Ali Naseri Moghadam; Hassan Bayat; Mohammad Hossein Aminifard; Farid Moradinezhad
Abstract
Introduction: Salinity and drought have adverse impacts on crop production throughout the world, especially in arid and semiarid areas. Salinity decreases crop growth and yield through modifications of ion balance, water status, stomatal behavior, photosynthetic efficiency, salinity-induced nutrient ...
Read More
Introduction: Salinity and drought have adverse impacts on crop production throughout the world, especially in arid and semiarid areas. Salinity decreases crop growth and yield through modifications of ion balance, water status, stomatal behavior, photosynthetic efficiency, salinity-induced nutrient deficiency and changes to the soil structure. Drought is another one of the main factors limiting the growth and development through the anatomical, morphological, and physiological and biochemical changes that the severity of drought damage varies depending on the duration of the stress and plant growth stage. Water stress reduces relative water content, photosynthesis pigments, stomatal conductance, biomass, growth and ultimately plant performance. Narcissus (Narcissus tazetta L. cv. ‘Shahla’) belongs to the Amaryllidaceae family is grown as a cut flower, landscape and medicinal plant that grows throughout the world except tropical regions. It is necessary to know the tolerance of N. tazzeta to drought and salinity stress in order to produce optimal product. According to previous studies, no complete research has been done on the effects of drought and salinity stress on N. tazzeta. Therefore, the present study was carried out with the aim of investigating the combined effects of drought and salinity stress on growth, flowering and biochemical characteristics of N. tazzeta.
Materials and Methods: This research was carried out in Faculty of Agriculture, University of Birjand, in 2017. A pot experiment was conducted in completely randomized deign with factorial arrangement and three replications. The treatments included sodium chloride (NaCl) in four levels 0 (control), 20, 40 and 60 mM and drought stress in four levels 30, 50, 70 and 90% of field capacity. The plants were harvested four months after the start of salt and drought treatments. The investigation traits were included vegetative, reproductive and biochemical characterizes. Measured traits were included root length, volume of root, root fresh weight, bulb length, bulb fresh weight, shoot fresh weight, total dry weight, flower diameter, flower crown diameter, stem diameter, days from planting to flowering, days from flowering to senescence, antioxidant activity, total phenolic content and total soluble sugar of leaf and root. The data were analyzed by SAS version 9.4 and the means separated by Duncan's multiple range test at p < 0.05. Excel was used to draw graphs.
Results and Discussion: The results of simple effects showed that drought and salinity stresses decreased the values of flowering stem diameter, flower diameter, root length, root volume, root fresh weight, bulb fresh weight, bulb length, shoot fresh weight, total dry weight and days from flowering to senescence. In contrast, the values of the number of days from sowing to flowering, total soluble sugars of leaf and root, antioxidant activity and total phenolic content increased under the influence of these two stresses. The results of interaction effects showed that the destructive effects of salinity and drought stress were intensified in co-application conditions, so that the lowest values of growth and reproductive traits were observed in the most severe stress (30% field capacity × 60 mM salinity). Usually, root and shoot length in sodium chloride solution is reduced due to the toxicity of ions and their negative effects on cell membranes. Drought stress and salinity reduce cell division and also reduce the size of cells and consequently the length of the plant decreases. Delay in flowering is due to multiple stresses (osmotic imbalance, nutrient insufficiency and cellular toxicity) that is caused by salinity and drought stresses. These stresses produce ROS compounds that damage the proteins, lipids, carbohydrates, and nucleic acids. Plants for scavenging and detoxifying these compounds from the cell surface use enzymatic (catalase, superoxide dismutase, etc.) and non-enzymatic (phenolic compounds and carotenoids) defense systems that increase the antioxidant activity of the plant.
Conclusion: The results of this study showed that drought and salinity stresses had negative effects on growth and flowering traits, which was exacerbated by the combined application of these two stresses. On the other hand, the highest levels of antioxidant activity, total phenolic content and total soluble sugars were obtained under severe stress conditions (drought or salinity). Salinity and drought stress reduced the flowering rate, quality of flowers and the flower life on the plant, but all the levels of stress reached to flowering stage. Also, the growth of narcissus plant was not affected by the highest levels of drought (30% crop capacity) and salinity (60 mM) stress. In general, the results showed that both drought and salinity stress reduced the growth and yield of narcissus flower, but the destructive effects of salinity stress on the growth, ornamental and physiological traits of narcissus flower were more than drought stress.
Mehdi Ghesmati; Farid Moradinezhad
Abstract
Introduction: Sour cherry is one of the most strategically important horticultural products in the Khorasan Razavi province that proper nutrition can improve the performance of the plant. This fruit is rich in vitamins, antioxidants, and soluble fiber, which is very useful for lowering blood ...
Read More
Introduction: Sour cherry is one of the most strategically important horticultural products in the Khorasan Razavi province that proper nutrition can improve the performance of the plant. This fruit is rich in vitamins, antioxidants, and soluble fiber, which is very useful for lowering blood pressure. Proper nutrition is one of the important factors in determining the quantity and quality of the fruit. In arid and semi-arid regions, micronutrient elements availability is one of the factors that limits growth, yield, and quality of fruit trees , because absorption of nutrients being limited due to the alkalinity of the soil. So, the use of an appropriate method to provide the required nutrients by plants is necessary. Foliar application of nutrient is one of the important ways in the food supply for plants. Hence, spraying is an effective way to reduce nutritional disorders in plants. Therefore, the objective of this study was to evaluate the effect of foliar application of iron and zinc micronutrients on the yield and physicochemical properties of sour cherry fruit.
Materials and Methods: In order to investigate the effect of spraying of iron chelate and zinc sulfate on yield and qualitative characteristics of the sour cherry fruit, a factorial experiment was conducted in a randomized complete block design with 4 replications in the commercial orchard of Astan Quds Razavi, Mashhad, Iran. The first factor was spraying iron 6% Fe-EDDHA at 3 levels (0, 2 and 4 g l-1) and the second factor was spraying zinc sulfate at 3 levels (0, 2 and 4 g l-1). The treatments were applied in two stages, 20 days after the whole flowering stage and 20 days after the first spraying. Spraying chemicals was done in the morning when temperature and humidity were not high.. Fruit and leaves samples were collected, at the commercial maturity stage of fruit, from each tree include one kilogram of fruit and half kilogram leaves. Thereafter, healthy fruits and leaves of the same shape, size, and color were selected to determine the biochemical properties of fruit and chlorophyll leaves. In this experiment, 36 grilled cherry trees of 10 years old with a spacing of 3×4 m were used. The general conditions of the selected trees were similar to other garden trees, and irrigation (dripping), pest and disease control were applied uniformly to all treated trees. The studied traits included the fresh weight of fruit, dry matter percentage, fruit yield, fruit juice acidity, soluble solids, total antioxidant, trace related to chlorophyll content, iron and zinc concentration in leaves.
Results and Discussion: The results showed that different levels of iron chelate, zinc sulfate, and their interaction increased fruit fresh weight, dry matter percentage, fruit yield and chlorophyll traits. An individual application of 4 g l-1 of iron or zinc, and also their combination application showed the greatest values on evaluated traits In addition, the soluble solids, total antioxidant, and iron leaf values were only affected by different levels of chelate iron, which improved with increasing spraying levels of the studied traits. Sprayed with zinc sulfate could increase the concentration of zinc in the leaves but the acidity of juice was not affected by the treatments. The results showed that different levels of zinc significantly affected all quantitative traits of sour cherry fruit than iron chelate. However, spraying with iron chelate had a significant effect on the quality traits of fruit, including total soluble solids and total antioxidants. Moreover, the combination effect of chelate iron and zinc sulfate in comparison to their individual application had a better effect on the quantitative and chlorophyll traits of the cherry leaf. The highest increase in both zinc and iron content of leaf samples were obtained in trees that were treated with 4 g l-1 of zinc or iron solutions, respectively. The results show that foliar application of high concentrations of both chemicals increased zinc or iron content of leaf samples about 30% compared to the control. Thus, not only higher yield but also quality improvement of sourcherry fruit occurred in treated trees. Our results was in accordance with the findings of previous studies on different fruit tress like grapes, pistachio and orange. According to the results, it can be concluded that spraying with zinc sulfate and iron chelate during plant growth season can increase yield and improve the physical and chemical properties of the sour cherry fruit.
Farid Moradinezhad; Sara Hassan Pour; Mohammad Hassan Sayyari Zahan
Abstract
Introduction: Seedless barberry (Berberis vulgaris L. var. asperma) is one of the most important horticultural and medicinal crops and also valuable fruit in South Khorasan province. Fresh barberry fruit has a very short shelf life, due to the sensitive juicy fruit tissue in the ripening stage and decay ...
Read More
Introduction: Seedless barberry (Berberis vulgaris L. var. asperma) is one of the most important horticultural and medicinal crops and also valuable fruit in South Khorasan province. Fresh barberry fruit has a very short shelf life, due to the sensitive juicy fruit tissue in the ripening stage and decay during storage. Hence, most of the harvested fruits are dried traditionally or processed as juice, jam, and other products. However, the quality of both fresh and dried fruit is low due to different environmental stresses such as drought and salt stress and consequently deficiency of minerals during growth and development and also at harvest and during storage. It has been reported that pre-harvest foliar spray of calcium salts and salicylic acid can improve resistance to pathogens before harvest and reduce physiological disorders during handling and storage in many fruits. However, there is no information regarding the effect of calcium and salicylic acid spray as well as storage duration on fresh seedless barberry fruit. The objective of the current study, therefore, was to investigate the effects of the preharvest application of calcium chloride and salicylic acid on physiological attributes and postharvest quality of barberry fruits during long-term cold storage.
Materials and Methods: The experiment was conducted as split-plot in time and in a randomized complete block design with five treatments and in three replicates in the Research Orchard of Agricultural Faculty of the University of Birjand during 2014. Fifteen similar and 25-years old trees were used for the experiment. Pre-harvest treatments of foliar spraying were salicylic acid (1 and 3 mM) and calcium chloride (1 and 2%) and distilled water as control. Sprays were applied at 30 and 15 days before harvest. Fruits were harvested at commercial ripening stage, packed in plastic boxes and stored at cold room at 4±0.5 °C and 85±5 RH. Physicochemical and quality evaluations including fruit fresh weight and volume, and juice volumes of 100 berries, pH, total soluble solids (TSS), titrable acidity (TA), ascorbic acid, weight loss, electrolyte leakage of fruit and calcium content of leave and fruit were measured at harvest and after 30, 60 and 90 days of storage. Analysis of data was performed using Gen Stat program (ver 12) and comparison of means was done by LSD test at 5% probability.
Results and Discussion: The analysis of variance showed that the main effects of foliar spray with calcium chloride, salicylic acid and interaction of treatments were significant in storage time. The results showed that 1 mM of salicylic acid increased the fruit fresh weight, fruit volume and fruit juice, pH, total soluble solids, ascorbic acid and titrable acidity compared to other treatments. It has been reported that salicylic acid increases cell division and growth resulting in greater yield. It was also observed that application of salicylic acid at 3mM reduced electrolyte leakage significantly that can be useful to reduce chilling injury. The lowest weight loss was obtained in sprayed fruit with calcium chloride (2%) during cold storage, in agreement with the previouswork on plum. Foliar application of calcium chloride increased the calcium content of leave and fruit, although calcium application was not a significant effect in fruit tissue. Generally, using of chemical treatments increased the physicochemical characteristics of the fruit in seedless barberry, among them calcium chloride 2% and salicylic acid at 1 mM were most effective.
Conclusions: It can be concluded that pre-harvest spraying of seedless barberry shrub with salicylic acid and calcium chloride can improve the quality of fruit as well as extend the storage life. This is because a foliar application with salicylic acid and calcium chloride significantly affected fresh fruit weight, weight loss, fruit volume, electrolyte leakage, pH, TSS, TA and ascorbic acid in treated fruit compared to the control. Salicylic acid at 3 mM significantly decreased electrolyte leakage, which can be used as a useful tool for increasing resistance to chilling injury during long-term storage. However, further studies are needed as the effect of chemical sprays on fruit quality and quantity properties depend on different factors such as tree age and types, environmental conditions during and after the spray and also chemical concentration.
