Nutritional status of Washington Navel orange orchards in arid lands of southern Iran

Nutrient deficiency may be a reason for citrus decline in many countries. In the current investigation, soil and leaf samples of 63 Washington Navel orange orchards in arid lands of southern Iran (Darab region) were analyzed to study the nutritional status of orange orchards and to find relationships between soil properties and nutrients content of soils and orange leaves. The soils differed widely in clay content (3–37%), pH value (7.04–7.95), calcium carbonate equivalent (18–86%), and organic matter content (0.3–12%). These soils represented a wide range of plant nutrients concentration. Majority of the studied soils had sufficient concentrations of all nutrients (except Fe). Results indicated that pH, organic matter, clay, and calcium carbonate contents are the most important characteristics that control the soil nutrients availability. The mean contents of N, K, P, Fe, Mn, Zn, and Cu in leaves were 2.59, 0.84, and 0.14% and 66, 44, 17, and 12?mg?kg^?1, respectively. Most orchards showed K, Fe, and Zn deficiencies. We found no relationships between nutrients content in leaf and soil (except for K, Mn, and Zn); and this indicated that soil analysis may not be a reliable method for most nutrient deficiency diagnosis.     

Compatibility of Natural Dyes on Aluminum Pre-Mordanted Woolen Yarns by Determination of Diffusion Coefficient

In the present research, a method of assessing relative compatibility rating of single and binary mixtures of walnut green shell, cochineal, and weld natural dyes on aluminum pre-mordanted woolen yarns was proposed, where a proportion of the calculated diffusion coefficients of dyes was postulated. To calculate the diffusion coefficient values, the uptake behavior of dyes was derived as the K/S and the exhaustion curves by dyeing the woolen yarn samples with the individual dye as well as with the mixtures of dyes obtained from practical conditions of dyeing. A typical method was employed to dye the samples at two temperatures of 80 and 95 oC. The method proposed for determination of the compatibility of dyes was more verified at higher temperature, that is, 95 oC, against a conventional method of solution analysis. The results of compatibility showed that the selected binary mixtures of cochineal-weld have an excellent compatibility. The other mixtures, that is, walnut green shell-cochineal and walnut green shell-weld showed weak-moderate and very weak compatibility, respectively.     

Potassium Fixation and Release in Some Calcareous Soils under Orange Cultivation

Eurasian Soil Science - Arid and semiarid soils of southern Iran may fix a large content of applied potassium (K), but the fixed K may be gradually supplied to plants. Sixteen representative soils...     

Effect of vermicompost on some morphological,physiological and biochemical traits of bean (Phaseolus vulgaris L.) under salinity stress

Vermicompost can play an effective role in plant growth and development and also in reducing harmful effects of various environmental stresses on plants due to its porous structure, high water storage capacity, having hormone-like substances and plant growth regulators and also high levels of macro and micro nutrients. The aim of this study was to investigate the effects of vermicompost and salinity interactions on some morphological and physiological features and concentration of mineral elements of bean (Phaseolus vulgaris L. cv. Light Red Kidney) cultivar. A factorial experimental with five different volumetric ratios of vermicompost and sand, including to: 0:100; 10:90; 25:75; 50:50 and 75:25 and four levels of salinity [20, 40, 60 and 80 mmol l^?1 sodium chloride (NaCl)], and control was conducted base on Randomized Complete Block Design with three replications. Bean seeds were sowed in plastic pots, the seedlings being sampled 42 days old (flowering stage).The results showed that vermicompost had significant effect on all studied traits under stress and non-stress (p ≤ 0.05).In this experiment, the vermicompost significantly increased the photosynthetic rate and concentrations of potassium (K⁺) and calcium (Ca²)⁺in leaf and root tissues. In salinity levels of 20, 40 and 60 mmol l^?1NaCl, all subjected ratios of vermicompost and in 80 mmol l^?1NaCl the ratios of 10% and 75% vermicompost, significantly ameliorated negative effects of salinity. In both stress and non-stress conditions, using 10% volume of vermicompost is recommended to improve the growth of bean plants.     

Improvement in estimation of soil water retention using fractal parameters and multiobjective group method of data handling

Soil water retention characteristic is required for modeling of water and substance movement in unsaturated soils and need to be estimated using indirect methods. Point pedotransfer functions (PTFs) for prediction of soil water content at matric suctions of 1, 5, 25, 50, and 1500 kPa were developed and validated using a data-set of 148 soil samples from Hamedan and Guilan provinces, Iran, by multiobjective group method of data handling (mGMDH). In addition to textural and structural properties, fractal parameters of the power-law fractal models for both particles and aggregates distributions were also included as predictors. Their inclusion significantly improved the PTFs’ accuracy and reliability. The aggregate size distribution fractal parameters ranked next to the particle size distribution (PSD) in terms of prediction accuracy. The mGMDH-derived PTFs were significantly more reliable than those by artificial neural networks but their accuracies were practically the same. Similarity between the fractal behavior of particle and void size distributions may contribute to the improvement of the derived PTFs using PSD fractal parameters. It means that both distributions of the pore and particle size represent the fractal behavior and can be described by fractal models.     

Potassium isotherm partitioning based on modified quantity‐intensity relation and potassium buffering characterization of soils of North India

Background : Potassium (K) availability in soil and plant uptake is restrained by the dynamic interactions among the different pools of K. Aims : To understand these interactions, a study was undertaken to assess the quantity–intensity (Q/I) and buffering characteristics of rainfed maize (Zea mays L.) growing soils. Ten contrasting soils were evaluated for K partitioning changes in exchangeable K (ΔEK) and non‐exchangeable K (ΔNEK) pools in the soil‐solution phase and buffering characteristics using a modified version of Q/I approach. Results : The partitioned Q/I isotherms showed strong adsorption with the increase in K concentration ratio (CR^K) and the changes due to ΔEK were higher than changes due to ΔNEK. Total buffering capacity (PBC^K) significantly correlated (r = 0.92, p <0.01) with clay content with a major share contributed by buffering capacity owing to non‐exchangeable K ( ${\mathrm{PBC}}_{\Delta \mathrm{NEK}}^K$) rather than exchangeable K ( ${\mathrm{PBC}}_{\Delta \mathrm{EK}}^K$). The fixation capacity (β) factor, the magnitude of added K converted into a non‐exchangeable pool, ranged from 41 to 63%, whereas release (α) factor, the magnitude of added K converted to the exchangeable pool, ranged from 19 to 36%. Both threshold solution K (CK_r) and threshold exchangeable K (EK_r) values were found to be high in Satran clay loam (S2) and lower in Doon silty clay loam (S3) soils. The equilibrium exchangeable K (EK_o) was found close to minimum exchangeable K (E_min) in Doon silty clay loam (S3) and Babaweyl sandy clay loam (S1) soils and overall E_min constituted about 8.94 to 0.57% of the EK_o. Conclusion : It may be concluded that K Q/I isotherm partitioning provides a valuable insight to assess the dynamic relations. The ratio of α/β (K recharge index) could be used to evaluate the K enrichment capacity of soil to K additions while EK_r and E_min can be potentially useful in the elucidation of exchangeable K as K fertility index especially in soils with poor K fertilizer management.     

Effects of potassium silicate and nanosilica on quantitative and qualitative characteristics of a commercial strawberry (fragaria × ananassa cv. ‘camarosa’)

Silicon (Si) is considered as a beneficial element to higher plants especially under stress conditions. A factorial experiment, in a completely randomized design with four replications, was used to investigate the effects of two application methods (spraying and soil drenching) and eight levels of Si compounds including 0, 5, 10 and 15 mM of potassium silicate (K₂SiO₃) and 0, 5, 10 and 15 mM of nanosilica (SiO₂). The results indicated that Si application (all or some treatments) decreased transpiration, specific leaf area, petiole length, and promoted the flowering, fruit firmness, leaf/crown number, fresh and dry weight of shoot and root, water use efficiency. They also showed it did not affect the fruit set percentage, yield, chlorophyll index, total soluble solid, leaf area, fresh and dry weight of crown, photosynthesis, stomatal conductance, internal carbon dioxide (CO₂) concentration and mesophyll efficiency of strawberry. The results suggest the beneficial effects of Si on growth and development of strawberry.     

Supercritical carbon dioxide extraction of essential oils from Perovskia atriplicifolia Benth

The supercritical fluid extraction (SFE) of the aerial parts of Perovskia atriplicifolia Benth. was studied. The effect of different parameters such as pressure, temperature, modifier identity, and modifier volume on the SFE of the plant was investigated. The extracts were analyzed by GC and GC-MS and compared with the essential oil obtained from P. atriplicifolia Benth by steam distillation. The supercritical extracts and the steam-distilled products had very different compositions. The main constituents of the oil obtained by steam distillation were 1,8-cineole, limonene, camphor, beta-caryophyllene, alpha-pinene, camphene, and alpha-humulene. On the other hand, the major components of SFE extracts were 1,8-cineole, limonene, camphor, beta-caryophyllene, gamma-cadinene, alpha-pinene, and alpha-terpinyl acetate. The results showed that increasing the temperature from 35 to 65 degrees C (at a constant pressure of 100 atm) drastically reduced the number of extracted components. Also, the number of extracted constituents and the percent of main analytes increased when lower pressures were used. Using different modifiers (e.g., methanol, ethanol, dichloromethane, and hexane) for the extraction of the plant at low pressure (100 atm) and temperature (35 degrees C) showed that hexane was more selective than the other modifiers.     

Molecular aspects of drought tolerance in bread wheat (T. aestivum)

In order to evaluate molecular indices of drought tolerance and selection of drought tolerance genotypes in bread wheat a randomized complete block design was carried out with three replications in the field of research station of Sararood, Kermanshah, Iran. Positive significant correlation coefficient was observed between grain yield and proline, soluble sugar and total protein under rainfed condition. Based on the grain yield, proline content, soluble sugar and total protein the genotypes were classified into four clusters using cluster analysis and UPGMA method. Genotypes numbers 4, 9, 10, 11, 18 and 19 in the first clusters indicated the highest performance.     

Preparation of magnetic and conductive graphite nanoflakes/SrFe<Subscript>12</Subscript>O<Subscript>19</Subscript>/polythiophene nanofiber-nanocomposites and its radar absorbing application

This study, we synthesized graphite-nanoflakes (GNFs) by acid treatment and thermal shock and then using the ultrasonic irradiation technique to exfoliate flake-carbon. The SrFe₁₂O₁₉ nanoparticles (NPs) were coated by co-precipitate method on GNFs after by alkaline treatment. Finally nanocomposite (GNF/SrFe₁₂O₁₉/PTh) was prepared by in-situ oxidative polymerization method in presence of thiophene (Th) as monomer. The magnetic and electrical conducting properties of the resulting nanocomposites were measured by using vibrating sample magnetometer and standard four-point-probe method, respectively. The synthesized nanocomposites were characterized by X-ray diffraction (XRD) and fourier transform infrared spectra (FTIR). In addition, morphological analyses were investigated by scanning electron microscopy (SEM). A minimum reflection loss (RL) of GNFs/SrFe₁₂O₁₉/PTh with 50 % wt GNFs/SrFe₁₂O₁₉ as core were observed ?28 and ?39 dB at 9.7 and 12 GHz for a 1.5 mm thickness. The results indicated that we can perform good microwave shielding in X-band (8–12 GHz) by these nanocomposites.