Journal of Agricultural Science and Technology
Volume:14 Issue: 2, Mar 2012

Household data are used in this study to assess the transaction costs of obtaining credit from formal and semiformal institutions in rural Iran. A survey was employed to gather the data needed to determine the transaction costs that must be borne by the borrower in each step of the credit procurement process. Data were collected from a random sample of 459 households, including 272 borrower households. OLS regression and F-test (in view of the authors, OLS is not regression but a method of estimating a regression. F-test is not an econometric method but perhaps a statistical one and still it is a key statistics toll of either ANOVA or a regression. So these cannot be employed to investigate something. On the other hand, regressions have been estimated below, and surely one should be able to assign names of them) were employed to analyse the transaction cost factors affecting the procurement of credit facilities. Similar to many financial institutions operating in other developing countries, access to a loan in Iran imposes high transaction costs upon mostly poor rural households. The results reveal that the transaction costs of receiving a loan are on the average equivalent to nine percent of the total loan size. Formal and semiformal institutions impose significantly different costs upon the rural loan applicants. Results reveal that contractual form, loan size, how far the borrower being away from the financial centre along with other borrower peculiarities are important determinants of transactions’ costs.

Nearly just a decade ago, olive leaf moth, Palpita unionalis, was identified as an exotic pest from an olive grove in Roodbar, Iran. In order to plan an IPM programme regarding olive, a series of laboratory and field studies were carried out during 2001-2003 in Qazvin Province. To study the emergence time, number of generations, feeding behaviour and developmental periods at field, five trees (Zard cultivars) were selected within two groves, twenty infested branches of which (4 per tree) were taken to be covered with fine mesh net. They were monitored weekly. In the laboratory, a number of the pest pupae were taken to predefined conditions and reared at 25±0.5°C, 65±5% RH and 12:12 L:D. Then, the developmental period at various life stages, adults’ life span, females’ fecundity as well as sex ratios were determined. The field results showed that it took 34.2±2.1 days from neonate larval stage to adult emergence. Moreover, it was revealed that the pest had 4 to 5 overlapping generations per year. Based on the laboratory experimental results, embryonic developmental time, whole larval stages, pupal duration and female and male longevity took 5.8±1.08, 21.6±0.33, 8.33±1.0 and 12.6±1.3, and 13.5±1.1 days, respectively. Besides, females laid 182.33±18.1 eggs, on the average.

Grape berry moth, Lobesia botrana (Denis and Schiff.) is a destructive pest of grapevine in Orumieh (Northwest, Iran) vineyards. It is mainly controled through application of broad-spectrum insecticides, which can adversely affect vineyard ecosystem and consequently human health. Since a first step in setting up an IPM program is to assess the biological control agents within the ecosystem, so in this research work the larval parasitoid complex of Grape Berry Moth (GBM) on vine was identified, and its natural potential in controlling the pest compared for different generations and in different locations in Orumieh during 2004-2006. Adults of the larval parasitoids of GBM were recorded from laboratory-reared larvae, which had been collected on damaged inflorescences of the first generation and berries of the second and the third generations. Rate (%) of parasitism on L. botrana larvae was estimated as the number of parasitoids over the total count of parasitoids and moths. Six larval parasitoids of the host were found: Enytus apostata Gravenhorst, 1829; Pristomerus vulnerator (Panzer, 1799); Temelucha sp. (Hymenoptera: Ichneumonidae), Nemorilla maculosa (Meigen, 1824) (Diptera: Tachinidae), Habrobracon hebetor (Say) and Bracon sp. (Hymenoptera: Braconidae). Total parasitism varied from 1 to 16.8%, with an average of 7.7% as revealed through the present study. A comparison of the means of the larval parasitism rate showed a significant difference at 5% level between different generations and localities. The highest rate of parasitism occurred in the first generation in all localities, as well as in years.

Two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most injurious pests of fruits, vegetables and ornamental plants worldwide, both outdoor and indoors. Currently the main method of control of this pest is through application of pesticides which is mostly accompanied by the resistance of the pest against pesticide(s). The resurgence of resistant mite populations brings about further contamination of foodstuff and environment. Essential oils obtained from the aerial parts of plants may have the potential to be an alternative to synthetic pesticides, since they have been demonstrated to posses a wide range of bioactivities against insects and mites. So, the aim of the current study was to investigate the effect of essential oils extracted from three different medicinal plants namely: Mentha longifolia, Salvia officialis (both Lamiaceae) and Myrtus communis (Myrtaceae) against T. urticae. The LC50 values of essential oils of M. longifolia, M. communis, and S. officialis against T. urticae were 20.08, 53.22, 60.93 µl L-1 air, respectively. This shows that M. longifolia possesses the highest lethal activity whereas S. officialis the lowest. Also, essential oils of M. longifolia, M. communis, and S. officialis were demonstrated to possess repellency effect with ED50s of 147.47, 138.80 and 164.41, µl L-1 air, respectively. These data suggest that essential oils of all the three plants have the potential to be employed in the pest management programs designed for a control of T. urticae under greenhouse conditions.

To determine the droplet characteristics of agricultural spray nozzles through Water Sensitive Paper (WSP), the non-circular and overlapped spots appearing on the water sensitive paper surfaces are eliminated. In the conventional approach, the procedure is done according to the subjective self determined estimation of the operator. The objective of this study was to develop a practical alternative to the conventional approach to Spot Elimination (SE) from WSP surfaces. Droplet samples were taken through application of seven different spray nozzles. Papers were placed within and outside the domain of spraying area and scanned at 600 pixels per inch resolution following their collection. The diameter and roundness values of each spot on multiple WSP samples were determined through image processing software. The overlapped spots and the non-circular ones were manually eliminated by the operator. Spot Roundness (SR) ranged from 0.051 to 6.283 and from 0.130 to 6.283 prior to, and following SE, respectively. Results indicated a linear relationship between minimum SR value and volume median diameter of the droplets. Regression analysis revealed the optimal SR variation interval to be between 0.765 and 2.356 for SE. Characteristics of the spots remaining out of this range were compatible with the characteristics of the droplets conventional SE (when the spots subjectively eliminated). When the volumetric diameters (DV) in the conventional SE approach were compared with the optimum SR variation interval (for 10, 50 and 90 percent ratios) their absolute relative error ratios and confidence intervals at 95% level of significance level found as 2.8%±1.4, 1.8%±0.9, and 3.8%±1.5, respectively.

Mechanical properties of non-split pistachio nuts are among the lada required for the design of equipment needed for processing of the nut. Unsplit pistachio nut samples were uniaxially loaded to determine the nut’s needed splitting force and energy, as well as Poisson’s ratio and Young’s modulus of elasticity. The tests were carried out at four moisture contents (5, 10, 15 and 20% wb), under four loading rates (10, 20, 30 and 40 mm min-1), and on two varieties (O’hadi and Badami) of the nut. The highest splitting forces for the varieties (281.9 N for Badami and 102.4 N for O’hadi) were obtained at a moisture content of 5% wb and loading rate of 40 mm min-1, while the lowest forces, 97.0 N for Badami and 16.8 for the case of O’hadi, occured at moisture contents of 20% wb along with loading rate of 10 mm min-1. Different trends were observed between O''hadi and Badami varieties for the required energy to split nuts with increasing moisture content and loading rates. By increasing moisture content, Poisson’s ratio for unsplit pistachio nuts increased from 0.374 to 0.388 and from 0.326 to 0.337 for O’hadi and Badami varieties, respectively. Young’s modulus exhibited an indirect relationship with moisture content while a direct relationship with loading rate, in either of the varieties. Increase in moisture content from 5 to 20% wb led to a decrease in Young''s modulus, from 322.59 to 223.23 MPa and from 816.25 to 719.28 MPa, for O’hadi and Badami variety nuts, respectively.

Drying behavior of two types of pomegranates as well as the effect of drying conditions on moisture loss trend and on effective diffusion coefficient of arils are discussed in this article. Also, an appropriate mathematical drying model as well as the activation energy of sweet and sour pomegranate arils, dried in vacuum and microwave driers are pursued and presented. Results of regression analysis of the studied models indicated that Midili and Page models exhibit the best fit to the data obtained for vacuum and microwave drying, respectively. Effective diffusion coefficient of pomegranate arils was estimated in the ranges of 0.74×10-10 to 52.5×10-10 m2 s-1 and 3.43×10-10 to 32.05×10-10 m2 s-1 for vacuum and microwave driers, respectively. Activation energy figures for the vacuum drier were 52.27 and 52.83 kJ while for microwave drier they were 17.22 and 23.83 kJ for the cases of sweet and sour variety pomegranates, respectively.

Mechanical damage due to harvesting, handling, and other processes is an important factor that affects the seeds quality. Seed damage results in lower grain value and more storability problem and reduces seed germination and seedling vigor and subsequent yield of crops. Tests were conducted to determine the percentage of physical damage (PPD) and percentage of loss in germination (PLG) of wheat seeds due to impact. The effect of wheat seed cultivar and impact velocity was determined. Wheat seed cultivars selected for testing included: Kohdasht, Maron, Simereh, Sardari and Zagros. Four impact velocities: 10, 20, 30 and 40 m s-1 were used. Results showed that effects of impact velocity and seed cultivar on seed damages were significant. PPD to seeds was higher than PLG in higher impact velocities. It found that the total damage of seeds increased from 4.17% (0.48 PPD and 3.68 PLG) to 73.32 % (47.59 PPD and 25.73 PLG) as impact velocity increased from 10 to 40 m s-1 for all wheat cultivars studied. Impact results indicated that Sardari wheat cultivar was more susceptible to PPD (27.39 %), while Maron seeds were more susceptible to PLG (14.70%). Among the cultivars studied, Sardari wheat seeds showed the highest level of total damage i.e.sum of PPD and PLG.

Among cereals, oats are unique for their benefiting from high protein as well as lipid content. However, insufficient gluten content creates a big challenge to making breads out of this kind of cereals. Flour made of one type of bread wheat cultivar plus two types of improved oat lines were employed in this study to make composite oat-wheat flour bread. According to the data obtained from farinograph readings, water absorption capacity and the duration of the dough development increased with an increase in the dough’s proportion of oat. The data obtained from the extensograph readings showed that the dough energy increased but extensibility property decreased with increase in the proportion of oat in the dough. Breads with 10% oat flour were ranked highest by the panelists. However, from a sensory point of view, the 10% formula was found to be inferior to control (bread baked from 100% wheat flour). Overall, considering the substantial nutritional benefits of oat, a certain level of compromise in the sensory properties can be made by offering breads with 20-30% rate of oat content.

Prangos ferulacea (Apiaceae) is a perennial herb with a distribution from East Europe to Middle East and Central Asia. The plant’s leaves are used as animal fodder. Its fruits and roots possess biological traits that provide it with the potential to be used for medicinal purposes. The essential oils obtained through hydrodistillation from aerial parts of Prangos ferulacea at the vegetative and flowering stages were analyzed through GC and GC-MS. Thirty-one vs. seven compounds were identified in the vegetative and flowering stages’ oils, respectively. While the essential oil of aerial parts at vegetative stage was dominated by α- pinene (57%), the oil at flowering stage was characterized by (E)-anethol (95.5%). The latter exhibited significant phytotoxic and fungitoxic effects in lettuce and against Sclerotinia sclerotiorum, respectively.

Excessive vegetative growth may bring about improper pollination and consequently lead to reduced fruit set and misshapen fruits. Paclobutrazol (PP333) reduces vegetative growth. On the other hand, balanced nutrient uptake at all developmental stages increases fruit quality and yield. An experiment was conducted with the aim of reducing vegetative growth and improving yield of strawberry, Selva cultivar, using combinations of PP333, boron and zinc. Results indicated that PP333 reduced vegetative growth by reducing both fresh and dry weights of shoots while simultaneously some such reproductive characters as inflorescence and fruit number were increased. Boron (H3BO3) alone had no effect on reproductive growth. A combination of PP333 plus B (100- 00 mg l-1) was the most effective in increasing fruit number as well as fruit weight. Paclobutrazol combined with zinc sulfate (ZnSO4) at concentrations of 100- 100 mg l-1 PP333×ZnSO4 had positive effects on reproductive growth including inflorescence number and yield. Zink sulphate at concentration of 100 mg l-1 with no PP333 and H3BO3 application increased yield, inflorescence and fruit number as compared with other treatments.

Mango (Mangifera indica L.) production is on the rise in various subtropical zones throughout the world. The cultivation of this fruit tree is feasible along the coast of Granada, where some 1,500 ha are presently grown. In 2006, the EU exported 118 thousand tonnes of mangoes at a value of 131 million euros. This study was conducted to assess the physico-chemical quality characteristics of some mango fruit cultivars growing under a Mediterranean subtropical climate in Spain. A number of twenty-five fruits from eight Florida and one Australian cultivars were collected from different trees at the preclimacteric hard-green stage, and weighed. Osteen fruits bore the greatest weight (69795 g) with their pulp:seed ratio ratios (20:2) significantly higher than those in the other cultivars tested. The lowest pulp:seed ratios were recorded for the cultivars Kensington (6.3) and Sensation (7.6). The fruits with the highest percentages of flesh belonged to cvs. Gleen, Palmer, and Osteen, each averaging 85%. The seed-weight of the fruits of cv. Osteen proved the lowest (4.2%) among all the cultivars, confirming the most desirable relationship with the pulp. The highest acidity (0.22%) went to Valencia Pride while Lippens contained the highest Total Soluble Solids (TSS). The TSS:TA ratios proved the highest for cvs. Kent (382) and Lippens (333), which might be indicative of the effect on their flavour. All the mango cultivars tested in this subtropical marginal area, especially cvs. Osteen and Tommy Atkins, met the standard parameters for high-quality fruits, and can be recommended for their performance and sustainable yield in such type of environments.

In the face of limited water resources, better utilization and operation of irrigation networks is essential. Use of control systems is considered as one of the most assured ways to achieve the aim. In the course of the present study, two centralized controllers are applied to the west canal of Aghili irrigation district in I. R. Iran. The proposed control algorithms consist of a distant Downstream PI Feedback control (DPIF), and a distant Downstream PI Feedback along with Feedforward control (DPIFF). In the controllers, each water-level regulator is adjusted as based on water levels in all the pools of the canal. The test case canal and flow scenarios are simulated using SOBEK. The controllers are evaluated using the simulation results. The results indicated that both of the proposed controllers possess the considerable needed potential to closely match the discharge (at the cross regulators) with those ordered by water users while properly maintaining the water level throughout the length of the canals of the irrigation system. It is apparent that the DPIFF controller is more effective than DPIF controller in providing a desirable performance. Use of these algorithms makes demand oriented water distribution as well as a better performance of the system possible. The DPIFF controller as the main control system accompanied by a local controller as a backup system can be recommended to present an efficient robust control system for the canal.

The objective of this research was to evaluate and to quantify the magnitude of the genotype environment interaction effects on mung bean grain yield and to determine the winning genotype for the test environments. Seven mung bean genotypes were tested at three locations for over two years. The grain yield data for each environment (location year combination) was first subjected to analysis of variance using generalized linear model. Mean grain yields of genotypes for the environments were computed to generate a genotype and environment two-way table data for the GGE biplot analysis. The analysis revealed the presence of significant genotype x environment interactions for grain yield. Location effect explained more than 60% of the total grain yield variation. GGE biplot analysis depicted the adaptation pattern of genotypes at different environments and discrimination ability of testing environments. MH-96-4, shown to have the potential of combining high yield with stable performance, can be recommended for production in mung bean growing ecologies in southern Ethiopia.

Wheat Streak Mosaic Virus (WSMV) causes extensive economic damage to wheat (Triticum aestivum L.) in many regions of the world. The present study was conducted to find out if the variations in biochemical changes in reaction to WSMV infection in F2 generation of either potentially resistant (Adl-Cross) or susceptible (Marvdasht) cultivars are genetically inherited. A factorial experiment was employed with two factors of: genotypes (Adl-Cross, Marvdasht, reistant F2s and susceptible F2s), and inoculation (either infected or non infected) at Shiraz University, Iran during 2007-2009. Leaves of seedlings were harvested at different time intervals for total protein, total phenolic compounds and peroxidase activity analysis. Results indicated that virus infection caused stress in all genotypes. Total protein reduction in the inoculated resistant Adl-Cross and in its F2s was not significant whereas it was significant in the inoculated susceptible Marvdasht and its susceptible F2s. Viral infection reduced peroxidase activity in the susceptible Marvdasht cultivar and in its susceptible F2s whereas in Adl-Cross and in its resistant F2s the activity was increased. It is speculated that peroxidase enzyme may affect synthesis of compounds effective in resistance to wheat streak mosaic virus. The trend in the increase in phenolic compounds indicated that their formation and accumulation is faster in the resistant genotypes as compared with the susceptible ones. It appears that the extent of total protein, total phenolic compounds as well as peroxidase activity changes in response to WSMV are inherited by the next generations and these biochemical changes in a genotype could be adopted as selective factors in the preliminary experimental stages of selection for tolerance to the virus.

Lentil wilt, caused by Fusarium oxysporum f. sp. lentis is one of the main limiting factors to successful lentil cultivation. Effect of four antagonistic fungi, namely: Piriformospora indica, Sebacina vermifera, Trichoderma viride and Trichoderma harzianum as well as combinations among them were evaluated against Fusarium wilt of lentil. In in vitro experiments, the effect of the antagonistic fungi against the pathogen were evaluated in dual cultures of volatile metabolite and colonization. Results revealed that antagonistic fungi could produce a proper zone of inhibition. In pot culture experiments, two isolates of pathogen were inoculated within three time schedules, namely: 10 days prior to sowing, concomitant with sowing and 10 days past sowing. Seventeen treatments, including two controls and fifteen combinations of antagonistic fungi were employed to inoculate seeds concordant with sowing. Plant height, plant dry weight, root length, root dry weight along with disease severity were assessed at the flowering stage. Maximum plant height and minimum disease severity with regard to the two isolates of pathogen were observed in pots treated with S. vermifera+T. harzianum.

Genetic structure and pathogenic diversity of Sclerotinia sclerotiorum, the causal agent of canola white stem rot, were assessed through Mycalial Compatibility Groupings (MCGs), a comparison and comparing of isolate virulence. Fifty-seven isolates from three different regions in Golestan Province were selected for mycelial compatibility and as well for virulence tests. Within the 57 tested isolates, 35 MCGs were identified, 42.86% of which being constituted of single isolate specimens, were all collected from Ali Abad region. The observed MCGs differed within the three regions. From among the 35 MCGs, 25.71%, 28.57% and 45.72% belonged to Kalaleh, Hashem Abad and Ali Abad, respectively. In Kalaleh, nine MCGs were identified all of which fell into two isolates. Ten MCGs were identified within the Hashem Abad region, eight of which represented two isolates and the remaining were constituted from three isolates. Sixteen MCGs were detected in Ali Abad for which, except one MCG which was constituted of two isolates, the rest belonged to one isolate. Moreover, no MCG was identified as common among these regions. Shannon diversity index (Ho) of MCGs for the whole regions found to be was 0.86 (Htot). Partition of total diversity (Htot) showed that 95.45% corresponded to a variation in diversity within S. sclerotiorum populations. Variation in isolate virulence was tested using a petiole inoculation technique under greenhouse conditions. Isolate virulence varied within the three regions. Moreover, in most cases the differences in virulence of isolates within MCGs were significant. The data indicated that populations of S. sclerotiorum obtained from the studied regions were composed of a heterogeneous mix of MCGs, therefore the population structure of this pathogen as well as variations in virulence of isolates must be considered in disease management systems in these regions.

Sediment yield data, collected for most regions in Iran has been insufficient and not so reliable and there is still not any sufficiently reliable methodology available for sediment yield assessment in the country as a whole. On the other hand, an attainment of reliable sediment yield data is a must and key requirement for the design of effective sediment management as well as control strategies. Sediment deposition in reservoirs is assumed as a very useful tool in providing such data. The main objective of the present research was to discuss a combination of both source fingerprinting technique and reservoir sediment survey to provide reliable data on sediment yield of geological formations for three small catchments in Semnan Province, Iran. Throughout the study, the volume and mass of deposited sediments in reservoirs were initially assessed. Fingerprinting technique was employed to identify the contribution to, as well as the specific sediment deposition yield of each geological formation into reservoir sediments. Results indicate that there is a high spatial variation in Specific Sediment Yield (SSY) among the geological formations in all the three catchments varying from 2.98 t ha-1 year-1 to 0.16 t ha-1 year-1. The results also emphasize the importance of Quaternary Units and Upper Red Formation as the dominant surface sources within some vast areas of the catchments.

Sewage effluent is the carrier of huge amounts of N (0.09 to 0.16%), P (0.023 to 0.029 %), and K (0.11 to 0.18%) and as well as it is rich in organic carbon (3.27%). Transfer of the toxic trace metal (Pb) from the contaminated site can be seized out from the food chain through application of FeSO4.7H2O and CaSO4 in a larger area. The efficacy of the toxic metal immobilization through an application of FeSO4.7H2O and CaSO4 was studied in the laboratory and tested in the field. In batch experiments, application of FeSO4 at the rate of 5% (on soil weight basis) indicated a greater decrease in soil pH (from 7.54 to 5.55) in half an hour of shaking period as a result of which water soluble and exchangeable Pb concentrations decreased by 100%. Application of CaSO4 also decreases soil pH, as well as Pb concentration in soil solution. Pot culture experiments with two flower and leafy vegetable plants also show decrease in bioavailability of Pb in FeSO4 treated soils.

Aggregate stability is an important soil property because it dictates how strongly a soil can resist water erosion. The objectives in this study were: (1) to compare the stability of six soil aggregate size fractions, primarily to determine if aggregate stability varies with aggregate size, and (2) to determine with which aggregate size fraction the stability of most soils would be different from one another. Eight soils classified as Ultisols and Oxisols and from varying land uses, of different textures and overall acceptable aggregate stability were sampled and each separated into six aggregate size fractions of: 5-8, 3-5, 2-3, 1-2, 0.5-1, and 0.25-0.5 mm. Aggregate stability of whole soils and of individual aggregate size fractions were determined through wet-sieving, using nested sieves. It was shown that: (1) the kind of relationship between soil aggregate stability and aggregate size depended on both factors of soil type and individual aggregate size; (2) the stability of any two soil aggregate size fractions would become progressively less linearly related as the differences in aggregate size became more pronounced; (3) for the same soil, the stability of the large aggregate size fractions of > 0.5 mm were significantly different from that of the small aggregate size fractions of 0.25-0.5 mm; and (4) the differences in aggregate stability among whole soils were due more to the differences in the stability of the soil aggregate sizes larger than 3 mm. The study revealed that for Ultisol and Oxisol soils, it was not necessary to measure the stability of individual aggregate size fractions. Instead, the stability of a single aggregate size fraction could be used to represent the macroaggregate stability of whole soils.