نشریه روابط خاک و گیاه
پیاپی 25 (بهار 1395)

The first experiment was performed to evaluate the effect of vermicompost extract (20, 40, 60, 80, 100%) on seed germination and seedling growth of Plantago psyllium. In second experiment, the effect of solid vermicompost with 4 levels (0, 25, 50, 75) on the emergence and subsequent growth of plantlets was investigated. The 20 and 40% increased germination capacity, germination index, and length of root, shoot, vigor index and decreased mean germination time and T50. In second experiment 25% increased emergence energy, emergence rate, emergence index and emergence cofficiennt and decreased mean emergence time. 25% and 50% treatments increased the diameter, length, dry and fresh weight of root and aerial parts and length and width of leaves, and a, b, total chlorophyll and carotenoid in 3 old months's plant. But high concentrations were decreased these parameters. Thus, the effect of vermicompost on seed germination and subsequent growth of plantlets is dependent on concentration.

Heavy metals (HMs) are hazardous environmental pollutants which by entering the food chain cause harm to humans, plants and other organisms. In order to study the effects of salinity and lead (Pb) and cadmium (Cd) HMs on spinach plant, a factorial, pot experiment, based on complete randomized blocks design, was carried out in 2013 in College of Agriculture, Shahrood University of Technology. Treatments consisted of three levels of salinity (0, 4 and 8 dS/m) as factor A and HMs at four levels (control, Cd, Pb and Cd) as Factor B. results revealed that salinity had no significant effect on fresh and dry weight of spinach; but HMs treatment caused significant changes in these traits. Minimum and maximum fresh and dry weights were obtained in the Cd and Cd treatments, respectively. Besides photosynthetic pigments of flavonoids and anthocyanin, salinity had significant effect only on chlorophyll a, chlorophyll b, cartenoid contents and reduced them at 8 dS/m level. Salinity treatment, without affecting potassium content, increased sodium and soluble carbohydrates in spinach leaves. Interaction between salinity and HMs was only significant for carbohydrate, chlorophyll a and chlorophyll b. The highest amount of carbohydrate was obtained in the Cd and 8 dS/m treatment and the highest amount of chlorophyll a and chlorophyll b was obtained in the no salinity (control) and Pb treatment.

This pot experiment was conducted to investigate the effects of ordinary and nano forms of zinc oxide on growth and ion content of four wheat cultivars (Niknejad, Iniya, Rowshan and Moghan2) under three salinity levels (0, 75 and 150 mM NaCl). In this experiment, shoot and root dry weight, and concentration of potassium, sodium and zinc in shoots were measured. Results showed that with an increase in salinity level, the shoot and root dry weight and concentration of potassium and zinc in shoot was decreased, but shoot/root dry weight ratio, sodium concentration and sodium/potassium ratio in shoots were increased. Plants provided with nano zinc oxide had higher concentration of zinc, as compared to the ordinary form of zinc oxide. Significant reduction of sodium/potassium ratio in shoots occurred due to plant nutrition of nano zinc oxide. As a result of application of nano zinc oxide, shoot dry weight was increased in Niknejad and Iniya wheat cultivars, but it was decreased in Rowshan and Moghan2 cultivars. The results of this experiment showed that there was significant variation among wheat cultivars in response to the application of nano zinc oxide.

Salt problems are of great concern in arid and semi-arid regions and can severely limit plant growth and yield. Vermicomposts have high porosity, aeration, drainage, and water-holding capacity and contain nutrients in forms readily taken up by plants. This research was conducted to investigate the effect of different rates of vermicompost (0, 100, 200 and 300 g), mixed with farm soil, on catalase (CAT) and ascorbate peroxidase (APX) enzymes and some of the morphological traits of Festuca arundinacea cv Queen, under salinity stress (0, 3, 6 and 12 dS/m) conditions. Results showed that the highest activities of CAT (50.47 Ug/FW) and APX (715.53 Ug/FW) was obtained at NaCl concentrations of 12 dS/m with 300 g vermicompost. The highest values of leaf area (10.41 cm2), shoot length (28 cm) and dry shoot weight (46.07 g) were obtained when plants were grown in soil with 300 g vermicompost. The present findings revealed that salinity (NaCl) and application of vermicompost triggered an antioxidant response in Festuca arundinacea. Therefore, application of vermicompost not only can increase plant growth and anti-oxidant enzymes activity, but also could be an effective solution to reduce the effects of high concentrations of sodium chloride on growth of Festuca arundinacea cv Queen in saline soils.

This research was conducted to find an appropriate method to increase rooting percentage in difficult to root olive cultivars. This experiment, with 15 treatments and 2 cultivars (Fishomi and Shiraz) was arranged as a split-plot based on completely randomized design and four replications. The main factor was cultivar and the sub-main factor was hormonal treatments. Treatments consisted of indole-3-butyric acid) IBA ((concentrations of 2000, 4000 and 6000 mg/L) and naphthalene acetic acid )NAA( with concentration of 2000 mg/L alone or with 2% ascorbic acid and 3.5% H2O2. Meanwhile, distilled water was taken as control treatment. After 110 days, number of rooted cutting, number of cuttings with buds, number of roots per cutting and root length in each cutting. Results showed that rooting percentage in Shiraz cultivar was more than Fishomi cultivar. Hormonal treatments had significant difference in all the measured traits (P≤0.01). Combination of 4000 mg/L IBA for 5 seconds plus 3.5% H2O2 for 30 seconds was the most effective treatment in rooting of the olive cuttings. Also, the next effective treatment on rooting of the cuttings was 4000 mg/L IBA for 5 seconds plus 2% ascorbic acid for 15 minutes. Therefore, with regards to the results of this research, it could be stated that using cofactors plus rooting hormones, has had positive effects on improving the rooting in difficult to root olive cultivars.

Energy consumption is very high in greenhouses mainly due to off-season production. The main source of its energy supply is fossil fuels. Due to the disadvantages of fossil fuels consumption and preventive laws in the incoming years, study on reducing consumption and replacing a part of them with renewable energy is essential. In this research, a solar heating system, equipped with a concentrator and Fresnel lens, adjustable to all regions in Iran, was designed and manufactured in Faculty of Agriculture, Tarbiat Modares University. Thermal heating requirement of a cucumber greenhouse was calculated and then solar heating system and thermal storage system were designed and manufactured. For more energy saving, besides insulation of the reservoir tank with an elastomeric layer, cupper tubes and paraffin was used. Then, behavior of the system was evaluated under three thermal conditions of 35, 50 and 65°C. The results of variations of water temperature in the tank showed that mean descending rate of temperature, with a higher initial temperature, has been faster in the tank as compared to the tank with lower initial temperature. But, with proper volume and insulation and use of phase-change materials, particularly in the melting point range of paraffin, temperature in the tank remains constant and the cooling process is slower. Therefore solar heating system and thermal tank with suitable volume and insulation can be used for heating the greenhouses.

Due to the many restrictions on the use of soil and water resources, increasing greenhouse plants’ yield is important. In order to study the effect of humic acid (HA) on some growth and physiological traits of strawberry (Fragaria ananassa var: Selva), an experiment was conducted as a completely randomized design with factorial arrangement with three replications. The experimental factors included HA type (HA extracted from vermicompost, HA extracted from vermicompost in combination with 10 mg indole acetic acid, and commercial HA), three different concentrations of HA (0, 15 and 30 mg/L) and two methods of HA application (foliar and nutrient solution). The results showed that the highest yield, chlorophyll and total soluble solids was obtained from foliar application of 15 mg/L extracted HA, the highest ion leakage was achieved from foliar application of 30 mg/L extracted HA from vermicompost in combination with 10 mg indole acetic acid, and the highest dry weight of roots was obtained from nutrient solution application of 30 mg/L HA extracted from vermicompost in combination with 10 mg indole acetic acid. In general, 15 mg/L HA, extracted from vermicompost, sprayed as foliar application, was more successful in most studied traits.

In order to investigate the effects of nutritional role of maternal-plant phosphorus (P) on seed production and quality of black seed (Nigella sativa L.) in a calcareous soil, three experiments were conducted at research greenhouse of Ferdowsi University of Mashhad, Iran, in 2012 and 2013. The first and the second experiments were conducted as a complete randomized design based on factorial arrangement. Seven fertilizer treatments (‍control, vermicompost, sulfur, vermicompost sulfur, vermicompost Thiobacillus bacteria, sulfur Thiobacillus and vermicompost sulfur Thiobacillus) and three levels of P (0, 30 and 60 kg/ha) were the first and the second experimental factors, respectively. The first experiment lasted 63 days, to biologically oxidize the sulfur, and at the end of this period, black seeds were sown. After determining the emergence percentage, the third experiment was conducted. In the third experiment, seed priming (distilled water, solution of 500 mM KH2PO4 and unprimed) was applied in the treatments with seed emergence of less than 60%, and a control treatment (selected treatment with the highest emergence from the second experiment) were considered. Based on the results of the first and the second experiments, application of vermi-compost Thiobacillus bacteria and vermicompost sulfur Thiobacillus bacteria had significant effects on increasing seed weight per plant and qualitative traits such as emergence percentage and seed vigor. In addition, a significant positive correlation was observed between qualitative traits of seeds and soil available P and P content of maternal plant. In the third experiment, P-priming with 500 mM KH2PO4 solution had significant effects on increasing emergence percentage and decreasing mean emergence time.

Iron (Fe) and zinc (Zn) deficiency has been known as a key factor in limiting crop production in calcareous soils of arid and semi-arid regions. Since the components of organic matter can change Fe and Zn availability, this study was conducted to investigate the effects of humic treatments including humic acid (HA), fulvic acid (FA), vermicompost (Verm), HA and HAᐏ镺 and mycorhiza inoculation on some growth characteristics of soybean and Fe and Zn uptake under greenhouse conditions. Results showed that significant differences among humic substances and mycorrhiza were recorded for soybean growth and Fe and Zn uptake. The response of soybean plants to humic substances was different. The largest increases in plant height, shoot fresh weight, shoot dry weight, root fresh weight and root dry weight were found in humic acid amended soil, being 0.9 fold, 2.37 fold, 6.11 fold, 3.54 fold and 5.5 fold, respectively, as compared to the control. Mycorrhiza also improved soybean growth characteristics. Humic treatments (with an exception for humic acid and vermicompost) increased Fe and Zn content of soybean aerial parts. The highest Fe content (657.3 mg/kg) and Zn content (87.4 mg/kg) was measured in plants treated with fulvic acid. Mycorrhizal inoculation resulted in 10% increase in Fe and 64% in Zn content of soybean as compared to control plants. The results of this research revealed that application of humic acid and mycorrhiza can improve soybean growth by increasing the uptake of Fe and Zn.

Floating culture of lettuce is developing because of the increase in water use efficiency and chemical fertilizers. In order to assess replacement time of nutrient solution and concentration of replenishment solution on growth and yield of Butterhead lettuce, a factorial experiment was conducted through completely randomized design with three replications. Each experimental unit was a 60×40×15 cm (36 L) plastic box, and four plants were grown in a spacing of 20×25 cm apart on polyester sheets. The nutrient solutions were replaced with new solutions once every 3, 4 and 5 weeks. For compensating the removed water and depleted nutrients from the solution, replenishment solutions with ⅓ and ⅔ strength were added to the tank once a week. Plants were harvested 35 days after transplanting. Results showed that there was no significant difference in fresh head weight, head periphery, number of leaves per plant, leaf dry weight, root weight, and stem length and diameter among treatments. The interaction effects between replacement time × concentration of replenishment solution was not significant for none of the growth parameters. Fresh head weight and number of leaves per plant were 265-312 g (mean 286 g) and 32-37 leaves, respectively. Chemical analysis of lettuce-head tissue indicated that concentration of macro-and-micronutrients was in optimum range in all the treatments. Head weight per plant was found significantly and positively correlated with number of leaves/plant, root weight, stem diameter and head periphery. Results of the present experiment indicated that lettuce growth and nutrients could be managed well by adding replenishment solution with ⅓ strength, without replacing the nutrients solution.

Extensive use of chemicals in crop production has attracted global public concerns in terms of their effects on human health. The issue has led to movement toward reducing chemicals and replacing with environmentally-friendly compounds during production processes of agricultural crops. An experiment was carried out to evaluate the effects of fertilizers with biologic origin, including seaweed extract and amino acids and their combination, on five cultivars of greenhouse tomatoes (Sweet million, Golden cherry, M09, EDU and Guiza) in soil culture system under greenhouse conditions. The results showed that the use of fertilizers containing amino acid has generally more positive effects than seaweed extract on tomato plant yield. The impact of tomato cultivar on response to fertilizers showed that fruit length, diameter and weight of cherry tomatoes (Sweet million, Golden cherry, M09) were not affected as much as large tomatoes (EDU and Guiza) by fertilizers containing amino acids or seaweed extract. In most cases, fruit quality characteristics including percentage of titratable acidity, soluble solids content and vitamin C were greater when fertilizers containing amino acids were used.

Jasmonate is a plant regulator that plays an essential role in signaling pathway and triggering the expression of plant defense-genes in response to abiotic stresses. Hence, the effect of methyl jasmonate on quantity and quality of chamomile flowers under salinity stress was investigated with a factorial experiment, based on a randomized complete blocks design with three replications, in the research greenhouse of University of Zanjan. Five concentrations of Methyl jasmonate (0, 75, 150, 225 and 300 µM) was sprayed on chamomile plants which were growing under different concentrations of NaCl (2, 6, 10 and 14 dS/m). Results showed that the effects of methyl jasmonate and salinity were significant on all the traits. The highest values for plant height, total dry matter per pot, number and flower dry weight per pot and Flavonol-O-glycoside were obtained at 75 µM methyl jasmonate and salinity level of 6 dS/m. Flower yield and the amount of Flavonol-O-glycoside were decreased by increasing the salinity and methyl jasmonate concentrations over 6 dS/m and 75 µM, respectively. A significant positive correlation was revealed among all traits and dry weight of flower. Also, Flavonol-o-glycoside showed a positive and significant relationship with total dry matter per pot and flower dry weight. In general, concentration of 75 µM methyl jasmonate and salinity of 6 dS/m increased Flavonol-O-glycoside production of chamomile.

Cucumber represents one of the most important fruit vegetables in the world which has an undeniable role in human nutrition and especially vegetarian nutritional diets. Therefore, yield and quality improvement of this crop is very important. This study was carried out during 2014 to evaluate the effects of foliar application of some chemical fertilizers compared to their soil application on greenhouse cucumber growth and development. The experimental design was completely randomized design with 6 treatments and 6 replications. Treatments were control (without fertilizer application), soil application of NPK, soil application of Biomin amino-chelate, foliar application of Biomin amino-chelate, soil application of Humifolin and foliar application of Humifolin. The results of means comparison showed that fertilizer treatments had significant effect on vegetative and reproductive growth of greenhouse cucumber. Soil-applied Humifolin, soil-applied NPK and then soil-applied Biomin treatments resulted in higher chlorophyll index, number of lateral shoots, shoot fresh weight, total fruit yield, fruit dry weight percentage and fruit soluble solids. Foliar application of Biomin in recommended concentration (0.2 %) resulted in leaf chlorosis and reduced plant growth and yield. While, foliar application of Humifolin caused better growth and development of the plants. In general, in this study, soil-applied treatments, especially Biomin amino-chelate, led to better plant performance, as compared to foliar application treatments.

An experiment was conducted to determine the responses of 27 Iranian local and improved rice genotypes to two salinity levels (0 and 100 Mm NaCl) at Soilless Culture Research Center of Isfahan University of Technology. The treatments were arranged as factorial in a completely randomized design with three replications. The results showed that there was considerable variation in agro-morphological characters among Iranian rice genotypes under saline and non-saline conditions. A great variation in salt tolerance was observed among local genotypes of north, improved genotypes of north and local genotypes of center of Iran. Root growth was more sensitive to salt stress than shoot growth and responds more quickly to the stress. The salt-tolerant rice genotypes had more green leaf area duration as a major factor for salinity tolerance. Average total biomass of local genotypes of north, improved genotypes of north and local genotypes of center of Iran under non-saline conditions were 0.94, 1.09 and 1.38 and under saline conditions were 0.46, 0.59 and 0.58 g/plant, respectively. The highest and lowest tolerance to 100 mM NaCl salinity among local genotypes of north were observed in Daylamani and Domsorkh, among improved genotypes of north in Neda and Shiroodi, and among local genotypes of center of Iran in Jozdan and Zayandehrood, respectively. The genetic variation for salinity tolerance in Iranian rice genotypes may improve salt tolerance and increase rice production under saline conditions.

Soil salinity is a serious environmental problem that has negative impacts on growth and production of plants. On the other hand, application of chitosan has recently been increased to enhance the resistance to different stresses, such as salinity. In order to study the effect of chitosan seed-priming on alleviation of salinity stress in fenugreek (Trigonella foenum-graecum L.) a factorial experiment, based on completely randomized design with three replications, was conducted in 2014 in the Research Greenhouse of University of Zabol. Chitosan pretreatment, taken as the first factor, was applied at three levels (0, 0.5 and 1 g/l) and sodium chloride (NaCl) was the second factor at four levels (0, 50, 150 and 250 mM). Before planting, the seeds were soaked for 6 hours in the chitosan solutions. NaCl was applied to the plants by irrigation water (after 2-leaf stage), with 3-day intervals. Results indicated that increasing salinity stress reduced growth characteristics, content of photosynthetic pigments, leaf relative water content, chlorophyll index and increased the amount of anthocyanin and proline. Seed-pretreatment by application of 0.5 mg/L chitosan, under salinity stress, increased plant dry weight, length of stem and roots, and leaf relative water content, as compared to the control treatment. In addition, under the salinity level of 250 mM, application of 1 g/L chitosan increased chlorophyll a, chlorophyll b and carotenoids content by 43.7, 65.4 and 28 percent, respectively, as compared to the control treatment. The highest amount of anthocyanin was found in the 1 g/L chitosan treatment. In general, these results suggested that in salt-affected areas, seed pretreatment by application of chitosan could be utilized efficiently for reducing the salinity stress on leaf relative water content and photosynthetic pigments, and better growth and stablishment of fenugreek plant.