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Agricultural Science and Technology - Volume:11 Issue: 2, Apr 2009

Journal of Agricultural Science and Technology
Volume:11 Issue: 2, Apr 2009

  • تاریخ انتشار: 1388/01/11
  • تعداد عناوین: 12
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  • S. S. Hosseini, J. Spriggs Page 101
    Government interventions in agricultural markets in order to stabilize commodity prices and producer incomes have had a long tradition. Intervention has been at both the state and country levels and has been for the most part in the form of commodity-based schemes. This study represents an attempt to develop an appropriate methodology for analyzing the aggre-gate effects of a particular type of policy rule. This type of policy rule is one for which the unit of observation is the individual farm unit rather than the individual unit of commodity. The methodology developed in this paper represents an initial attempt to provide the necessary mi-cro-macro modeling with supply response which is required for analyzing the aggregate effects of whole-farm income support programs. The methodology will be illustrated by an empirical application of the aggregate impacts of the whole-farm program in Saskatchewan, Canada.
  • A. Golizadeh, K. Kamali, Y. Fathipour, H. Abbasipour Page 115
    The development, survival, and reproduction of diamondback moth (DBM), Plutella xylostella (L.), were studied in laboratory at 25±1°C, 65±5% RH and a 14L: 10D hours photoperiodism on five host plants of: cauliflower (Brassica oleracea L. var. botrytis), two varieties of cabbage (B. oleracea L. var. capitata) namely ‘Globe Master’ and ‘Scarlet Ohara’, kohlrabi (B. oleracea L. var. gongylodes), and canola (B. napus L.). DBM larvae successfully survived on all host plants, although survival rate was lowest on canola (70.56%). The developmental time of immature stages ranged from 13.76±0.15 d on kohlrabi to 15.06±0.22 d on canola. The reproduction period and adult longevity were longest on cauliflower and common cabbage cultivar ‘Globe Master’ without any supplemental food while the highest fecundity of P. xylostella being also observed on these two host plants. The highest and lowest net reproductive rates were detected on cabbage cultivars, ‘Globe Master’ and ''Scarlet Ohara'', respectively. Mean generation time was the longest on cabbage cultivar ‘Globe Master’. The respective descending order of intrinsic rates of population increase was on cauliflower, cabbage cultivar ‘Globe Master’, kohlrabi, cabbage cultivar ‘Scarlet Ohara’ and canola. Cauliflower and cabbage cultivar ‘Globe Master’ were recognized as the most suitable host plants for DBM.
  • M. R. Bakhtiari, M. Loghavi Page 125
    In this study an innovatively designed tractor-mounted, ground-wheel driven, triple unit, row crop precision planter capable of planting three rows of garlic (Allium sativum L.) cloves on each raised bed was designed, fabricated and tested. The major components of this planter include; chassis and transport wheels, lister-bedder unit, seed hopper, seed metering drum, sweeper, knocker, seed tube, furrow openers and seed coverers. The metering drums and sweepers are driven by two ground wheels through a chain drive system. Laboratory evaluation of the planter components, especially the seed metering mechanism revealed a satisfactory performance of the planter components, except a few modifications which were needed before conducting field tests. The performance parameters measured/calculated during the field tests included: seeding mass rate, seeding depth, seed spacing, miss index, multiple index and seed damage. The results showed that the new machine is capable of planting 220,000 plants ha-1 at the seeding depth and spacing of 12.3 and 22.7 cm, respectively. Also, miss index, multiple index and seed damage were measured as 12.23, 2.43 and 1.41 percent, respectively.
  • Sh. Rafiee, M. Kashaninejad, A. R. Keyhani, A. Jafari Page 137
    Drying is an important operational step in pistachio processing. There is a decrease in moisture content of pistachio nuts from 56-57% (d.b.) to 5-6% during the drying process. Drying conditions affect the quality of dried pistachio nuts, therefore, this calls for an accurate description of the drying trend in the process. In this study finite element formulation and solution of diffusive moisture transfer equation was presented to improve the drying simulation of nut as an axisymmetric body. The Fick’s diffusive model was solved with effective moisture diffusivity of 5.24×10-10 m2 s-1 for 55°C and 7.01×10-10 m2 s-1 for 70°C. For experimentation, thin layers of pistachio nut, ‘Ohadi’ variety, were dried at high drying air temperatures (55 and 70°C), three replications for each treatment, along with drying air velocity and relative humidity of 0.5 m s-1 and 20%, respectively. Good agreement was observed when the output of model was compared with the experimental data. Mean Relative Deviation (MRD) calculated for the model and the experimental data for the air temperatures 55 and 70°C, were found to be 6.2% and 8.1%, respectively.
  • S. R. Hassan, Beygi, B. Ghobadian, R. Amiri Chayjan, M. H. Kianmehr Page 147
    The use of neural networks methodology is not as common in the investigation and prediction noise as statistical analysis. The application of artificial neural networks for prediction of power tiller noise is set out in the present paper. The sound pressure signals for noise analysis were obtained in a field experiment using a 13-hp power tiller. During measurement and recording of the sound pressure signals of the power tiller, the engine speeds and gear ratios were varied to cover the most normal range of the power tiller operation in transportation conditions for the asphalt, dirt rural roads, and grassland. Signals recorded in the time domain were converted to the frequency domain with the help of a specially developed Fast Fourier Transform (FFT) program. The narrow band signals were further processed to obtain overall sound pressure levels in A-weighting. Altogether, 48 patterns were generated for training and evaluation of artificial neural networks. Artificial neural networks were designed based on three neurons in the input layer and one neuron in the output layer. The results showed that multi layer perceptron networks with a training algorithm of back propagation were best for accurate prediction of power tiller overall noise. The minimum RMSE and R2 for the four-layer perceptron network with a sigmoid activation function, Extended Delta-Bar-Delta (Ext. DBD) learning rule with three neurons in the first hidden layer and two neurons in the second hidden layer, were 0.0198 and 0.992, respectively.
  • M. Barzegar, B. Jalali Page 161
    This paper presents a total of 11 known crustacean parasite species from 51 host species belonging to 7 families, with 17 genera reported from cultured and wild fishes in three faunal regions of Iran. Among them, one belonging to Branchiura order, namely Argulus foliaceus, was found on Capoeta capoeta in Makoo Reservoir as well as on Cyprinus carpio, Chalcalburnus sp., Hypophthalmichthys molitrix and Mastacembelus mastacembelus in Zarivar Lake. The other 10 species belonging to Copepoda order include 1) Ergasilus sieboldi, found on the gills of 2) Barbus sharpeyi, B. luteus, Aspius vorax and Cyprinus carpio; 3) E. peregrinus on Ctenopharyngodon idella and Leuciscus cephalus in Khandaqloo Reservoir; 4) Lamproglena compacta and 5) L. polchella on the gills of infected fish species inhabiting Tigris, Caspian and Oriental Regions of Iran. 6) Tracheliastes longicollis on the fins of Capoeta capoeta and Leuciscus cephalus; 7) T. polycolpus on the fins of Capoeta trutta, C. capoeta and Leuciscus cephalus in water bodies situated in Azerbaijan Province (Caspian Region) and Kurdistan Province (Tigris Region), 8) Achtheres percarum on the skin and fins of Sander lucioperca and Perca fluviatilis in Anzali Lagoon and Sefid-rud River in North of Iran (Caspian Region); 9) Pseudotracheliastes stellatus on the skin of acipenserids in Caspian Sea and finally 10) the most economically significant parasite, Lernaea cyprinacea, which is commonly found on cultured cyprinids in ponds and natural water bodies. Furthermore, several unknown crustacean species belong to both orders identified to genus level, which need further study for a detailed description. Geographical distribution as well as host ranges of the mentioned parasites are presented and discussed.
  • R. Farhoosh, M. R. Moosavi Page 173
    Frying oils showed an increase in Peroxide Value (PV) at the initial stages of the frying process followed by a decrease, and there was no correlation between PV and Total Polar Compounds (TPC) in the same set of frying oils. All the frying oils had PVs lower than 4.42 meq O2 kg-1 oil during the frying process and, consequently, none of them was above the limit of 10 meq O2 kg-1 oil for edible oils. The variations of Conjugated Diene Value (CDV) presented a pattern different from that of PV. CDV had a good linear relationship with TPC during initial stages of the frying process and then reached a plateau (R2= 0.9838). The plateau occurred beyond the TPC of 24-27% for the frying oils, and there was an obvious increasing trend before the range mentioned. The contents found for conjugated dienes of the frying oils during the frying process ranged from 5 to 42 mmol L-1. Assuming that the limit of acceptance for TPC is 24%, this roughly corresponded to 29 mmol L-1 for CDV.
  • Dr M. Alizadeh *, H. Mohammadi, Dr M. Rezazad Bari, Dr A. Khosrowshahi, Dr H. Tadjik Page 181

    A model capable of predicting the minimum content of Aflatoxin M1 (AFM1) in Iranian while brine cheese has been developed using a chemometric approach to determine the optimum processing conditions. Renneting temperature, cut size, stirring time, press time, curd size and saturated brine pH were all regarded as process variables. Three-dimensional response surface and contour plots were drawn. The minimum content of AFM1 (116.9 ng kg -1 dry matter) was predicted when the processing variables were: Renneting temperature= 40°C, Cut size= 0.5 cm, Stirring time= 10 minutes, Press time= 20 minutes, Curd size= 64 cm3, Saturated brine pH= 4.6. These values predicted for optimum process conditions were in good agreement with experimental data.

  • A. Nafees, A. R. Khan Page 191
    The work described here is unique since the low seeded (0-6 seeds per fruit) Kinnow (Citrus reticulata) germplasm was grown in dense plantation (P P: 1foot and L L: 2 feet) in the NIAB (Nuclear Institute for Agriculture and Biology, Faisalabad, Pakistan) field. Growth and development patterns of the fruits were studied. The low seeded germplasm contains 3,500 plants developed through natural and induced variability in Kinnow mandarin. The area is surrounded by other cross compatible Citrus varieties. The germplasm flower was hermaphrodite, off-white, the color of the anthers yellow, and the number of petals was five and all other flower characteristics were variable. In 2005 the fruiting was in 596 plants and the maximum fruit range was 21-40 in 99 plants followed by 41 to 75 in 98 plants. In 2006, 322 plants bore fruit and 1-5 fruits per plant were found in 93 plants followed by 6-10 fruits per plant in 61 plants. In 2007, 551 plants had first time bearing and the maximum fruit range per plant was 11-20 in 116 plants followed by 21-30 in 99 plants. It was found that the Kinnow fruit gains maximum weight during August-October whilst the volume of the fruit increases during August-November. Initially the height and diameter were identical in May giving the fruit a round shape and then the gradual increase in height slowed down, resulting in an oblate to subglobose shape of the fruit. In mid-January the average fruit weight was 192 grams and the average peel weight was 45 grams. Peel thickness was more at stalk end as compared to stylar end. All low seeded fruits had their navel at the stylar opening point. The maximum number of fruits had 11 segments but the segment range was 9-14 per fruit. In mid-January the juice pH, juice acidity and TSS had variable values in plants indicating variation in the fruit physiological maturity time within the germplasm. The growth of fruits was similar to that reported in low density orchards
  • J. M. V. Samani, P. Fathi Page 199
    Mathematical simulation of flow toward drains is an important and indispensable stage in drainage design and management. Many related models have been developed, but most of them simulate the saturated flow toward drains without a due consideration of the unsaturated zone. In this study, the two dimensional differential equation governing saturated and unsaturated flow in porous media is numerically solved and water table variations between drains predicted. By introducing and linking a proper optimization model to the numerical one, saturated and unsaturated soil hydrodynamic parameters were estimated within the inverse problem technique context. Data for calibration and verification were provided through a conduction of laboratory experimentation. Other laboratory data were also employed for the proposed model evaluation. The results indicated that in addition to a prediction of the water table variations between drains, the inverse problem model can be employed to estimate the unsaturated soil hydrodynamic parameters with a high degree of precision.
  • T. Anand, A. Chandrasekaran, S. Kuttalam, T. Raguchander, R. Samiyappan Page 211
    The compatibility studies of Pseudomonas fluorescens (Pf1) with azoxystrobin at different concentrations viz., 100, 150, 200, 250 and 300 ppm revealed that it was compatible with all the concentrations of azoxystrobin tested and the growth of the bacterium was unaffected even at the maximum concentration of 300 ppm. The field experiment revealed a foliar application of Pf1 (2.5 kg ha-1) and azoxystrobin (250 ml ha-1) combined, reduced downy mildew as well as powdery mildew disease severities more than azoxystrobin (250 and 500 ml ha-1) alone. An application of Pf1+azoxystrobin treatment recorded only 2.22 and 1.00 Percent Disease Index (PDI) of downy mildew and 1.85 and 0.50 PDI of powdery mildew during the first and second seasons, respectively. The treatment also recorded a maximum fruit yield of 14.30 and 15.65 tonnes ha-1 for the first and second seasons, respectively. Application of Pf1 along with azoxystrobin significantly increased the survival of Pf1 in the phylloplane of cucumber crop. In addition, there was multifold increase in peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, ß-1, 3 glucanase, chitinase and phenolics in plants treated with Pf1+azoxystrobin.
  • J. Ryan, M. Abdel Monem, A. Amri Page 227
    The West Asia-North Africa region, which is characterized by a typical Mediterranean climate, is the center of origin of cereals, notably wheat (Triticum spp.) and barley (Hordeum spp). However, cereal production, which is primarily rainfed, is mainly constrained by drought due to the low rainfall accompanied by high temperatures. Cereals have been traditionally grown following a fallow period in order to achieve acceptable yields on stored soil moisture, but they are increasingly grown either continuously or in rotation with legumes, either food or forage. Barley is grown throughout the Mediterranean region, generally in the drier zones and often on shallow soils and with application of minimum or no fertilizers. The medium-rainfall zone of central Morocco (200-500 mm yr-1) is typical of the region as a whole. In order to provide a rational basis for barley fertilization, especially as regards nitrogen (N), a field trial was established near Settat, involving five barley varieties (ACSAD-60, Tessaout, Asni, Arig-8, and ACSAD-176), along with four N application at four levels (0, 40, 80, and 120 kg N ha-1), grown on a shallow soil (Petrocalcic Palexeroll) for two growing seasons that varied in terms of total rainfall (Year 1, 261mm and Year 2, 302 mm) as well as within-season distribution. There were considerable differences between crop years, with significantly higher yields in the second growing season when rainfall was heavy at the critical tillering and stem-elongation growth stages. Nitrogen consistently increased dry matter and grain yields in either year, generally being significant up to 80 kg ha-1. There were significant differences observed among varieties, as well as interactions of varieties with years. The six-row variety Arig-8 was consistently the best while the two-row Asni, the lowest yielding variety. Where an economic analysis was done on yield data (Year 1), N fertilization up to at least 80 kg ha-1 was considered as profitable. Crop N uptake varied with varieties and increased with increasing fertilizer. N Recovery was variable and generally less than 50%. In contrast to many other fertilizer trials with barley in the region, this trial from central Morocco showed highly significant yield increases in response to applied N for barley varieties, most of which performed similarly. Therefore, N fertilization of barley in Morocco’s semi-arid cereal-producing zone on shallow soils, where root growth and moisture-holding capacity are limited, should be promoted.