Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
A Case Study Investigating Farmers’ View Regarding Soil
Analysis: Estimates Using a Logit Model
467
476
EN
O.
Karkacıer
Department of Management, Faculty of Agriculture, University of Gaziosmanpasa, Tokat, Turkey.
Z.
Gokalp Goktolga
Department of Management, Faculty of Economics and Administrative Science, Cumhuriyet University,
Sivas, Turkey.
The objective of this study was to assess the level of knowledge of the Turkish farmers
with regard to fertilizer usage. Farmers in the Kazova district of Turkey's Tokat Province
were interviewed regarding their soil maintenance practices. The interview was based on
a standardized questionnaire the answers being recorded at the time of interview. Simple
random sampling method was used to determine the sample size of the research.
According to the results, sample size was determined as 61 farmers. The fundamental
question (dependent variable) was to determine if farmers have the soil in their fields
analysed. The independent variables were: education level of farmers (EDU); whether the
farmer shares information regarding fertilization (EI); whether the farmer sows
according to the results of the soil analysis (SA); whether the farmer uses pesticides
(UPI); and the level of concern the farmer has for production rate (PQ). With the
exception of farmers' concern over production rate (PQ), all the independent variables
had a positive effect on weather or not farmers have the soil in their fields analysed. The
econometric model selected for the analysis is a binomial logit model in which the
dependent variables take only two values: either 1 or 0. Cronbach’s Alpha coefficient was
calculated as 0.7358.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Economic Optimal Allocation of Agriculture Water:
Mathematical Programming Approach
477
490
EN
A.
Keramatzadeh
Department of Agricultural Economics, Tarbiat Modares University, Tehran, Islamic Republic of Iran.
A. H.
Chizari
Department of Agricultural Economics, Tehran University, Karaj, Islamic Republic of Iran.
R.
Moore
Department of Economics and Finance, Saint Martin’S University, United States of America
Due to increasing demand for the scarce available water throughout the world it is an
extremely important matter, in water management, to make serious attempts in
determining its true economic value. This paper discusses the optimal allocation of water
to agriculture, the relatively true economic value of water as well as the cropping patterns
for the Shirvan Barzo (SB) dam area in North Khorasan Province of Iran. The analysis is
based on linear programming (LP) and on multi goal linear programming (MGLP)
models for determining solutions that can maximize net return to farmers. In the study,
the priority of goals is developmental, social, economical, and environmental respectively.
The results indicated that optimizing the cropping patterns along with proper the
allocation of irrigation water has yet substantial potential to increase the net return from
agriculture. It has already decreased the applied water as much as 19 percent. The results
show that the economic value of each unit of agricultural water is estimated to be between
107 to 1296 IRR×104 per cubic meter. This suggests managing the allocation of water
based on optimal models and bring water prices close to its true economic value to
motivate the farmers to economize in the applied water.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Factors Influencing Knowledge Sharing among Personnel of
Agricultural Extension and Education Organization in
Iranian Ministry of Jihad-e Agriculture
491
501
EN
Gh.
Pezeshki Rad
Department of Agricultural Extension and Education, College of Agriculture, Tarbiat Modares
University, P. O. Box: 14115-336, Tehran, Islamic Republic of Iran.
N.
Alizadeh
Department of Agricultural Extension and Education, College of Agriculture, Tarbiat Modares
University, P. O. Box: 14115-336, Tehran, Islamic Republic of Iran.
N.
Zamani Miandashti
Department of Agricultural Extension and Education, College of Agriculture, Shiraz University, Shiraz,
Islamic Republic of Iran.
H.
Shabanali Fami
Department of Agricultural Extension and Education, College of Agriculture, University of Tehran,
Karaj, Islamic Republic of Iran.
The main purpose of this study was to investigate factors influencing knowledge
sharing among the personnel of Agricultural Extension and Education Organization in
the Iranian Ministry of Jihad-e Agriculture. A survey method was employed for the
study, and 110 personnel randomly selected as a sample out of 140 who were busy
working in the organization. Data was collected through a questionnaire employed as the
tool of the study. The reliability of the questionnaire was determined as 0.93. The
personnel were of the belief that knowledge sharing happened in their organization to a
large extent. According to the study, there existed significant relationships between the
factors of social trust, relational social capital and attitude toward knowledge sharing,
and the dependent variable of knowledge sharing. A stepwise regression analysis
indicated that relational social capital and attitude towards knowledge sharing could
explain about 37 percent in the variations of knowledge sharing.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Design, Construction and Evaluation of a Fan Speed
Controller in a Forced Convection Solar Dryer to
Optimize the Overall Energy Efficiency
503
515
EN
N.
Bagheri
Department of Agricultural Machinery, University of Tehran, Karaj, P. O. Box: 4111, Islamic Republic of
Iran.
A.
Keyhani
Department of Agricultural Machinery, University of Tehran, Karaj, P. O. Box: 4111, Islamic Republic of
Iran.
S.
Mohtasebi
Department of Agricultural Machinery, University of Tehran, Karaj, P. O. Box: 4111, Islamic Republic of
Iran.
A. R.
Alimardani
Department of Agricultural Machinery, University of Tehran, Karaj, P. O. Box: 4111, Islamic Republic of
Iran.
Sh.
Rafee
Department of Agricultural Machinery, University of Tehran, Karaj, P. O. Box: 4111, Islamic Republic of
Iran.
G. H.
Mansoori
Department of Agricultural Machinery, University of Tehran, Karaj, P. O. Box: 4111, Islamic Republic of
Iran.
To increase agricultural crops’ quality and to minimize losses in the final product and
used energy during the drying process, major drying system parameters should be
continuously controlled. Precise control of such parameters is attained by using automatic
control systems. To optimize the overall dryer efficiency in a forced convective solar
dryer, a controller was designed, constructed and evaluated. The dryer fan speed was
chosen to be the controlled variable. Based upon the mathematical relations and a
monitoring of the air inlet temperature to the collector, the air outlet temperature from
the collector and the air outlet temperature from the drying chamber, the dryer efficiency
was determined. Using the dryer control program the current and the optimized dryer
efficiencies were calculated, compared and the fan speed changed accordingly to maintain
the optimized efficiency. Experiments were carried out in three replications (in three
days) with the results showing that the system was capable of controlling the fan speed to
obtain the optimum efficiency. The dryer equipped with the designed control system
worked with its highest efficiency throughout the day. Statistical analysis showed that the
control system highly improved the dryer efficiency throughout its operation at a 1%
probability level.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Nondestructive Determination of Tomato Fruit Quality
Parameters Using Raman Spectroscopy
517
526
EN
A.
Nikbakht
Department of Mechanical Engineering in Agricultural Machinery, Faculty of Agriculture, Urmia
University, Urmia, Islamic Republic of Iran.
T.
Tavakkoli Hashjin
Department of Agricultural Machinery Engineering, Faculty of Agriculture, Tarbiat Modares University,
P. O. Box: 14115-336, Tehran, Islamic Republic of Iran.
R.
Malekfar
Department of Molecular and Atomic Physics, Faculty of Sciences, Tarbiat Modares University, Tehran,
Islamic Republic of Iran.
B.
Ghobadian
Department of Agricultural Machinery Engineering, Faculty of Agriculture, Tarbiat Modares University,
P. O. Box: 14115-336, Tehran, Islamic Republic of Iran.
Tomato is a major fruit, as well as a major food science product. There is a need of
determining the quality attributes of this fruit (nondestructively) due to the increasing
demand of the in agro-industrially controlled areas. Most of the commonly employed
techniques are time consuming and involve a considerable degree of manual work.
Sample preparation, juice making, and laboratory tests are among the limitations. Raman
spectroscopy was applied in this study to measure such important quality parameters of
tomato as SSC, pH and color. A dispersive Raman instrument was employed and
reference analyses were carried out to make calibration models regarding the spectral
features and target attributes. Analysis of the spectra revealed that all the three
characteristic bands of cartenoids, lycopene, and carotene, were significantly
recognizable. Also there were several strong to medium bands recognized as related to
carbohydrates. Principal Component Regression (PCR) and Partial Least Square (PLS)
were selected as the multivariate calibration models. The prediction models proved to be
robust resulting in a desirable mapping between the spectra and output attributes. The
Root Mean Square Error of Predictions (RMSEP) through PLS and PCR for modeling
the color index using the whole spectrum was obtained as 0.33 and 0.38, respectively.
RMSEP for mapping the SSC using PLS and PCR models was resulted in respective
figures of 0.30 and 0.38. PCA interpretation depicted that Raman spectra could make a
favorable distinction among the samples based on their maturity stages. As a result, there
is a great potential to use Raman spectroscopy in industrial approach and in line control.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Effect of the Three Herbal Extracts on Growth Performance,
Immune System, Blood Factors and Intestinal Selected
Bacterial Population in Broiler Chickens
527
539
EN
S.
Rahimi
Department of Poultry Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic
Republic of Iran.
Z.
Teymori Zadeh
Department of Poultry Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic
Republic of Iran.
M. A.
Karimi Torshizi
Department of Poultry Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic
Republic of Iran.
R.
Omidbaigi
Department of Horticultural Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Islamic
Republic of Iran.
H.
Rokni
Applied Scientific Education Institute of Jahad-e-Agriculture, Tehran, Islamic Republic of Iran.
A research study was conducted to evaluate the effects of three herbal extracts and an
antibiotic –virginiamycin- on growth performance, immune system, blood factors and
selected intestinal bacterial populations in broiler chickens. A total of four hundred and
eighty 1-day old male broiler chicks were assigned to the basal diet (control) , basal diet
supplemented with 15 ppm of virginiamycin, basal diets with a 0.1% dose of either thyme
(Thymus vulgaris), coneflower (Echinacea purpurea), garlic (Allium sativum) or a blend of
the three extracts in the drinking water. The highest and the lowest body weight and
weight gain were related to virginiamycin and coneflower, (P< 0.05) respectively. The
lowest and the highest feed conversion rates were respectively related to virginiamycin
and coneflower (P< 0.05). Relative weight of bursa Fabricius in the garlic group showed a
significantly more increase as compared with other groups, while the relative weight of
spleen was unaffected by treatments. Cutaneous basophils hypersensitivity response (to
phytohemaglutinin injection) and antibody response to Sheep Red Blood Cells (SRBC)
was higher in coneflower group (P< 0.05). Antibody responses to Newcastle Disease
vaccine (LaSota) was unaffected by treatments but coneflower improved antibody levels
(P> 0.05). Garlic (Allium sativum) significantly reduced the serum levels of cholesterol,
LDL, and triglyceride as well as significantly increasing the level of HDL. Thyme (Thymus
vulgaris) improved hematocrit percentage and hemoglobin concentration, but not
significantly. The colony forming units of Escherichia coli in digesta of ileo-cecum in the
blend group showed a significantly lower number compared with control. However, there
was no difference observed in E. coli counts between blend group and others, except for
control. The lactic acid bacteria counts in the thyme group increased as compared to
other groups, except for coneflower (P< 0.05).
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Standardized Ileal Digestible Threonine Requirements and Its
Effects on Performance and Gut Morphology of Broiler
Chicks Fed Two Levels of Protein
541
552
EN
M.
Zaghari
Department of Animal Science, College of Agriculture, University of Tehran, Karaj, Islamic Republic of
Iran.
F.
Zaefarian
Department of Animal Science, College of Agriculture, University of Tehran, Karaj, Islamic Republic of
Iran.
M.
Shivazad
Department of Animal Science, College of Agriculture, University of Tehran, Karaj, Islamic Republic of
Iran.
The objective of this study was to determine the effects of 8 levels of threonine (0.4, 0.5,
0.6, 0.7, 0.8, 0.9, 1.0 and 1.1%) and 2 levels of protein (17.5 and 20.5%) on growth
performance, gut sizes and morphology as well as to estimate Standardized Ileal
Digestible (SID) Thr requirements in Ross 308 males at 0 to 21 days of age. Chicks were
randomized into 64 battery cages (5 chicks per replicate). FI was lower for broiler given
the high CP diets as compared to those fed on low CP diets. BWG and FCR improved up
to 0.7% Thr in both CP levels. Fitted broken lines indicated break points at 0.62 and
0.66% SID Thr for weight gain at 17.5 and 20.5% crude protein, respectively. Significant
interaction was found between CP and Thr on relative weight and length of duodenum
and jejunum (P< 0.05). Thr supplementation significantly affected villus height, epithelial
thickness, goblet cell number and crypt depth in duodenum, jejunum and ileum (P< 0.01).
Low CP diets adequate in Lys, Total Sulfur Amino Acid (TSAA) supplemented with Thr
may result in optimal BWG and FCR as well as in growth of intestinal length. Such
parameters of gut functionality as microvilli height, crypt depth and epithelial thickness
seemed to be improved with even higher levels of dietary SID Thr levels.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Identification of Fatty Acid in Mackerel (Scomberomorus
commersoni) and Shark (Carcharhinus dussumieri) Fillets and
Their Changes during Six Month of Frozen Storage at -18°C
553
566
EN
S.
Nazemroaya
Department of Fisheries, College of Natural Resources and Marine Science, Tarbiat Modares University,
Noor, Islamic Republic of Iran.
M. A.
Sahari
Department of Food Technology, Collage of Agriculture, Tarbiat Modares University, P. O. Box: 14115-
336, Tehran, Islamic Republic of Iran.
M.
Rezaei
Department of Fisheries, College of Natural Resources and Marine Science, Tarbiat Modares University,
Noor, Islamic Republic of Iran.
Changes in the fatty acid composition and biochemical indices of mackerel (which has a
substantial lipid content) and shark (which has negligible lipid content) fillets stored at -
18°C for up to six months were measured. Lipid content was measured (6.35% and
1.38%) in mackerel and shark, respectively; however it decreased during frozen storage
in both fish species. In analysis of fatty acids the amount of PUFA, especially -3 ones,
was more predominant in mackerel than shark, nevertheless, fatty acid composition has
changed in both species during frozen storage. The amount of saturated fatty acids in
contrast with unsaturated fatty acids increased due to oxidation of PUFA. The decrease in
PUFA compounds (40.1% and 23.94%) was as follows: -3 (48% and 42.83%), -3/ -6
ratio (41.36% and 50%), PUFA/SFA ratio (56% and 42.23%) and EPA+DHA/C16 ratio
(55.55% and 46.66%) in mackerel and shark, respectively. For both species, tiobarbituric
acid (TBA), peroxide (PV), free fatty acids (FFA) and total volatile base nitrogen (TVB-N)
values were significantly (P< 0.05) increased with storage time. The results showed that,
among these indices, changes in the PV and TBA in mackerel were significantly (P< 0.05)
larger than in shark; but changes of FFA and TVB-N in shark were significantly (P< 0.05)
higher than in mackerel. It means that oxidative and hydrolytic deterioration are
promoter factors of biochemical changes in mackerel and shark, respectively.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Influence of Withania coagulans Protease as a Vegetable
Rennet on Proteolysis of Iranian UF White Cheese
567
576
EN
A.
Pezeshki
Department of Food Science and Technology, Faculty of Agriculture, University of Tabriz, Tabriz,
Islamic Republic of Iran.
J.
Hesari
Department of Food Science and Technology, Faculty of Agriculture, University of Tabriz, Tabriz,
Islamic Republic of Iran.
A.
Ahmadi Zonoz
Department of Food Science and Technology, Faculty of Agriculture, University of Tabriz, Tabriz,
Islamic Republic of Iran.
B.
Ghambarzadeh
Department of Food Science and Technology, Faculty of Agriculture, University of Tabriz, Tabriz,
Islamic Republic of Iran.
Extraction of protease from Withania coagulans’ fruits and the effect on proteolysis of
Iranian UF white cheese in comparison with pure chymosin and fungi rennet (fromase)
were investigated during ripening. The results indicated that, except for pH which was
significantly (P< 0.05) lower in cheeses made with Withania coagulans, there was no
significant difference observed among the cheeses produced with different rennet
preparations as in moisture, fat and salt contents during ripening. The values of pH 4.6-
SN and the Urea-polyacrylamide gel Electrophoresis (PAGE) pattern revealed severe
proteolysis in cheeses produced with Withania coagulans’ enzyme as compared with
animal and fungi rennets. The caseins s1- and disappeared in cheeses made with
Withania coagulans enzyme preparations. Furthermore, a noticeable increase of soluble
nitrogen in 12% trichloroacetic acid (SNTCA) was observed during ripening of cheeses
made with vegetable rennet, probably due to an unspecific proteolitic activity of Withania
coagulans enzymes as compared to other rennets.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
In-house Production of Lactose-hydrolysed Milk by
Beta-galactosidase from Lactobacillus bulgaricus
577
584
EN
A.
Jokar
Fars Research Center for Agriculture and Natural Resource, Zarghan, Shiraz, Islamic Republic Iran.
A.
Karbassi
Department of Food Science, College of Agriculture, Shiraz University, Shiraz, Islamic Republic of Iran
Crude Enzyme (beta-galactosidase) Extract (CEE) was produced by Lactobacillus ssp.
bulgaricus CHR Hansen Lb-12 and was applied in sterile milk which had been processed
through Ultra High Temperature method (UHT milk), for hydrolyzing lactose. Lactosehydrolyzed
milk was also produced by a pure and commercially available betagalactosidase
(Maxilact). Optimum quantities of CEE and Maxilact enzyme, for
producing lactose-hydrolyzed milk, during 6 hours of processing, were 0.418 and 0.512 U
ml-1, respectively. Using more than 0.418 U ml-1 CEE resulted in unacceptable acidity.
Acidity of lactose-hydrolyzed milk produced through 0.418 U ml-1 of CEE was
significantly increased from 15 to 17 ºD, while enhancement of acidity in lactosehydrolyzed
milk produced through Maxilact enzyme was not significant. Total count of
lactose-hydrolyzed milk by 0.418 U ml-1 CEE, after 6 hours of processing was significantly
increased from 5 to 30 CFU (Colony Forming Unit). Sensory evaluation of lactosehydrolyzed
milk and ordinary UHT milk (as control) did not show any significant
differences with respect to acceptability of sweetness, taste, aftertaste and color.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Microbiological and Physicochemical Properties of Pecorino
Romano Cheese Produced Using a Selected Starter Culture
585
600
EN
N. P.
Mangia
Department of Environmental Agricultural Sciences and Agro-Food Biotechnologies, University of
Sassari, 07100 Sassari, Italy.
M. A.
Murgia
Department of Environmental Agricultural Sciences and Agro-Food Biotechnologies, University of
Sassari, 07100 Sassari, Italy.
G.
Garau
Department of Environmental Agricultural Sciences and Agro-Food Biotechnologies, University of
Sassari, 07100 Sassari, Italy.
P.
Deiana
Department of Environmental Agricultural Sciences and Agro-Food Biotechnologies, University of
Sassari, 07100 Sassari, Italy.
The effect of a selected autochthonous starter culture made up by Streptococcus
thermophilus, Lactobacillus delbrueckii subsp. lactis and Lactobacillus helveticus on the
microbiological and physicochemical properties of Pecorino Romano cheese during
ripening was investigated. The suitability of the experimental starter culture was tested at
industrial scales in cheese-making trials of Pecorino Romano. Pecorino Romano cheese
manufactured by use of scotta-fermento served as control. The lactic microflora increased
significantly in experimental cheeses as compared to the control and this was also
accompanied by a substantial decrease of spoilage microorganisms in experimental
cheeses. Free amino acids (FAAs) were more abundant in experimental cheeses,
arginine+g-aminobutyric acid and leucine in particular. These differences could be likely
due to a different enzymatic activity of the selected starter culture as compared to the
scotta-fermento used in the control trials. Oleic (C18:1), palmitic (C16:0), butyric (C4),
stearic (C18:0) and myristic (C14:0) acids were the most abundant Free Fatty Acids
(FFAs) detected in both brand of cheeses at the end of ripening. Overall, the level of FFAs
in experimental and control cheeses did not show significant differences, even if the
average values in experimental cheeses were always slightly higher than those recorded
for the control. Moreover, the average content of FFAs of Pecorino Romano was found
the lowest when compared with the other Sardinian PDO cheeses; most likely the high
content of sodium chloride and the low aW of Pecorino Romano influenced all the lipase
activities, even those present in the rennet paste. Despite this, the employment of the
selected starter culture revealed useful to improve the physico-chemical features of
Pecorino Romano while preserving its tipicity.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
The Physiological Response of Three Iranian Grape Cultivars
to Progressive Drought Stress
601
609
EN
N.
Ghaderi
Department of Horticultural Science, Faculty of Agriculture, University of Tehran, Karaj, Islamic
Republic of Iran.
A. R.
Talaie
Department of Horticultural Science, Faculty of Agriculture, University of Tehran, Karaj, Islamic
Republic of Iran.
A.
Ebadi
Department of Horticultural Science, Faculty of Agriculture, University of Tehran, Karaj, Islamic
Republic of Iran.
H.
Lessani
Department of Horticultural Science, Faculty of Agriculture, University of Tehran, Karaj, Islamic
Republic of Iran.
Investigating the role of drought stress conditions on physiological characteristics of
plant may provide means to understand basic drought resistance. Differences in leaf
emergence rate, leaf relative water content (RWC), membrane stability index (MSI), leaf
mass area (LMA), net photosynthesis (Anet), stomatal conductance (gs), transpiration rate
(E), intercellular CO2 concentration (Ci), water use efficiency (Anet/gs) and recovery of gas
exchange were investigated in two-year-old grapes of three Vitis vinifera L. cultivars
("Khoshnave", "Bidane-Sefid" and "Askari"), subjected to progressive drought stress
(soil water potential: -0.2, -0.6, -1, and -1.5 MPa). The results showed temporary
reduction in RWC, MSI, leaf emergence rate, LMA, Anet, gs and E. Ci decreased with
increasing drought stress. "Khoshnave" grape showed a higher photosynthesis rate than
"Bidane-Sefid" and "Askari". Higher LMA of "Khoshnave" may be attributed to the
potential for carbon absorbance and higher Anet as compared to the other two cultivars.
Complete recovery of Anet for all cultivars occurred one day after rewatering at -0.6 MPa
and four days after rewatering at -1 MPa treatments. Complete recovery of gs was not
observed in either one or four days after rewatering except for "Askari". The results
showed that Anet of "Khoshnave" recovered quickly as compared to those in the other two
cultivars. Water use efficiency was maximum in all cultivars under -1 MPa treatment.
Similar patterns of Anet/gs were observed for the three cultivars. "Khoshnave" had higher
Anet/gs as compared to "Askari" and "Bidane-Sefid" under severe drought stress
conditions. "Khoshnave" cultivar, with a higher Anet, higher leaf emergence rate, higher
LMA, rapid recovery of Anet, higher Anet/gs was found to be promising for cultivation in
rain-fed areas across the west of Iran in comparison with the other cultivars.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Total Oxalate-Soluble Pectin Concentration in Asian Pear
(Pyrus serotina Rehd) Fruit in Relation to Ripening,
Storage and Internal Browning Disorder
613
628
EN
K.
Arzani
Department of Horticultural Science, College of Agriculture, Tarbiat Modares University, Tehran, Islamic
Republic of Iran.
H.
Khoshghalb
Department of Horticultural Science, College of Agriculture, Tarbiat Modares University, Tehran, Islamic
Republic of Iran.
M. J.
Malakouti
Department of Soil Science, College of Agriculture, Tarbiat Modares University, Tehran, Islamic
Republic of Iran.
M.
Barzegar
Department of Food Science and Technology, College of Agriculture, Tarbiat Modares University,
Tehran, Islamic Republic of Iran.
Oxalate Soluble Pectin (OSP) is related to fruit firmness with respect to the chelation of
calcium ions with carboxyl groups of adjacent polyuronide chains. This study was carried
out to explore the effect of time of fruit harvest, foliar spray with CaCl2 during growing
season on OSP, Polygalacturonase Activity (PGA), fruit firmness and the effects on fruit
shelf life, quality and Internal Browning (IB) disorder. Fruit samples were collected from
Asian pear (Pyrus serotina Rehd.) trees ‘KS’9 and ‘KS’13 on European pear (Pyrus
communis L.) seedling rootstocks. Fruits were picked on the 1st and 15th August, 2006 and
stored at 1ºC and 80-85% relative humidity (RH). Five stages of extraction were
performed on fruit samples including one pre-harvest, one at the time of harvest, and
three following fruit harvest. Results indicated that OSP increased slightly during fruit
ripening as well as during storage. In both the studied cultivars, the level of OSP in fruit
harvested fifteen days after Optimum Time for Harvest (OTH) was higher than that
harvested at OTH. The level of OSP in fruit softened after harvest significantly increased
starting from the time of harvest. The relationship between flesh firmness, IB and OSP
concentration showed the highest correlations in the both of the studied cultivars among
PGA. In conclusion, flesh firmness and IB were correlated with the extent of OSP
concentration. In addition, fruit, sprayed with CaCl2 and harvested early, contained less
OSP, PGA and IB following long-term storage.
Tarbiat Modares University
Journal of Agricultural Science and Technology
1680-7073
13
4
2011
7
1
Predicting Dryland Wheat Yield from Meteorological Data
Using Expert System, Khorasan Province, Iran
627
640
EN
A.
Khashei-Siuki
Department of Irrigation and Drainage Engineering, College of Agriculture, Tarbiat Modares University,
Tehran, Islamic Republic of Iran.
M.
Kouchkzadeh
Department of Irrigation and Drainage Engineering, College of Agriculture, Tarbiat Modares University,
Tehran, Islamic Republic of Iran.
B.
Ghahraman
Department of Irrigation, College of Agriculture, Ferdowsi University of Mashhad, Mashhad, Islamic
Republic of Iran.
Khorasan Province is one of the most important provinces of Iran, especially as regards
agricultural products. The prediction of crop yield with available data has important
effects on socio-economic and political decisions at the regional scale. This study shows
the ability of Artificial Neural Network (ANN) technology and Adaptive Neuro-Fuzzy
Inference Systems (ANFIS) for the prediction of dryland wheat (Triticum aestivum) yield,
based on the available daily weather and yearly agricultural data. The study area is
located in Khorasan Province, north-east of Iran which has different climate zones.
Evapotranspiration, temperature (max, min, and dew temperature), precipitation, net
radiation, and daily average relative humidity for twenty-two years at nine synoptic
stations were the weather data used. The potential of ANN and Multi-Layered Preceptron
(MLP) methods were examined to predict wheat yield. ANFIS and MLP models were
compared by statistical test indices. Based on these results, ANFIS model consistently
produced more accurate statistical indices (R2= 0.67, RMSE= 151.9 kg ha-1, MAE= 130.7
kg ha-1), when temperature (max, min, and dew temperature) data were used as
independent variables for prediction of dryland wheat yield.