Medicinal Plants
M. Yadegari
Abstract
Introduction
Hyssopus officinalis L. belongs to the family Lamiaceae, and is one of the endangered endemic species in Iran. This plant is rich in essential oil, flavonoids, monoterpene glycosides, trypanocidal terpenoids, rosmarinic acid, and linolenic acid6. The main compounds of the essential oil ...
Read More
Introduction
Hyssopus officinalis L. belongs to the family Lamiaceae, and is one of the endangered endemic species in Iran. This plant is rich in essential oil, flavonoids, monoterpene glycosides, trypanocidal terpenoids, rosmarinic acid, and linolenic acid6. The main compounds of the essential oil from H. officinalis L. collected from natural habitats are α-pinene, Sabinene, 3-Carene, Beta-Pinene, Cis- Pinocamphone, Myrtenol, Pinocamphone and Camphor. The environmental factors cause changes in the growth, quantity, and quality of active substances (such as alkaloids, glycosides, steroids and volatile oils) in the medicinal and aromatic plants. Among environmental stresses, water deficit stress plays an important role in the biosynthesis of secondary metabolites in medicinal and aromatic plants in arid and semi-arid regions like Iran. Drought stress has detrimental effects on growth and yield and can upset the balance between the antioxidant defense system and free radicals by stimulating a series of biochemical reactions, where free radicals cause cell damage. In sustainable production systems of medicinal and aromatic plants, stable quantitative and qualitative functions can be achieved under conditions of environmental stress and it is possible to improve the production of secondary metabolites in these plants under adverse environmental conditions. Therefore, this study was done to evaluate the organic elicitors on the physiological and phytochemical properties of H.officinalis to determine and introduce the best elicitor under water stress.
Materials and Methods
This investigation was done from spring (May) 2022 to fall (September) 2023 at the Research Farm (latitude. 32°20′ N, longitude. 50°51′ E, altitude. 2061 m). Based on the Köppen climate classification, the climate of the area of study is classified as cold and semiarid. The present study was conducted in a randomized complete block design (RCBD) with three replications to investigate the effect of foliar application of different organic elicitors (chitosan, salicylic acid and phenylalanine) with control level (without any spraying) on the physiological and phytochemical characters of H. officinalis L. In each year, treatments were performed in 3 stages (end of vegetative, beginning of flowering and 50% of flowering) and in full flowering, harvesting was done. 3 irrigation regimes (4, 6, 8 day interval) in main plots and foliar application of elicitors in sub plots were done. The essential oils were extracted by hydro-distillation and analyzed using GC/MS.
Results and Discussion
According to obtained results, applied organic elicitors significantly influenced the physiological and phytochemical characters of H. officinalis L. However the assayed traits showed slightly variation during the studied years. In two years, the highest chlorophyll content (17.12-17.31 mg.Kg-1 FW) and total phenol content (1.77-1.81 mg.g-1 DW) were obtained in chitosan (0.5 mg.l-1) and phenyl alanine (1000 mg.l-1) treatments respectively. In most of measured characters, plants treated with chitosan (0.5 mg.l-1) and phenyl alanine (1000 mg.l-1) were in the same group. Amounts of some characters in plants treated with phenyl alanine (2000 mg.l-1) and salicylic acid (3 mM) lesser than control plants. The main constituents of essential oil were Sabinene, 3-Carene, Beta-Pinene, Cis- Pinocamphone, Myrtenol, Pinocamphone and Camphor (cyclic monoterpenes) that made the most components of essential oil plants. Among of elicitors, the chitosan effect on increasing of physiological and phytochemical characters such as the chlorophyll content was higher than other elicitors. Applied elicitors showed significant effects on essential oil content and composition of H. officinalis L. The highest essential oil content (0.89-0.91 %) was obtained from the treated plants by chitosan (0.5 mg.l-1). According to the biennial results of the chemical analysis of the essential oils from plants treated with treatments by GC/MS, the most important chemical compounds that determine the quality of H. officinalis L. essential oil including Beta-Pinene (17.93-18.53 %), Pinocamphone (24.97-25.12 %) and Cis-Pinocamphone (42.87-45.12 %) were identified. Cis-Pinocamphone belonging to bicyclic monoterpene was the predominant constituent of essential oil of H. officinalis L.
Conclusion
According to the results of this study, water deficit stress caused significant phytochemical changes in the H. officinalis L. essential oil. The main constituents of the volatile oils of H. officinalis L. were Sabinene, 3-Carene, Beta-Pinene, Cis- Pinocamphone, Myrtenol, Pinocamphone and Camphor were identified in the H. officinalis essential oil. Generally, Foliar application of chitosan and phenyl alanine significantly increased the monoterpenes compounds in essential oils of Hyssopus officinalis L., so that the content of these compounds and essential oil content in treated plants by organic elicitors 63% was more than the control plants. Finally, the application of chitosan at 0.5 mg.l-1 can be a good strategy to improve physiological and essential oil quantity and quality of H. officinalis L. in cold and semi-arid climates.
Medicinal Plants
M. Naseri
Abstract
Introduction
Saffron is a plant belonging to the lily family, which is one of the most valuable species of medicinal plants and is often cultivated in areas with dry climates. Saffron is the main source of income for many farmers in the rural areas of the east of the country and after pistachio; it ...
Read More
Introduction
Saffron is a plant belonging to the lily family, which is one of the most valuable species of medicinal plants and is often cultivated in areas with dry climates. Saffron is the main source of income for many farmers in the rural areas of the east of the country and after pistachio; it is the most valuable agricultural product in Iran. The yield and quality of saffron is influenced by various economic, social, educational and cultural characteristics of saffron growers. Considering the effect of various environmental factors on the growth and performance of saffron, the process of examining the suitability of land for its cultivation requires the use of comprehensive and diverse spatial information. Applying appropriate management methods to solve the existing limitations will lead to the actual performance approaching the potential performance. Considering that the level of planting saffron in many parts of the country is increasing, and on the other hand, based on the long-term average statistics, its yield has decreased significantly, the need for continuous monitoring of the level of planting and yield is one of the essential issues of managers. The purpose of this research was to investigate the relationship between climatic and management factors with saffron yield and to determine the most important parameters affecting yield using saffron information in the Kadkan section of Torbet Heydarieh. It was done to analyze and check the performance of saffron in 2021.
Materials and Methods
In order to investigate the cultivation of saffron and its yield in the Kadkan of Torbat-Hydaria, the data of the cultivation area and yield in 2021 were analyzed. A questionnaire was used to collect data. The questionnaire included information on cultivation area, production rate, and type of irrigation, age of the farm, education and age of the farmer. In this regard, the questionnaire was conducted from 447 people (at the level of 302 hectares) of saffron farmers. The information of these questionnaires was used to analyze the cultivation of saffron in Kadkan of Torbat Heydarieh in 2021.
Results and Discussion
The saffron yield recorded was 3.8 kg of dry stigmas per hectare, signifying a decrease when compared to previous years, with a decline of 26% and 56% compared to 2019 and 2018, respectively. Analysis of the results revealed that the highest saffron yield was observed in four-year-old farms, amounting to 4.17 kg per hectare. Conversely, fields irrigated from the river exhibited the lowest yield at 2.76 kg per hectare, as per the findings of the current study. Based on this study, there was no significant difference between the yield of saffron stigma in pressure irrigation (4.07 kg/ha) and flood irrigation (4.03 kg/ha) of the researched fields. The yield in saffron farms had an inverse relationship with the age of the farmer, so that with the increase in the age of the farms that were covered by the age of the farmers, the yield decreased and the farms that were under the management of younger people, the yield was higher. According to the results, the saffron farms that were cultivated under the management of uneducated farmers had the lowest yield (2.8 kg/ha) and those with university education had the highest yield of saffron stigma (1.5 kg/ha). The results of the cultivated area data showed that with the increase in the cultivated area of saffron, its yield decreased (the regression coefficient with the first-order model was 26% and the second-order model was 38%).
Temperature and rainfall are two influencing factors on saffron performance. In 2016 and 2017, the yield of saffron decreased significantly due to the following reasons: Decrease in rainfall compared to previous years, Improper distribution of rainfall during the vegetative growth period of saffron, The lower and more negative temperatures in 2019 (November, December, December, February and March) compared to the mentioned years caused a decrease in dry stigma harvest in 2014 compared to 2016 and 2018. Given that the majority of saffron farms in the Kadkan district are approximately 4.16 years old (as indicated in Table 2), it is anticipated that the yield of farms in this district may decline in the upcoming year. However, it's important to note that this prediction is solely based on the age of the farms, and actual outcomes may vary depending on climatic conditions. Due to the prevalence of small-scale ownership of saffron farms in Kadkan, managed within a family exploitation system, the management of these smaller farms is typically more manageable. Consequently, it is foreseeable that smaller farms may experience an increase in yield. Therefore, based on these considerations, saffron cultivation is recommended particularly for small-scale owners rather than larger landholders.
Pomology
E. Safavi; M. Yadegari; S.A. Mousavi; B. Haghighati
Abstract
Introduction
Water shortage is very frequent in many countries, and, together with the rising demand for industry, growth of human population, climate change and specifically the trend towards irrigated agriculture, has led to widespread problems of water scarcity, especially in Middle East countries. ...
Read More
Introduction
Water shortage is very frequent in many countries, and, together with the rising demand for industry, growth of human population, climate change and specifically the trend towards irrigated agriculture, has led to widespread problems of water scarcity, especially in Middle East countries. This situation imposes the need to optimize water use in all human activities. Among the different productive uses of water, agriculture is by far the main water user in most water scarce regions and, consequently, any potential improvement in the use of the available water resources may play a significant role toward achieving a more sustainable use of water. Plant responses to water deprivation are usually monitored through selected morphological and physiological parameters which have been proven to be good indicators of drought in different studies. Some of the most important standards for evaluating plant genotypes under drought stress are measurements of morphological parameters such as height, leaf characters and root growth.
Materials and Methods
To compare the growth response of different almond cultivars to different levels of water stress, an experiment was conducted as a split plot in the base of randomized complete block design with three replications in the Agricultural and Natural Resources Research Center of Chaharmahal and Bakhtiari Province in two growing season 2019-2020 and 2020-2021. Different irrigation periods based on the percentage of usable soil moisture between filed capacity to wilting point, including 70% filed capacity (control or no stress), 50% filed capacity (mild stress), 30% filed capacity (medium stress) and 10% of field capacity (severe stress) were considered as the main factor of the experiment. The sub-factor included 14 commercial cultivars of almonds (Mamaei, Rabi, Saba, Araz, Eskandar, Aidin, Shahrood 6, 7, 8, 10, 12, 13 and 21 and GN vegetative rootstock), all of which were grafted on GN rootstock. In this study, uniformly grafted seedlings in terms of age, stem diameter and height were selected and planted. In the second year after planting the seedlings, in order to apply drought stress, tubes for hygrometer (TDR) were installed in each experimental plot and based on soil moisture content, irrigation cycle was determined for different treatments.
Results and Discussion
In both years, three months after applied water stress growth traits and nutrient concentrations in the leaves of treated seedlings were measured. Based on the results of analysis of variance, the morphological traits of almond seedlings were significantly affected by cultivar type and drought stress level. In all almond cultivars, the highest height was belonged to seedlings that were grown in non-stress conditions and with increasing the drought stress intensity, the height of almond seedlings was decreased. Under severe drought stress, GN and Mamaei cultivars had the highest (183.93 cm) and the lowest (94.60 cm) height, respectively. Seedling height in GN, Shahrood 12, Saba and Shahrood 10 cultivars showed the lowest decrement under severe drought stress. In all cultivars, drought stress caused a significant reduction in the length and width of the seedlings crown, and the greatest decreasing was recorded in severe drought stress (10% FC). Under severe drought stress, cultivar GN had the largest crown and cultivars Rabi, Shahrood 7 and Eskandar had the smallest crown. Increasing the drought stress intensity significantly reduced the branches growth of seeding in terms of number and length of sub-branches. As the intensity of drought stress increased, the length of sub-branches decreased however the number of intermediates in sub-branches increased. In non-stressed condition, the cultivar GN had the longest branch (55.95 cm), which was significantly higher than the other studied almond cultivars. The shortest branches were also observed in Saba (29.94 cm) and Eskandar (29.47 cm) cultivars. Increasing drought stress caused a significant reduction of leaf area in all studied cultivars and the highest decreasing was observed under severe drought stress. The GN (37.76 cm²) and Shahrood 10 (31.81 cm²) had the highest leaf area in non-stress and drought stress conditions. Under severe drought stress (10% FC) cultivar Shahrood 6 showed the lowest leaf area. The results of this study showed that increasing the intensity of dehydration significantly reduced the amount of nitrogen, phosphorus, manganese and zinc in the leaves of the studied cultivars of almonds, however, the amount of potassium and iron in stressed plants increased under drought stress. Based on the results of the present study, under severe drought stress the GN, Shahrood 8 and Shahrood 12 cultivars in terms of growth indices including seedling height, stem diameter, canopy growth, branch growth and concentration of macro and micro elements was superior compared with the other studied cultivars.
Conclusion
Based on the results of this study, drought stress significantly reduced growth indices and nutrient concentrations, although the reaction of almond cultivars to different levels of drought stress was different. In this study, among the studied almond cultivars GN, Shahrood 8 and Shahrood 12 cultivars in terms of growth characters including seedling height, stem diameter, canopy growth, branch growth and concentration of macro and micro elements showed higher tolerance to different level of drought stress. These cultivars less affected by the high intensities of dehydration. Therefore, GN, Shahrood 8 and Shahrood 12 cultivars can be used in future studies to evaluate the possibility of cultivating these cultivars in areas with water deficit.
Pomology
M. Nazeri; S.J. Tabatabaie; Y. Sharafi
Abstract
Introduction
Water scarcity is one of the most important limiting factors threatening the production of horticultural crops. Approximately, 45% of the world's arable land is subject to permanent or intermittent water shortages, and approximately 50% of the world's annual yield is lost due to drought. ...
Read More
Introduction
Water scarcity is one of the most important limiting factors threatening the production of horticultural crops. Approximately, 45% of the world's arable land is subject to permanent or intermittent water shortages, and approximately 50% of the world's annual yield is lost due to drought. Due to climate changes, especially the increase temperature and decrease rainfall in recent years in Iran, most of the gardens are facing limited water resources. In order to reduce water stress, increasing water use efficiency by naval technics seems to be crucial. Peach fruit growth mainly depends on adequate water supply. Therefore, water stress reduces the growth of the fleshy part and the quality of the peach fruits. Split root means placing a part of the root in different conditions compared to the remains of the root. Studies on split root culture were done in the laboratory for the first time. Increasing water holding capacity by split root system may improve soil- plant water availability. Furthermore, many studies indicated that Mycorrhiza and Trichoderma fungi improve the absorption of water and nutrients by plant. Increasing the absorption of water and nutrients leads to increasing growth and yield. The aim of this research was to improve the water efficiency and the use of low-yielding lands by placing a bag containing pumice and inoculating the roots with fungi.
Materials and Methods
This experiment was performed as a factorial experiment based on randomized complete blocks design with three replications for two years. Treatments included placing the bag close to the trunk of peach trees in three levels (without bag, one bag and two bags), different levels of irrigation (50, 75 and 100% of field capacity) and root inoculation treatments with mycorrhiza, Trichoderma fungi and control without fungus. Redtop peaches grafted on GF677 rootstock were planted in May 2018. The bags were placed at a depth of 60 cm and at a distance of 40 and 60 cm from the tree trunk. The bags size was 40 liters filled with pumice. At 20 cm from the top of the bag, three holes were made to remove excess water from that part and as a signal to cause the root to move towards the bag. For plants treated with mycorrhiza, 250 g of Mycorrhiza glomus was mixed and for plants treated with Trichoderma, 4.5 g of Trichoderma harizanium was mixed with pumice in the bag. In treatments with no bag placement, the plant roots were inoculated with fungi. Characteristics such as relative water content (RWC), yield, total soluble solids (TSS), titratable acidity (TA), TSS/TA, total phenol and fruit anthocyanin were measured at the end of growing season. Fruit skin color characteristics including L*, a*, b*, Chroma and Hue were measured with a colorimeter. Statistical analysis was performed by SAS software version 9.1. Mean data were compared using Duncan's multiple range test. drawing diagrams done by Excel software.
Results and Discussion
The results showed that bag placement increased RWC. The highest RWC of leaf was measured in the treatment of placing two bags, 75% irrigation and root inoculation with Trichoderma fungus. In the main effect of bag placement, irrigation levels and root inoculation, the highest RWC of leaf was observed in placing a bag, 100% irrigation and root inoculation with Trichoderma fungus, respectively. The treatment one bag, 100% irrigation and root inoculation with mycorrhiza improved vegetative growth and produced the largest trunk diameter. Yield in terms of fresh weight of fruit in two-bag placement, 100% irrigation and root inoculation with mycorrhiza was increased by 1.8 compared to the control. The highest TA was measured in the treatment of placing a bag, 50% irrigation and root inoculation with mycorrhizal fungus. Treatment without bag placement, 75% irrigation and without fungus inoculation had the highest total soluble solids and TSS/TA of fruit. The index ratio of TSS/TA is used to determine the taste of the fruit. The highest total phenol and anthocyanin of fruit was observed in treatments without bag under 50% irrigation levels. One bag placement, 75% irrigation without fungal inoculation treatment and no bag placement treatment, 50% irrigation, mycorrhiza inoculation caused the a* and L* of the fruit skin increased. The interaction effect of the three factors of bag placement, irrigation levels and root inoculation with fungus had no significant effect on Hue and b*.
Conclusion
The results of this experiment showed that water consumption can be reduced by placing a bag. The finding of the experiment led to the conclusion that a bag placement treatment, 75% irrigation and inoculation with mycorrhizal fungus improve fruit yield and quality of peach trees
.
Growing vegetables
M. Najafi; H. Arouiee; M.H. Aminifard
Abstract
Introduction: The deficiency of organic matter in the soil is one of the factors limiting cultivating and growing of plants. While the organic matter is the main factor of soil fertility and the ideal organic matter content of agricultural soils is about 4-6% according to the experiments performed, this ...
Read More
Introduction: The deficiency of organic matter in the soil is one of the factors limiting cultivating and growing of plants. While the organic matter is the main factor of soil fertility and the ideal organic matter content of agricultural soils is about 4-6% according to the experiments performed, this amount is very low in arid and desert areas such as those in Iran. The significant capability of humic fertilizers in the rapid improvement of soil fertilization level is quite recognizable. Humic acid has a direct role in determining the producing potential of the soil. Humic substances can have a positive effect on plant growth in different ways. Humic acid results in an increasing nitrogen uptake by plants and stimulates and enhances the uptake of Ca, Mg, P, and K. By enhancing the resistance to environmental stresses, increasing chlorophyll concentration and thus affecting photosynthesis, amino acids are effective in plant growth and yield. Given the conditions that agriculture faces, drought is the main limiting factor of agricultural production in the present and future. Research has reported that the improvement of plant growth under stress conditions by application of humic substances and amino acid. The use of these factors that increase plant growth in stressful conditions and improve yield is a useful and effective method. The aim of this study was to investigate the effect of organic fertilizers on growth traits of cucumber plants under drought stress.Materials and Methods: In order to explore the effect of drought stress on cucumber plant, an experiment was carried out in the research field of agriculture faculty of Ferdowsi University of Mashhad in 2015-2016. This study was performed as a factorial design in a completely randomized block design with three replications. The first factor was fertilization at four levels (control, humic acid application (200 ppm), glycine amino acid and glutamic acid application (6 liters per hectare), and combined application of humic acid (200 ppm), glycine amino acid and glutamic acid (6 liters per hectare), and the second factor was irrigation at three levels of 3, 5 and 7 days. Furrows with 2 m apart, 40 cm deep, 50 cm wide and 20 m long were created. Following the soil irrigation, the cucumber seeds were planted on the edge of the experimental hills (4-5 seeds per hill) that were spaced 50 cm apart. The treatments were applied via irrigation at specified concentration. At the end of the experiment Morphophysiological traits were measured.Results and Discussion: The results showed that drought stress reduced fresh and dry weights of plant, a number of branches, root length, stem length, and internode length. The amount of available water to plants affects their growth traits. Increasing irrigation interval decreased vegetative growth parameters in this plant, which is undoubtedly due to the lack of water available to the plant. Drought stress leads to stomata closure, plant wilt, swelling reduction, and reduced water content and total potential of the leaf, resulting in decreased cell division, especially in shoots and leaves. As a result, the first effects of dehydration in plants can be seen in their smaller leaf size and lower height than normal conditions. The highest level of drought stress (7 days) decreases all the traits. Unfortunately, the use of humic acid and acid amine had no effect on the highest levels of stress (7 days). The application of humic acid alone could improve the effects of drought stress on the plant. Humic acid enhances plant growth by affecting plant cell metabolism as well as chelating power, increasing nutrient uptake, and increasing nitrogen content. Experimental studies have shown that glycine betaine strengthens enzymatic structures and activities and protein components, and cell wall stability against the damaging effects of environmental stresses is considered to be one of its activities. It seems that organic matter and humic compounds including humic acid through positive physiological effects including effects on plant cells metabolism, increased leaf chlorophyll concentration, increased metabolism within cells, and increased durability of photosynthetic tissues (Increasing leaf durability) leads to increase of production performance and biomass production in plants.Conclusion: The use of humic acid alone led to improved leaf area, root length, and other traits. These factors caused an improvement in the photosynthetic rate in the plant, resulting in improved yield and growth under drought stress conditions (increased irrigation intervals). The protective and moderating role of the humic acid application under drought stress is one of the reasons for growth improvement by these compounds. In general, the combined application of humic acid and amino acid in the form of irrigation fertilizer in cucumber under drought stress improved growth traits and prevented yield reduction.
rahmatollah gholami; issa arji
Abstract
Introduction: Olive (Olea europaea L.) is an ever-green and drought-tolerant tree grown on regions with limited water resources to produce oil and table products. Due to existing appropriate environmental conditions in our country for its growing, and also considering public desperate needs to ...
Read More
Introduction: Olive (Olea europaea L.) is an ever-green and drought-tolerant tree grown on regions with limited water resources to produce oil and table products. Due to existing appropriate environmental conditions in our country for its growing, and also considering public desperate needs to its oil product, olive is economically considered to be an important fruits to be cultivated. The problem of supplying sufficient water for irrigation olive orchards, due to serious threats of ongoing drought and reduction in water resources, is one of the main limiting factors on the way to develop olive industry in country. Accordingly, some suitable approaches like using tolerant cultivars, mulches, reduction of plant transpiration, plant growth regulators, and recently evaluating proper time for irrigation have been examined to increase efficiency of water use. According to this approach, irrigation schedule is designed mainly based on maintaining plant’s water status internally and regarding maximum level of water potential at particular stages of plant cycling, especially at time of lowest sensitivity of fruit growth to drought stress.
So far, many studies performed over effects of drought stress and water deficit on vegetable growth of olive under pot conditions. With respect to establishing olive orchards on different regions of country and appearing serious drought threats, it is imperative to investigate the effects of regulated irrigation deficit on all bearing fruit trees. Hence, determining the insensitive stages of fruit growth toward regulated irrigation deficit has been received great attentions in terms of economical yield. The purposes behind doing the current study were to investigate and compare effects of different regulated deficit irrigations on vegetative and reproductive parameters of olive grown under field conditions.
Materials and Methods: This study was aimed to investigate the effect of regulated deficit irrigation regime on vegetative, oil yield and oil content and water use efficiency of zard cultivar under field condition. This experiment was conducted in Javanmiri region (Geographical characters was longitude of 58˚, 45΄ E and latitude of 35˚, 34΄ N and the height of sea level 1215m) located in Kermanshah province. An experiment was conducted based on a randomized complete block design with three replications. Adult olive zard cultivar was uesd. Each experiment unit consists of three trees. Vegetative and reproductive traits were evaluated according to I.O.O.C. descriptors. five irrigation regimes including of full irrigation (as control), regulated deficit irrigation (100% of full irrigation during growing season and no irrigation during pit hardening), irrigation in three stages (before flowering, pit hardening and before harvesting), 60% of full irrigation (continuous deficit irrigation) and no irrigation (Rainfed). To evaluate the effect of irrigation regimes, some vegetative traits including current season growth and current season diameter, dry and fresh oil content, fruit mass percent, oil and fruit yield and water use efficiency were measured. Collected data were analyzed using SAS program.
Results and Discussion: Obtained results showed that the highest oil and fruit yield were observed at full irrigation and regulated deficit irrigation (100% of full irrigation during growing and no irrigation during pit hardening, but the lowest one found at Rainfed. The water use efficiency of oil yield of T3 was higher than 100ETc and other treatments.
In the arid and semi-arid as well as sub-tropical regions, water shortage is a normal phenomenon and seriously limits the agricultural potential. Therefore, under irrigation or rain-fed conditions, it is important for the available water to be used in the most efficient way. Regulated deficit irrigation is an optimizing strategy under which crops are allowed to sustain some degree of water deficit and yield reduction. During regulated deficit irrigation the crop is exposed to certain level of water stress either during a particular period or throughout the growing season. The main objective deficit irrigation is to increase water use efficiency (WUE) of the crop by eliminating irrigations that have little impact on yield, and to improve control of vegetative growth (improve fruit size and quality).
Conclusion: According to the results of this research, it can be concluded that regulated deficit irrigation had a significant effect on reproductive traits. Using regulated deficit irrigation improved pomological characteristics of olive including oil and fruit yield under drought stress and helped to save irrigation water in olive orchards.
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 ...
Read More
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.
seyyed mousa mousavi; mehrangiz chehrazi; Esmaeil Khaleghi
Abstract
Background and objectives: Water stress is one of the most important environmental stresses in agriculture and urban landscape management. Water stress has been defined as the induction of turgor pressure below the maximal potential pressure. Previous studieshave showed that drought had been negative ...
Read More
Background and objectives: Water stress is one of the most important environmental stresses in agriculture and urban landscape management. Water stress has been defined as the induction of turgor pressure below the maximal potential pressure. Previous studieshave showed that drought had been negative effects on morphological, physiological and biochemical characteristics of plants. Changes in protein expression, accumulation, and synthesis have been observed in many plant species as a result of plant exposure to drought stress during growth plants. The maintenance of plant water potential during water deficit is essential for continued growth and can be achieved by osmotic adjustment mechanisms resulting from the accumulation of compatible solutes such as proline in the cytoplasm. Proline acts as a "compatible solute", i.e. one that can accumulate to high concentrations in the cell cytoplasm without interfering with cellular structure or metabolism. Proline has a protective action which prevents membrane damage and protein denaturation during water stress. Accumulation of sugars in different parts of plants is enhanced in response to the variety of environmental stresses. Marigold(Tagetesspp.) is a genus of annual or perennial, belonging to the Asteraceaefamily, that is used as a marginal flower in the landscape.Due to the fact that drought stress is one of the most important problems especially in the agricultural industry and also in the landscape, it is necessary to study the damaging effects of drought stress on plant characteristics. Therefore, the aim of this study was to investigate the effect of different levels of water stress on physiological and biochemical characteristics of two types of pot marigold.
Materials and Methods: A research was conducted in order to investigate the effect of different levels of water deficit (100 as control, 75 and 50 percent of potential evapotranspiration (ETcrop)) on trend changes of leaf proline, total soluble sugars, relative water content and soluble protein changes in two species of pot marigold (French and African) as a factorial experiment based on a randomized complete block design with three replications. In this experiment, two species of pot marigold seeds (African and French) were planted in the trays including cocopeat. Then seedlings were transplanted to pots with 19 × 16 cm dimensions. After transplanting, the seedlings were irrigated well for 3 weeks. Then plants were irrigated with 100%, 75% and 50% ETcrop. Parameters such as leaf proline and total carbohydrates content, leaf relative water content were measured three times at intervals of once every 21 days but the amount of soluble proteins was measured one time in 63 days after treatment. Data analysis was performed using MSTATC software and mean comparison was done by Duncan's multiple range test at 5% and 1% probability.
Results: The results showed that leaf proline and total soluble sugars increased with incrementin levels of water deficit and the trend changes of leaf traits were increased with the passing of time. So that, in 43 days after water stress treatment, leaf proline content had an increase of 3 or 4 times in 50% Etcrop irrigation treatment compared with the control and 75% Etcrop irrigation treatment, respectively. The highest levels of leaf proline (119.28 mg per gram of fresh weight) and total soluble sugars content (1.8 mg per gram of fresh weight) was related to 50% ETc treatment. The amount of leaf total soluble sugars was also higher in African species compared with French species. The results showed that the leaf soluble proteins and relative water content decreased with reducingirrigation, so that the lowest amount of relative water content (57.9%) and soluble protein (31.57mg per g fresh weight) were obtained in 50% ETc treatment.
Conclusion: When the plants were exposed to progressive drought stress, changes appeared earlier in relative water content, whereas later effects in the levels of free proline, total soluble sugar, total soluble protein. The results showed that irrigation had significant effects on all evaluated parameters such as leaf proline, total soluble sugers, RWC and soluble proteins. Our findings also showed that there was no significant difference between control treatment and 75% ETcrop treatment in the measured indices and it's importancfor optimal management of water in landscape couldbe considered. Finally, it can be expected that African species is better than French species for planting in landscape.
M. Jaberi; R. Baradaran; S.Gh. Mousavi; M. Aghhavani Shajari
Abstract
Introduction Drought is one of the most important factors whichdecrease crop production in arid and semi-arid regions of the world (1, 20). Appropriate nutritional management has an effective role in the resistance to environmental stresses on crops (7). An important issue about sustainability of food ...
Read More
Introduction Drought is one of the most important factors whichdecrease crop production in arid and semi-arid regions of the world (1, 20). Appropriate nutritional management has an effective role in the resistance to environmental stresses on crops (7). An important issue about sustainability of food production is the maintenance of soil fertility through the use of organic matter and biofertilizers. One option to increase agricultural production is the use of beneficial soil microorganisms such as PGPR and fungi (45). This group of bacteria through biological fixation of nitrogen, increase phosphorus and potassium solubility, an increasethe availability of mineral elements in the soil, inhibits pathogen appearance and producehormones that regulate the growth of plants to affect crop yield (18, 47). Mycorrhiza enablesymbiosis with the roots of most crop plants, through the availability of phosphorus, nitrogen and other nutrients and thus increases water absorption and produces plant hormones, increases resistance to pathogens and environmental stresses, strengthens the soil microbial community and induces improving the growth and performance of plants in agricultural systems (5, 32, 37, 40).Fenugreek (Trigonella foenum- graecum L.)is an annual herbaceous plant that reaches a height of 50 cm (14). Since limited water is at very critical level now, the importance of further research in this area is felt. So, the study of medicinal plants considring water management and organic food is very important. Therefore, the aim of this research is to evaluate the effect of organic and biofertilizers and irrigation on yield and yield components of fenugreek in Birjand.
Materials and Methods In order to study the effects of irrigation intervals and biofertilizers on quantitative traits and yield of fenugreek, an experiment was carried out in a split plot based on a complete randomized block design with 3replications at the research station, Faculty of Agriculture, Azad University, Birjand, Iran, during 2010-2011. Experimental treatments were irrigation intervals in three levels (every 6, 9 and 12 days) and biofertilizer in five levels (nitroxin, biophosphorus, and micorhyza fungi G. mosseae, G. intraradices and control-no fertilizer). Fenugreek was planted through furrow in mid-April 2010. The distance between rows and between plants was 30 and 10 cm, respectively. Seeds were covered by Nitroxin (including: Azotobacterchroococcum, Azospirillum lipoferum and Azospirillum brasilense) and biophosphrous (including: Pseudomonas fluorescens) and then were cultured.They were used at a depth of 2cm below the seed from Glomusintraradiceand Glomus mosseae. Fenugreek was harvested in early July when the plants became yellow and at least 80% of the pods were reached. Statistical analysis of the data was performed using SAS 9.1 and MSTATC. Mean comparison were compared by the Duncan test at 1% and 5% level of probability.
Results and Discussion: Results of statistical analysis showed that irrigation treatments and biofertilizers had significant effect on most indices. Interaction effect of irrigation and biofertilizer were significant on seed and leaf yield (p
M. Azizi; S. Shahriari; H. Aroiee; H. Ansari
Abstract
Peppermint (Mentha piperita L.) from Lamiaceae family is one of the most important medicinal plants, used in food, sanitary and cosmetic industries. A field experiment was carried out in Ferdowsi University of Mashhad in 2010-2011 to evaluate the effects of three irrigation levels (100, 80 and 60 percent ...
Read More
Peppermint (Mentha piperita L.) from Lamiaceae family is one of the most important medicinal plants, used in food, sanitary and cosmetic industries. A field experiment was carried out in Ferdowsi University of Mashhad in 2010-2011 to evaluate the effects of three irrigation levels (100, 80 and 60 percent of water requirements calculated by evaporation pan class A) and two mulch types (black plastic and wood chips) in comparison to control (without mulch) on physiological parameter and essential oils content in a factorial experiments on the basis of Randimised Complete Block Desing with four replications. The data obtained from each harvest analyzed as a factorial experiment on the basis of randomized complete block design with four replications and the results of two harvests analyzed as split plot on time. The results of two harvest indicated that peppermint plants grow better in the first harvest than the second harvest. Plants collected in the first harvest showed higher dry matter and essential oil yield. The highest dry herb yield (44.12 g/plant), the highest percentage of essential oil (2.835 %v/w) and the highest essential oil yield (116.7 l/ha) detected in plots treated with third level of irrigation and use of wood chips mulch. In conclusion the results also confirmed that the highest dry herb and the highest oil yield per area unit were observed in plots treated with third level of irrigation with use of wood chips mulch.
