Journal of Agricultural Science and Technology
Volume:14 Issue: 7, Dec 2012

Iran is one of the countries facing the most severe farmland fragmentation (FF) in rural areas and farmland consolidation (FC) is generally regarded as being a suitable instrument to solve this problem. A case study in the central area of Iran was conducted to explore landholder''s attitudes towards issues related to FF and FC. Randomized stratified sampling frame was used to select 146 landholders in 10 villages that operated under Land Renovation and Development Schemes (LRDS). A questionnaire in several sections was developed to address main issues concerning FF and FC. Findings showed that increasing production input costs (labor, fuel, and machinery) is the most severe predicament caused by FF. Landholders believed that partial inheritance system, population increases and lack of job opportunity in off-farm interrelated together are main determinants of FF. Also reduction of land in the process of consolidation operates as a key restraint factor against FC. Physical investments by government and access to credit and loan operate as promoter factors of FC according to landholders’ view. Their most preferred options of FC are the government sponsored farming in rural production cooperative units including traditional cooperatives and informal peasantry societies to facilitate voluntary land consolidation.

All species in the genus Lysiphlebus Förster (Hymenoptera: Braconidae, Aphidiinae) are solitary endoparasitoids of aphids, which are one of the most difficult and unknown taxonomic groups to identify. A pair of species-specific primers as a molecular marker was designed to identify the most abundant and important aphid parasitoid wasp, L. fabarum Marshall, collected from Guilan province (Iran). This primer pair, which produces a 148 bp fragment length, was developed for L. fabarum by using the ATPase 6 gene region of mitochondrial DNA. The lower detection limit to amplify DNA of L. fabarum in a singleplex PCR was determined to be 72 pg of parasitoid DNA/µl PCR which was enough to detect this parasitoid in early life stages within its host. The L. fabarum eggs cannot be detected within Aphis fabae Scopoli (Hemiptera: Aphididae) earlier than 12 hours after oviposition. A pair of species specific primers designed for L. fabarum can be used to monitor the wasp populations under field conditions.

In the present study, an attempt has been made to use Data Envelopment Analysis (DEA) for assessing the technical efficiency and return-to-scale for greenhouse cucumber production in Iran. For this purpose, the data from greenhouses in Esfahan province, during one period of plant cultivation in one year including spring plants were randomly collected. The results indicated that total input energy, total output energy and energy ratio were 436,824 MJ ha-1, 128,532 MJ ha-1 and 0.29, respectively. DEA can be used to optimize the performance of any cucumber greenhouse. Based on input-oriented CRS and VRS models of DEA, the average values of pure technical efficiency, technical efficiency and scale efficiency were found to be 0.95, 0.83 and 0.88, respectively. Also the results revealed that, on average, about 30.27% of the total input energy could be saved without reducing the cucumber yield from its present level by adopting the recommendations based on the present study.

Calving records of Iranian buffaloes from April 1991 to June 2010 comprising 1,151 herds with 34,911 calving events were used to evaluate reported secondary sex ratio, stillbirth, and calf birth weight. Logistic regression models were applied to analyze stillbirth and calf sex at birth, and statistical analysis of calf birth weight was performed using a linear mixed model. Overall, the ratio of males to females was 53:47. It was observed that there were no significant effects of herd, calving year, season of calving, dam parity or interactions between these effects on the odds of male or female rates in Iranian buffaloes. Greater odds of calf stillbirth existed for calves born from primiparous buffaloes than from multiparous ones (Odds Ratio (OR)= 1.83; P< 0.0001). The greatest odds of stillbirth was for spring season (OR= 2.47; P< 0.0001), and male births had greater odds of stillbirth than female ones in Iranian buffaloes (OR= 1.21; P< 0.01). In general, male calves were heavier than the female calves at birth (P< 0.01) and the birth weights of calves from cows of parity 4 and beyond were significantly more than the weights of calves from cows of other parities (P< 0.01). Fall-born calves had significantly greater body weight at birth than calves born in other seasons (P< 0.01). It seems that providing good management practices for primiparous and multiparous buffaloes to minimize stress before parturition can reduce stillbirth incidence.

Campylobacter is known to be one of the most common causes of human intestinal disorders. Since poultry are known to be the main reservoirs for this pathogen, decreasing this bacterium in intestinal tract could be beneficial in reducing contamination of poultry products. The effects of probiotic (PrimaLac®), medicinal plant (Sangrovit®) and organic acid (Selko-pH®) as broiler feed additives on cecal colonization, and fecal excretion of broilers were studied. Other parameters such as performance, immune response and intestinal morphology were also determined. A total of 300 broiler chicks (Cobb 500) were divided into 5 groups. Groups consisted of unsupplemented feed (negative and positive controls), probiotic, medicinal plant and drinking water containing organic acid mixture. Except for the negative control group, all chickens were orally challenged with (109 cfu mL-1) Campylobacter jejuni at day 21. Cecal and fecal samples were collected for Campylobacter count. Body weight (BW), feed intake (FI) and feed conversion ratio (FCR) were determined weekly and cumulatively. BW and FI in the probiotic treated group were higher (P< 0.05) than the positive control group. On day 49 all supplemented treatments showed a reduction of Campylobacter colonization in cecal contents (P< 0.05). Fecal samples showed reductions (P< 0.05) on day 35 and 42. Villi height of duodenum and jejunum in the probiotic and medicinal plant treated groups were improved (P< 0.05). Immune response was significantly higher in these two groups (P< 0.05). These effects could be due to the antibacterial effects of the used feed supplements. Our results indicate that these feed additives could be potential treatments for reducing Campylobacter in the intestine of broilers. Probiotic and medicinal plant improve growth performance of these birds.

The antioxidant properties and total phenols’ content of 80% methanol, acetone and water extracts of olive leaves procured through Microwave Assisted Extraction (MAE) were examined. Two varieties of olive namely: Cronaiky and Roghani were the ones studied. Various experimental models were employed for antioxidant activity evaluation of the extracts. The results revealed the highest phenolic content (230.50 mg tannic acid equivalent g-1 extract) and the lowest IC50 in DPPH (86.81 µg ml-1 of extract), reducing power (166.45 µg ml-1 extract) and total antioxidant capacity (128.32 µg ml-1 of extract) indices were attributed to the methanol extract of Cronaiky variety. The efficacy of the extracts at three experimental levels (200, 500, 1,000 ppm) in blocking the oxidation process was investigated using peroxide value and thiobarbituric acid index for sunflower oil during its heating at 70°C (oven test method). The lowest peroxide value and thiobarbituric acid index was observed for the methanol extract of Cronaiky at its 1,000 ppm concentration. This extract was competitively comparable with BHA and BHT at either of the tested levels (100, 200 ppm). Thus, methanol extract of Cronaiky olive variety can be employed in place of synthetic antioxidants to establish oxidation stability in edible oils.

The objective of this study was to assess the microbial contamination of Razavi Khorasan (Iran) hot red pepper. The natural occurrence of aflatoxins and ochratoxin A in those samples was also investigated. For this purpose, 36 samples of this kind of pepper were collected from a farm and sun-dried. Standard and established methods were used for both microbiological analyses and mycotoxins identification. Total aerobic mesophilic counts of samples varied from 102 to 4×106 cfu g-1. Coliforms were present at high levels in all samples ranging from 1.9×102 to 3.52×106 cfu g-1that may indicate inappropriate hygienic quality of samples. 42% of the samples were of unsatisfactory quality due to the presence of E. coli. In all samples examined, sulphite-reducing clostridia (SRC) was below detection limit and Salmonella spp. was not detected. Fungi were found in all of the collected samples. Mold and yeast were generally high ranging from 2.4×103 to 4.6×106 cfu g-1and the most predominant fungal genera were Aspergillus spp., Penicillium spp and Rhizopus spp. Considering the results obtained, the samples analyzed contain a high level of microorganisms and only two samples (6%) had acceptable levels for all microbial factors according to EU Commission Recommendation (directive2004/24/EC). 69% and 17% of samples were found contaminated with total aflatoxins and ochratoxin A, respectively, that might contribute to health hazards for humans. Overall, The Razavi Khorasan hot red pepper samples collected for this study were contaminated with microorganisms and mycotoxins, which suggests that hygiene practice pre- and post-harvesting must be improved if the region is to exploit fully the potential for this valuable product.

In this study, we investigated the effects of osmotic process with or without ultrasound on solid gain (SG) and water loss (WL) of cranberries. Response surface methodology was used to model and determine the optimum processing conditions for WL and SG during osmotic dehydration of samples. Sucrose (40-60%) and salt (0-8%) concentrations, temperature (30-50°C) and frequency of ultrasound (0-130 kHz) were the factors investigated with respect to WL and SG. Experiments were designed according to a second-order Central Composite Design (CCD) in the form of a Face-Centered Cube (FCC) with these four factors, each at three different levels, including central and axial points. All experiments were conducted in triplicate. Experiments were conducted in a shaker with constant 150 rpm agitation and solution to sample mass ratio of 10/1 (w/w). Analysis of variance (ANOVA) was performed to check the adequacy and accuracy of the fitted models. Statistical analysis of results showed that the linear terms of all the process variables had a significant effect on WL. Except for temperature, all other parameters had a significant effect on SG. Optimum operating conditions were found to be sucrose concentration of 50.1%, salt concentration of 8%, temperature of 50°C and ultrasound frequency of 130 kHz.

Gundelia tournefortii L. is a well known plant in mountains of Iran and is found all over the country. It traditionally has some medicinal applications. In this research, Gundelia tournefortii L. seed was studied as a source of edible oil. Oil was extracted with immersion method using diethyl ether as a solvent. Acidity, saponification, ester, iodine, peroxide and refractive indices, average molecular weight of fatty acids, unsaponifiable matter, viscosity, color and density of extracted oil were evaluated. In addition, fatty acid composition of oil was determined using gas chromatography analysis. The results showed that seed oil content and saponification value of its oil were 22.8% and 166.05, respectively. Oleic and linoleic acid contents of oil were 27.99% and 54.59%, respectively. It was indicated that the extracted oil is an unsaturated oil and melts at ambient temperature. Beta-sitosterol and stigmasterol were the main unsaponifiable matters of the oil. Color analysis revealed that the predominant color was yellow (0.8 red, 14 yellow). The results indicated that Gundelia tournefortii L. seed can be potentially applied as an excellent oil for human consumption.

Tea leaves contain unsaturated fatty acids, key precursors of volatile compounds contributing to tea aroma quality. Tea is cultivated in areas with diverse environmental conditions. Nitrogenous fertilizers influence tea yields and quality. A previous single site study demonstrated that increasing nitrogenous fertilizer rates raised fatty acid levels. However it is not known if the magnitudes and patterns of the responses are replicated in different locations due to variations in growth factors. Nonetheless, there is a single fertilizer rate recommendation in all tea growing locations in Kenya. This study assessed possible variations in patterns and magnitudes of fatty acids in a single cultivar grown under similar nitrogenous fertilizer rates in different locations. Trials were conducted in five locations using clone BBK 35, receiving varying nitrogenous fertilizer rates. Fatty acids in two leaves and a bud were quantified as methyl esters. The levels varied (P≤ 0.05) with locations and increased (P≤ 0.05) with nitrogenous fertilizer rates. The rates of increase differed with locations leading to significant (P≤ 0.05) interaction effects. Thus, similar fertilizer rates in different locations result in different fatty acid levels, explaining differences in tea aroma quality from different locations even with the same agronomic inputs. The results demonstrate the need to develop region-specific agronomic inputs for the production of same tea quality.

Factor is introduced for direct head loss calculation and sizing in dual-diameter laterals of sprinkler and trickle irrigation systems when the Hazen-Williams equation is to be applied. Application of this factor prevents trial and error and uses fewer head-loss equations in calculating the total friction loss and designing dual-diameter laterals. The proposed factor is a function of total number of outlets on the lateral, number of outlets on the smaller-diameter section of the pipe and ratio of smaller diameter to the larger diameter pipe. By solving two practical examples, the advantage of this factor over other approaches was shown. It was also demonstrated that design of lateral sizing by the given equations is simpler, easier and more accurate than the previous methods.

Zagros (drought tolerant) and Pishtaz (drought susceptible) cultivars were classified on the basis of shoot dry weight and were used as plant material in this study. Total chlorophyll, carotenoids, antocyanins, proline, soluble sugar contents, lipid peroxidation, antioxidant enzyme activities and protein patterns were determined. Seedlings of wheat genotypes were grown in nutrient solution cultures under 16 h d-1 period at room temperature. With the decrease in osmotic potential, total chlorophyll initially increased but then decreased in the tolerant cultivar. The amount of total carotenoids and antocyanins in both cultivars increased in response to drought stress. However, the increase was only significant (P< 0.05) at some osmotic potentials. The increase was more pronounced in the tolerant cultivar. Soluble sugars and proline increased significantly in both cultivars, but were higher in the tolerant one. The sensitive cultivar showed higher rates of lipid peroxidation as compared to the tolerant cultivar. Antioxidant enzymes activities increased with the decrease in osmotic potential in both cultivars. The tolerant cultivar exhibited a higher antioxidant activity compared to the sensitive one. SDS-PAGE showed new protein bands under water stress. These results indicated that proline, soluble sugars contents and antioxidant enzyme activities are part of the defense mechanisms which confer water deficit tolerance to wheat cultivars. APX= Ascorbate peroxidase; CAT= Catalase; GR= Glutathione reductase; MDA= Malondialdehyde; ROS= Reactive oxygen species, SOD= Superoxide dismutase.

Dunaliella is a green halotolerant microalga, which has several industrial applications e.g. β-carotene production. Identification of different Dunaliella species has been carried out by morpho-physiological and recently molecular studies. To achieve an improved understanding of taxonomy, these studies are required to be in linkage. The present study describes molecular and specific morpho-physiological properties of a Dunaliella isolate obtained from Gavkhooni salt marsh in Iran. Phylogenetic analysis of Internal Transcribed Spacer region demonstrated that the isolate was associated with different species except D. salina (CCAP 19/18 and 19/30) and D.viridis. 18S rDNA size of the isolate was identical to that of D. tertiolecta and intron-lacking strains of D. salina. 18S rDNA fingerprint profile and phylogenetic analysis revealed D. tertiolecta as the closest taxon to the isolate. Features of optimum growth salinity (1.5-3% w/v) and maximum carotenoid per cell (0.7 pg cell-1) were comparable with reported data for D. terrtiolecta. Morphological characteristics including the size and color of the cells, presence and location of stigma and refractile granules were similar to those of D. tertiolecta. Totally, considering molecular and morpho-physiological properties, the isolate was attributed to the species D. tertiolecta and was named as Dunaliella tertiolecta ABRIINW-G3.

This study was conducted to determine the effects of arbuscular mycorrhizal fungi (Glomus mosseae and Glomus intraradices) symbiosis on mineral uptake of two pistachio cultivars (Pistacia vera cv. Qazvini and Pistacia vera cv. Badami-Riz-Zarand) grown in the greenhouse under different drought stress levels. Drought stress (DS) reduced the mycorrhizal colonization in both cultivars as well as nutrient uptake. The mycorrhizal plants had higher P, K, Zn and Mn concentrations than non-mycorrhizal plants regardless of soil moisture conditions while Cu and Fe concentrations were unchanged. Distribution of elements was affected by AMF treatments where all except P were accumulated more in leaves than in roots. Contrastingly, under drought conditions, the absorbed elements tended to remain in root tissue. In the case of P and Mn uptake, Qazvini was superior in comparison with Badami. In conclusion, it is suggested that AMF inoculation improves drought tolerance of pistachio cultivars at least in part through the enhanced uptake of slowly diffusing mineral ions such as PO42- and Zn2+. Moreover, arbuscular mycorrhizal (AM) colonization provides better osmotic adjustment which can be correlated with K+ accumulation in top portions of inoculated plants. Results of this study also emphasized that ‘Qazvini’ cultivar may be more tolerant to drought than ‘Badami’.KeywordsDrought stress; Mycorrhizae; Nutrition; Pistachio

To investigate the root anatomy and hydraulic conductivity of wheat cultivars, including Shiraz, Bahar, Pishtaz, Sistan, and Yavaros, a series of controlled environment (growth chamber) experiments were hydroponically conducted at University College of Dublin (UCD), Ireland in 2010. Bahar, Pishtaz and Sistan cultivars were employed as tolerant to drought and Shiraz and Yavaros as sensitive. Twelve plants from each wheat cultivar in three replications were compared in a completely randomized design. Seminal roots had four to five cortical cell layers, and typically one large central metaxylem and 5±1 (in Bahar) to 7±1 (in Yavaros) smaller and circularly arranged peripheral metaxylem vessels. Stellar cells were less lignified in adventitious roots, as compared with seminal roots, and mature xylem vessels of seminal roots of Shiraz and Yavaros cultivars had more lignified walls compared to the other cultivars of the 18 day old plants. Lateral roots of Shiraz cultivar showed the most lignified walls compared to the other cultivars. The highest root hydraulic conductivity in seminal roots was observed in Bahar with the lowest surface area and lignified cell walls. Type of cultivar had also a noticeable effect on flow rate of seminal roots and varied from 2.81 in Shiraz to 3.76×10-10 m s-1 in Bahar cultivar. With respect to flow rate and osmotic driving force of seminal and adventitious roots, Bahar and Sistan cultivars had the highest hydraulic conductivity. It was concluded that at the early growth stage of wheat cultivars (3rd leaf stage), root anatomical structures of Bahar and Sistan were more efficient in water uptake and this might be attributed to the less lignified cell wall of the peripheral and central metaxylem zones of the roots in these cultivars.

All of the tea plantations in Iran are concentrated in the Caspian Sea region on soils previously developed under deciduous natural forests. This research conducted to study the effect of land use change (from forest to tea) on selected physico-chemical and mineralogical properties of soils under humid climate and mountainous landscape in Northern Iran. Three transects facing west to northwest in both tea plantation and the nearby natural forest were selected. A total of 18 soil profiles formed on different physiographic positions i.e. summit, shoulder and foot slope were studied and morphological features of the soils were described. Soil samples taken from each horizon were analyzed. A two factor completely randomized design was used to take soil samples from surface horizons in each transect. Results showed that after changing forest to tea cultivation pH, cation exchange capacity, clay content and the amount of organic carbon of the soils were decreased at P< 0.01 significance level, but bulk density was increased compared to soils under natural forest. X-ray diffractograms of clay fractions showed that vermiculite, vermiculite–illite mixed layers and hydroxy interlayered clay minerals were the major clay components. Soils under tea cultivation possessed highly developed and more prominent argillic horizons and contained more clay fraction in the lower horizons in all physiographic positions.

To study the effects of soil amendments on physical and hydraulic properties of a saline-sodic sandy clay loam soil, a field experiment was carried out as a complete block design with three replications. The treatments in this research consisted of control (B), 10 ton ha-1 gypsum (G), 10 ton ha-1 urban solid compost (C), three levels of vinyl alcohol acrylic acid (S1= 0.05%, S2= 0.1%, S3= 0.2%), CS1, CS2, CS3, GS1, GS2, GS3CGS1, CGS2, and CGS3. Four months after applying the treatments, water contents were measured at 9 pressure heads for each treatment and data obtained were fitted to Van Genuchten equation. The parameters of this equation (i.e. θs, θr, α, and n) were determined by the least square error method. Also some physical properties including bulk density (Bd), mean weight diameter (MWD) of aggregates, plant available water content (PAWC), and the slope of water retention curve at inflection point (S index) were measured. The results showed that all treatments increased saturated water content (θs) significantly (P< 0.05) compared with the control (B). A similar trend was observed for residual water content (θr). The highest and lowest values of α were noted in B and S2 treatments, respectively. PAWCs increased significantly in all treatments compared with control ones except for G, GS1, GS2,and GS3 treatments (P< 0.05). Adding the soil amendments increased the values of S index and MWD and decreased Bd, significantly compared with the B treatment. It seems that the mixture of vinyl alcohol acrylic acid at 0.1% with urban solid compost or gypsum is a suitable amendment for increasing AWC and improving physical quality of studied saline-sodic soils.

Soil erosion causes sediments to be detached from their source materials and transported as suspended particles. The present study was conducted to evaluate the effects of sand exploitation on the distribution of suspended sediments in the Educational and Research Forest Watershed of Tarbiat Modares University, which comprises approximately 50,000 ha. Fifty-one water samples were collected before and after sand mining between November 2007 and June 2008. The settling rates of the primary particles of suspended sediments were then analyzed based on the principle of sedimentation described by Stokes’ law and using the modified pipette technique. Analyses of the samples indicated that the Suspended Sediment Particle Size Distribution (SSPSD) was significantly affected by sand mining. Specifically, an independent samples T-test demonstrated that the mean contents of sand, silt and SSC during and after sand mining differed significantly (P< 0.01), with respective values of 74.19±13.4 and 9.75±13.8, 81.77±4.5 and 2.96±2.7% and, 7.66±7.7 and 0.34±0.3 g l-1 being observed. Additionally, no significant difference was found between data sets collected before and during sand mining for hydrologic and SSPSD characteristics at 1%, which clearly proved consequent effects of sand mining on SSPSD.