Journal of Agricultural Science and Technology
Volume:15 Issue: 2, Mar 2013

In recent years, consumers’ concerns about environmental and health issues related to food products have risen; consequently, the demand for organically grown products has increased. In this respect, the aim of this study was to investigate factors affecting consumers’ potential willingness to pay premium prices for organic food products in Tabriz, Iran. An Ordered Logit regression model was applied to obtain the value of willingness to pay and determine the factors affecting it. Survey results showed that about 95 percent of the respondents were willing to pay a premium; while about 10 percent of them were willing to pay more than 35 percent premium for organic food products. Results revealed that factors like "individual’s income", "family dimension", “environmental concerns" and "wholesome diet", besides "the general criteria of shopping", and "consumers’ awareness of these products’ characteristics" significantly increased consumers’ willingness to pay a premium. According to the results, married respondents as well as females were willing to pay a higher premium. In addition, those who had children younger than 10 years old, elderly, or people with family members having special disease were significantly willing to pay a higher premium price for these products. More than 80 percent of the consumers mentioned "absence of certifications and organic labels", "lack of advertisement", and "higher prices" as their most important problems in purchasing organic food products.

An explanatory survey was carried out in 2008 to investigate the relationship between Entrepreneurial Orientation (EO), environmental factors, human capital and organizational characteristics vs. entrepreneurial performance among entrepreneurial firms in Iranian agricultural sector. Data were obtained from a sample of 120 Iranian agricultural establishments, using an interview-oriented questionnaire. The hierarchical regression analysis revealed that: although there is a positive direct relationship between EO and entrepreneurial performance in an agricultural business setting, applying main-effect or contingency models only, provides a distracting picture of entrepreneurial performance in agricultural settings. It was also found that configurational approach may better explain the relationship between EO, environmental factors, human capital and organizational characteristics vs. entrepreneurial performance over and above contingency and above main- effect models.

In order to compare photosynthetic features of triticale, bread wheat, and barley under water deficit conditions, this experiment was carried out in Kurdistan province in western Iran. Four genotypes of triticale, three cultivars of bread wheat, and a new variety of barley were compared under well watered (Ψsoil= -3 bars) and soil water deficit (Ψsoil= -12 bars) conditions in a randomized complete block design (RCBD) with a split-plot arrangement. Biomass production at anthesis accompanied with gas exchanges and chlorophyll fluorescence of flag leaves, as indicators of photosynthetic function of plant, were determined in each treatment. The results showed that by imposing water deficit, photosynthetic rate (Pn) was reduced in all studied genotypes irrespective of plant species. Under water deficit conditions, the highest Pn (6.86 and 5.90 µmol m-2 s-1) was found in bread wheat variety Pishgam and, triticale genotype No. 1, while the lowest value (3.63 µmol m-2 s-1) was found in barley variety Bahman. Similar trend was observed for the maximum quantum yield of primary photochemistry (Fv/Fm) and performance index (PI). Significant positive correlations were found between biomass production at anthesis and both Pn (r= 0.83**) and Fv/Fm (r= 0.77*). Our data revealed the better performance of Pishgam than Alvand and Zarrin in the reduction rate of biomass at anthesis and photosynthetic features against soil water deficit conditions. Overall, triticale was less affected by water deficit in comparison with wheat and barley in terms of photosynthetic function as indicated by less reduction in Pn, PI, and Fv/Fm.

Production of lignocellulolytic enzymes by the thermotolerant Fomes sp. EUM1 was determined in solid cultures using corn stover (CS) as a sole substrate or supplemented with 20 % wheat bran (CS+WB). This supplementation increased (P< 0.05) enzymatic activity per gram of initial dry matter (gdm) for xylanases and cellulases: 160 IU g dm-1 and 37 IU g dm-1, respectively; while laccases reached a similar yield (3.3 IU g dm-1) for both cultures. Nevertheless, laccases showed different stability patterns at 39°C and pH 6: half-life time (t½) was doubled in extracts from CS+WB (23.5 h); whereas t½ for the other enzymes from both cultures showed no difference. Both extracts by Fomes sp. EUM1 and a commercial enzymatic product were used on forages: corn stover, (CS), sugarcane bagasse (SCB), and alfalfa hay (AH). The fractional rate of gas production (FR; ml g-1 h-1) increased (P< 0.05) at 9 hours in CS compared to the sample without enzymes. The use of any enzymes favoured higher maximum gas volume (Vm; h-1) on SCB. The in vitro digestibility (IVD) of CS after using the commercial product was 12% higher, while our extracts from CS and CS+WB showed 16 and 21% improvements (P< 0.05), respectively, suggesting a higher specificity of these enzymes produced on the same substrate (CS). In addition to the proven stability, the versatility of extracts from CS and CS+WB was confirmed by the increase in IVD values for SCB (up to 100%) in relation to the control without enzymes.

DPPH radical-scavenging activity of the bene hull oil (BHO), sesame oil (SEO), rice bran oil (RBO), the oil's methanolic (CH3OH/H2O, 80:20 v/v) or hexane extracts, and their unsaponifiable matters fraction were measured and compared with each other. As a radical-scavenger, SEO was significantly stronger than RBO and BHO, respectively. Unlike BHO and RBO, the unsaponifiable (USM) fraction of the SEO could not considerably scavenge the free radicals at the concentrations studied. The contribution of aqueous methanolic and hexane extracts of the SEO to the inhibition of the DPPH radicals were calculated to be about 75 and 25%, respectively. The aqueous methanolic extract of the RBO could not considerably scavenge the free radicals at the concentrations experimented and the inhibition activity belonged mainly to the hexane extract. The DPPH radical-scavenging active components of the BHO were approximately distributed equally (48 and 52%) between the two extracts.

The suitability of milk preserved by refrigeration and CO2 addition for the manufacture of plain yoghurt using two commercial strains of Lactobacillus delbrueckii ssp. Bulgaricus and Streptoccocus thermophilus and probiotic yoghurt by Lactobacillus acidophilus was evaluated. Yoghurts (plain and probiotic) manufactured after milk pasteurization, from fresh and refrigerated CO2 treated samples (pH= 6.2), were compared with the corresponding controls (fresh and refrigerated). The multiplication and acidification capacity of the starter were neither affected by the previous refrigeration and CO2 addition of raw milk nor by the residual CO2 present in the pasteurized milk. CO2 addition of raw milk slightly enhanced viscosity and reduced synersis of yoghurts. The taste panel preferred yoghurts made from CO2 treated milks to the corresponding controls during cold storage. These results support the suitability of CO2-addition in preservation of milk for manufacturing of yoghurts.

Spaghetti samples were prepared by replacing wheat flour with defatted soy flour (DSF) at 0, 10, and 20% levels (w/w). Each sample had 4% gluten. In addition, xanthan gum was added at three levels (0.0, 0.2, and 0.4%) to spaghetti dough containing 20% soy flour as a modifying agent. Samples were extruded at 35 or 50oC and dried at, respectively, 52oC for 21h or 72oC for 6 hours. The color, protein content, cooking loss, cooked weight, and firmness of all spaghetti samples were measured. A trained sensory group evaluated chewiness, firmness, stickiness, color, and flavor. The overall results showed that increasing protein level in spaghetti caused an increase in the firmness and cooking loss with a decrease in cooked weight and consumer acceptance. However, when xanthan gum was added to spaghetti dough containing 20% DSF, the positive properties of spaghetti, including cooked weight and consumer acceptances, were improved significantly and its negative aspects, including firmness and cooking loss, were reduced noticeably. When xanthan gum and DSF levels reached, respectively, 0.4 and 20%, and the spaghetti dough was extruded at 50oC followed by drying at average temperature of 72oC, the best spaghetti in terms of physico-chemical and organoleptic properties was obtained.

In order to determine the effects of fish size and weight on its salinity tolerance, the chloride cells (CCs) immunolocalization changes were examined in Caspian salmon (Salmo trutta caspius) parrs, with the same age (about 2 years old) but different types (type A: 4.88 g, 8.36 cm; type B: 14 g, 11.84 cm; type C: 24.05 g, 14.08 cm). Fish survival rate, blood osmolality, gills CCs histological and immunohistochemical changes were investigated following their transfer from freshwater (FW) to the Caspian Sea water (CSW). The survival rate increased in larger sizes and blood osmolality showed a tendency to increase in parallel with salinity. After 10 days in CSW, some abnormalities were observed in gill structure such as: lamellae cohesion, lamellae rupture and separated lamella from filament epithelium that were shown in all types. These abnormalities in type B were less than the other types. Gill CCs were observed on the gill filament and lamellae. In direct transfer of Salmon parrs to the CSW, changes in number, sectional area, and the surface occupied by CCs in the gill tissue were observed in all the three types. In the type B, the number of CCs did not change, however, in the type C, they decreased, while in the type A, there was significant increase. But in the CSW, the occupied surface by gill CCs in the type C, was reduced significantly compared to other types. According to the present results, among the Salmon parrs with the same age, the fish with type A lacked osmoregulation, while the type B had better compatibility with the CSW. However, after reaching the size of the type C and considering osmultification, it is probable that the type B fish would become compatible with the fresh water environment and they will not have osmoregulation ability in saline water for the long term.

Collagen, which is widely distributed in pluricellular animals, is one of the most fundamental constituents of the extracellular matrix, and plays mechanically or physiologically important roles in their bodies. In this study, the biochemical and physical characteristics of pepsin-solubilized collagen from the mantle of Yesso scallop (YMPC), a by-product of processing, was determined. Electrophoretic patterns showed that scallop mantle collagen contained α1 and α2 chains, which was similar to the patterns of bovine tendon type V collagen. The YMPC showed different profiles in molecular, amino acids, peptide maps from those of bovine tendon collagen and lower denaturation temperature. Electron microscopic view of YMPC showed a sponge-like structure in part. These results indicated that YMPC may become a sustainable source of useful collagens for various purposes including value-added biomaterials. It may also be useful in a variety of applications as an alternative of vertebrate collagen, which has been widely used.

In the present study, the effects of different cadmium (Cd) levels of irrigation water (0, 5, 10 and 20 mg L-1) on corn plants (foliage) under different irrigation intervals (1, 3, and 7 days) were investigated. Clear Cd toxicity symptoms appeared on the plants at the end of the experiment. The results showed that stem dry weight (DW) followed by transpiration (T) and plant height were the measured plant parameters most sensitive to increasing Cd levels of irrigation water. In addition, Cd reduced water uptake by corn and led to more soil moisture. The results also demonstrated that corn might produce more shoot biomass with Cd application, which should be taken into consideration if no visible symptoms of Cd toxicity and considerable amounts of the metal uptake are present. Cadmium application through irrigation did not show a marked impairment in the nutrient status of the plants. Moreover, accumulation of Cd in the leaves was more than the stems by 24, 56, and 27% at 1, 3, and 7-day irrigation frequencies, respectively. Also, corn stem was found to be more sensitive to Cd than leaf. The results showed that corn might be used for phytoremediation of Cd under optimum moisture conditions and light contamination of the soil. Furthermore, shoot Cd concentration followed an asymptote pattern as a function of soil Cd, which was expressed by a plateau-type model under each irrigation interval.

The aim of this study was to analyze the stress response during 3 hours net confinement stress and recovery period of 22 hours in normal (STD) and in 17α-hydroxylase deficient common carp (E5). Fish were raised for 6 months and sampled at T0 (control, unstressed), 5 minutes, 20 minutes, 1 hour and 3 hours of exposure to net confinement, and after 1 hour, 4 hours, and 22 hours of recovery. At every sampling time, blood was collected to determine cortisol, corticosterone, glucose, lactate and free fatty acids (FFA) levels (5 fish per strain). Fish and head kidney were weighed before and after dissection, respectively, to determine head kidney somatic Index (HKSI). Morphometric analysis of head kidney tissues indicated that the head kidney somatic index was significantly higher in E5 fish (0.076±0.021) compared with STD fish (0.045±0.015). Also, significant differences in cortisol and corticosterone as well as in glucose, lactate and FFA values were observed between the two strains of E5 and STD. Moreover, the pattern of changes of glucose and FFA during stress and afterward indicated a significant difference compared to the T0. Results support the conclusion that the reduced capacity of ill fish to produce cortisol is caused by a deficiency in 17α-hydroxylase activity. A reduced cortisol output leads to increased stimulation of adrenals by adrenocorticotropic Hormone (ACTH), resulting in increased outputs of corticosterone.

This study was carried out to investigate impacts of Myrobalan rootstock and Blackthorn interstem on fruit growth, physico-chemical features and bioactive compounds of two apricot cultivars (‘Harcot’ and ‘Roksana’) in 2010 and 2011. Fruits of both cultivars on Myrobalan and/or Blackthorn grew with a classic double sigmoid curve from full bloom time to harvest. During growth and development periods, average fruit weight of both cultivars significantly increased, but differences between rootstock and interstem were not found. Myrobalan induced higher values of most fruit physical features (fruit thickness, sphericity, aspect ratio, surface area, fruit volume, flesh firmness) and some chemical attributes (soluble solids content and titratable acidity), whereas Blackthorn induced only higher ripening index values. Regarding cultivars, ‘Roksana’ possessed better physical features, except flesh firmness, and higher soluble solids content, ripening index value, total flavonoids content and total antioxidant capacity. Present results confirm the better adaptation of Myrobalan rootstock with ‘Roksana’ and ‘Harcot’ scion cultivar to sandy loam and acidic soil than Blackthorn interstem.

The effect of different storage temperatures on senescence and postharvest performance in cut scapes of three Iris species (Iris germanica, Iris reticulata and Iris kashmiriana) was studied with the aim to develop a cost-effective storage protocol so as to bring out the transportation of these cut flowers. The scapes were subjected to two different storage treatments-dry storage and wet storage. For dry storage, the scapes were wrapped in moistened filter papers and kept at different storage temperatures [RT (20±2oC), 10and 5oC] for 72 hours. For wet storage, the scapes were kept in buckets containing distilled water (DW) and kept at different storage temperatures [RT (20±2oC), 10oC and 5oC] for 72 hours. After 72 hours storage, the scapes were transferred to flasks containing either DW or sucrose 0.15 M (SUC). Storage of buds for 72 hours at 5oC, followed by transfer to DW and SUC improved longevity in all the three species. Cold storage treatment before transfer to holding solutions improved floral diameter, membrane integrity and maintained higher fresh and dry mass of flowers, sugar content, and soluble proteins. In all the three species studied, enhanced vase life was found associated with the decrease in the total phenolic content of the perianth tissue. In conclusion, our results suggest that wet and dry storage of premature scapes of Irises for 72 hours at 5oC, and placing them in sucrose improves the cut flower performance and can be used as effective postharvest storage treatments for these beautiful cut flowers.

The use of chlorophyll fluorescence (ChlF) technique was evaluated on nondestructive measurement of sugar content during fruit development. Multivariate models, principal component analysis (PCA), and partial least-squares regression (PLSR), were developed for the classification and prediction of fructose, glucose, and sucrose in fig fruits. The results of this study showed a significant correlation between fluorescence parameters and sugar content during fruit development. The PCA-ChlF can be used as a fast screening method for discriminating the degree of maturity based on sugar content. In addition, the root mean squared error (RMSE) and coefficient of determination (R2) of PLSR-ChlF for predicting sugar content were 2.01 g 100 g-1 DW and 0.96 for fructose, 1.03 g 100 g-1 DW and 0.99 for glucose, and 0.17 g 100 g-1 DW and 1.00 for sucrose, respectively. Therefore, ChlF combined with chemometrics may be a potential tool to nondestructively evaluate sugar accumulation in not only fig fruits, but also any other chlorophyll-containing fruit during development.

Water quality assessment provides a scientific basis for water resources development and management. This case study proposes a Factor analysis- Hopfield neural network model (FHNN) based on factor analysis method and Hopfield neural network method. The results showed that the factor analysis (FA) technique was introduced to identify important water quality parameters. Results revealed that biochemical oxygen demand, permanganate index, ammonia nitrogen, nitrogen, Cu, Zn and Pb were the most important parameters in assessing water quality variations of the study area. Considering these parameters, water samples of the sampling sites were classified as follows: six into Class III, eight into Class IV, and six into Class V. Afterwards, a water quality map was based on the results of water quality assessment by Factor analysis-Hopfield neural network model. It showed that the southwestern part of the study area had a generally optimum water quality, while in the northeastern part, the quality was seriously degraded. Factor Analysis-Hopfield Neural Network was much better than the Hopfield Neural Network in effectively reducing the degree of Hopfield neural network over-fitting caused by the inputs, thereby achieving more reasonable results. The comparisons with BPANN, fuzzy assessment method, and the Nemerow index method indicated that the FHNN model provided more reliable judgment and valuable information than the three other water quality classification methods.

Vacuolar H+-translocation pyrophosphatase (V-PPase) and Na+/H+ antiporter (V-Na+/H+) are important transporters in plant cells and have essential roles against abiotic stresses. In this study, the effects of salt stress were surveyed on the transcription of V-PPase pump and Na+/H+ antiporter genes at early times of NaCl treatment in roots of halophytic grass Leptochloa fusca through the Real Time PCR. The first results showed that L. fusca has high ability for accumulating Na+ under saline conditions. Real-Time PCR analysis demonstrated that the expression level of V-PPase and V-Na+/H+ increased in response to different levels of NaCl treatment, but the transcriptional increase of V-Na+/H+ gene was higher than that of the V-PPase gene, indicating that V-Na+/H+ had a crucial role in salt tolerance in this plant. These results indicated that coordinate up-regulations of V-PPase expression and Na+/H+ antiporter expression were correlated with Na+ sequestering into vacuoles of L. fusca. It was also shown that increase e in the expression level of V-Na+/H+ and V-PPase was correlated with the accumulation of sodium in roots, suggesting a physiological role for these antiporters and pump in Na+ compartmentation during adaptation to high salinity.

Roots of Helianthemum species were collected from various rangeland sites in Fars, and other provinces in Iran. The partial small subunits of ribosomal DNA genes were amplified with the genomic DNA extracted from their roots by nested polymerase chain reaction (PCR) using the universal fungal primer pair ITS1/ITS4 and specific primer pair FTC/RTC, which was designed based on internal transcribed spacer 1, 2 and 5.8S gene of rDNA sequences of Terfezia claveryi. The nested-PCR was sensitive enough to re-amplify the direct-PCR product, resulting in a DNA fragment of 500 bp. The efficacy of the nested-PCR showed that it could re-amplify the direct-PCR product and detect 2fg genomic DNA. Restriction fragment length polymorphism (RFLP) was analyzed using the two restriction enzymes Hinf I and Alu I. Nucleotides sequence analysis revealed that the sequences from infected Helianthemum species were close to those of T. claveryi. With the nested PCR method, H. lipii and H. salicifolium were confirmed as host plants of T. claveryi in greenhouse inoculated plants and also in the rangelands of different areas in Fars and other provinces inIran.

Dry bubble disease is one of the most important serious diseases of the cultivated white button mushroom (Agaricus bisporus (Lange) Imbach). It is a cosmopolitan disease having a worldwide distribution. Ten isolates of Lecanicillium fungicola var. fungicola (Preuss) Zare and Gams were collected from mushroom farms. Sensitivity of the isolates to benomyl, carbendazim, carbendazim+iprodione and prochloraz manganese were studied. All the isolates were resistant to benomyl(ED50= 415.45-748.12 mg L-1), carbendazim (ED50= 1123.87-1879.59 mg L-1) and iprodione+carbendazim (ED50= 415.45-748.12 mg L-1). However, most of the isolates were sensitive to prochloraz manganese (ED50=1.62–12.58 mg L-1). As the primary source of the pathogen inoculum is casing soil and insects, stringent environmental hygiene of the mushroom houses will play a very important role in preventing and controlling the disease.

Quinol oxidation inhibitors (QoIs) are one of the most important classes of fungicides used in agriculture. They block electron transfer between cytochrome b and cytochrome c1, thereby impeding the production of ATP via oxidative phosphorylation. QoI fungicides are generally at high risk of provoking resistance in fungal phytopathogens. Resistance has been reported in more than thirty species, amongst others, in Botrytis cinerea. In various QoI-resistant monosporic B. cinerea isolates from Hungary, a G-to-C point mutation was identified in the mitochondrial gene that encodes the QoI target, cytochrome b, resulting in a glycine to alanine substitution at position 143 (G143A). Analysis of Hungarian group I and group II strains further indicated the frequent occurrence of an additional group I-type intron in the cytb gene directly downstream of the glycine-143 codon. Mutual presence of distinct mitochondrial DNAs specifying different cytb alleles (heteroplasmy) has also been detected in monosporic strains. Remarkably, a number of group II field isolates were found to be highly resistant to azoxystrobin although they did not appear to carry the G-to-C mutation (G143A) generally associated with fungal QoI-resistance.

D-CODER is a fertilizer with a new slow-release mechanism consisting of an organo-mineral matrix that releases the nutrients only in the presence of growing plants. Pot and field experiments were carried out to study the release pattern of N from D-CODER. The experiments included grown and bare soil plots. The fertilizer treatments were D-CODER, ammonium nitrate (ANpreplant), and the control. A fourth treatment was added to the cultivated plots, consisting of splitting the ammonium nitrate application of 25% at preplant and 75% as top-dressing (ANsplit). In the bare soil pots, 35 days after the fertilizer application (DAFA), NO3-N concentrations in the extracts of anion exchange membranes incubated in the soil for ANpreplant, D-CODER, and the control treatments were 118.5, 82.5 and 34.5 mg L-1, respectively, suggesting that part of N from D-CODER had not yet been released. In the pots cultivated with ryegrass, 209 DAFA, N recoveries for D-CODER, ANpreplant, and control treatments were 0.94, 0.86 and 0.20 g pot-1, respectively, suggesting that in the presence of the growing plants the release of N from D-CODER had not been restricted. Furthermore, soil NO3-N levels in the bare soil plots of the field experiment were significantly higher in D-CODER (38.1 and 6.8 mg kg-1 on November and March) in comparison to ANpreplant (26.3 and 5.1 mg kg-1 on Nov. and March) treatments, suggesting that N from D-CODER was better protected from leaching. In the absence of growing plants, D-CODER provided some protection of N at least until 65 DAFA. In cultivated soils, it seemed less effective, particularly if the risk of nitrate leaching persisted for a long period of time. In these situations, a split application of N was a better strategy.