SODIUM CHLORIDE PRIMING IMPROVES SALINITY RESPONSE OF TOMATO AT SEEDLING STAGE

We aimed to investigate whether sodium chloride seed priming and irrigation at seedling stage enhance response of 5-leaf stage tomato plants (Lycopersium esculentum Mill.) to high salt stress. Three experimental groups were as; non-primed seeds, seeds primed with 0.05M sodium chloride (NaCl), and seeds primed and irrigated with 0.05M NaCl starting from sowing to salt stress application. Sodium chloride solutions (0.1M, 0.2M, 0.4M, and 0.6M) were added to cups under pots in every 2 days for 10 days to treatment groups. Control groups were irrigated with distilled water at the same time intervals. At least two experimental setups contained at least four plants, and two samplings of leaf and root tissues were performed for analysis of each plant to evaluate changes in pigment and proline contents, lipid peroxidation and electrolyte leakage levels, and ascorbate peroxidase and catalase activity. Priming reduced mean germination time, and increased final germination percentage together with energy of germination. Increased root and hypocotyl lengths as well as increases in fresh weights supported enhanced seedling vigor. Considering growth and stress parameters such as chlorophyll content, chlorophyll to carotenoid ratios, and lipid peroxidation and electrolyte leakage were less affected in primed plants. Moreover, improvement of the accumulation of osmoregulating defense molecules, such as proline and anthocyanin, and of the inductions of the antioxidative enzyme system points out to higher adaptive response of these plants against deleterious effects of salt.     

Accumulation of weathered p,p'-DDTs in grafted watermelon

The grafting of melon plants onto cucurbit rootstocks is a common commercial practice in many parts of the world. However, certain cucurbits have been shown to accumulate large quantities of weathered persistent organic pollutants from the soil, and the potential contamination of grafted produce has not been thoroughly evaluated. Large pot and field experiments were conducted to assess the effect of grafting on accumulation of weathered DDX (the sum of p,p'-DDT, p,p'-DDD, and p,p'-DDE) from soils. Intact squash (Cucurbita maxima × moschata) and watermelon (Citrullus lanatus), their homografts, and compatible heterografts were grown in pots containing soil with weathered DDX at 1480-1760 ng/g soil or under field conditions in soil at 150-300 ng/g DDX. Movement of DDX through the soil-plant system was investigated by determining contaminant levels in the bulk soil and in the xylem sap, roots, stems, leaves, and fruit of the grafted and nongrafted plants. In all plants, the highest DDX concentrations were detected in the roots, followed by decreasing amounts in the stems, leaves, and fruit. Dry weight concentrations of DDX in the roots ranged from 7900 ng/g (intact watermelon) to 30100 ng/g (heterografted watermelon) in the pot study and from 650 ng/g (intact watermelon) to 2430 ng/g (homografted squash) in the field experiment. Grafting watermelon onto squash rootstock significantly increased contaminant uptake into the melon shoot system. In the pot and field studies, the highest stem DDX content was measured in heterografted watermelon at 1220 and 244 ng/g, respectively; these values are 140 and 19 times greater than contaminant concentrations in the intact watermelon, respectively. The xylem sap DDX concentrations of pot-grown plants were greatest in the heterografted watermelon (6.10 μg/L). The DDX contents of the leaves and fruit of watermelon heterografts were 3-12 and 0.53-8.25 ng/g, respectively, indicating that although the heterografted watermelon accumulated greater pollutant levels, the resulting contamination is not likely a food safety concern.     

Determination of volatile compounds in different hop varieties by headspace-trap GC/MS--in comparison with conventional hop essential oil analysis

A headspace (HS)-trap method in combination with gas chromatography (GC)-mass spectrometry (MS) was developed for the determination of volatile constituents in hops. The highly sensitive HS-trap system reduces the detection limit by using up to four trap enrichment cycles. Seventy hop samples of different varieties and cultivation regions, from the 2008 harvest, were examined using the HS-trap-GC-MS method and the established "European Brewery Convention" (EBC) method for hop essential oil analysis. Twenty-one different volatiles were quantified for each hop sample. For all compounds, except caryophyllene oxide, a strong correlation was found between the results of the HS-trap method and the EBC method. Experiments have revealed that the EBC method using steam distillation is not appropriate for thermolabile compounds, such as caryophyllene oxide, due to decomposition during boiling. The HS-trap method is fast and sensitive, requires small sample amounts and minimal sample preparation, and is easy to apply.     

Multilayer Perceptron Neural Network Approach to Estimate Chlorophyll Concentration Index of Lettuce (Lactuca sativa L.)

Nitrogen is an essential nutrient for greenhouse-grown lettuce (Lactuca sativa L.); however, excessive nutrient availability causes disease and detrimental effects on the leaf and root development. In this study, nitrogen content of the lettuce leaves was estimated by determining the chlorophyll concentrations of the leaves using image processing technique. The Hoagland solution was used as a fertilizer in five different doses (control, quarter of the solution, half of the solution, standard solution, and two times more of the solution). Multilayer perceptron neural network (MLPNN) model was developed based on the red, green, and blue components of the color image captured to estimate chlorophyll content and chlorophyll concentration index (SPAD values). According to the obtained results, the MLPNN model was capable of estimating the lettuce leaf chlorophyll content with a reasonable accuracy. The coefficient of determination was 0.98, and mean square error was 0.006 in validation process.     

Using Artificial Neural Network and Multiple Linear Regression for Predicting the Chlorophyll Concentration Index of Saint John’s Wort Leaves

This research investigates and compares artificial neural network and multiple linear regression for predicting the chlorophyll concentration index of Saint John’s wort leaves (Hypericum perforatum L.). Plants were fertilized with 0, 30, 60, 90, and 120 kg ha^?1 nitrogen [34% nitrogen ammonium nitrate (NH₄NO₃)]. Chlorophyll concentration index of each leaf was measured using SPAD meter. Afterwards, rgb (red, green, and blue color) values of all leaf images were determined by image processing. Values obtained were modeled using both multiple regression analysis and artificial neural networks. Using multiple regression analysis R² values were between 0.61 and 0.97. Coefficient of determination values (R²) using artificial neutral network values were found to be 0.99. Artificial neutral network modeling successfully described the relationship between actual chlorophyll concentration index values and predicted chlorophyll concentration index values.     

Soil Property Changes After Conversion from FOrest to Pasture in Mount Sacinka,Artvin, Turkey

Turkey's forests have been continuously facing conversion into both agriculture and pasturelands, causing not only degradation and fragmentation of forested lands but also negative changes in soil properties that have not been thoroughly investigated. In order to determine possible changes in some physical and hydrophysical soil parameters along with the dispersion ratio between natural coppice forests and the neighbouring forest‐to‐grassland converted areas, a foothill of Mount Sacinka in Artvin was chosen as a research area. Besides land use, possible effects of elevation change on soil properties due to the mountainous and moderately steep landscape of the region were also taken into consideration. The soil samples were analysed for soil texture, permeability, field capacity, bulk density, organic matter, pH and dispersion ratio. The results indicated that whereas permeability (43·05 mm h⁻¹ in forest and 18·82 mm h⁻¹ in pasture), field capacity (43·45% in forest and 38·08% in pasture) and organic matter (6·36% in forest and 5·34% in pasture) values turned out to be higher in forest soils, bulk density (0·91 g cm⁻³ in forest and 1·06 g cm⁻³ in pasture) and pH (5·89 in forest and 6·55 in pasture) values were low in grassland soils, meaning that conversion has negative effects on soil properties. Additionally, the mean dispersion ratios of 27·55% and 33·58% for forest and pastureland soils, respectively, indicated soil erosion problems in both land uses. In addition, as for elevation effect, forest soils especially showed better characteristics at higher elevations with high permeability, field capacity and organic matter and low pH and dispersion ratio. Copyright © 2015 John Wiley & Sons, Ltd.     

Quantitation of fatty acids, sterols, and tocopherols in turpentine (Pistacia terebinthus Chia) growing wild in Turkey

The chemical composition (fatty acids, tocopherols, and sterols) of the oil from 14 samples of turpentine (Pistacia terebinthus L.) fruits is presented in this study. The oil content of the samples varied in a relatively small range between 38.4 g/100 g and 45.1 g/100 g. The dominating fatty acid of the oil is oleic acid, which accounted for 43.0 to 51.3% of the total fatty acids. The total content of vitamin E active compounds in the oils ranged between 396.8 and 517.7 mg/kg. The predominant isomers were alpha- and gamma-tocopherol, with approximate equal amounts between about 110 and 150 mg/kg. The seed oil of P. terebinthus also contained different tocotrienols, with gamma-tocotrienol as the dominate compound of this group, which amounted to between 79 and 114 mg/kg. The total content of sterols of the oils was determined to be between 1341.3 and 1802.5 mg/kg, with beta-sitosterol as the predominent sterol that accounted for more than 80% of the total amount of sterols. Other sterols in noteworthy amounts were campesterol, Delta5-avenasterol, and stigmasterol, which came to about 3-5% of the total sterols.     

Comparison of artificial neural network and regression pedotransfer functions for prediction of soil water retention and saturated hydraulic conductivity

Modeling water flow and solute transport in vadose zone requires knowledge of soil hydraulic properties, which are water retention and hydraulic conductivity curves. As an alternative to direct measurement, indirect determination of these functions from basic soil properties using pedotransfer functions (PTFs) has attracted the attention of researchers in a variety of fields such as soil scientists, hydrologists, and agricultural and environmental engineers. In this study, PTFs for point and parametric (van Genuchten's parameters) estimation of soil hydraulic parameters from basic soil properties such as particle-size distribution, bulk density, and three different pore sizes were developed and validated using artificial neural network (ANN) and multiple-linear regression methods and the predictive capabilities of the two methods was compared using some evaluation criteria. Total of 195 soil samples was divided into two groups as 130 for the development and 65 for the validation of PTFs. Although the differences between the two methods were not statistically significant (p > 0.05), regression predicted point and parametric variables of soil hydraulic parameters better than ANN. Both methods had lower accuracy in parametric predictions than in point predictions. Accuracy of the predictions was evaluated by the coefficient of determination (R²) and the root mean square error (RMSE) between the measured and predicted parameter values. The R² and RMSE varied from 0.637 to 0.979 and from 0.013 to 0.938 for regression, and varied from 0.444 to 0.952 and from 0.020 to 3.511 for ANN, respectively. Even though regression performs insignificantly better than ANN in this case, ANN produces promising results and its advantages can be utilized by developing or using new algorithms in future studies.     

A NEW STRATEGY TO ENRICH CALCIUM NUTRITION OF FRUIT: SYNERGISTIC EFFECTS OF POSTHARVEST FOLIAR CALCIUM AND BORON SPRAYS

The objective of the study is to investigate the role of calcium (Ca) and boron (B) synergy in higher maintenance of Ca in fruit buds during senescence. To study the hypothesis, an experiment was conducted for two years in two ‘Starking Delicious’ apple (Malus domastica Borkh.) orchards established on seedling rootstocks in Banaz, Usak, Turkey. Treatments composed of postharvest foliar sprays of Ca at rate of 15.13 kg h^?1, B at rate of 2.47 kg h^?1 and their combination (Ca+B) compared with control trees sprayed with water. Fruiting spurs, flower ovaries, young and mature fruits were sampled and analyzed for their Ca, B, potassium (K) and magnesium (Mg) contents. Fruit were stored for six months and quality attributes were studied. Results put forth that Ca+B treatments significantly increase fruit Ca and B concentrations and firmness. The results displayed that postharvest B spray improves Ca nutrition of fruits through synergism of Ca+B on Ca translocation.     

Effects of chloride and partial substitution of reduced forms of nitrogen for nitrate in nutrient solution on the nitrate,total nitrogen,and chloride contents of onion

An experiment was conducted to determine the effects of chloride (Cl) and reduced forms of nitrogen (N) on the nitrate (NO₃), total N, and Cl concentrations in onion (Allium cepa L.) plants using a non‐recirculating nutrient film growing system. The reference treatment was a nutrient solution containing 19 mM NO₃ and 1.25 mM ammonium (NH₄). The results from this treatment were compared with that obtained using mixed amino acid, urea, and glycine treatments with or without additional Cl (10 mM) in which 20% of the NO₃ in the reference treatment was substituted with one of these reduced forms of N. Fresh and dry weights of the onion plants were not affected by the treatments. The NO₃ content was considerably lower in the mixed amino acid treatment, being 4236 mg NO₃/kg FW as compared to either the reference, urea, or glycine treatments. The NO₃ contents of the plants in these treatments were 5393, 5339, and 5261 mg NO₃/kg FW, respectively. The presence of Cl in the nutrient solution also reduced the NO₃ content of the plants from 5816 to 4299 mg NO₃/kg FW. The reduced‐N treatments increased the total N contents of the plants. The Cl content of the plants was increased by the Cl supplied and by the reduced forms of N in the nutrient solution.