Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Six-cold-month Precipitation over Southwestern and Central Iran and its Relation to E1 Ninio Southern Oscillation
1
12
FA
M. J. Nazemosadat
A. R. Ghasemi
The present study evaluates the influence of the El Ninio Southern Oscillation (ENSO) phenomenon on the cold season precipitation over Isfahan, Fars, Khuzestan, Chaharmahal-Bakhtyari, Bushehr and Kohgiluyeh-Boyerahmad provinces.
The results indicate that the occurrence of La Nina events caused a 20% to 50% reduction in precipitation over Bushehr, Chaharmahal-Bakhtyari and southern Fars. The cold event did not change the total precipitation over the other parts of the region. In contrast to La Nina episodes, the occurrence of El Ninio events caused a 20% to 70% increase in rainfall in most of the study area. While the most highly wet conditions are related to the El Ninio events, the occurrence probability of the severe droughts has found to be low during such events. In association with La Nina events, the occurrence probability of severe drought was found to be low. Only in Khuzestan and southern parts of the Fars Provinces, this probability has increased to about 0.5.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Using Slot to Control and Reduce Local Scour at Round-nosed Rectangular Bridge Piers
13
28
FA
M. Heidarpour
H. Afzalimehr
M. Naderi Bani
The use of slot through a pier is a new method proposed to control local scour at bridge piers. In this study, control of local scour at bridge pier is studied using 20 pier models under clear water conditions. The models consist of one circular pier without slot, three round-nosed piers without slot, and 16 piers with slot. Two slot lengths were chosen (yl=b and yl=2b, where y1 is the length of slot and b is the width (diameter) of the pier). Furthermore, they were located at two positions (near the bed and near the water surface).
The results showed that for a circular pier, the slots with the lengths of b and 2b, located near the water surface, had no influence on the equilibrium scour depth. It was also found that for all piers, maximum reduction in scour depth occurred for piers with a slot length yl=2b and close to the bed. Also, the efficacy of a slot for scour protection in the case of a round-nosed pier was more than a circular pier (with a diameter equal to the width of a round-nosed pier).
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Estimating the Efficiency of Apple Producers in Khorasan Province
29
39
FA
S. Dehghanian
M. Ghorbani
In this study, efficiency of apple producers in Khorasan Province was determined by a cross sectional data of 212 apple producers.
Mean technical, allocative, and economic efficiencies were estimated to be around 31, 28, and 9 percent, respectively. A high potential was also detected for increasing these efficiencies. Apple producers’ age and education had positive effects and risk aversion had a negative effect on technical efficiency. Waste reduction, optimal use of inputs, introduction of technical-extension services, and apple insurance are suggested to increase efficiencies.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
In vitro Propagation of Sugarcane (Saccharum officinarum)
41
50
FA
A. A. Ramin
Experiments were carried out in order to micropropagate sugarcane cultivars through shoot tip and auxilliary bud culture. Rinsing of four cultivars of sugarcane, namely CP-48-103, CP-57-614, CP-69-1062, and NCO-310 in 75% alcohol for 60 seconds and their subsequent disinfection with sodium and calcium hypochloride (1.5% active material) for 15 minutes decreased a significant amount of infection of explants in the medium. The use of the Murashing and Skoog (MS) solid and liquid medium with 1 mg/l Indole Butyric Acid (IBA), 1 mg/l Kinetin, 100 mg/l mio-inositol, 1 mg/l Thiamin HCl, and 2% sucrose had significant superiority (P<0.05) to 1/2 MS solid medium. Also, to increase the multiplication in a sterile medium (In vitro), two kinds of solid and liquid MS medium, with a hormone combination of 1 mg/l IBA, 2 mg/l Kinetin and 1 mg/l 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H-purine (BAP) were applied which yielded the highest amount of proliferation. The plants formed roots in Schenk and Hildebrandt (SH) medium with a hormone combination of 5 mg/l IBA and 1 mg/l Kinetin. When activate charcoal was used in the medium, a higher percentage of the plants became rooted and a larger number of adventitious roots were produced than in the dark-light or light treatments.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Evidences of Climate Change Recorded in Quaternary Paleosols from Isfahan and Emam-Gheis (Chaharmahal & Bakhtiary)
51
69
FA
S. Ayoobi
A. Jalalian
M. Karimian Eghbal
Investigation of paleosols plays a great role in paleoecological and paleoclimatological studies. They are also important in soil survey and planning, as they exhibit characteristics different from younger soils. Paleosols are those soils which formed under conditions different from present ones, and are either buried within sedimentary sequences or those which lie on persisting surfaces. Although such soils are widespread in central Iran and Zagros Zone, they have not been studied adequately. Paleosols are identified by different parameters such as morphological, physical, chemical, mineralogical, and micromorphological characteristics. In this study, morphological, physical, and chemical properties of three paleosols from Isfahan and Chaharmahal & Bakhtiary provinces were investigated. The profiles were on different landforms including alluvial fan, dissected old plain, and old lagoonal deposits. Soil profile in Segzi site, on old lagoonal deposits, had a very dark and thick layer at a depth of 45-60 cm containing some macrofossil shells. This shows that this area was covered by brackish water during the early Holocene. In Sepahanshahr profile, presence of strong clay coating and high concentrations of CaCO3 indicates a wetter environment in the past than the present conditions with a precipitation of only 100 mm. In Emam-Gheis profile, a buried paleosol was identified with strong clay coating and free CaCO3 horizons that shows more humid conditions. Evidences obtained from the three paleosols studied indicate that effective moisture in central Iran and Zagros regions during Late Pleistocene had been higher than its present levels.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Genesis and Micromorphology of Saline and Gypsiferous Aridisols on Different Geomorphic Surfaces in Nough Area, Rafsanjan
71
93
FA
M. H. Farpour
M. K. Eghbal
H. Khademi
Gypsiferous Aridisols are of great importance and extent in arid and semi-arid environments. There is a close relationship between soil genesis and landscape positions. This study aimed to determine the genesis and classification of gypsiferous soils and to investigate the relationship between micro-and macro-morphology of gypsum crystals and geomorphic positions in Rafsanjan area. The study area is located in Nough, 30 km north of Rafsanjan with a mean annual precipitation of 60 mm. Seven representative pedons were selected on different geomorphic positions. Physico-chemical, micromorphological, XRD, and SEM observations were performed on soil samples. Rock pediment geomorphic surfaces, that are in fact peripheries of old closed water bodies in central Iran, are the source of gypsum in the area. Large gypsum pendants and microforms of lenticular, vermiform, platy, and interlocked gypsum plates are found in rock pediment. The amount of gypsum and the size of pendants decrease moving down the slope. Lenticular and interlocked gypsum plates are found in a transition of pediment and playa. Puffy ground is observed on the saline surface of playa. Lenticular and vermiform gypsum crystals increase down the slope, but alabastrine gypsum is the most dominant form of gypsum in the playa surface. Large amounts of soft gypsum nodules are found on the rock pediment surface (western slope). In addition, spindle form of gypsum and palycrete bundles are observed in this position. Wind action played a significant role in the genesis and development of soil in rock pediment. A close relationship was found between morphology of gypsum crystals and geomorphic positions.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Effects of Sewage Sludge and Soil pH on Micronutrient and Heavy Metal Availability
95
106
FA
S. Vaseghi
M. Afyuni
H. Shariatmadari
M. Mobli
Excessive application of sewage sludge leads to the accumulation of potentially toxic elements in soils. The objective of this greenhouse study was to examine the DTPA–extractability of Fe, Zn, Cu, Mn, Pb, Cd, Ni, and Co in relation to soil pH and to investigate the concentrations of these metals in corn (Zea mayz). The study was conducted using a factorial experiment in a completely randomized design with three replications. Sewage sludge was applied at 0, 50, 100, and 200 t/ha on four soils [Langaroud (pH= 4.8), Lahijan (pH= 5.7), Rasht (pH= 6.8), and Isfahan (pH= 7.9)]. Application of sewage sludge significantly increased DTPA-extractable Fe, Zn, Cu, Pb, Cd, and Ni in all soils. The increasing effect was in accordance with sludge level. Langaroud soil had the highest and Isfahan soil the lowest levels of DTPA-extractable metals. Application of sewage sludge increased plant growth and metals in the foliage of corn plants. The metal concentration in corn tissues also increased with decreasing soil pH. Overall, the application of sewage sludge as an organic material, particularly in acid soils, may increase availability of heavy metals, which may, in turn, result in soil pollution. Therefore, addition of sewage sludge to soils should be managed on the basis of the changes in soil heavy metal concentration.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Estimation of Cation Exchange Capacity from Some Soil Physical and Chemical Properties
107
118
FA
F. Nourbakhsh
A. Jalalian
H. Shariatmadari
Cation exchange capacity (CEC) is one of the most important chemical characteristics which influences soil quality from different aspects. At the same time, CEC is an input parameter of many computer models being applied in soil science and agriculture. Methods of CEC determination are always time-consuming and laborious. Therefore, developing a model for CEC estimation from other soil properties is essential. The objective of this study was to understand the associations between CEC (as a dependent variable) and sand, silt, clay, organic matter and pH (as independent variables). In this study 464 soil samples from A, B, and C horizons of different soils were used. Results revealed that CEC is negatively correlated with sand (r=-0.389***) and is positively correlated with organic matter (r=0.772***), clay (r= 0.391***) and silt (r= 0.233***). No significant correlation was observed between CEC and pH. Stepwise regression analysis showed that both organic matter and clay enter the model and that coefficients of determination (r2) for the multiple models are higher than those of simple linear correlations. Other parameters could not increase the r2 considerably. Correlation analysis on data from A, B, and C horizons revealed that the CEC of organic matter in different horizons are not the same. Separation of Aridisols could not increase the r2 of the model and the accuracy of the estimations. Correlation studies in acid soils showed that the contribution of organic matter in CEC is much higher than that of clays.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Determination of Phosphorus Fractions in Some Calcareous Soils in Fars Province and their Relationships with Soil Physico-chemical Properties
119
128
FA
Sh. Mahmood-Soltani
A. Samadi
Knowledge of forms of phosphorus (P) is important in the evaluation of soil P status and also in understanding soil genesis and fertility. Amounts and distribution of P in different organic and inorganic fractions were examined in 39 soil samples of Fars province. Soils were sequentially extracted to determine organic P and inorganic P fractions.
Total P with an average of 597 mg/kg soil was lower in the light soils (482 mg/kg) as compared with the heavy soils (690 mg/kg). Organic P constituted considerable portions of TP (27%). Calcium phosphates with an average of 424 mg/kg soil and being comprised of 71% inorganic P was the dominant form of soil phosphorus. Simple regression analysis indicated that there were significant positive relationships between organic P, Ca phosphates and Al-Fe phosphate values with CEC and clay content. Stepwise multiple regression analysis showed that a combination of soil properties such as clay content and equivalent calcium carbonate (CCE) increased correlation coefficients (R). Alghough multiple regression model was significant (at P<0.05), the relative contribution of each soil property in Al-Fe-P fraction was not considerable.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Effects of Early Spring and Summer Planting on Agronomic Traits in Edible-oil Genotypes of Flax in Isfahan
129
143
FA
G. Saeidi
In order to investigate agronomic traits and yield potential of edible-oil flax (Linum usitatissimum L.) as a second crop in Isfahan region, different genotypes were evaluated in separate experiments in early spring (April, 7) and summer (July, 16) planting dates, using a Randomized Complete Block Design with three replications. The experiments were conducted in agricultural research farm, Isfahan University of Technology in the year 2000. The results showed that summer planting considerably and significantly reduced number of seedlings per unit area, days to 50% flowering, and seed yield. However, maturity of the plants was delayed because of summer planting. According to overall average obtained for genotypes, seed yield was 1472 and 213 kg/ha in the first and second planting dates, respectively. There was a significant difference between genotypes for number of seedlings per unit area, days to 50% flowering and maturity in both planting dates. However, genotypes were significantly different for seed yield in the first planting date. Summer planting also non-significantly reduced yield/plant, capsules/plant and 100-seed weight and increased seeds/capsule. The differences between genotypes for these traits in both planting dates and for seeds/capsule in the first planting date were significant. The significant interaction between genotypes and planting dates on seeds/capsule and 100-seed weight was because of increasing or decreasing levels of these traits in some genotypes when planting date was delayed. The results of regression analysis, correlation coefficients and path analysis showed that in both planting dates, capsules/plant followed by seeds/capsule and 100-seed weight were the major components of yield/plant. Capsules/plant had the most (approximately 80%) contribution in variation of yield/plant in both planting dates. The number of plants per unit area affected yield/plant via indirect and negative effect of capsules/plant.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Effects of Dietary Cumulative Levels of Cotton-seed Meal on the Performance of Broiler Chickens at Different Ages
145
151
FA
A. A. Gheisari
O. Saraeian
M. Toghiani
D. Asadian
This experiment was conducted to study the effects of using cotton-seed meal on the performance and carcass yield of broiler chickens at different ages. The experiment was performed in a completely randomized design with four treatments and five replicates for each treatment. The experimental treatments included the levels of 0, 3.5, 7, and 10.5% of cotton-seed meal in diets fed to chickens at 7-21 days of age. Except for the control group, these levels for grower (21-42 d of age) was increased to 7, 14, and 21% and for finisher (42-56 d of age) to 14, 21, and 21%, respectively. For the purposes of this study, 260 day-old chicks were reared in litter until 7 days of age. On day 7, chicks were divided into 20 pens with 13 chicks in each pen. NRC (1994) recommendation was used in balancing experimental diets. The chickens were weighed weekly throughout the experimental period (7-56 d). The main observations were body gain, feed intake and feed conversion ratio. Physical analysis of carcass was done at the end of the experimental period and percentages of carcass, abdominal fat, liver, pancreas and digestive tract to live body weight were calculated.
The use of cotton-seed meal and the increase of the levels through different ages had no significant effects on body weight, daily gain, feed intake, feed conversion ratio, and carcass components. Increasing the level of cotton-seed meal in the diet at 7-21 days of age had significant effects on feed intake (P<0.05) and increased it. The results of this experiment indicate that we can use cotton-seed meal at levels of 7,14, and 21% of diets, respectively, in starter, grower and finisher stages without having any adverse effects on the performance and carcass yield of broiler chickens.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Effect of Energy Level and Time of Feed Replacement from Starter to Finisher Diets of Broilers Weighted Less than Two kg
153
161
FA
S. Maghsoud Lou
A. Golian
F. Eftekhar Shahroudi
M. Nassiri Mahallati
H. Kermanshahi
An experiment with a 33 factorial arrangement in a completely randomized design with 450 day-old broilers was conducted to study the effect of energy level and time of change from starter to finisher diets on performance and economic aspects of broilers. Broiler chickens were fed at three levels of dietary energy (2800, 3000, and 3200 KcalME/Kg) from 1-42 days of age. Starter and finisher diets were changed at 16, 21, and 26 days of age and then finisher diets were fed up to 42 days of age.
The effect of diet energy and changing time from starter to finisher diets on body weight and feed conversion at 26 days of age were significant (P<0.01). By increasing energy level and changing time from starter to finisher diets, at this age, body weight increased and feed conversion ratio decreased. Energy conversion decreased by decreasing the levels of energy content of diet and increasing time of change from starter to finisher diets (P<0.01). At 42 days of age, the effects of diet energy and changing time from starter to finisher diets did not show any significant effects on feed and energy conversion in contrast, body weight at this age increased significantly as a result of increasing time of change from starter to finisher diets (P<0.05). From 1-42 days of age, the interaction between diet energy and changing time from starter to finisher diets on feed and energy conversion was significant (P<0.05). The results from this study suggest that increasing diet energy and changing time from starter to finisher diets for producing broilers with less than 2 kg will improve their general performance.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Effect of Different Levels of Dietary Calcium and Available Phosphorus on the Performance of Isfahan Native Breeder Hens
163
172
FA
M. Pakdel
J. Pourreza
S. Ansari
In a 3×3 factorial experiment, 90 72-week-old native breeder hens of Isfahan were kept in cages (one bird/cage). The effect of three levels of dietary calcium (3.27, 2.62, and 1.96%) and three levels of dietary available phosphorus (0.25, 0.20, and 0.15%) on egg production and egg shell traits were investigated. Each treatment contained five replicates of two birds (10 birds per treatment). The experimental diets were fed 8 weeks (from 72 to 80 weeks of age).
Dietary calcium and available phosphorus levels had no significant effects on feed consumption, shell thickness and shell breaking strength. Decreasing dietary calcium or available phosphorus levels (1.96% calcium and 0.15% available phosphorus) caused a significant (P<0.05) linear increase in egg production, egg weight and improvement in feed conversion. The results from this study showed that high egg production, maximum calcium retention in the shell and optimum feed conversion were observed in native breeder hens during late growing period with 1.96% calcium and 0.15% available phosphorus.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Some Physico-chemical Characteristics of Tea-seed Oil
173
183
FA
D. Ataii
M. A. Sahari
M. Hamedi
In this study, some physico-chemical characteristics of Iranian tea-seed oil (Lahijan variety) were compared with those of the oils from sunflower seed (Fars variety) and olive (Gilezeytoon variety) in terms of fatty acid contents, peroxide value, iodine value, saponification value, and oil shelf-life. Also the shelf-life of sunflower and olive oils containing 5% and 10% tea-seed oil were compared against control sample shelf-life. Tea-seed oil was found to be suitable and stable in nutritional properties. At a temeprature of 63oC, tea-seed and olive oils were found to have identical shelf-life values, which was higher than that of sunflower oil. Furthermore, the shelf-life of sunflower oil increased when mixed with tea-seed oil.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Study of Canned Sausage Production and its Physicochemical Changes During Processing and Storage
185
197
FA
S. Cheraghi Dehdezi
Sh. Dokhani
M. Shahedi
Canning of sausage is one of the methods to extend the shelf life of sausage with lower percentage of additives such as nitrite. This method reduces transport and storgae costs, too. The present stduy was carried out in two stages. The first stage consists of preparing sausages with four different formulations in Isfahan Senobar Factory and producing canned sausage. In the second stage, physicochemical and organoleptic experiments were carried out. Canned (214409) and bottled (No. 10-67) sausages were produced and sterilized in autoclave (absolute pressure=2 atm) to give F value = 4 min. Cans and jars were filled with skinless sausage of 22 calibre and brine (2% and 25oC) at a sausage/brine ratio of 1:1. Chemical composition such as moisture, fat and protein were measured according to the standard and AOAC methods. Physical experimets including measurement of texture shear strength were performed in sausage and canned sausage over the 3-month storage period. Factorial experiments in completely randomized design was used to investigate and analyze statistical data in this study. The Duncan’s multiple range test was used to compare data averages. Moisture content increased and sausgae texture shear strength decreased in all formulations as a result of sterilization. Moisture content increased in four canned sausage formulations while protein and fat decreased (by the end of the second month of storage). Also, sausage texture shear strength was observed at this time to decrease. In organoleptic evaluations, four canned sausage formulations were not significantly different in flavor, texture, and color (P<0.01).
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Interactions Between Root-lesion Nematode (Pratylenchus vulnus) and Two Species of Fusarium on Growth and Development of Maple Seedlings in Behshahr Area of Mazandaran Province, Iran
199
209
FA
A. Kheiri
A. Borhani
S. M. Okhovvat
H. Eshtiaghi
In an etiological study on stunted, nursery grown maple seedlings, a species of root-lesion nematode (Pratylenchus vulnus) and two species of fusarium (Fusarium oxysporum and F. solani) were isolated from the infected roots. Interactions between the nematode and the two fungi in a complete randomized design with six treatments and four replications were carried out under greenhouse conditions. Nematodes were surface sterilized and reared on sterilized carrot discs. Then the maple seedlings at two-leaf stage were inoculated with a population density of 40 nematodes/100 gr soil in pots. The results indicated singnificant differences between the treatments. Seven months after inoculation, the treatments with nematode alone showed a high mortality rate of about 75% along with a severe increase in population up to about 11.2 and 1266 nematodes/gr of soil and roots, respectively. In treatments with nematode and each of the two-fungus species, the deleterious effects of fungi on nematodes were observed through decrease of nematode population. It was also shown that F. oxysporum was more effective than F. solani in nematode control.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Transferring OF2 and VAP Genes into Sugarbeet by Agrobacterium rhizogenes to Study Nematode Resistance
211
223
FA
P. Norouzi
D. Cai
M. A. Malboobi
B. Yazdi Samadi
OF2 and VAP genes, probably involved in signal transduction of sugarbeet nematode resistance, have already been cloned in bacterial vector by AFLP molecular marker and a two-hybrid system, respectively. To examine their capability to introduce resistance in sugarbeet, the genes were transferred to plant expression vectors. For this reason, OF2 gene after isolation was inserted within T-DNA of pAM194 binary vector, downstream of CaMV35S constitutive promoter and also inserted within T-DNA of modified pBin121 binary vector, downstream of HS1pro-1 gene inducing promoter (responsible for nematode resistance). VAP gene after isolation was inserted within T-DNA of pAM194 plasmid, downstream of CaMV35S constitutive promoter. Thus, three new constructs were made in which genes of signal transduction pathway were expressed to give beet cyst nematode resistance. These plasmids were separately transferred to Agrobacterium rhizogenes, strain AR15834. In the next step, petiole explants of sugarbeet were inoculated with the bacterial cells. Transformation-derived hairy roots were analyzed by GUS staining and/or PCR and were then inoculated with nematode larvae. Primary results showed partial resistance against nematode larvae in some hairy roots. As a result, this resistance can be related to OF2 and VAP genes effect.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Comparison of the Effects of Three Insecticides and Release of Green Lacewing, Chrysoperla carnea (Steph.), against Nymphal Stages of Greenhouse Whitefly, Trialeurodes vaporariorum West
225
234
FA
Z. Ahmadzadeh
B. Hatami
Greenhouse whitefly, Trialeurodes vaporariorum West. is one of the most important pests of the field crops and ornamental plants in greenhouses. Pest control is based on using chemical insecticides and biological control agents. In this study, the efficiency of the green lacewing, Chrysoperla carnea ( Steph.) with release ratios of 1:1, 1:5, 1:10, 1:15, and 1:20 (predator:prey) using eggs in chrysobag and the effect of three insecticides including Confidor (35% Sc), Permethrin (25% Ec) and Dimilin (25% Wp) at concentrations of 0.3 ml/l, 0.3 ml/l and 0.15 g/l in water, respectively, were investigated. In one experiment, the eggs of the green lacewing were released on tomato plants that were infested with 150 different nymphal instars of the pest. Control treatment included chrysobag whithout any egg. After 11 days, nymphal mortality was calculated. In insecticidal experiments, in control treatment, only water was sprayed. Both experiments were conducted in a randomized complete block design with four replications in a greenhouse with 25±5 °C, 50-60% RH and 14:10 LD period light conditions. The means of data were compared using Duncan Multiple Range Test. The results showed that the maximum nymphal mortality of 52.42% was due to the release ratio of 1:1 (predator:prey) however, this was not sufficient and did not control the pest population. The results of the chemical control also revealed that one application of Confidor caused the highest mortality about 88% that was more effective in reducing pest population compared with the release of predator eggs. Neither method had absolute control. In general, results indicated that to be more effective the two methods need to be applied more than once, and they must be combined into one or with other control methods.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Evaluating a Machine Vision System by Measuring Some Physical Characteristics of Pistachio Nuts
235
243
FA
A. Ghazanfari-Moghaddam
In order to increase the role of machine vision in agricultural research in Iran, especially for measuring physical attributes of seeds, a machine vision system was developed using a computer, a capture card, a video camera and a light box. All equipment was purchased from domestic markets. Computer programs were developed for hardware setup and for image processing applications. The programs perfomed tasks such as image acquisition and display, color conversion, image segmentation, object counting, and measurement of some physical attributes of the objects by analysing their images. The system was used to measure some physical attributes of pistachio nuts. The machine vision measurements were statistically compared with the measurements obtained by the conventional manual methods.
The results indicated that there was generally no significant difference between the two methods. However, the time consumed by the machine vision method was far less than the time taken by manual methods. The experimental results also showed that there were many sources of error and limiting factors in using machine vision for measuring physical attributes of seeds.
Isfahan University of Technology - Journal of Crop Production and Processing
2251-8517
7
3
2003
10
1
Comparison of Dry and Semi-dry Fertilization in Rainbow Trout (Oncorhynchus mykiss) with Emphasis on Larval Survival Rate
245
254
FA
O. Farhadian
M. R. Ahmadi
Oval fertilization and survival rates at incubation stage form the most important issues of concern in rainbow trout hatcheries in Iran. Hatchery managers tend to use the best method in fertilizing the ova in order to obtain the highest survival rates. A survey of common fertilization methods may help to determine the best one. In this study, the ova from two groups of 3-5 year-old and younger than 3 years broodstocks were fertilized employing dry and semi-dry methods in normal water and dry and semi-dry methods in fertilization solution. The experiment was carried out in a completely randomized design as a 422 factorial arrangement and with two replicates.
The analysis of final results indicates that the highest survival rates of eggs and larvae were obtained in semi-dry fertilization. These rates significantly increased when fertilization solution was used (P<0.05). Moreover, the survival rates of eggs and larvae of 3-5 year-old broodstocks were higher than those of younger than 3 years. On the other hand, type and methods of fertilization showed no significant differences with degree-day (sum of heat) at developmental stage but the age of broodstocks made significant differences with degree-day from fertilization to the first hatching stage (P<0.05).