Pomology
Farhad Azarmi-Atajan; Mohammad Hossein Sayyari Zahan; Abdollah Mirzaei
Abstract
IntroductionPhosphorus (P) is one of the most important nutritional elements of plants and it is necessary for the development of plant roots. Due to the high cost of chemical fertilizers, it is important to use cheap sources such as rock phosphate (RP) to supply P needed by plants. The efficiency of ...
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IntroductionPhosphorus (P) is one of the most important nutritional elements of plants and it is necessary for the development of plant roots. Due to the high cost of chemical fertilizers, it is important to use cheap sources such as rock phosphate (RP) to supply P needed by plants. The efficiency of RP is low and its use alone cannot supply the P required by the plant. One of the ways to increase the efficiency of RP is to use phosphate solubilizing bacteria (PSB). Considering the salinity of soil and irrigation water in many pistachio-growing areas of Iran, the use of salt-resistant PSB can increase their resistance to salt stress in addition to supplying the P required by pistachios. Materials and MethodsIn order to investigate the role of PSB in supplying the required P of pistachio seedlings under saline conditions, a factorial experiment was conducted in the form of a completely randomized design with 3 replications in greenhouse conditions. The factors included PSB at three levels [control (PSB0), Pseudomonas sp. 1 (PSB1) and Pseudomonas sp. 2 (PSB2)], RP at two levels (0 and 30 mg P from rock RP) and irrigation water salinity at three levels (0, 5 and 10 dS/m). The bacteria used in this study were able to produce ACC-deaminase, indole acetic acid and dissolve tricalcium phosphate in vitro. For inoculation, inoculum containing each bacterium with a population of 108 cells/ml was prepared in the nutrient broth medium and each pistachio seed (P. vera L. cv. Badami) was inoculated with 500 µL of bacterial inoculum. The plants were irrigated with non-saline water for four weeks and then with saline water until harvesting based on experimental treatments. During the growth period, the soil moisture of the pots was kept at about 80% of the field capacity by weight method. Finally, shoot and root sampling was performed and various characteristics such as shoot and root dry weight, chlorophyll, carotenoids, proline, soluble sugars, RWC, MSI and phosphorus as well as sodium concentrations were measured. Analysis of variance of traits was performed using SAS software and the means were compared using the LSD method with a probability level of P≤0.05. Results and DiscussionThe results showed that water salinity decreased the dry weight of shoot and root, chlorophyll a, chlorophyll b, carotenoids, relative water content (RWC) and membrane stability index (MSI) of leaf and p concentration of shoot and root of pistachio seedlings. Auxin produced by bacteria can directly increase cell division and growth or indirectly increase ACC-deaminase production. On the other hand, proline, soluble sugars and sodium were accumulated in the leaves of seedlings with increasing water salinity. According to the results, although the use of RP alone did not show significant effect on the studied indicators, its simultaneous use with PSB had the greatest role in improving the growth of pistachio seedlings, especially in saline conditions. The highest amount of dry weight of shoot (1.89 g.plant) and root (1.59 g.plant), chlorophyll b (1.30 mg/g fresh weight), carotenoids (1.35 mg/g fresh weight), soluble sugars (59.1 mg/g fresh weight), proline (36.7 mg.g-1 fresh weight), leaf RWC (91 %), leaf MSI (84%) and the P concentration of shoot (0.39 %) and root (0.35 %) was obtained from the simultaneous application of RP and PSB (especially PSB2) in non-saline conditions. The PSB increase soil P availability by reducing of soil pH by release of protons and organic acids and mineralization by production of acid phosphatases. Bacteria, in addition to increasing soil P availability, improve phosphorus uptake and chlorophyll content in plants by affecting root morphology and its development in soil. On the other hand, inoculation with PSB (both separately and together with rock phosphate) reduced sodium accumulation in the aerial parts and roots of pistachio seedlings. ConclusionUnlike pistachio trees, the tolerance of pistachio seedlings to salt stress is low. According to the results, the salinity symptoms were visible in the pistachio seedling leaves at the water salinity level of 10 dS/m, which caused the drying of the lower leaves and the burning of the edges of the young leaves. On the other hand, although the application of RP alone did not have significant effect on increasing the tolerance of plants to salt stress, the simultaneous use of RP with PSB increased growth, the accumulation of proline and soluble sugars, the concentration of chlorophyll and carotenoids, the amount of RWC and MSI and P concentration of pistachio seedlings, especially in saline conditions. Therefore, the use of PSB can help the growth and establishment of pistachio seedlings under salinity stress conditions and increase the efficiency of RP and supply P needed by the seedlings.
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 ...
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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.
Mina Motamednezhad; Seyyed Vahid Eslami; Mohammad Hassan Sayyari Zahan; Sohrab Mahmoodi
Abstract
Introduction: Cultivation of medicinal and aromatic plants has always had a special situation in the traditional system of agriculture and these systems have played a major role in the diversification and sustainability of agricultural ecosystems. Tend to produce medicinal and aromatic plants and demand ...
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Introduction: Cultivation of medicinal and aromatic plants has always had a special situation in the traditional system of agriculture and these systems have played a major role in the diversification and sustainability of agricultural ecosystems. Tend to produce medicinal and aromatic plants and demand for natural products, especially in terms of ecological culture in the world is increasing. Ajowan is an annual herbaceous plant from the Apiaceae family. Biological fertilizers produced by the activity of microorganisms are associated with nitrogen fixation or availability of phosphorus and other nutrients in the soil. Enrichment means increasing the concentration of nutrients in plants especially micronutrients. Application of biological fertilizers instead of using chemicals is one of the most important nutritional strategies in sustainable management of agro ecosystems. In this regard, the effect of enrichment with bio-fertilizers and micronutrients on Ajowan (Carum copticum L.) germination characteristics was studied at Birjand Agricultural Research Laboratory.
Materials and Methods: A factorial experiment based on a CRD (completely randomized design) was conducted with three replications at Birjand Agricultural Research Laboratory during 2011. Experimental treatments consisted of bio-fertilizer application with three levels including without inoculation, and seed inoculation with Azospirillum and Azotobacter and seed enrichment with ten different treatment levels including without enrichment, and enrichment using 1, 2 and 3 mM of Fe, Zn and Mn elements. Bacteria were provided by Soil and Water Research Institute of Tehran. Initially, the seeds were disinfected through immersing them in 1% sodium hypochlorite for 3 minutes and then washing them with the tap water for 2-3 times. For the Enrichment of seeds, depending on the treatments, Petri dishes were treated with 10 ml of micronutrients solution for 24 hours. Then for bacterial inoculation depending on the type of treatments, seeds were soaked in 7 ml of inoculums containing 108 alive and active bacteria per ml for 5 hours. In each treatment, 15 seeds were placed in Petri dishes sealed with parafilm and placed in a germinator set at 70% RH and 25/15 °C. The traits studied were: germination percentage, germination rate, root and shoot length, as well as root and shoot fresh and dry weight. Before analyzing the data, normality test was performed and analysis of variance was performed using Genstat and graphs were drawn using Excel software.
Results and Discussion: The Analysis of variances results showed that seed inoculation with biological fertilizers and micronutrients significantly increased germination rate, root and shoot length, root fresh weight and dry weight of root and shoot of Ajowan compared with the control. Results showed that there were not significant differences between treatments in terms of germination percentage. Using micronutrients for seed enrichment caused increased germination rate. The maximum germination rate value was obtained from the Mn 1mM treatment (2.164 seeds per day), and. its minimum value was obtained from Zn1 (1.55 seeds per day). The maximum and minimum values of root length were obtained from the combined treatments of azotobacter + Fe2 and Azospirillum + Zn3, respectively. The maximum and minimum values of shoot length were obtained from the combined treatments of azotobacter + Mn2 and Azospirillum + Zn3, respectively. The highest and lowest values of shoot dry weight were obtained from azotobacter + Fe3 and azotobacter, respectively. The highest and lowest values of root dry weight were obtained from Zn1 (2.35 mg) and Mn2 (0.4 mg), respectively. The highest and lowest values of root fresh weight were obtained from Azospriliium+ Mn3 and Azospriliium+ Zn2, respectively. The highest and lowest values of shoot fresh weight were obtained from Azotobacter+Mn2 and Mn3, respectively.
Conclusion: During the evaluation of the measured traits regarding to bio fertilizers application on ajowan, it was observed that all biological treatments were superior to the control (non-biological fertilizer) and Azotobacter was the most effective amongst them. Bio fertilizers applications used in this study showed significant effects on root and shoot length, as well as fresh weight of root and shoot. The use of micro-nutrients on ajowan, showed that the application of 1 and 2 mM of Mn and all three concentrations enhanced the examined characteristics, while the application of 1 mM of Zn was just effective on root and shoot dry weight. Overall,application of these micronutrients had significant effects on germination rate and root length and fresh weight of root and shoot as well as dry weight of shoot and root.
