جستجوی مقالات مرتبط با کلیدواژه « Greenness Index » در نشریات گروه « کشاورزی »

Quinoa (Chenopodium quinoa L.) is a dicotyledonous, allotetraploid, three-carbon, annual, optional salt-loving plant and is native to South America and the Andean highlands. The growth period of the plant varies between 70 and 240 days depending on the cultivated area. The main product of this plant is the seed, which has a high nutritional value in terms of protein, amino acid balance, unsaturated fat, vitamins, and minerals. Like other plants, quinoa faces various environmental stresses during its growth period, and its growth and yield are a function of environmental factors and their mutual effects. The occurrence of high temperatures during the sensitive stages of plant growth, such as flowering and seed formation, may cause a significant decrease in quinoa yield, and high temperature has been cited as one of the most important challenges for the cultivation and expansion of quinoa in the world. Salicylic acid acts as a signal molecule and plays an important role in regulating growth and development processes in plants under environmental stress. Salicylic acid increases the content of relative humidity, accumulation of dry matter, and the amount of chlorophyll.

The objective of this research is to assess the physiological responses of quinoa cultivars to varying planting dates and the impact of foliar application of salicylic acid in mitigating the adverse effects of end-of-season heat stress during the 2021-2022 crop year. The study was conducted at the research farm of the Faculty of Agriculture, Shahid Chamran University of Ahvaz, using a split-split plot design within a randomized complete block framework, with three replications. In this experiment, three factors a) planting date including October 12, November 11, and December 11, and b) foliar application of salicylic acid in the two stages of budding and the beginning of flowering including non-application, 1.5 mM and 3 mM and c) Quinoa cultivars including Titicaca, Giza, Q12 and Redcarin were investigated.

The effect of investigated factors such as planting date, salicylic acid, and variety on different traits had statistically significant differences. The results showed that the maximum amount of stomatal conductance and the relative content of leaf water belonged to the date of October 12. The highest biological yield and seed yield were observed under conditions of application of 1.5 and 3 mM salicylic acid, respectively. Probably, salicylic acid has increased the growth and accumulation of dry matter by improving carbon fixation, synthesis of metabolites, and maintaining the water status of plant tissues. Based on the results of the comparison of the mean of the three-way interaction, the maximum amount of biological yield and seed as the most important goals of quinoa plant cultivation, respectively, in the treatment of not using salicylic acid in the Redcarin cultivar on the planting date of December 11 and the application of 3 mM salicylic acid was obtained in the variety Redcarin on the planting date of October 12. The highest rate of net assimilation and the growth rate of the product belonged to the treatments of no application of salicylic acid in the Redcarin cultivar on December 11 and no application of salicylic acid in the Giza cultivar on October 12, respectively. The treatment of not using salicylic acid in the Redcarin variety on the planting date of October 12 was also able to achieve a high harvest index.

 According to the obtained results, it seems that to achieve a high seed yield of quinoa, it is possible to benefit from the treatment of 3 mM salicylic acid in the Redcarin variety on the planting date of October 12.

The study of the climatic condition of Iran shows that arid and semi-arid areas are often scattered in the central areas of Iran, and salinity in these areas is one of the limiting factors for crop production. Fenugreek is a genus of Fabaceae family and one of the important products of semi-arid regions. This medicinal plant is used in the treatment of a wide range of diseases such as diabetes. Fenugreek seeds and its leaves are rich in minerals, protein and carbohydrates. The expansion of fenugreek cultivation in the world has caused this plant to face abiotic environmental stresses during the growing season. Silica plays a role in reducing the amount of sweating and preventing the side paths of sweating. Therefore, this research was conducted with the aim of evaluating the effect of silica fertilizer in increasing salinity tolerance of fenugreek plants.

The present study was conducted in order to investigate the effect of silica fertilizer on some morphological and physiological characteristics of edible and medicinal fenugreek plant in the fall of 2022 in Behbahan city in the form of pots in the form of a completely randomized design with three replications in the open air. The treatments included salt stress at three levels (0, 75 and 150 mM sodium chloride) and silica fertilizer at two levels (0 and 3 g/l) and a total of 18 pots. Fenugreek seeds are obtained from a reputable seed store (Rahimi vegetable seed store in Behbahan city). Fenugreek seeds were planted in small plastic pots with a height of 7 cm and a diameter of 8 cm filled with garden soil, leaf soil and perlite (ratio 1:1:1) so that finally there were five plants in each pot.

The results showed that in the fenugreek plant, the maximum root length (6.95 cm) and the dry weight of the aerial parts (0.046 g) in the treatment without salt stress (control) and without the use of silica fertilizer and the lowest root length (2.63 cm) ) and the dry weight of aerial organs (0.03 g) was observed in the treatment of 150 mM salinity stress and without the use of silica fertilizer. Also, the decrease in chlorophyll fluorescence (Fv/Fm ratio) in response to salinity stress was lower than the decrease observed in salinity stress without using silica fertilizer. In the salinity stress of 150 mM and the use of silica fertilizer 3 g/liter, the amount of chlorophyll fluorescence (Fv/Fm ratio) was 0.09 more than in the treatment of salinity stress of 150 mM and no silica fertilizer. The highest value of greenness index (SPAD) was obtained in the condition without salinity stress (11.60) and the lowest value was obtained in the salinity stress of 150 mM (2.30), which was significant at the five percent level. Stress causes disturbances in the path of electron transfer and destruction of tissues related to photosynthesis, and in this way, it prevents the optimal energy consumption of the plant. In this study, silica treatment reduced the negative effects of severe salinity on root length, wet and dry weight of shoot and chlorophyll fluorescence, and reduced the harmful effects of salinity on fenugreek plants.

In this experiment, it was observed that the application of silica fertilizer in severe salinity stress significantly reduced the amount of chlorophyll fluorescence in comparison with its non-application. The present study showed that adding silicone fertilizers to saline soils reduces the negative effects of salinity stress in fenugreek plants.

The present research was conducted to investigate the effect of foliar application of Zargreen organic liquid fertilizer on the growth and chemical composition of tomatoes under drought stress in greenhouse conditions in the Faculty of Agriculture of Shiraz University on May 2022. Treatments consisted of four levels of foliar application of Zargreen amino acid fertilizer (with concentrations of 0, 2.5, 5, and 7.5 L/1000L), and three soil moisture levels (field capacity (without stress), 75 and 50% of field capacity, FC). During the growing season three times; 1.5 months (at the end of vegetative growth and beginning of flowering), 2.5 months (at the stage of fruit development), and 3 months (at the stage of fruit ripening) after planting, Zargreen organic liquid fertilizer solutions were used with the mentioned concentrations for foliar spraying. The interaction effect of Zargreen organic fertilizer and moisture levels showed that the highest greenness index was observed with the highest level of soil moisture stress and the highest level of applied organic fertilizer. Application of 2.5, 5, and 7.5 L/1000L of Zargeen fertilizer increased the mean value of plant height by 8, 9, and 14%, respectively, compared to the control. The lowest shoot fresh weight was obtained without application of the organic fertilizer at the highest level of applied moisture stress. While at the same stress level, the highest shoot fresh weight was observed with the addition of 7.5 L/1000L of the organic fertilizer. The highest shoot zinc and copper concentrations were obtained in the plants grown at the highest moisture stress and the highest level of organic fertilizer application. It can be concluded that adding organic compounds improves the plant's tolerance to environmental stresses by modifying the physiological processes of the plant.

In order to evaluate the effects of soil and foliar applications of Zargrain organic fertilizer on water-use efficiency, yield and yield components of wheat under drought conditions, two separate factorial experiments (completely randomized design of three replications) were conducted in the greenhouse. Treatments in the first experiment were four levels of foliar application (zero, 2.5, 5 and 7.5 L/1000L) and three moisture levels (field capacity, 75 and 50% of field capacity(FC)) and in the second experiment four levels of soil application (zero, 5, 10 and 20 L/ha) and the mentioned moisture levels. Greenness index, number of claws, number and height of spike, number of seeds per spike, plant height, fresh and dry weights were measured and water-use efficiency was calculated. Both soil and foliar applications methods increased grain yield, plant dry weight, greenness index and water-use efficiency compared to control. Application of 20 L/ha caused a 13% increase in the number of spikes, and the application of 5 to 20 L/ha increased the number of seeds in spike by 22 to 31%, respectively. The number of seeds per spike increased by 7.5 L/1000L foliar application. The highest greenness index (38% increase in 0.75FC treatment) and water-use efficiency (0.55 g/L in 0.5FC condition) was observed with soil application of 20 L/ha fertilizer. Fertilizer application in dry conditions prevented dry-weight loss and soil application was more effective. Application of fertilizer increases the growth/performance of the plant and it can be used to improve the quantity/quality of the yield, especially in arid/semi-arid regions.

The use of optical sensors in assessing crop health, plant fertilizer demand, and yield prediction is the new method in the agricultural sector. Grennseeker optical sensor is one of the latest tools that has recently gotten much attention from worldwide farmers and researchers. Detailed examination of the variables mentioned above and measuring canopy coverage can improve production management and minimize input consumption. Therefore, this study aimed to investigate the GS sensor's ability to assess the nutritional status and surface area of the canopy and predict the performance of the garlic crop. In this research, five N-fertilizer treatments of N0, N50, N100, N150, and N200 were applied to garlic in a randomized complete block design with three replications. The image processing results in Labview software showed that the best separation performance for the elimination of background from the canopy could be achieved with the function of G-R. The results revealed that the best correlation coefficient between NDVI and LAI was 0.69, but no significant relationship was found between N and NDVI. Finally, it can be concluded that the GS could not estimate the N level of garlic. However, it could perform well in estimating tuber yield and canopy performance  satisfactorily.

In the last two decades, soil contamination with heavy metals, including lead (Pb), has been increasing. Pb is the most important heavy metal that has polluted the environment and caused symptoms of plant toxicity such as limiting root and shoot growth, blackening of the root system and decreasing photosynthesis and the quantity and quality of yield. In many agricultural areas of Iran, including Zanjan, the presence of heavy metals, especially Pb, is always associated with the growth stages of plants, including medicinal plants. Native medicinal plants of Iran, including Lallemantia iberica have an important role in the treatment and prevention of diseases. The seeds of this plant are reconstituent, stimulant, diuretic, and expectorant and have a high content of oil and omega-3 fatty acid alpha linolenic acid. The use of polyamines such as putrescine (Put) is one of the new strategies to reduce the harmful effects of environmental stresses such as heavy metals. Polyamines, as plant growth regulators, have a protective role against membrane damage and lipid peroxidation and are involved in regulating processes such as cell division, enzyme activity, vascular differentiation, flowering, fruit ripening, and root growth. Due to the contamination of agricultural soils near the industrial areas with heavy metals and the need for medicinal plants in the country, this study was conducted to investigate the effect of Put spraying on the growth and tolerance of L. iberica to Pb stress.

The experiment was conducted as a factorial based on a randomized complete block design with six replications (three replications for grain yield and three replications for other traits) at the research greenhouse of the Faculty of Agriculture, the University of Zanjan in February 2018. The experimental factors were Pb stress in four levels (control, 300, 600 and 900 mg Pb/kg soil) from the source of Pb(NO3)2 and Put in two levels (0, and 0.5 mM). The Pb amount in the test soil was measured at the beginning of the experiment and considered as control. The Put spraying was performed before flowering begins (with the observation of the first flower bud) during 2 steps (half concentration at the 10-leaf stage and the other half 7 days later to prevent Put accumulation). Greenness index, proline content, leaf area, leaf, stem, and capsule dry weight, total shoot dry weight, root length and dry weight, and tolerance index at the flowering stage and grain yield at the harvest stage were measured. Analysis of variance was done by using SAS (9.1) software. Mean comparison was performed by Duncan multiple range test at 5% probability level.

The main effects of Pb stress and Put spraying on all the traits were significant. The interaction effect between them on greenness index, proline content, leaf, stem, and capsule dry weight, total shoot dry weight, root length, tolerance index, and grain yield was significant while its effect on leaf area and root dry weight was not. Pb stress, especially at 900 mg concentrations, decreased leaf area, greenness index, leaf, stem, and capsule dry weight, total shoot dry weight, root length and dry weight, tolerance index, and grain yield and increased proline content. The highest grain yield and tolerance index was obtained in the non-added Pb. Within each four Pb levels, Put spraying had the maximum amount of measured traits than the non-Put. Growth restriction and improper development of the root system under Pb stress reduced water and nutrient uptake and subsequently affected chlorophyll and photosynthesis, thereby reducing leaf area, shoot growth and plant yield, which the positive and significant correlation of root length with total shoot dry weight, leaf area, and greenness index (r=0.87***, r=0.61**, and r=0.9***, respectively) confirms the above content. The positive role of the Put can be due to its effect on increasing cell division, which ultimately improves plant growth. Positive and high correlations of leaf area with grain yield (r=0.69***) and greenness index with grain yield (r=0.87***) confirm that any factor which increases leaf area enhances producing and storing assimilate in the plant, leading to increased grain yield.

Overall, measured traits affected by increasing Pb concentration in the soil, however, Put spraying had improvement effects on these traits and with an increasing root length, greenness index and leaf dry weight led to an increase in the tolerance index of L. iberica under Pb stress. Also, the highest grain yield was found in Put spraying under control. Therefore, given the crisis of the increasing concentration of heavy metals, especially Pb in the agricultural soils, Put application can be suggested to increase Pb tolerance in L. iberica and to use this plant in Pb-contaminated areas to restore lost vegetation.

Carla is a medicinal plant whose fruit is used to treat diabetes. In this study, the effect of water stress and biochar on the qualitative and quantitative parameters of Carla plant was investigated. The experiment was performed in greenhouse conditions in a factorial manner and in a completely randomized design with three replications. Treatments included three irrigation water treatments (50%, 75%, and 100% of the water requirement) and four biochar treatments (zero, 1.25%, 2.5%, and 5% by weight of potting soil). During the growing season, water treatments were applied by weekly weighing of the pots and replenishing the water loss up to Field Capacity. The amount of water added to each pot was measured. Harvest at 50 days after planting was done once a week. A total of five harvests were performed. In each harvest, quantitative parameters including plants height, number, weight, diameter and length of fruit, and qualitative parameters of fruit sugar content, greenness index, and leaf area index in each pot were carefully measured. Also, the yield and efficiency of irrigation water consumption at the end of the planting season was determined in each treatment. The results showed that the effects of irrigation water and biochar levels were significant (at 1% and 5% probability) on the measured parameters. With decrease in irrigation water, the amount of quantitative parameters and plant yield decreased. The highest value of the measured parameters was obtained from 100% irrigation water treatment, which was not significantly different from the 75% irrigation water treatment. The use of biochar up to 2.5% by weight of soil increased the parameters. Use of the right amount of biochar reduces the negative effects of stress and improves plant growth compared with the control treatment. Therefore, use of biochar for plants, especially when the plant is under water stress, can be recommendable. In order to reduce the amount of water used in greenhouses and improve plant growth and yield, biochar use is advisable, however, its use under field conditions should be tested.

Intercropping in compared to monoculture can increase yield sustainability. Deficit irrigation as a limiting factor for growth, affects the plantchr('39')s yield characteristics. Therefore, The aim of this study was to investigate the effect of cultivation type: monoculture tomato (T), monoculture basil (B) and intercropping (50T:50B), and different moisture levels including four irrigation periods based on soil field capacity (FC): irrigation without water stress in the root zone 0.85‒1FC, and deficit irrigation levels of 0.7‒0.85FC, 0.5‒0.7FC and 0.3‒0.5FC, with a factorial arrangement (with two factors) in a completely randomized design and a total of 12 treatments in three replications. Plant characteristics including greenness index, stomatal conductance, leaf area index, leaf temperature and fresh and dry weights were measured. Based on the results, the highest fresh and dry weights of aerial part of the tomato were obtained in 0.7‒0.85FC treatment with intercropping (349.73 and 69.42 g per plant) and their lowest values were obtained in the irrigation level 0.3‒0.5FC with monoculture (204.66 and 40.42 g per plant). Tomato leaf area index was not significantly decreased up to water stress level of 0.5‒0.7FC. For basil, the highest fresh and dry weights of the plant (91.71 and 16.39 g per plant) and leaf area index (1845.99 cm2 per plant) were obtained in monoculture, and at non-stress level and 0.7‒0.85FC, respectively. Tomato was dominant in intra-specific competition with basil and significantly influenced basil yield. Finally, according to the results of this study intercropping of basil and tomato and water level up to 50% of field capacity resulted in reduction of water loss and increased fruit yield of two plants by considering consumed water.

Water stress is the most important abiotic stress in crop production. Silicium (Si) is the second most abundant element in the soil with beneficial effects on plant tolerance to biotic and abiotic stresses. In order to evaluate the effect of this element in increasing tolerance to water deficit in wheat, a factorial experiment was conducted based on a completely randomized design with three replications in the greenhouse of College of Agriculture, Shiraz University, Shiraz, Iran. Treatments included four wheat cultivars, Shiraz, Sirvan, Ofogh, Baharan, foliar silicon application in two-levels, zero (control), and 3 mM, and three levels of water deficit (field capacity, 40% and 60% of field capacity). The results showed that water deficit reduced spike length (31%), dry matter per plant (41%), grain yield (25%), greenness index (11%), flag leaf relative water content (24%), catalase (24%), peroxidase (70%) and superoxide dismutase activity (41%). Baharan and Sirvan cultivars were superior for greenness index and peroxidase activity. However, foliar silicon application at 3 mM concentration ameliorated the negative impacts of water deficit stress. Foliar application of silicon enhanced all the above parameters including antioxidants. For a majority of the measured characteristics, it was evident that Baharan and Sirvan, as water deficit tolerant cultivars, and Ofogh, were superior compared to Shiraz cultivar. The results showed that foliar application of silicon increased the activity of antioxidant enzymes and as a result ameliorated the negative impacts of water stress.

IntroductionOilseed rape (Brassica spp L.) is one of the valuable oilseed crops which has been attracting attention in recent years. Iran is located in a semi-arid region, and water shortage has caused problems, namely providing drinking water as much as water supply for crop production. Not only does Plant Growth Promoting Rhizobacteria (PGPR) make plant growth stimulating hormones like Auxin and Gibberellin but also can ease stress conditions by producing ABA. Consequently, considering the current water shortage crisis in Iran, we took three main criteria into account: the roles of PGPRs in increasing resistance to abiotic stress, relief of drought effects, and the importance of cultivation of oilseed rape. The present research has been compiled to study drought and some Plant Growth Promoting Rhizobacteria (PGPR) on Physiological Traits and Ultimate Yield of Cultivars of Oilseed Rape.
Materials and MethodsThe current study was done on the basis of two simultaneous experiments (under stress and non-stress experiments) during 2010- 2011 growing season at Agriculture and Natural Resources Research Station of Torogh, Mashhad is situated in East-North of Iran (36° N, 59° E, 1003 ASL ) . Two research sites (under stress and no-stress fields) were selected beside each other. This region has a semi-arid climate (annual rainfall 286 mm). The experimental design was factorial based on randomized completely block design with three replications in each experiment. The first treatment was Plant Growth Promoting Rizobactria, including B0: no inoculation (control), B1: co-inoculation (Pseudomonas flourescens 169. putida 108), B2: inoculation with P. flourescens 169 and B3: inoculation with P. putida 108. Second treatment was cultivar, including Hayola401 and Hayola330 cultivars belong to Brassica napus, Parkland and Goldrush cultivars belong to B. rapa and BP18 and landrace cultivars belong to B.juncea .Greenness index, plant height, relative water content, canopy temperature depletion , harvest index and final seed yield were measured in the present study as well. In addition, variance analysis (ANOVA) was performed using SAS ver. 9.1 software.
Result and DiscussionThe examination of physiological characteristics including Harvest Index (HI), chlorophyll content, and Relative Water Content (RWC) showed that there is a considerable difference between location, cultivar, and bacteria cultivar. At the second stage of sampling, due to the reduction of cell water content and enhancement of concentration of cell content in stress field, the chlorophyll rate was enhanced in stressed locations. While findings in RWC showed that Pseudomonas putida had the highest percentage (64.23%), and no inoculation had the lowest RWC (60.32%). Therefore, inoculation treatment, specifically the individual inoculation in the study of RWC, could ease the effects of drought stress. Results of the final stem height were significant, only in cultivar level and BP.18 with 1.24m was the highest and Hayol 330 with 0.9m was the shortest cultivars regarding to stem height. Individual and interaction effects of bacteria with other treatments on harvest index were significant. In current study, it seems that application of bacteria treatments has caused better formation of final seed yield .There was a considerable difference between location, cultivars and interaction of location×cultivar regarding to ultimate yield. Final seed yield in non-stress location (1351.85 Kg.ha-1) was significantly higher than in stress location (535.38 Kg.ha-1). In the study of both morphological and physiological traits and final seed yield of the current research, Hayola hybrid showed more superiority than other cultivars.
ConclusionIt seems the individual application of either P. flourescens 169 or P. putida 108 leads to better formation results than two mixed strains of the aforementioned bacteria. In the current study, Hayola hybrids showed a better function in physiology and ultimate yield; therefore, plantation of these hybrids would be valuable even in water deficits as well as application of PGPR.

Drought is one of the most important factors limiting crops growth and production and use of plant growth regulators to cope with water stress is of interest to many researchers. In order to study the effects of two plant growth regulators, brassinosteroid (BR) and salicylic acid (SA) on germination and growth of two wheat cultivars in water deficit conditions, a greenhouse experiment was designed and carried out at College of Agriculture, Shiraz University, Shiraz, Iran in 2014. The experiment was factorial based on randomized complete block design, with four replications. Treatments composed of two wheat cultivars (Shiraz and Sirvan), two moisture regimes (50 and100% FC) and growth regulators (BR and SA). In this experiment water stress significantly increased greenness Index (50.58%) and significantly reduced relative water content (10.24%), spike dry weight (17.22%), one hundred seed weight (14.14%), shoot dry weight (8.74%) and seed weight per plant (19.21%). However, plant spray with 25 and 50 µg.L-1 BR and 1mM SA could offset some of the adverse effects of water stress. Furthermore seed priming with BR increased the percentage and rate of seed emergence. Sirvan as a tolerant cultivar for all of the measured traits was shown to be superior to Shiraz, as a sensitive cultivar.

Drought and its resulting stress is one of the most important common environmental stresses that limit agricultural productions. In order to evaluate the effect of cattle manure biochar on the growth, yield, and water use efficiency of spinach at different soil moisture status, a factorial completely randomized design with 3 replications was conducted under greenhouse conditions during October 2014 to January 2015. Treatments consisted of four biochar levels (0, 1.25, 2.5 and 5% wt of initial soil) and three soil moisture levels (FC (without stress), 0.7FC, and 0.55FC). To compensate the water losses via evapotranspiration, the pots were weighted every day and water stress was imposed by adding the water required in each treatment. Total water consumption during the growing season was also determined. Results indicated that application of both soil water stress levels resulted in significant reduction in leaf area, stomatal conductance, water consumption, and fresh and dry weight as compared to those of the controls (without water stress and biochar application). The greenness index significantly increased by 14%, 14%, and 11 % as compared to that of the control when soil moisture level of 0.55 FC was applied at the first, second, and third growth stages (40, 55 and 70 days after planting), respectively. Application of biochar also significantly increased greenness index, leaf area, and stomatal conductance as compared to that of the control. Soil moisture stress up to 0.7FC decreased the plant water consumption; however, it did not affect the water use efficiency, significantly; while water stress level of 0.55 FC decreased water use efficiency significantly. In general, application of 1.25 biochar (25 ton/ha) as compared to the control decreased the negative effects of water stress on plant (reducing leaf area, fresh and dry weight, etc.) and improved plant growth indices and increased the growth of plant at all of the applied water stress levels. Therefore, in order to reduce water consumption and improve the growth and yield of plants, biochar application, especially under drought stress conditions or in greenhouse conditions, is recommended. Meanwhile, performing such an experiment under field conditions is also suggested.