In this study the number of branches, umbels per plant, 1000-seed weight, seed yield per plant and hectare, harvest index, essential oil percentage and yield, infected plants and proline contents were assessed. The results showed that irrigation treatment had a significant effect on all the studied traits except number of branches and umbels per plant. The irrigation cutoff at flowering stage caused a significant increase in seeds per umbel, infected plants and seed yield per plant and hectare Whereas harvest index, essential oil percentage and yield and proline contents were higher in irrigation cutoff treatment compared to completely irrigated treatment. The value of decrease in seed yield per hectare as affected by irrigation cutoff was so lower than that per plant; because more infected plants were observed in completely irrigatedtreatment in comparison with cutoff irrigated treatment. Decreasing the value of the seed yield per plant and hectare affected by irrigation cut-off were 58 and 15%, respectively. Proline contents in irrigation cut-off treatment were about two times more than completely irrigatedtreatment. Khorasan and Kerman ecotypes had higher value in comparison with Esfahan in all studied traits.. Seed yield per hectare for Kerman, Khorasan and Esfahan ecotypes were 525, 306 and 525 kg, respectively. The highest essential oil yield (14.92 kg ha-1) was gained in 1 Mm spermidine for Khorasan ecotype and the lowest (6.87 kg ha-1) was observed in 0 Mm spermidine for Esfahan ecotype. There was no significant difference between foliar application levels in terms of the studied traits such as….
Conclusion: Irrigation cutoff at flowering stage caused a significant increase in seeds per umbel, infected plants and seed yield per plant and hectare Whereas harvest index, essential oil percentage and yield and proline contents were higher in irrigation cutoff treatment compared to completely irrigated treatment. Khorasan and Kerman ecotypes achieved higher potential for cultivation in Kerman climate condition compared to Esfahan ecotype.
simin irankhah; Ali Ganjeali; Mehrdad Lahouti; Mansour mashreghi
Abstract
Introduction: Fenugreek (Trigonellafoenum-graecum L.) is a traditional medicinal plant belonging to the legume family Fabaceae. Diverse groups of microorganisms are symbiotic with Fenugreek roots system. This integration leads to significant increases in the development and production by increasing nitrogen ...
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Introduction: Fenugreek (Trigonellafoenum-graecum L.) is a traditional medicinal plant belonging to the legume family Fabaceae. Diverse groups of microorganisms are symbiotic with Fenugreek roots system. This integration leads to significant increases in the development and production by increasing nitrogen fixation, phytohormones production, siderophores and phosphate solubilization. Plant growth-promoting bacteria increase plant growth byimproving nutrientuptake and phytohormones production. In addition, the beneficial effect of these bacteria could be due totheirinteractionwithArbuscularMycorrhizal fungi(VAM). Drought is one of the major limiting factors for crop production in many parts of the world including Iran. Symbiotic microorganisms can enhance plant tolerance to drought. This experiment was carried out to investigate the effect of Vesicular ArbuscularMycorrhiza (VAM) and Plant Growth Promoting Rhizobacteria (PGPR) on morphological and biochemical characteristics of Fenugreek in drought stress conditions.
Materials and Methods: The experiment was carried out in completely random design with 3 replications.There were four treatments including inoculation with Pseudomonas putida, inoculation with Glomusintraradices, combined association of Pseudomonas putida and Glomusintraradices and untreated as a check under drought stress (40% of field capacity) and non-stress conditions (80% of field capacity). In this experiment fiveseeds were sowninplastic pots. Before sowing, seeds were inoculated with microorganisms. In order to inoculation ofseed with Mycorrhizal fungi, for each kilogram of soil, 100 grams of powder containing 10 to 15 thousand spores of fungal soil (produced by the biotech company Toos) was added to three centimeters of soil in the pot. For seed inoculation with Plant Growth Promoting Rhizobacteria, the growth curve of the bacteria was drawn at first and then the best time for the growth of bacteria was determined. The bacteria at the best time and at a dilution of 0.5 McFarland was added to the seed.Pots were placed in a growth chamber (with a temperature of 25 ° C and 16 hours of light and 8 hours of darkness photoperiod).After ten days of planting, the water treatment was applied and continued until the end of the experiment.
Results and Discussion:The results showed that the use of co -inoculation treatment ofP.putidaandG.intraradicesand application of G.intraradices aloneat non-stress conditions did not make a significant difference on the amount of plant biomass. In drought conditions, application of G.intraradice alone had significant difference (P≤0.05) compare with control (no inoculation microorganisms) for biomass.In stress conditions, P.putida inoculation and also in combination with G.intraradicesincreased biomass in compare with control (no inoculation of micro-organisms), but this increasing was not statistically significant.VAMare important ecological symbiotic with roots are important component of the ecosystem and affect the absorption of minerals through the roots. The results of the present study showed that the amount of phosphorus in all of treatments was increased and the greatest increase was related to G.intraradicetreatment.The results also showed that drought stress increased the leaf soluble proteins in compared with non-stress condition. Increasing the concentration of soluble proteins under drought stress can be related to increased protein synthesis that maybe related to adaptation and reprogramming under new situation and itprotect the cells against stress. The results showed that the use of co -inoculation treatment ofP.putidaand G.intraradices, as well as each individual treatment, increased the amount of soluble proteins in leaves.In the case of the Diosgenin percentage, drought stress reduced the amount of Diosgenin percentage. Underdrought stress conditions, use of co -inoculation treatment ofP.putidaand G.intraradicesand application of G.intraradicewithout presence of bacteria made a significant increase in plant Diosgenin concentration.
Conclusion: Theresults revealed that seed treatment with Pseudomonas putida and Glomusintraradices increased the biomass, protein content, phosphorus uptake and diosgenin percent in Fenugreek under drought stress condition. Since Diosgenin is very important medicinal compound, inoculation of fenugreek with these microorganisms can be a way to increase the Diosgenin production.
Gholam Hossein Davarynejad; S. Shirbani; M. Zarei
Abstract
Introduction: The amount of water available to plants includes one of the most important factors that affect the growth of plants. The objective of the present study was to investigate and compare the tolerance of different fig types (Ficus carica L.) to different low irrigation treatments.
Materials ...
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Introduction: The amount of water available to plants includes one of the most important factors that affect the growth of plants. The objective of the present study was to investigate and compare the tolerance of different fig types (Ficus carica L.) to different low irrigation treatments.
Materials and Methods: A factorial trial based on a completely randomized design with 3 replications was carried out in Ferdowsi University of Mashhad. The treatments of this experiment were four levels of irrigation including; supplying enough water to pots (100% field capacity), mild stress (75% field capacity), average stress (50% field capacity) and severe stress (25% field capacity) on Green, Black, Shah Fig and Matthew cultivars. Some of morphological and physiological traits like stem growth, leaf umber, leaf area, root length, root area, fresh and dry weight of shoot and root, root to shoot ratio, relative water content, electrolyte leakage, total chlorophyll and proline were measured.
Results and Discussion: According to the results, significant differences were observed between different irrigation treatments for all measured parameters. The highest level of stem growth, leaf umber and leaf area were detected in control treatment (100% field capacity), while the lowest contents were observed in severe stress (25% field capacity). The results showed that the fresh and dry weight of shoot and root decreased with increasing drought stress, so that the lowest amounts were observed in severe stress treatment (25% field capacity). The levels of relative water content was significantly affected by different irrigation treatments, since treated plants with severe stress treatment (25% field capacity) had the lowest relative water values, while the highest levels was observed in control treatment (100% field capacity). The highest and lowest of total chlorophyll content was observed in control treatments (100% field capacity) and severe stress (25% field capacity), respectively. Among the study treatments, severe stress treatment (25% field capacity) had the highest amount of root length, root area, root to shoot ratio and control treatment had the lowest root length, root area, root to shoot ratio. The obtained results detected that electrolyte leakage increased with increasing drought stress. The severe stress treatment (25% field capacity), had the highest proline content, followed by the average stress treatment (50% field capacity), while the lowest value was observed in control (100% field capacity). A variation in terms of all measured parameters also was observed among the cultivars and the differences were statistically significant. Among the presently tested cultivars, Black has the best resistant ability to drought stress than in other cultivar.
Conclusion: This research showed all measured parameters were significantly affected by irrigation treatments and cultivars. These data demonstrated that cultivar was the main parameter which influences the morpho-physiological properties in figs.
I. Arji; B. Hassani; H. Ghamarnia
Abstract
Introduction: Since Iran is located in arid and semi-arid region of the world, so consumption and saving of water must be taking into account. Water is often a valuable natural resource, thus proper application methods - for increase water efficiency can be very important. Regulated deficit irrigation ...
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Introduction: Since Iran is located in arid and semi-arid region of the world, so consumption and saving of water must be taking into account. Water is often a valuable natural resource, thus proper application methods - for increase water efficiency can be very important. Regulated deficit irrigation (RDI) is one of the most important methods to increase water use efficiency and fruit quality. Apple is one of the most important fruit trees from economical point of view. Studies showed that regulated deficit irrigation led to growth reduction in apple trees and sometimes fruit quality increased. The aim of this study was to evaluate the effect deficit irrigation on vegetative growth and fruit quantity and quality of Golden delicious apple trees in Gahvareh region of Kermanshah province.
Materials and Methods: This experiment was conducted on 10 years old Golden delicious apple trees in a randomized complete block design with 5 irrigation treatments and three replications during 2006. Three apple trees assigned to each experimental unit. Irrigation treatments were: T1= early deficit irrigation (40% water requirement), T2= early deficit irrigation (60% water requirement), T3= late deficit irrigation (40% water requirement), T4=late deficit irrigation (60% water requirement), T5=control (C) (100% water requirement). Early deficit irrigation starts 55 days after full bloom (15th Jun) and continued 60 days (16th Aug), while late deficit irrigation starts 115 days after from full bloom (16th Aug) and continued 40 days near to harvesting time (23th Sept). Control trees were full irrigated based on water requirement, which calculated based on national water document of Iran and irrigation amount was calculated based on the following formulas: Q=0.0184.L.H3/2
Where Q is volumetric flow rate (liter/Second), L is parshall flume crown length (cm) and H is water height (cm). Irrigation time was calculated based on national water document of Iran and volumetric flow rate as this formula Q.t = di.a, where Q is volumetric flow rate (liter/Second), t is time based on second, di is net water requirement and a is irrigated area. To evaluate irrigation effects some vegetative (shoot growth and trunk cross sectional area); reproductive (fruit volume, fruit weight and yield) and quality (Total soluble solid, total sugar, nitrogen, phosphorous, potassium and calcium) traits were measured.
Results and Discussion: Results showed that deficit irrigation had no effect on trunk cross sectional area, but shoot growth was affected significantly by deficit irrigation by. So, regulated deficit irrigation (RDI) can be used to control excessive vegetative growth in apple trees. There were no significant differences of fruit volume and weight of trees under deficit irrigation than the control exception to secondary 40% treatment. Fruit yield did not have significant differences under early and late 60% treatment in compare to the control. Where yield reduction was only 4 and 8 % in late and early 60% deficit irrigation respectively in compare to full irrigated trees. Water deficit had positive effect on qualitative traits of apple fruit, So that total soluble solids (TSS) and total sugar concentration (TSC) of fruit were higher in trees subjected to deficit irrigation as compared to the control. Regulated deficit irrigation led to 7-18% and 1.8-15% increase in total soluble solid and total sugar content in compare to full irrigated trees. Relative water content (RWC) was significant based of the time of applying deficit irrigation. Deficit irrigation did not have significant effect on fruit minerals such as P and K in compare to the control, but N content had significant reduction in deficit irrigation treatments in compare to the control and Ca fruit content of control trees had significant different in compare to trees were subjected to early deficit irrigation (40% of water requirement).. RDI favored reproductive growth over vegetative growth by suppressing vegetative growth. Water saving in deficit irrigation was 41, 27, 18 and 12 percent in early 40%, 60% and late 40% and 60% of water requirement respectively. Therefore, regulated deficit irrigation (RDI) applied with good intensity and at the right time not only reduces the amount of water used but also increased the yield performance and some fruit qualitative properties. RDI can be used to control vegetative growth and improve yield efficiency of apple trees.
Conclusions: Regulated deficit irrigation is more effective for water saving with a higher WUE and not reduction of fruit quality rather than to contain excessive vegetative growth in apple trees. Therefore, RDI can be suggested for commercial use and can be adapted successfully for the regions in similar soil and climate conditions. In general water deficit irrigation can cause increases quality of fruit in the Golden Delicious apple trees. Therefore, it is recommended to apply 60% of the water requirement for this cultivar.
M. Jahan; Sh. Ghalenoee; A. Khamooshi; M.B. Amiri
Abstract
Introduction: Basil (Ocimum basilicum L.) is an annual herbaceous plant that belongs to lamiaceae family. This plant is native of India country and other countries in south of Asia. Nowadays, the use of water superabsorbent polymers is increased in agriculture and their role in reducing the drought stress ...
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Introduction: Basil (Ocimum basilicum L.) is an annual herbaceous plant that belongs to lamiaceae family. This plant is native of India country and other countries in south of Asia. Nowadays, the use of water superabsorbent polymers is increased in agriculture and their role in reducing the drought stress and increasing the crops production has been demonstrated in many researches. Superabsorbent polymers can absorb lots of water and keep it in their structure and give it to plant under drought stress conditions (9). Humic substances are a group of heterogeneous molecules that are bonded together by weak forces, therefore they have high chemical stability. Humic acid comprise 65 to 80 percent of total soil organic matter (6). According to medicinal importance of Basil and its roles in the food and pharmaceutical industries, beside the limited water resources and need to increase water use efficiency through using ecological inputs, this study designed and conducted aimed to evaluate agroecological characteristics of Basil as affected by application of water-saving superabsorbent and humic acid under irrigation intervals.
Materials and Methods: In order to evaluate the effects of different amounts of water-saving superabsorbent and foliar application of humic acid and irrigation intervals on some quantitative characteristics of basil (Ocimum basilicum L.), a split strip plot experiment was conducted based on RCBD design with three replications at The Research Farm of Ferdowsi University of Mashhad, Iran during growing season of 2012-13. Experimental factors included three levels of water-saving superabsorbent (0, 40 and 80 kg ha-1) as the main plot factor, two levels of humic acid (0 and 3 kg ha-1) as the sub plot factor and two levels of irrigation interval (5 and 10 days) as the strip plot factor. Studied traits were seed number and weight per plant, plant height, number of lateral branches per plant, seed yield, biological yield and harvest index.
Results and Discussion: The results showed that interaction of superabsorbent and humic acid had a significant effect on seed yield (p≤ 0.05), as the highest seed yield (2638.8 kg ha-1) obtained from application of 40 kg ha-1 superabsorbent without humic acid. Evaluation of the superabsorbent and irrigation intervals interaction revealed that in all levels of superabsorbent, dry matter yield under irrigation interval of 5 days was more than irrigation interval of 10 days, so that dry matter yield at irrigation interval of 5 days and 0, 40 and 80 kg ha-1 levels of superabsorbent increased 13, 50 and 17% compared to irrigation interval of 10 days, respectively. Seed number per plant significantly was affected by interaction effects of humic acid and irrigation interval, so that in condition of using of humic acid in irrigation interval of 10 days, seed number per plant increased by 26% compared to control. The triple interaction of superabsorbent, humic acid and irrigation interval had significant effect on branch number per plant, as in irrigation interval of 5 days, in both conditions of application and no-application of humic acid, the highest branch number per plant observed in 40 kg ha-1 level of superabsorbent. In general, the combined use of 40 kg ha-1 water-saving superabsorbent and humic acid in different levels of irrigation, particularly under drought stress condition, while improved quantitative characteristics of basil, played an effective role in alleviation the devastating effects of drought stress. It seems that the appropriate level of water-saving superabsorbent (40 kg ha-1) increased morphological characteristics and seed yield of Basil through the absorption of water (4) and improvement of soil physical characteristics. It seems that humic acid increased quantitative characteristics of Basil by increasing activity of growth hormones such as auxin and improving nutrient uptake. In most of the studied traits, efficiency of humic acid improved in conditions of superabsorbent application and the plant could use the humic acid more efficient.
Conclusions: The cost of this study has been funded by Research and Technology Deputy of Ferdowsi University of Mashhad, Faculty of agriculture, the financial supports is appreciated.
M. Kafi; N. A. Khoshkholghsima; A. Liaghat
Abstract
Decrease in genome content may play a role in environmental adaptation. Many studies were reported significant correlation between genome size, weather condition and germination percentage. Relative genome content and its correlation with seedling establishment of 14 populations of tall fescue collected ...
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Decrease in genome content may play a role in environmental adaptation. Many studies were reported significant correlation between genome size, weather condition and germination percentage. Relative genome content and its correlation with seedling establishment of 14 populations of tall fescue collected from various regions in Iran and two commercial tall fescue cultivars were studied under drought conditions. Results showed that except one entry diploid (Brojen = 2x), all entries were hexaploid (6x). Cluster analysis revealed that the populations fell into four groups. Isfahan (Group II: average DNA content 17.92 pg) and Ghochan (Group VІ: average DNA content 18.56 pg) with 100% and 6.7% final emergence and 8.8, 2.3 cm leaf length respectively in 40% FC soil water content wree the most tolerable and sensitive entries under drought stress. Relative genom content of the wild populations and two commercial cultivar were negatively correlated with emergence (r=-0.56) and leaf length (r=-0.61). The reduction in genome size may be a mechanism of adaptation to arid environments. The drought tolerance was observed among the entries that grouped in cluster I and II represent potentially useful germplasm for a breeding program.
mohammad saeed tadaion; gholamreza moafpourian; neda maftoonazad
Abstract
To survey the effects of nutritional and growth regulator components on adverse effects of recent consecutive droughts, an experiment was conducted on uniform grape trees (VitisviniferaL.clv.'Khalili') in Bavanat and Shiraz (Akbar-Abad) regions in 2010- 2011.Trial was arranged in a Randomized Complete ...
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To survey the effects of nutritional and growth regulator components on adverse effects of recent consecutive droughts, an experiment was conducted on uniform grape trees (VitisviniferaL.clv.'Khalili') in Bavanat and Shiraz (Akbar-Abad) regions in 2010- 2011.Trial was arranged in a Randomized Complete BlockDesign (RCBD), with three replication and five trees per each plot. Experimental treatments consist of Farmer traditional condition (ctrl.),foliar application of 3% folvicacid,foliar application offosnutrenaminoacid fertilizercontain(8.4% free proline),foliar applicationofbrassinosteroid(0.4 mg.L-1),soil application of brassinosteroid(0.2 mg.L-1) and synchronize foliar applicationoff 3% folvic acid,fosnutrenamino acid fertilizercontain 8.4% free proline andbrassinosteroid (0.4 mg.L-1)in developing period of growth cycle.The results obtained from the evaluation of drought resistance indices as photosynthesis efficiency, stomata conductance, transpiration rate, water use efficiency, relative water content, leaf proline concentration, soluble sugar, chlorophyll a, b and a/b ratio on full expansionleaf of vine illustrate the significant effect of foliar application ofbrassinosteroidas growth bio-promoter on the increasing of potential drought resistance and yield of Khalili grape trees.The highest yield in this experiment belong to synchronize foliar application of folvic acid, fosnutren amino acid fertilizer contain 8.4% free proline and brassinosteroidtreatments in developing period of growth cycle and then respectively to foliar application ofbrassinosteroid, foliar application of fosnutren amino acid fertilizer contain 8.4% free proline, soil application of brassinosteroidandfoliar application of folvicacidwith 64.5, 46.2, 44.1, 39.8 and 20.3 percent yield increment in comparison with control.
Amir Sadeghi; Nematollah Etemadi; mahboobe shams; fateme nyazmand
Abstract
In this study, the effect of drought stress on morphological and physiological characteristics of wheatgrass and tall fescue was investigated in a factorial-split plot in time arrangement based on a completely randomized design with three replications. After turf establishment, half pots were exposed ...
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In this study, the effect of drought stress on morphological and physiological characteristics of wheatgrass and tall fescue was investigated in a factorial-split plot in time arrangement based on a completely randomized design with three replications. After turf establishment, half pots were exposed to drought stress and the half other were completely irrigated. Based on the results tall fescue had higher color and lower percent leaf firing during first 10 days of drought stress, but after this period, the percent leaf firing in tall fescue increased, so that it had higher percent leaf firing and lower color than wheatgrass in the end of experiment. The results showed that under drought stress conditions was not observed the significant difference between two species in leaf relative water content. In wheatgrass, proline content of stressed plants was equal to control plants during first 10 days of drought stress but with prolonged stress treatment, the proline content increased significantly. Despite wheatgrass which had moderate rate for closed stomata percentage during stress period, tall fescue showed a great increased in this index and reached to 89.52% at the end of 20th day. Also in drought stress, the stomata density increased and stomata diameter decreased significantly. Therefore, based on the results in long drought stress, wheatgrass had higher drought resistance than tall fescue.
R. Gholinegad; A. sirousmehr; B. Fakheri
Abstract
In order to study the effects of drought stress and organic fertilizers (compost and vermicompost) on some physiological and biochemical characteristics of borage, an experiment with complete randomized block design in split plot arrangement with three replications was conducted in Zabol University, ...
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In order to study the effects of drought stress and organic fertilizers (compost and vermicompost) on some physiological and biochemical characteristics of borage, an experiment with complete randomized block design in split plot arrangement with three replications was conducted in Zabol University, Zabol, Iran. The treatments included 3 levels of stress as a witness or 100% of field capacity, 80%field capacity(mild stress) and 60% field capacity (tension) as the main factor and use organic fertilizers, including control (nofertilizer), consuming 40 tons of compost per ha, and consumes 4 ton of vermicompost per ha, were considered as minor. Results showed that chlorophyll index (SPAD) decreased with increasing severity of dehydration and the amount of chlorophyll fluorescence were added. The highest chlorophyll a (11.383 mg/g) in conditions stress and application of compost obtained and it was reduced with increasing stress intensity level and the lowest (5.763mg/g) in severe stress and lack of fertilizer application, respectively. The same trend was observed for total chlorophyll content. Most of the enzymes catalase, ascorbate peroxidase and polyphenol oxidase in conditions of severe stress and lack of application and at least 100% of field capacity and compost application, respectively. Proline at 60% field capacity and no application of any fertilizer (20.213 mmol/g wet weight) was a significant difference with other compounds treatments. Drought stress affected the dry weight of the borage plant and cut it and dry yield (6.134826 kg/per ha) in the water level control was not a significant difference with mild stress (80% field capacity). Overall production in drought conditions and the amount of enzyme scavengers, hydrogen peroxide and free radicals increases , then, in order to have acceptable performance of dry borage, crop irrigation to 80% capacity seems appropriate.
M GH; Ali Momenpour; A.R. Abdolahpour; A.R. Sheiykh Eshkevari
Abstract
In this research, the effect of irrigation duration on growth characteristics of Thomson navel orange grafted on three rootstocks was evaluated in Complete Randomized Block Design in Iran Citrus Research Institute. Factors included rootstock in three levels (Poncirus (Poncitus trifoliate), citrange (Citrus ...
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In this research, the effect of irrigation duration on growth characteristics of Thomson navel orange grafted on three rootstocks was evaluated in Complete Randomized Block Design in Iran Citrus Research Institute. Factors included rootstock in three levels (Poncirus (Poncitus trifoliate), citrange (Citrus sinensis Poncitus trifoliata) and sour orange (Citrus aurantium)) duration of irrigation in four levels (2, 4, 6 and 8 once days) and time in six levels (T1, T2, T3, T4, T5 and T6). In the during irrigation, vegetative traits such as scion height, leaf number, diameter of rootstock and scion, leaf water content and chlorophyll value were measured. Also, at the end of the experimental period, amount of nitrogen, phosphorus and potassium in soils mixtures were determined. The results showed that time of sampling, type of rootstock and duration of irrigation can affect on growth characteristics of studied rootstock and scion. Height of scion, leaf number, diameter of rootstock and scion were increased so that the increase for all traits to time T3 was significant, but from time T3 to T6 was not. The difference among different rootstocks in the absorption of nutritional elements in short time (two days) was more. Poncirus rootstock in uptake of nutritional elements in drought stress was more efficient than other rootstocks and with increase in intervals of irrigation, amount of nitrogen, phosphorus and potassium in soil mixture of Poncirus rootstock, was less. Overall, studied rootstocks in this research which are common citrus rootstocks in north of Iran, in drought stress conditions, did not show superiority over others in growth characteristics.
M. Haghighi; M. Mozafariyan; Z. Afifipour
Abstract
The superabsorbent polymer withholding water and disperse it gradually to roots increase soil water capacity. To study the effect of superabsorbent polymer on decreasing water stress effect as well as increasing irrigation efficiency a factorial experiment based on randomized block design with 4 replicates ...
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The superabsorbent polymer withholding water and disperse it gradually to roots increase soil water capacity. To study the effect of superabsorbent polymer on decreasing water stress effect as well as increasing irrigation efficiency a factorial experiment based on randomized block design with 4 replicates was design. Treatments were 0, 10 and 20 % V superabsorbent and irrigation levels 25, 50 and 100% field capacity in greenhouse of Shiraz University. The results were shown that drought stress decreased chlorophyll content, fresh and dry weight but did not effect on fruit parameters at 5%. Superabsorbent improved tomato growth in stress condition and in 50% FC,10% superabsorbent increased relative water content to 14%and fresh weight of root to 60%. Chlorophyll content increased to 22% in 25%FC with 20% superabsorbent relative water content and root fresh weight increased 28 and 53% respectively. In 25%FC with 20% superabsorbent. Superabsorbent elevated hazardous effect of drought stress and with holding the water in root zoon cues normal plant growth.
