Medicinal Plants
S. A. Mousavi; F. Nekounam; T. Barzegar; Z. Ghahremani; J. Nikbakht
Abstract
Introduction
Physalis peruviana L. is a short perennial shrub that is a member of the Solanaceae family. These fruits have many benefits for human health because of their nutritional and bioactive compounds (vitamins (A, B, C and K), essential fats and etc.) and reduced the risk of diseases such as ...
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Introduction
Physalis peruviana L. is a short perennial shrub that is a member of the Solanaceae family. These fruits have many benefits for human health because of their nutritional and bioactive compounds (vitamins (A, B, C and K), essential fats and etc.) and reduced the risk of diseases such as cancer, malaria, asthma, hepatitis, dermatitis and rheumatism. Therefore, it has received special attention for cultivation all over the world. Increasing crop production and mitigating abiotic stresses are major challenges under extreme climatic environments and intense farming activities. Crop management strategies such as deficit irrigation can decrease soil evaporation, runoff, and plant transpiration, and increase water use efficiency (WUE) and water conservation. In addition to these practices, organic input, which includes the application of organic materials such as compost and humic substances, is an additional strategy that increases soil water retention and can potentially improve plant WUE. Water is crucial for agriculture and needs to be used effectively due to climate change and drought in Iran. For this reason, to adapt to water deficit scenarios, deficit irrigation applications are increasing in importance. Water availability is expected to be a growth limiting factor that would affect fruit yield in Physalis peruviana due to reduced flower set and elevated floral abscission rate.
Materials and Methods
In order to investigate the effect of humic acid on physiological characteristics, yield and fruit quality of Physalis peruviana under deficit irrigation conditions, a split plot experiment based on randomized complete block design with three replications was conducted during 2021. Treatments consisted arrangement of three levels of irrigation (starting irrigation at 100, 80 and 60% ETc (crop evapotranspiration)) and three levels of humic acid (0, 1.5 and 3 kg ha-1). The seeds of Physalis peruviana were sown in seedling trays contain peat moss. The seedlings were grown under normal conditions (25±2 °C/day and 20±2 °C at night with 60-65% RH). Plant height, total chlorophyll, fruit yield per plant, total soluble solid content, titratable acidity, vitamin C content and water use efficiency were measured. Statistical analyses were performed with SAS V9.3, and means comparison were separated by Duncan’s multiple range tests at p < 0.05.
Results and Discussion
The results showed that deficit irrigation significantly reduced growth, fruit yield, vitamin C and increased water use efficiency (WUE) and Total soluble solid content of Physalis peruviana. The soil application of humic acid significantly increased total chlorophyll, fruit quality and yield, and decreased leaf electrolyte leakage under normal and deficit irrigation, thus, the deficit irrigation 60 ETc% decreased the plant height by 18.6% and the fruit yield by 22.2% compared to irrigation 100 ETc%. The maximum plant length (200.3 cm), total chlorophyll content (2.42 mg g-1FW) and fruit yield (4793.3 kg ha-1) were observed in plants treated with 3 kg ha-1 humic acid under 100% ETc irrigation. The highest value of total soluble solid (12.6 B°), antioxidant activity (90.06 %) and WUE (1.23 kg m-3) were obtained with 3 kg ha-1 soil application of humic acid under deficit irrigation 60% ETc. The application of 3 kg ha-1 humic acid under 100 and 80 %ETc irrigation increased the fruit yield by 25% and 4%, respectively, compared to the control plants (non treated with humic acid) under irrigation100 ETc% and under deficit irrigation 60 ETc%, with decreasing 11% fruit yield, water consumption was saved by 40%. Soil and crop management practices that alter plant water and nutrient availability could affect the processes of crop evapotranspiration and WUE, which can influence the yield and fruit quality by changing the internal nutrient and water balance. Incorporating organic matter within a crop growth system either as leaf spray or soil mix is a complementary strategy to improve crop growth and WUE. By inducing antioxidant enzyme activities, HS could assist plants in stomata functioning, thereby closing stomata more efficiently under drought stress, which results in plant water conservation. The reason of the difference between WUE values probably appeared due to the differences on Physalis peruviana yield. WUE showed an upward trend with an increasing in irrigation.
Conclusion
Study results suggest that soil application of humic acid with increasing vitamin C, TSS and TA, improved fruit quality. According to the results, application of 3 kg ha-1 humic acid is suggested to improve fruit yield and quality of Physalis peruviana under normal and deficit irrigation conditions.
Growing vegetables
N. Zeinali Pour; F. Aghebati
Abstract
Introduction
Drought stress is one of the most common environmental stresses that limits agricultural production through disruption of physiological processes and reduces plant performance. Since in most parts of the world, including in Iran, melon plants and generally pumpkins are cultivated in hot ...
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Introduction
Drought stress is one of the most common environmental stresses that limits agricultural production through disruption of physiological processes and reduces plant performance. Since in most parts of the world, including in Iran, melon plants and generally pumpkins are cultivated in hot and dry areas, and in these areas the main challenge is due to the limitation of suitable water for agriculture, the possibility of various types of stress, including water deficit stress (partial or severe) in the cultivation of these plants is relatively high. From this point of view, it seems necessary to study and know the tolerant cultivars and masses and ways to improve water management. Among the physiological characteristics, leaf water status, membrane stability, photosynthesis changes and related factors are of special importance in relation to tolerance of stressful conditions and especially dehydration. A review of scientific sources shows that due to the relative importance of melons among fruit vegetables, no comprehensive research has been done on the effect of water stress on the yield and stress level evaluation indicators in Garmak and Dudaim groups. This research has tried to investigate and evaluate this issue in some products of this group of vegetables that have been less studied.
Materials and Methods
This experiment was carried out in the form of a split plot design in the form of randomized complete blocks and in four replications in the Mahan greenhouse complex located 25 km from Kerman province. Experimental treatments include; There were three plants (Shahdad and Isfahan cantaloupe (Garmak) and Birjand dudaim (Cucumis melo group dudaim)) and three levels of irrigation in order to apply stress (starting irrigation at matric potentials of -45 (control), -55 and -65 kPa). The parameters of net photosynthesis rate, stomatal conductance, leaf transpiration rate, leaf chlorophyll index, water potential, osmosis and turgor potential of leaves, water use efficiency and leaf relative humidity were measured and evaluated.
Results and Discussion
Based on the results of the first and third tables, the three population were different in the changes in the net rate of photosynthesis under different levels of dehydration stress, but the change process in them was largely similar. The highest rate of net photosynthesis and leaf stomatal conductance was obtained in Isfahan cantaloupe population plants under control irrigation (-45 kPa), which, of course, did not have a significant difference with plants under -55 kPa dehydration stress, and the lowest rate of these traits in Birjand dudaim under irrigation at matric potential -65 kPa was measured. A more severe level of dehydration stress (starting irrigation at matric potential of -65 kPa) reduced the net photosynthetic rate in all three plants compared to control irrigation (-45 kPa). It seems that under the conditions of this experiment, the reduction of the relative humidity of the leaves occurs following the reduction of the water potential in the leaves and leads to the closing of the stomata in order to increase the resistance of the mesophyll cells against the dehydration stress and parallel to these changes, the reduction it happens in the amount of stomatal conductance and as a result the rate of net photosynthesis. The rate of leaf transpiration in matric potentials of -55 and -65 kPa has decreased significantly compared to control irrigation. The decrease in transpiration rate in plants under stress is probably due to stomatal closure and reduction of stomatal conductance. Plants under stress prevent excessive water loss through transpiration by regulating stomata. Based on the results of the second and fourth tables, by measuring the water potential, osmosis and turgor potential of the leaves of the three population used, it was shown that the water potential of the leaf decreased with the increase in the water stress levels. The slope of this decrease is such that the potential values are equal to the osmotic potential values of the leaf and the turgor potential, which is the result of the difference between the osmotic and water potentials of the leaf, also decreases, but it is the turgor pressure that has increased and in a more positive way. even at the end of the stress period and at the most extreme level of stress, it reaches zero. This same turgor pressure maintains the normal state of the membrane in cells under dehydration stress. In fact, the extreme level of water stress in this experiment significantly reduced the osmotic potential of the leaf. The highest amount of osmotic potential (8.5 Bar) for these plants was obtained in the usual or control irrigation treatment and the lowest (22 Bar) in the more severe level of dehydration stress treatment (watering as soon as the matric potential reaches -65 kPa) was obtained. At matric potentials of -45 and -55, there was no significant difference between the three population in terms of leaf relative humidity percentage, but in Garmak and Dudaim populations, the relative humidity of leaves was significantly reduced by applying stress at the matric potential of -65 kPa. This is despite the fact that in the Isfahan cantaloupe, the decrease in the relative humidity of the leaf was not significant. The existence of this difference in the reduction of the relative humidity of the leaves in the conditions of stress between the three plants may be due to the genetic differences in the ability of the stomata of the plants to lose water. In fact, more drought tolerant population (Isfahan Garmak) compared to Shahdad Garmak and Birjand dudaim have better maintained relative humidity until the end of the stress.
Conclusion
Plants with the ability to regulate osmosis can be considered as drought tolerant plants. This adjustment in the plants of this experiment occurred in the condition that in all three population, the osmotic potential decreased by -19 to -22 Bar. This event is to some extent guaranteeing the performance of pure photosynthesis, although at a low rate in these plants, in the condition that the water potential of the cell has become negative at the level of severe water deficit stress, at the end of growth.
Growing vegetables
M. Amiri roudan; M. R. Hassandokht; D. Sadeghzadeh-Ahari; A. Mousavi
Abstract
Introduction
The use of natural and artificial mulches to reduce evaporation from the soil surface and retain moisture is one of the best measures to make optimal use of limited water resources and increase crop yields. Optimal production of plants in sandy soils has been challenged due to their ...
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Introduction
The use of natural and artificial mulches to reduce evaporation from the soil surface and retain moisture is one of the best measures to make optimal use of limited water resources and increase crop yields. Optimal production of plants in sandy soils has been challenged due to their low capacity in water retention and also production of plants in arid and semi-arid regions due to water shortage and drought stress. Water scarcity is increasing as a result of global warming, and attention is being paid to the methods that lead to water storage. Therefore, it is necessary to increase water consumption efficiency with new technologies. One of the new methods of water retention in the root zone is the use of a water retaining layer below the soil surface. By preserving water and elements in the root zone and creating a stable environmental state, it increases local production and economy by reducing soil erosion and groundwater pollution. Also, due to limited water resources, it is necessary to seek solutions to conserve water and increase water use efficiency. Mulch is considered as one of the best ways to retain water in the soil and reduce soil evaporation. Therefore, in this study, the application of impermeable soil layer on morphophysiological and biochemical traits of eggplant (Solanum melongena L.) was investigated using date leaf mulch under deficit irrigation stress.
Materials and Methods
This study was conducted in Roudan, Hormozgan, Iran. Main plot includes deficit irrigation stress in three levels (100, 70,40 % of plant water requirement), sub-plot includes mulch in two levels (date leaves and no mulch) and sub-sub-plot includes impermeable layer in three levels (0, 100, 120 cm). Eggplant seeds of the local variety Rudan were planted in the seedling tray and transplanted when the seedlings were about 15 cm long or 5-6 leaf stage. Shortly after transplanting the seedlings to the field, daily irrigation was performed. CROPWAT software was used to calculate 100 % of the water requirement. Stress was applied using drippers with lower flow rate or reduced irrigation hours and by installing water meters.
Results and Discussion
The results showed that the highest plant height (78 cm) belonged to date palm mulch, layer impermeable at depth of 120 cm and 100% water requirement. The use of date palm mulch and impermeable layer, especially the impermeable layer, has led to an increase in the number of leaves and fruits in the eggplant. The highest number of leaves (189) belonged to the treatment without mulch and with an impermeable layer of 120 cm soil depth in 100 % water requirement and the lowest (75.13) belonged to the treatment without mulch and impermeable layer in 40 % water requirement. The highest number of fruits belonged to the treatment without mulch and impermeable layer at depth of 120 cm and 100 % water requirement and the highest amount of dry matter (12.5%) belonged to the treatment of date palm mulch and impermeable layer at depth of 120 cm and 100 % water requirement and the lowest (1/9%) belonged to date palm mulch without impermeable layer and 70% water requirement. The results showed deficit irrigation stress reduced the amount of chlorophyll a, b and total in eggplant. The use of date palm mulch and impermeable layer in water requirement of 70 and 40 % has increased the amount of chlorophyll, which seems to be used in case of water shortage, reduce the adverse effects of dehydration and prevent the destruction of chlorophyll in eggplant. The highest amount of total chlorophyll belonged to the 100 % water requirement, without the use of date palm mulch and impermeable at depth of layer 120 cm. The highest amount of proline in this study belonged to treatment without date palm mulch, application of impermeable layer at depth of 0 cm and water requirement of 40 % and the lowest belonged to the treatment of date palm mulch, application of impermeable layer at depth of 120 cm and 100 % water requirement. The highest amount of eggplant water use efficiency was obtained in 40 % water requirement, use of date palm mulch and impermeable layer at depth of 120 cm. The results of this study also showed that deficit irrigation stress reduced fruit yield in eggplant and the use of date palm mulch and impermeable layer also increased eggplant yield. This increase in fruit yield is especially noticeable in the use of date palm mulch and impermeable layer at depth of 120 cm.
Conclusion
It seems that the impermeable layer and date palm mulch have reduced the negative effects of water stress on the plant, increased fruit yield and water use efficiency and reduced the effects of stress.
Pomology
Atiyeh Abdoli; Javad Ramezani Moghadam; Yaser Hosseini; Mohammad Reza Nikpour; Hadi Dehghan
Abstract
Introduction: Nowadays, the decrease of water resources and increasing salinity of irrigation water are evident in most parts of Iran. Increased salinity of irrigation water can impair plant metabolism, decrease biomass and stem length. On the other hand, water stress decreases root length and weight ...
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Introduction: Nowadays, the decrease of water resources and increasing salinity of irrigation water are evident in most parts of Iran. Increased salinity of irrigation water can impair plant metabolism, decrease biomass and stem length. On the other hand, water stress decreases root length and weight and crop yield. One way to reduce the negative effects of moisture stress is management of irrigation time. This can be investigated by changing the percentage of moisture permitted depletion and selecting the one with the lowest yield depletion. On the other hand, the amount of damage to the crop can be reduced by examining different amounts of water salinity and its effect on crop yield. Therefore, in this study, the effects of different amounts of irrigation water salinity and irrigation time management on tomato yield under greenhouse conditions were investigated. Materials and Methods: This study was carried out in greenhouse (No. 2) of Faculty of Agriculture and Natural Resources of University of Mohaghegh Ardabili. In this research, the effect of different values of salinity (in different irrigation times) on root characteristics and yield of tomato (Saint Pierre cultivar) was investigated. The experimental design used in this research was a factorial experiment in a completely randomized block design with four replications. The applied treatments included salinity of irrigation water (four levels: S1=1.5ds/m, S2=2.5ds/m, S3=4ds/m and S4=7ds/m) and irrigation time management stress (in three levels, irrigation at 40, 50 and 65% field capacity, respectively, I1, I2, I3). The pots used in this study were incomplete cones with a height of 27 cm, a span diameter of 26 cm and a bottom diameter of 19 cm. In this study, indirect method (transplanting) was used for cultivating tomato. After cultivating the transplants in prepared pots, they were irrigated with pure water for two months to stabilize the transplants in order to avoid any stress effect on the transplants. The moisture meter (Model: PMS-714) was also used to measure daily soil moisture of the pots. Statistical analysis was performed by MSTATC software. The important characteristics investigated in this study were root length, root weight (dry and wet), root diameter and volume, plant yield, water drainage, evapotranspiration and water use efficiency. Results and Discussion:According to the results of this study, salinity values of irrigation water had a significant effect at 1% level on fresh and dry root weight, root diameter and volume, total evapotranspiration, total water use, total water drainage output, crop yield and the number of blooms. On the other hand, irrigation water salinity had no significant effect on the number of unripe fruits at 5% confidence level. For example, the highest fresh and dry weight of roots were 26.17 and 6.3 g for S2 treatment, respectively. However, the difference in root weight values for S2 and S1 treatments (Mean equal to 27.5%) was not significant. Also, with increasing salinity of irrigation water above 2.5 dS/m, root weight (dry and fresh) decreased significantly (at 1% level). The reason for the decrease in root weight at high level of salt concentrations can be due to the accumulation of salt (including potassium, sodium, etc.) in various organs of the plant including the root. On the other hand, the results showed that the effect of irrigation time management was significant only on root diameter and weight of ripe fruit at 5% and 1%, respectively. According to the results of this study, irrigation can be achieved with 50% moisture allowable depletion instead of 40% moisture permitted depletion without significant change in the weight of ripe tomato fruit. This can certainly cause saving of irrigation water that can be very effective in the current condition of Iran and lack of water resources. In this study, the relationship between evapotranspiration and crop yield and the relationship between these parameters, were investigated. Results showed that, tomato yield coefficient of response to moisture stress (Ky) varied from 0.4 to 1.20. Also the average response coefficient of tomato to water stress was 1.12. This value was close to the mean Ky provided by the FAO (Ky = 1.05). The slight increase in Ky value obtained from this study is probably due to the salinity stress applied to the tomato plant. Conclusion: This study was conducted to investigate the effect of salinity stress on yield and root characteristics of tomato under irrigation time management and greenhouse conditions. The results showed that the effect of irrigation salinity was significant on yield, yield components and root characteristics (e.g., root weight, diameter and volume, yield, evapotranspiration and drainage output). On the other hand, moisture stress induced by irrigation time variation had no significant effect on yield, yield components and root characteristics of tomato except in two cases. This study indicated that the effect of salinity irrigation water is more effective than water stress on reduction yield. Also, according to the results of this study, the use of 2.5 dS/m irrigation water salinity instead of 1.5 dS/m in most cases had no significant effect on yield reduction but may also increase it. The results of this study show that under current conditions of Iran (increasing quantitative and qualitative shortage of water resources) it is possible to use lower quality waters such as treated wastewater and agricultural wastewater (with management of salinity and leaching) to achieve the acceptable yields for crops.
Mohammad Mahmoodi Sourestani
Abstract
Introduction: Mediterranean climate conditions induce several stresses that plants have to cope with, especially during summer months when high temperature and radiation levels along with low water availability in the soil prevail for long periods. Variation in physiological traits such as photosynthesis ...
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Introduction: Mediterranean climate conditions induce several stresses that plants have to cope with, especially during summer months when high temperature and radiation levels along with low water availability in the soil prevail for long periods. Variation in physiological traits such as photosynthesis and plant water status and their association with morphological characters can play an important role in the adaptability of the species to environmental constraints. The previous studies show that scorching weather not only affects the rate of gas exchange, but also results in diurnal changes in activity. Thus, the impact of environmental stresses on plants growing in these conditions should be assessed by examining the evolution of their diurnal variations on leaf gas exchange. Aromatic plants represent a renewable source of valuable compounds that can be used in food, perfumery, and pharmaceutical industry. Among these plants, sweet basil (Ocimumbasilicum), holy basil (Ocimum sanctum), lemon balm (Melissa officinalisL.) and catnip (Nepetacataria) are very important for different industries. Studies on environmental physiology of medicinal plants are relatively scarce and very few information is available concerning the physiological basis of medicinal plant response to heat stress that is one of the most important factors limiting production of medicinal plants in Khuzestan province.
Material and methods: In order to evaluate the diurnal fluctuation of gas exchange of mentioned plants, an experiment was carried out in 2013 at research farm of Horticultural Science, Shahid Chamran University (31°20'N latitude and 48°40'E longitude and 22.5m mean sea level), Ahvaz (Iran), a site characterized by a semidry and scorching weather during late spring and summer. The experiment was arranged based on randomized complete block design (RCBD) with three replications and 4×8 factorial scheme (Four plants including lemon balm, catnip, holy basil and basil; and eight times of evaluation 7:00,9:00, 10:00, 11:00, 12:00, 13:00, 17:00 and 20:00 h). Land preparation consisted of disking and the formation of raised beds (15cm high and 45cm wide across the top) using a press-pan-type bed shaper. The plants were arranged on two rows on each bed, with 20 cm in-row and 40 cm between-row spacing. The plants were irrigated weekly as needed. Gas exchange parameters were investigated from June 9-11at end of vegetative phase under natural environmental conditions. The parameters of gas exchange were measured on the 5th and 6th nearly full expanded leaves between the hours of 07:00 and 20:00 during bright sunlight on clear and cloudless days. Determination of leaf net photosynthesis rate (Pn), stomatal conductance (gs) and transpiration (E) was made with Infra-red gas analyzer (LCA4, ADC Co. Ltd., Hoddesdon, UK).Instantaneous water use efficiency (WUEinst) and apparent quantum yield(AQY) were calculated as Pn/E andPn/PPFD ratios, respectively.
Result and discussion: The result showed that plant type had significant effect on all measured traits as well as record time. Interaction between plant type and record time were significant for PPFD, leaf temperature and net photosynthesis. The highest Pnof Lemon balm (8.97 µmol CO2 m-2 s-1), catnip (11.2 µmol CO2 m-2 s-1) and sweet basil (13.75 µmol CO2 m-2 s-1) were recorded at 9:00 when the photosynthetic photon flux density (PPFD) was 1488, 1598 and 1645 µmol photon m-2 s-1, respectively. Holy basil showed highest Pn (15.47 µmol CO2 m-2 s-1) at 10:00 when PPFD was 1821 µmol photon m-2 s-1.High irradiances caused photoinhibition of the four plants and it seems the four plants reach to light saturation point about 1500 µmol photon m-2 s-1.The midday depression of photosynthesis likely resulted primarily from long periods of high PPFD, limitation in stomatal conductance and high temperature. Catnip was more sensitive to high irradiance. The Pn had positive and significant correlation with gs in four plants. The stomatal conductance was also positively correlated with E in four plants. The plants represented double peak curve for WUE. The first and second peaks appeared at 9:00 and 17:00, respectively. The four plants also showed highest AQY at 7:00. There were significant difference between four plants for leaf temperature, gs, Pn, WUE and AQY. Lemon balm showed lower leaf temperature than other plants due to its high gs. The highest amounts of Pn, WUE and AQY were observed in holy basil.
Conclusion: In regard to Pn, WUE and AQY, it seems holy basil and sweet basil can tolerate weather condition of Ahvaz.
Peyman Jafari; Amirhooshang Jalali
Abstract
Introduction: The term of Mulch, is the German word (Molsh) means the soft, however, not soft, and made of plant debris or synthetic substances. Many positive effects attributed to the use of plastic mulch such as adjusting the temperature in the root environment, conserve moisture, reduce weeds, increase ...
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Introduction: The term of Mulch, is the German word (Molsh) means the soft, however, not soft, and made of plant debris or synthetic substances. Many positive effects attributed to the use of plastic mulch such as adjusting the temperature in the root environment, conserve moisture, reduce weeds, increase root growth, reduce soil erosion, and soil condensation and improve germination and early plant establishment. The use of mulch can reduce the harmful effects of salt in plants.
Materials and Methods: To evaluate the effects of black and clear polyethylene mulch on yield and yield components of melon in salinity stress condition, a study was conducted in 2011 using split plot randomized based on complete block design with three replications in Varamin region. Three salinity levels of irrigation water of 2, 5 and 8 dS-1 as main factor and three plastic mulch treatments (no mulch, clear mulch and black mulch) were considered as sub-plots. At harvest and after determining the yield and number of fruits harvested from each plot, the average number of fruits per plant was measured and fruit pulp thickness was recorded with calipers.
Results Discussion The results showed interactive effects of salinity and mulch on fruit yield, number of fruits per plant, average fruit weight, fruit length, days to first harvest and fruit soluble solids percentage were statistically significant. In salinity levels of 2, 5 and 8 dS m-1, fruit yield increased, respectively, 19.6, 59, and 45.4 %in clear mulch compared to control. Similarly these increases for the black mulch were equal to 15.7, 41.9, and 21.4 percent, respectively. With 2, 5 and 8 dS m-1 salinity levels, fruit yield in the first harvest were 7.44, 7.72, and 6.98 t ha -1, respectively, which was significantly higher than without mulch and black mulch. Mulch can reduce evaporation and increase the level of moisture in the soil and thereby dilute the salt and reduce the harmful effects of salinity. Some researchers believe that increase in crop yield by using plastic mulch than plant debris mulch is due to the simultaneous increase in moisture and soil temperature. Effect of plastic mulch on soil temperature and crop yield depends on the color and usually transparent plastic are more effective in this regard than black polyethylene mulch. In terms of rising temperatures in the microclimate around the plant roots, transparent mulches are more effective than dark mulches. Unlike dark mulch, clear mulch have minimal absorption of light, approximately 85 to 95 percent .The inner surface of clear mulch is covered with water that the short wave passes and outgoing long wave radiation is absorbed from the soil and thus prevent heat loss. Water use efficiency with use of clear and dark mulches in compared to control treatment was increased by 17.3 and 13.4 %, respectively. Under salinity conditions, plastic mulches can reduce the harmful effects of salinity. Water use efficiency in salinity 2, 5 and 8 dS m-1, respectively, were 12.6, 7.6 and 3.1 kg m-3.Research results indicated that when water use efficiency based on the economic performance expression (e.g. present study) reduced water use efficiency but when water use efficiency expressed based on the total dry weight, water use efficiency is independent of salt concentration and the amount of water use efficiency is the function of plant and plant yield.
Conclusion For using salty water, which may be unavoidable for many agricultural areas, use of mulch (especially transparent mulch) can have a significant role in increasing yield and more efficient utilization of water. From a practical perspective, in areas where irrigation water quality has declined due to reducing the level of the underground water table, the indiscriminate use of water resources and similar cases and use of these resources will lead to a gradual increase in soil salinity, application of mulch with the impact on the soil water content prevent of crop yield loss and cause earliness product.
Sonayye Beigi; Majid Azizi; Seyyed Hossein Nemati; Vahid Rowshan
Abstract
Introduction: Medicinal plants are rich in active substances and primarily have been used in the manufacture of many drugs. Basil (Ocimum basilicum L.) is one of the important medicinal plants whichbelongs to the Lamiaceae family. Basil essential oil content (between 0.5 to 1.5 percent) varies according ...
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Introduction: Medicinal plants are rich in active substances and primarily have been used in the manufacture of many drugs. Basil (Ocimum basilicum L.) is one of the important medicinal plants whichbelongs to the Lamiaceae family. Basil essential oil content (between 0.5 to 1.5 percent) varies according to climatic conditions of habitat location. Basilneeds a lot of water during growth period and it is very sensitive to water stress and shows wilting symptoms very soon after water shortage. Iran is located in an arid and semi-arid region which has little precipitation that is not enough for crop water requirements. Nowadays, the use of superabsorbent polymers is one of the ways to create sustainable agriculture and increase irrigation efficiency. They can store high water or aqueous solutions in root zone of plants and to reduce negative effects of drought stress. So, improvement of plant growth, increasing of irrigation intervals, reducing water loss and costs of irrigation is due to the application of superabsorbent polymers. Mucilages are also the herbal polysaccharides, soluble in water, and commonly include carbohydrates and can be used as hydrophilic polymers. The aims of this investigation were to study the effects of hydrophilic polymers on water use efficiency, morphological characteristics (dry matter, leaf area, and leaf number), essential oil quantity and yield of basil to harden plant to drought stress and to evaluate its potential to cultivate in arid regions. In addition, taking steps forward towards sustainable agriculture, by reducing the cost of agricultural production, helps protecting the environment.
Materials and Methods: This research was conducted as a pot experiment at the department of Horticultural Science‚ college of Agricultural‚ Ferdowsi University of Mashhad‚ Iran, during 2012-2013.The research was set out in a factorial experiment on the basis of completely randomized block design with three replications.Two hydrophilic polymer Stockosorb® (industrial) and malva leaf (herbal) with two application methods (mixed with soil, mixed with soil+root) at 4concentrations (0, 0.1%, 0.2% and 0.3% w/w) were used. Leaf number, leaf area, dry matter yield, water use efficiency, essential oil quantity and yield were measured. Improved seeds of Ocimum basilicum var. Keshkeniluvelou were sown and seedlings were transplanted to the pots in four-leaf stage. Hydrogels were prepared and mixed with water after weighing the polymers according to determined concentration. After establishment, all pots were irrigated with a determined amount of water after reaching to the highest concentration (0.3%) of the wilting point. So, in this state in addition to the treatment at 0.3% treatment, lower levels (0.2% and 0.1%)were reached to wilting point earlierand were exposed to water stress.
Results and Discussion: Superabsorbent polymers can by absorption of irrigation and rain water, prevent deep percolation of water and with decreasing irrigation interval and reduced water consumption and increase water use efficiency. The results showed that using Stockosorb superabsorbent polymer and malva leaf as herbal hydrophilic polymersare useful for water supply of the plant in water stress.Application of these substances on morphological characteristics, water use efficiency and basil oil, were superior to the control.According to the obtained results, malva leaf use in soil and roots in treatmentless than (0.1% and 0.2%)number and leaf area and higher than (0.3%)increased dry matter yield, water use efficiency and the essential oil quantity and yield. Stockosorb (0.2%) byboth applying methods increased dry matter yield and water use efficiency. Also Stockosorb (0.2%),soil application increased leaf number and area. The essential oil yield and quantity increasedwith use of Stockosorb in soil + root in for0.2% and 0.3% treatments, respectively.
Conclusion: Due to the importance of cultivation of medicinal plants to provide conditions to increase essential oil yield and quantity at the same time, the best method used were malva leaf and Stockosorb with concentrations higher than (0.3%) and soil application methodor the use of both polymers with application method in soil + root in the moderate concentration (0.2%).For that purpose, we obtained favorable conditions for improving the morphological characteristics, water use efficiency and increasing the quantity and of essential oil yield in drought stress simultaneously. The results showed that natural compounds can be a good alternative for chemical compounds, but further experiments are needed for their commercialization.
