Journal of Crop Production and Processing

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To study the effect of sowing date on quantitave and qualitative traits of soybean in Shahrekord region, an experiment was performed as split plot based on randomized complete blocks design with four replications at Agricultural and Natural Resources Research Centre of Chaharmahal-va-Bakhtiari, Shahrekord, in 2008. Four sowing dates (May 5, May 20, June 4 and June 19) and four varieties (M9, M7, L17 and Williams) were selected as main and sub plots, respectively. Results showed that maximum number of pods per plant, seeds per plant and biological yield were observed for M9 cultivar at 20 May sowing date. This sowing date had also the highest seed weight, oil percent and biological yield comared to other dates. The maximum protein percent was observed in June 4 (37.6%) and June 19 (38.4%) sowing dates. There was no significant difference between cultivars for oil and protein percent. There was no significant difference between three planting dates of May 5, May 20 and June 4 for seed yield. But minimum seed yield belonged to June 19 sowing date. In general, the M9 cultivar, with 2896.1 kg/ha seed yield, and then M7 cultivar with 2597.7 kg/ha seed yield, are recommendable as suitable soybean cultivars for cultivation in Shahrekord region.

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A total of adult leghorn roosters and 360 day-old broiler chicks were used in two completely randomized experiment to evaluate metabolizable energy (ME) and feeding value of faba beans in broiler rations. In a factorial arrangement with 10 treatments and 3 replicates chicks were fed isonitrogenous rations containing either 0, 10, 20 or 30 percent of raw, cooked or dehulled faba beans for 8 weeks. Data from sibbald procedure showed cooking had no significant effect on energy value of beans, while dehulled beans had a significantly (p < 0.05) higher energy value. Final body weights at 8th week of age were unaffected due to processing of beans. No significant differences were observed in liver weight, abdominal fat or feed efficiency ratio due to processing and/or percentage of beans in the ration. Raw, whole beans significantly (p < 0.05) increased percentage and weight of pancreas compared to those that had consumed dehulled beans. This indicates that trypsin inhibitor is located in hulls. Cooked beans reduced pancreas size to normal, indicating destruction of inhibitor due to cooking. One interesting point is that the control group which consumed more soybean meal had a pancreas weight of 4.67 grams comparable to 4.83 grams of pancreas weights of chicks consuming raw, whole beans. This last fact indicates that soybean meals might not have received enough heat treatments during processing, which requires further investigation.

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Unsuitable planting and weed competition are the most important factors that greatly reduce the yield of bean. In order to study the effect of planting date on yield and yield components of three white bean cultivars in weed infest and weed free condition a factorial experiment with randomized complete block design and three replications was carried out at Semirom in 2009. The treatments were planting date (May10, May 25 and June 9) and white bean cultivars (Shekofa, Pak and Daneshkade) and two levels of weed infestation (weedy and weed free). Results showed that planting date, weed competition and cultivars had significant effects on yield and yield components of white bean. The 30-day delay in planting date reduced the number of pods per plant, seeds per pod, 100 seed weight and biological yield of white bean cultivars, 22.5, 18, 20.1 and 22.5 percent respectively. Also weed competition, reduced the number of seeds per pod, 100 seed weight and biological yield respectively by 13.5, 5.7 and 27.1 percent. Result of planting date and weed competition interaction effects indicated that the weed competition decreased grain yield (53%) in third planting date more than others and delay in planting date was companion with increasing weed density and dry weight in flowering stage of bean. Also Shekofa cultivar had highest grain yield (3379 kg/ha) at the first planting date and weed free condition.

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Knowledge of the vegetative and reproductive characteristics of soybean cultivars with different growth habits and maturity groups is essential for the selection of a suitable variety as well as for providing optimum conditions for their growth. In 1994 in a field located in Kholenjan of Isfahan, Iran, nine indeterminate type cultivars belonging to different maturity groups, namely Williams, Wood Worth, Hack, Zane, Black Hawk, Bonus, Steel, S.R.F. and Harcor and one determinate cultivar belonging to maturity group III namely Hobbit, in a complete block design with four replications were evaluated. Indeterminate cultivars and higher maturity group cultivars produced more dry matter. On the whole, indeterminate cultivars with later maturity had longer main stem with more nodes, pods and grains. The determinate cultivar had more lateral branches, and more pods and grains in them but these traits did not show any specific trend in different maturity groups. Height of the first pod from ground surface in indeterminate cultivars was more than that of determinate cultivars. Number of pods per each node of main stem, number of grains per each pod of lateral branch and number of nodes per lateral branch showed no significant difference among cultivars. Classification of these cultivars based on the above characteristics showed that cultivars with different growth habits had basic differences and also that some cultivars showed some similarity to maturity groups which did not exist in the present study.

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Twenty-two surface soil samples (0-20 cm) from Fars province were extracted by five extractants (i.e., DTPA, 1.5 M NH₄H2PO₄, 0.1 NH₃PO₄, 0.05 MNa2EDTA, and 1% Na₂EDTA) and used in a 7-week greenhouse experiment which was a 22 × 3 factorial with 22 soils (clay 16-63% pH 7.8-8.2 electrical conductivity 0.32-1.78 dS m^-1 calcium carbonate equivalent 28-63% organic matter 1.1-4.9% cation exchange capacity 9-27 cmol kg^-1 and DTPA-extractable Mn 4-24 mgkg^-1), 3 levels of applied Mn (0, 10, 20 mg Mn kg^-1 as manganese sulfate), 3 replications, and soybean [Glycine max (L.) Merr., cv. Williams]. Application of Mn significantly increased top dry weight by 4 to 104%, averaging to about 12% over the control. But the increase in Mn concentration was not significant. Total Mn uptake also significantly increased but the apparent recovery of the applied Mn was very low (i.e., 0.05%). Soil pH, calcium carbonate equivalent, and clay content were found to be the properties influencing the extractability of Mn. The DTPA-extractable Mn, alone (with a critical level of 13 mg Mn kg^-1) or along with some soil properties, was the only form of Mn that could reasonably predict the plant responses.

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To study the sensitivity of chick pea, bean, lentil, rapeseed, sugarbeet and tomato to soil residual concentration of Idosulfuron-mesosulfurun herbicide, an experiment was carried out under controlled conditions at the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2010. The studied factors were the 6 mentioned crops, and 7 levels of soil residual concentration of Idosulfuron-mesosulfurun herbicide (0, 0.0015, 0.0037, 0.0079, 0.015, 0.031 and 0.047 mg per kg of soil). The factorial experiment was carried out as a completely randomized design with three replications. Crops' emergence percentage was determined one week after their emergence. Plants' survival percentage and shoot and root biomass production were measured 30 days after their emergence. Results showed that all mentioned characteristics decreased significantly (P<0.01) in the presence of soil residue of the herbicide. Increasing Idosulfuron-mesosulfurun residual concentration in soil decreased emergence and shoot and root biomass production. Bean had the lowest shoot (44%) and root (66.78%) biomass loss and tomato had the highest shoot (96.38%) and root (89.64%) biomass loss. Based on ED50 index, pea (0.0079 mg/kg soil) was the most tolerant and tomato (0.0003 mg/kg soil) was the most susceptible crop to soil residues of Idosulfuron-mesosulfurun, and other crops ranked in between as: tomato< sugarbeet< rapeseed< lentil< bean< pea. In general, these results showed that soil residue of Idosulfuron-mesosulfurun can injure rotation crops and it is important to consider their sensitivity in rotation programming.

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Limited time for crop residue decomposition and complete seedbed preparation in double-cropping necessitates reduced tillage which is associated with its shortcomings. Information about seedbed preparation aspects in double-cropping of wheat and mungbean in Isfahan is lacking. For this reason, the effects of various seedbed preparation methods on growth, seed yield and yield components of mungbean (experimental line 1-61-16) were studied in a wheat-mungbean double-cropping system during 1996 at the Agricultural Research Station, Isfahan University of Technology. Two residue management treatments (burned and nonburned) along with four tillage systems: moldboard plow, disk, khischee and no-till were laid out in a strip plot design within a randomized complete block design with four replications. Improved establishment and plant growth conditions associated with burning residue treatment significantly increased plant density, above ground plant weight, number of nodes per branch, plant height, number of pods per main stem and per square meter, number of seeds per pod on main stem and on branches, number of seeds per main stem, seed yield, biological yield and harvest index. Higher plant density in this treatment resulted in significant reduction in the number of branches and number of pods per branch. Desirable conditions for establishment and growth in disk and moldboard plow treatments significantly increased plant density, above ground plant weight, number of pods per main stem and per square meter, number of seeds per pod on main stem and on branches, number of seeds per main stem, seed yield, biological yield and harvest index. No-till treatment produced the least results in respect to the above traits. The results indicated that burning residues with disk tillage system might be an appropriate seedbed preparation method under conditions similar to this experiment.

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Variability of seed storage protein electrophoretic patterns revealed by SDS-Polyacrylamide gel electrophoresis and their possible relations with some morphological and phenological characteristics were studied using 193 accessions from Iran Mungbean (Vigna radiata L. Wilczek) Collection. Seed protein electrophoresis revealed six different patterns that were different in two albumin and four globulin subunits with molecular weights of 23500-34000. Pattern types 1 and 2 had a considerable frequency but pattern types 3, 4, 5 and 6 had low frequencies and probably had developed recently in mungbean evolution process. Cluster analysis of countries and cities using the frequencies of albumin and globulin subunits showed no relation between geographical diversity and similarity distances. The correlations of morphological traits and albumin and globulin subunits indicated a relationship between G1 and G2 subunits with 1000 seed weight and days to beginning of maturity. Therefore, selection based on protein patterns at preliminary stages of breeding programs might be effective in increasing seed yield together with earliness.

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The esterification process causes some desirable changes in physicochemical properties of fat by exchanging the acyl groups in triglyceride molecules. The aim of this study was to produce a suitable edible fat for industrial and home uses. In this study a mixture of 60 percent soybean oil and 40 percent edible tallow were inter-esterified, using 0.5 percent sodium methylate or ethylate as catalyst. The results obtained for solid fat contents and melting points indicated that the process of inter-esterification was accomplished in 30 minutes at 90°C. It was also observed that sodium methylate and. ethylate had similar effects on physical and chemical characteristics of the esterified blend. Iodine and saponification values indicated that the esterification process did not have any considerable effect on the degree of unsaturation or molecular weight of fatty acids. The peroxide values showed that the processing condition did not produce any peroxide. The esterified blend contained 1.10 percent trans fatty acids, which were originally present in the tallow. It is concluded that interesterification of soybean oil and edible beef tallow can be used as an alternative method to hydrogenation to produce a suitable plastic fat with low levels of trans fatty acids for the manufacture of different types of margarines and fats for home uses.

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This experiment was conducted in the Research Farm of the Faculty of Agricultural Sciences, University of Guilan in 2010 as an RCBD based split plot experiment with three replications. In this experiment five different amounts of soil moisture (Irrigation after depletion of 45, 55, 65, 75 and 85% of field capacity moisture) and two soybean cultivars (Gorgan-3 and Williams) was considered as main and sub plots, respectively. Results of ANOVA showed that moisture regime by cultivar interaction had significant effect on seed yield, number of pods per plant, number of seeds per pod and seed oil percent. Mean comparisons revealed that increasing soil water depletion resulted to decrease in seed yield, number of pods per plant and number of seeds per pod. Also, it resulted to decrease in grain yield of both cultivars, which was approximately 63% for Gorgan 3 and 2% for Williams. However, maximum (1667kg/ha) and Minimum (384kg/ha) seed yield were recorded for Gorgan 3 and Williams in 45% and 65% soil moisture regimes, respectively. The highest seed oil percentage was recorded for cultivar Williams which grown in 75% soil moisture while the lowest was for Gorgan 3 which grown in 55 % soil moisture regime. Seed protein also was affected by soil moisture regime, significantly with the highest (22.49%) and lowest (22.04%) in 55 and 85% soil moisture regimes, respectively. In this experiment Williams had low sensitivity index and high tolerance index while Gorgan 3 had high geometric mean productivity and mean productivity. Overall, Gorgan 3 had the highest seed yield in all soil moisture regimes. Its yield reduction percent was greater in drought stress prone treatments, in comparison with cultivar Williams which shows greater seed yield stability of the indeterminate Williams cultivar.

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To study the effect of organic growth stimulant and harvest time of soybean cultivar Williams on oil harvest index and protein yield, factorial experiment was conducted in complete randomized block design with 15 treatment and three replications of Rice Research Institute of Iran (Rasht) in 2012-2013 year. The experiment Treatments were including Kadostim (50.00), Aminol forte (20.00), organic manure (cow,10 ton.ha-1), magnetic water (20 lit.m-2) plus the control (no spray) and three harvest time 1. the first harvest when seed pods in main stem had 25-20% moisture, 2. the second harvest when in pods maturity (yellowing of more than 95% of pods) and seeds per pod in the main stem had 15-14% moisture, 3. the third harvest when the main stem had less than 14% moisture. Results showed that significant differences exist between the spray application and harvest time in oil harvest index and protein yields. spray application with kadostim had the maximum oil harvest index (8.7%) and biological yield (5933 kg.ha-1). Mean comparison of the interaction showed that spray application of kadostim at the second harvest produced highest grain yield (2853 kg.ha-1), oil yield (664 kg.ha-1) and protein yield (1019 kg.ha-1). The results of this experiment, it seems that Kadostim and organic manure spray application at the second harvest to help increase production, and a step towards reducing environmental pollution and sustainable agriculture is.

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The experiment was conducted in 2012 to evaluate the effect of salinity stress on oil percent, oil yield, seed yield and some physiological charactristics on three local populations of castor bean (Ricinus communis L.), at the University of Shahrekord, Iran. Experiment was carried out with three replications in a completely randomized design including five levels of salinity (1.2, 2, 2.6, 3.8 and 4.8 dS/m in soil saturation paste) as the first factor and castor populations (Shiraz, Kerman and Urumieh) as the second factor. The effect of salinity was statistically significant (α>0.01) on seed yield, oil percent and oil yield, chlorophyl a, chlorophyll b and proline, while a significant effect (α>0.05) was observed for total chlorophyl. The results also showed that different populations had a significant difference (α>0.01) with regard to all studied factors. The highest and the lowest proline content were observed for Kerman and Shiraz populations, respectively. Increasing salinity increased the leaf proline content while it decreased the chlorophyll content was decreased. At low salinity levels, Shiraz population resulted to the highest seed and oil yield. However, with increasing salinity, seed yield and oil content of Shiraz population was less than other populations. Although more research is needed in this respect, but it seems that in castor been Shiraz population for soils with a low salinity and Kerman population for more saline conditions can be recommended.

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To determine the relationships between yield and its components, and to find the direct and indirect effects of yield-related traits on soybean yield, 240 genotypes were grown in the Research Station, College of Agriculture, Karaj, Iran, in 1997-98 using an augmented design. The study of correlation analysis showed that number of seeds per plant and seed yield per plant had the highest significant correlation coefficient (r=0.92). Other significant correlation coefficients were found between biomass per plant and yield (r=0.86) and between number of pods per plant and yield (r=0.67). Results of stepwise regression analysis revealed that number of seeds per plant, seed weight, and number of seeds per pod were the three major traits affecting seed yield in soybean. However, path analysis showed that only two of the three above-mentioned traits, namely, number of seeds per plant and seed weight, are quite important for soybean selection programs. Stepwise regression analysis was used again, omitting number of seeds per plant, which showed that number of pods per plant, seed weight, plant height and number of days to 90% maturity, are important contributors to yield. Path analysis, this time, revealed that the correlation effects to plant height and number of days to 90% maturity on yield is due to the indirect effects exerted through other traits. It is concluded that three traits, namely, number of seeds per plant, seed weight and number of pods per plant have notable effects on soybean seed yield.

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In order to investigate the genetic diversity of morphological traits in 121 genotypes of lima, red and pinto beans, and to study the relation between characters, and to get better understanding of factors affecting the interaction between characters by multivariate analysis, an experiment was conducted in 1997 as a simple lattice design at the Research Station of Agricultural College, Isfahan University of Technology.

High variability was observed among genotypes for all characters studied. The phenotypic coefficients of variability were greater than the genotypic ones for all the traits. Among the characters studied seed yield, number of pods per lateral branches and main stem, length of lateral branches and main stem, number of nodes per lateral branches and main stem, 100-seed weight and number of lateral branches had the highest genotypic and phenotypic variability, while days to maturity had the lowest variability. Traits relative to lateral branches were more variable than the same traits in the main stem. Factor analysis for all the genotypes and, separately, for lima, red, pinto, determinate and indeterminate genotypes revealed 4 factors which justified more than 78.4 percent of the total variation. The results of the analysis based on all the genotypes showed that the first factor was mostly correlated to days to maturity, length of main stem and lateral branches, number of nodes per main stem and lateral branches, which was named “vegetative factor”. The second and third factors had the highest correlations with number of pods per main stem and lateral branches, number of seeds per pod in the main stem and branches and 100-seed weight, which were named “yield component factors”. The fourth factor showed the highest correlation with number of lateral branches and was named for this trait. The first and fourth factors were related to vegetative growth characteristics and physiological source. The second and third factors were related to physiological sink. On the basis of stepwise regression analysis, number of pods per lateral branches was the most important component of yield, and number of pods per lateral branches and main stem had the next following ranks. Number of pods per lateral branches and main stem had the highest relationships with yield.

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It is believed that various types of field bean, including pinto, white and red, differ in adaptability to high temperatures and may, thus, differ in response to delay in planting. In order to evaluate this response, an experiment was conducted during 1996 at the Agricultural Research Station, Isfahan University of Technology, using a randomized complete block design with split-plot layout. Main plots consisted of four planting dates (April 28, May 13 and 28 and June 13) and sub-plots included four genotypes of common bean (red bean, c.v. Naz pinto beans, experimental lines 11816 and 16157 and a white bean, experimental line 11805).

 Number of branches per plant, number of pods per branch and per unit area, number of seeds per pod of main stem and branch, number of seeds per main stem, per branch and per unit area, 100-seed weight and seed yield significantly reduced, while harvest index significantly increased by delay in planting and consequent increases in temperature and reduction in time for growth. The lower harvest index obtained with early planting was the result of the lower efficiency of the produced vegetative growth due to the coincidence of seed filling period with high temperatures. Pinto bean line 11816 ranked the highest for number of branches per plant and harvest index among the genotypes evaluated and produced the highest seed yield (3030 kg ha^-1). Although red bean Naz ranked the highest for number of pods and seed per main stem and per unit area, it had the lowest harvest index and 100-seed weight and, consequently, produced the least seed yield (2254 kg ha^-1). The results obtained indicate that delay in planting adversely affects bean seed yield. Pinto bean line 11816 may have higher yield potential among the genotypes studied at all planting dates under conditions similar to the present experiment. No specific relationship was observed between apparent seed characteristics and plant tolerance to heat.

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In order to investigate the effect of Hexaconazole (HEX) on quantitative and qualitative characteristics of two soybean (Glycine max L.) cultivars under water deficit stress, an experiment was conducted in the Faculty of Agriculture of Tarbiat Modares University in the year 2010-2011 as a factorial experiment in randomized complete block design arrangement. Factors examined in this study were soybean cultivars (L17 and Clark63), HEX concentration (0 and 35 mg/L) and water deficit stress levels (optimum irrigation and water deficit stress based on depletion of 60% of available soil moisture). Chlorophyll content, Fv/Fm, seed yield, yield components, biological yield, harvest index, protein and oil percentage of seeds were investigated. Results showed that water deficit stress and HEX application had significant effect on the most of traits and the cultivars showed different responses to the treatments. In both water treatments, HEX increased the yield of both cultivars but under water deficit stress increase in seed yield of L17 (35.99%) was higher than Clark63 (14.53%) in comparison with non- HEX application. Among the effective factors on seed yield, number of pods per plant had the highest share in the seed yield. Under water deficit condition, seed protein percent of Clark63 increased (6.14%) in response to HEX treatment but in L17 the content of protein was not affected by HEX. Oil percentage of seeds was not affected by any of the treatments. In both cultivars, HEX increased resistance to water deficit stress and the cultivars showed different responses to HEX treatment and under water deficit the yield response of L17 to HEX was more notable, although this combination improved the grain quality of clark63.

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Productivity of rainfed crops may be predicted using the climatic parameters. Crop yield prediction has an important role in agricultural policies including determining the crop price. Well-known prediction methods are regression method and arterial neural networks. In this paper soybean yield is predicted using Adaptive Nero-Fuzzy Interface System (ANFIS) and 11 years of climatic data (1998-2009) in Gonbad-e-Kavous region of Golestan province, Iran. Mean weekly rainfall, mean weekly temperature, mean weekly relative humidity and mean weekly sun shine hours were ANFIS inputs and its output was soybean grain yield (kg/ha). Stepwise Regression for Feature selection from climatic data was done with the SPSS18 software and ANFIS was created, trained and tested with MATLAB R2011a software. Trained ANFIS has ‘constant’ membership function in output layer and ‘gaussmf’ membership function in input layer. Each input has 3 membership functions and each output has one membership function. Root Mean Square Error (RMSE) criterion was used to evaluate the performance of the ANFIS. The results showed that the proposed ANFIS with 21 rules has a prediction error (RMSE) of 102.170.

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In order to study the effects of planting pattern and plant density on yield of soybean genotypes, an experiment was carried out in Safiabad Agricultural Research Center, Dezful, Iran in 2011. The experimental design was a factorial strip plot based on completely randomized block design with 3 replications. Planting pattern consisted of 3 levels (60 cm with 1 planted row, 75 cm and 90 cm with 2 planted rows) as vertical factor, a factorial of plant density (30, 40 and 50 plant/m²) and genotypes (504, L14 and DPX) was considered as horizontal factors. The means of planting pattern × density showed that the highest number of pods/plant (52.85) belonged to 60 cm with single row of plants and 40 plant m^-2. The lowest (28.35) number of pods/plant was observed in 90 cm with double rows planted and 50 plant m^-2. The genotypes responded to planting density differently. The highest (4936.11 kg/ha) grain yield belonged to DPX genotype with 50 plants m^-2. The lowest (4936.11 kg/ha) grain yield was achieved at L14 genotype with 30 plant m^-2. The results of this expriment suggested that planting pattern of 60 cm with single row of plants, 50 plant m^-2, DPX and 504 genotypes were probably suitable for this area.

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During the summer of 1998, leaf and pod blight symptoms of bean were observed in Arak, The survey in the following year showed that the disease had an increasing trend in bean-growing regions of Markazi Province. It appeared that more severe losses occurred in fields equipped with sprinkler irrigation system. Symptoms of diseased plants consisted of formation of irregular necrotic lesions on leaves surrounded by yellow halo. Under favourable conditions, these lesions gradually expanded and heavily infected leaves became blighted. The primary symptoms on infected pods were the development of water soaked spots which later turned to dark or reddish blotches. In attempts to investigate the causal agent, two types of a Gram negative bacteria with raised, yellow and translucent colonies were isolated from leaves and pods of blighted beans. All strains produced Xanthomonadin pigment and their inoculation on young bean plants induced disease symptoms similar to those observed under field conditions. Based on morphological, physiological and biochemical properties, the predominant pathogenic type was identified as Xanthomonas axonopodis pv. phaseoli. However, the other strain with the same properties, but capable of producing melanin pigment in nutrient media, was assigned to X. axonopodis pv. phaseoli var. fuscans.

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Iron (Fe) availability is low in calcareous soils of Iran due to high pH levels and presence of excessive amounts of CaCO₃. Overfertilization by phosphorus (P) fertilizers may also decrease Fe availability. The objective of this study was to evaluate the effects of P, Fe and their interactions on the growth and chemical composition of soybean [Glycine max (L.) Merrill] under greenhouse conditions. Treatments consisted of a factorial arrangement of P rates (0, 40, 80, 120 and 160 mg kg^-1 as KH₂PO₄) and Fe rates (0, 2.5, 5 and 10 mg kg^-1 as FeEDDHA) in a completely randomized design with four replications. Plants were grown for 8 weeks in a loamy soil, classified as Chitgar series (fine-loamy, carbonatic, thermic, Typic Calcixerepts). Results showed that P application up to 80 and Fe at 2.5 mg kg^-1 increased shoot dry matter. Phosphorus concentration, total uptake and P:Fe ratio in soybean increased by P application but decreased by Fe application. Application of Fe up to 2.5 mg kg^-1 increased dry matter but decreased it at higher rates. Concentration and total uptake of Fe increased by Fe application but decreased by P application. Interaction of P and Fe had no effect on shoot dry matter. Zinc (Zn) and copper (Cu) concentrations decreased significantly when P was added and manganese (Mn) concentration increased up to 40 mg P kg^-1 but decreased at higher rates. Iron application had no effect on soybean Zn and Cu concentrations but decreased Mn concentration at all rates. Prior to any fertilizer recommendations, it is necessary to study the effects of P, Fe and their interactions on soybean under field conditions.