Showing 344 results for Ph
A. Ghazanfari-Moghaddam,
Volume 7, Issue 3 (10-2003)
Abstract
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.
J. Yasrebi, N. Karimian, M. Maftoun, A. Abtahi, A. Ronaghi, M. T. Assad,
Volume 7, Issue 4 (1-2004)
Abstract
Twenty-five surface samples of calcareous soils of Fars Province were used to study the distribution of different nitrogen (N) forms to determine the relationship between the N forms and soil charcteristics, and to obtain regression equations for prediction of N forms from soil characteristics. The forms determined were: soil total nitrogen NO3-N by phenol disulfunic acid NO3-N extractable by 2 M KCl NH4-N extractable by 2 M KCl, 1 N sulfuric acid, and 0.25 N sodium hydroxide oxidative released N by acid permanganate and alkaline permanganate and NH4-N extractable by 2 M KCl at 100 oC. The highest amount of N was that released by alkaline permanganate which constituted 4.47% of soil total N and the lowest form was exchangeable NH4+ which amounted to only 0.6% of total N. Water soluble and exchangeable forms accounted for less than 2% of total N. Highly significant correlations were found between total N and acid permanganate-N (r=0.931) and total N and alkaline permanganate-N (r=0.850). Highly significant regression equations were obtained for prediction of soil total N, acid permanganate-N, and alkaline permanganate-N from soil organic matter (OM), which is an indication of a close relationship of these N forms with OM.
A. Enferad, K. Poustini, N. Majnoon Hosseini, A. A. Khajeh-Ahmad-Attari,
Volume 7, Issue 4 (1-2004)
Abstract
In a pot experiment, the growth (Dry matter) responses of 18 rapeseed varieties to three levels of NaCl salinity induced by 1.2, 6, and 12 dS.m-1 were investigated using a factorial experiment with a randomized complete block design in 3 replications. The results indicated that salinity reduced total dry matter, Na concentration, K/Na ratio, ion selectivity of K versus Na, and leaf water potential while it increased K concentration. However, the leaf water potential of the plants had the highest and a significantly negative correlation with total dry matter accumulation. Therefore, it seemed that leaf water content of the plants could explain the tolerance or sensitivity responses to salinity. The rapeseed varieties were accordingly ranked into different groups. The varieties viz, Alice, Fonax, DP.94.8 and Licord were classified as saline tolerant group, and varieties such as Okapi, Akamar and Eurol as saline sensitive group. The remaining eight rapeseed varieties were moderately tolerant. Moreover, the response of rapeseed varieties viz. Consul, VDH8003-98 and Orient were different such that the above explanation could not be applied to them. Therefore, halophytic strategies for these three varieties might be worth further investigation.
T. Najafi Mirak, A. Zali, A. Hossainzadeh, Gh. R. Rasoulian, A. Saeidi,
Volume 7, Issue 4 (1-2004)
Abstract
Russian Wheat Aphid (RWA) is a serious pest of wheat, barely and other small grains in cereal-producing regions of the world. The use of resistant cultivars is an effective management strategy to control this pest. In this study, 15 lines and 13 cultivars of durum and bread wheats along with two resistant and susceptible controls were used to evaluate their reaction to RWA under greenhouse conditions, using completely randomized design with four replications. Three seedlings at each plot were considered as an experimental unit. Five aphid nymphs (4-5 ages) were placed on each plant at 1-2 leaf stage. Leaf rolling and leaf chlorosis percentages were measured 21 days after infesting and used to screen the genotypes. Despite the relatively high linear correlation between two resistance components, leaf rolling and leaf chlorosis, estimated as 80%, analysis of variance indicated significant differences among genotypes. Eight durum lines DW9, DW14, DW4, DW2, DW7, DW8, DW12 and DW3 and one bread wheat cultivar (Azadi) were significantly more resistant than the resistant control (Halt). One durum line (DW13) and two bread wheat cultivars (Shiroodi and M-75-7) had higher leaf rolling and leaf chlorosis than the susceptible control (Sholeh). So they were selected as the most susceptible to the biotype of D. noxia. under study. Orthogonal comparison showed that durum lines were more resistant than bread wheat cultivars. These results were confirmed by Cluster Analysis based on leaf rolling and leaf chlorosis.
Sh. Dokhani, R. Beheshti,
Volume 7, Issue 4 (1-2004)
Abstract
The changes of main sugars and organic acids of Red delicious and Golden delicious apples from Semirom region in Isfahan Province were determined by high performance liquid chromatography (HPLC). The apples were harvested, graded and packed in three kinds of wood, car-board and perforated polyethylene film packages and stored for eight months at 0±0.5oC and 90 to 95% relative humidity for further analysis. Sucarose, glucose and fructose, as well as citric and L-malic acids were detected and quantified in all packed samples. The obtained data were analyzed with factorial experiment in completely randomized design and mean were compared by Duncan,s muliple range test. The results showed that fructose was dominant in both cultivars in all packages compared to other sugars. Golden delicious apples contained more sucrose and less glucose than Red delicious. All sugars decreased in packed apple samples during the storage period. The dominant organic acid of both cultivars was L-malic. Citric acid increased to its maximum level in Red or Golden delicious after one or two months of storage, respectively, and then decreased gradually by the end of storage period. In general, apples kept in perforated polyethylene films exhibited the best physiochemical properties during eight months of cold storage.
H. M. Takalloozadeh, K. Kamali, A. Talebi, Y. Fathipour,
Volume 7, Issue 4 (1-2004)
Abstract
The host-stage preferences of alfalfa black aphid, Aphis craccivora, by parasitoid wasp, Lysiphlebus fabarum, were studied under two trials under growth chamber conditions (55±5 %, R. H., L:D 14:10 H. and Tem. 20 ±2° C ). In the first trial, all stages of aphid in equal ratios, and in the second trial, variable ratios of 5:15, 15:15 and 15:5 of 3rd and 4th instar nymphs were used for parasitisation. The objective was to identify the most preferred stage of aphid for parasitism by Lysiphlebus fabarum. The results showed that 3rd instar nymphs of alfalfa black aphid were the most preferred stage with 38.75% of parasitism. Whereas 4th instar nymphs and adults had 23.75% and 21.25% parasitism, respectively. The first instar nymphs were not parasitized at all. In the second trial with variable ratios of 3rd and 4th instars of alfalfa black aphid, parasitism of 3rd instar in ratios 25, 50 and 75 percent of total population were 35.9, 55.74 and 79.6%, respectively, while those for 4th instar nymphs were 20.36, 44.26 and 64.09%, respectively. So there was a positive preference for 3rd instar and a negative preference for 4th instar nymphs.
Y. Asri,
Volume 7, Issue 4 (1-2004)
Abstract
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Kavir Biosphere Reserve covers an area of 686598 hectares situated in the northwest of Dasht-e-Kavir and east of Daryach-e-Namak. The Biosphere Reserve presents a variety of habitats, including cliffs and rocky outcrops, piedmont plains, gravelly, deserts and sand dunes, saline plains and salt marshes, and seasonal rivers and springs. The main aim of this research is to identify the plant species and to introduce of the flora in Kavir biosphere reserve. For this purpose, plant samples were collected from different habitats of the area in three growing seasons between 1994-1999. The life forms of species were determined and the biological spectrum of the area was plotted. The position of the area concerning phytogeographical classification was studied based on geographical data and references. A total number of 359 species and subspecific taxa was identified. These include 3 gymnosperms, 312 dicotyledones and 44 monocotyledones. Altogether, 43 families and 224 genera are known from the area. The following families have the highest number of species: Chenopodiaceae, Asteraceae, Brassicaceae, Poaceae, Boraginaceae, and Fabaceae. Therophytes with 198 species (55.1%) are the most frequent life forms in the area. The distribution of 245 species (68.3%) is restricted to Irano-Turanian region. Of these, 30 species (12.2 %) are endemics of Iran. . |
A. H. Ghanei, A. R. Hosseinpur,
Volume 8, Issue 1 (4-2004)
Abstract
Iron oxide-coated strips (Pi) can serve as a sink to continuously remove P from solution. In this way, probably, P extraction is analogous to P absorption by plant root. The objective of this study was to evaluate the iron oxide-coated paper strips to estimate the availability of soil P of corn (Zea mays) grown under greenhouse conditions in some soils of Hamadan Province. Sixteen soil samples with different physico-chemical properties were examined for available P by Olsen, Colwell, Mehlich1, 0.01 M CaCl2, AB-DTPA, 0.1 M HCl methods and two (Pi1, Pi2) Pi methods. Furthermore, the effects of two P levels ( 0 and 250 mg P Kg-1 soil) on the plant responses (P uptake, P concentration, and relative yield) were studied in the greenhouse experiment using 12 soil samples. The results showed that the amount of extractable P decreased in the order: 0.01 M Cacl2 < Pi2 < AB-DTPA < Pi1 < Olsen
J. Jamalian, Z. Sheikhol-Eslami,
Volume 8, Issue 1 (4-2004)
Abstract
Bread, the main staple food of Iran, imparts a major portion of energy and protein to urban and rural diets. Due to the use of flour with high extraction rate and improper fermentation of the corresponding dough, traditional breads have a rather high level of phytic acid. This has a detrimental effect on absorption and availability of minerals (Ca, Fe, Zn, Mg, Cr, Cu, etc.), carbohydrates, proteins and lipids, thus leading, for e.g., to iron-deficiency anemia in the present study, flours with different extraction rates (with known phytic acid content) were used for baking “Sangak” and “Lavash” breads and analyzed for phytic acid. Different levels of yeast, times of fermentation and extraction rates of flour were applied in the preparation of breads and their phytic acid levels were then estimated. Based on technological merits and residual phytic acid contents, breads prepared from two types of treatments were selected, their chemical composition, availabilities of iron and lysine as well as organoleptic characteristics were evaluated. Results indicated that under the employed conditions total destruction of phytic acid in “Sangak” and “Lavash” is rather impractical. A considerable reduction in phytic acid was noted: in “Lavash” bread using 2.5% yeast, 4 h of fermentation and a 50-50 blend of flours with 81.0 and 86.5% extraction rates and in “Sangak” bread with similar conditions (except for the flour which was a 50-50 blend of 86.5 & 97.5% extraction rates). Available lysine was similar in both of the selected breads compared to their respective references. Their available iron contents, however, were higher than their corresponding references (P ≤ 0.05 ). No significant differences were observed with regard to organoleptic evaluations of selected breads as compared to their references (P ≤ 0.05 ). Overall, the above-mentioned treatments are recommended for the baking of “Sangak” and “Lavash” breads.
J. Panahandeh, S. Massiha,
Volume 8, Issue 2 (7-2004)
Abstract
The commercial potato is an autotetraploid species. Certain allotetraploid species such as S. acaule despite theire identical ploidy level are not crossable with commercial potato due to their different endosperm balance numbers. The aim of this experiment was to investigate the possibility of germplasm transferring from allotetraploid species to cultivated potato by the use of diploid species and 2n gametes. For this purpose, one clone of S. phureja was crossed with S.acaule. The resulting F1 seeds were planted the next year. For evaluation of male fertility and unreduced gametes, the pollen samples of F1 hybrids stained with acetocarmin glycerol were assessed. For chromosome counting the tips of stolons were fixed and after staining with aceto – iron- hematoxilin were squashed. For future crossing some hybrids were grafted on tomato stocks. Cytologycal observation revealed that hybrids were triplod. Male fertility of hybrids as expected for odd ploidy was low, but approximately all of them had a few large stainable pollen (putative 2n). crossing of the hybrids as male parent with S. tuberosum was not successful, but reciprocal cross was successful and 72 seeds were obtained from 380 pollination . considering EBN, it is exected that the resulting seeds originate from fertilization of unreduced gametes of triploid and n gamates of S. tuberosum to be pentaploid or near pentaploid. The applications of these hybrid in potato breeding via ploidy manipulation have been discussed.
M. Farshadfar, E. Farshadfar,
Volume 8, Issue 2 (7-2004)
Abstract
Agropyron is one of the most resistant plants to biotic and abiotic stresses. It plays an important role in forage yield in rangelands. Genetic variability based on different markers is the important step in crop improvement. In order to evaluate the genetic variation of different Agropyron species based on morphological and chemical traits, this experiment was carried out in the Agriculture and Natural Resources Research Center of Kermanshah. The tiller numbers, spike length, spikelet numbers, length of flag leaf, width of flag leaf, plant height, peduncle length, ash percentage, organic matter, fiber, dry matter, fat and crude protein were registered. Statistical analysis of data was done by SPSS software. According to cluster analysis the tetraploid genotypes were classified into 5 clusters. Based on principal components analysis the length of flag leaf, spike length and plant height, and among the chemical traits of the ash percentage, organic matter, and crude protein had the highest portions of variance. The genetic parameters such as PCV, GCV, ECV, Hb and Ga for length of flag leaf were 0.274, 0.169, 0.215, 0.382, 3.05 and for spike length were 30.96, 21.64,22.139, 0.48, 5.786 and for plant height were 0.16, 0.084, 0.136,0.276, 6.054, respectively.
J. Pourreza, M.a. Edriss, H. Khosravinia, A. Aghaee,
Volume 8, Issue 3 (10-2004)
Abstract
In a completely randomized design, the effects of six different additive compounds including limestone, hydrochloric acid, zeolite, aluminum sulfate, pad ammoniac, and fatty acids on nitrogen, pH, temperature, moisture, water soluble phosphorus, and microbial count of litter of broiler chicken were investigated. Each compound was added at a level of one kg/m2 of litter. Six–hundred-and-sixteen (616) day- old broiler chickens (both sexes) were divided into 28 groups, 22 chicks per group. Four replications were allocated to each treatment from 1 to 56 days. All groups were fed with the same diet. Litter moisture was not affected by the treatment. Experimental treatments significantly (p<0.05) influenced the litter pH on day 21. The lowest pH was obtained with aluminum sulfate and the highest pH was obtained with limestone. At the end of the experimental period, all treatments had nearly the same pH levels. Litter temperature was not affected by the treatments . Experimental treatments had a significant (p<0.05) effect on litter nitrogen and bacterial count. Correlation between litter pH and nitrogen was significant and negative (r = -0.95, p<0.05). Effect of treatments on soluble P was significant and the lowest soluble P belonged to aluminum sulfate and pad ammoniac. Correlation between soluble P and pH was positive (r = 0.48, p<0.05). The results showed that some chemical compounds can be used to reduce litter pH, nitrogen, and soluble P and their effectiveness diminishes as chicks grow older.
M. Hajian Shahri, M. Abbasi,
Volume 8, Issue 4 (1-2005)
Abstract
In order to investigate variations of spore population, root colonization and also to determine mycorrhizal symbiosis in the root and rhizosphere of Pistachio trees (Pistacia vera) in natural forests, two study stations in Kalat (Chachaeh) and Sarakhs (Shorlogh) regions were selected. Sampling from soil and root of the trees were taken from under the canopy and from a depth of 30 cm. On a monthly basis. The roots were stained and the colonization rate and the variations of spore population were measured. Some soil characteristics including pH, moisture, organic material percentage and available phosphorus were determined, The correlation coefficients between the measured factors were calculated. The results indicated that vesicular – arbuscular mycorrhiza (VAM) was the only symbiotic mycorriza of pistachio trees. Average amounts of root colonization were 13% and 11% in Chahchaheh and Shorlogh stations, respectively. Also, average numbers of spores per 1 gram of dry soil in the above stations were 12 and 10, respectively. The correlation between the variation of spore population and colonization levels was positive but the correlation between spore population and soil moisture, organic material, available phosphorus and pH was negative.
F. Shir-Mohammad, N. Mahboobi Soofiani, J. Pourreza,
Volume 8, Issue 4 (1-2005)
Abstract
In order to investigate the effect of phytase and copper supplementaion on growth and carcass composition of common carp (Cyprinus carpio L.), in a completely randomized design with 3 ×2 factorial arrangement with three replicates the experimental diets including three levels of phytase 0, 500 and 1000 (FYT) kg-1 and two levels of copper 0 and 15 mg/kg were tested. Diets contained 0.72 percent total phosphorus. One hundred and forty four carps with a mean weight of 207±23 g were selected and allocated in eighteen cages (8 fish per cage). The experiment was carried out for 8 weeks and 2 weeks for acclimatization. Phytase supplementation caused no significant differences in weight gain (WG), feed conversion ratio (FCR), carcass index (CI), protein efficiency ratio (PER), liver, carcass and blood composition but increased apparent phosphorous digestibility (APD) significantly (P<0.04). Copper supplementation also caused no significant differences in WG, FCR, CI, PER, APD, liver copper, carcass composition, cholesterol (Ch), triglycride (TG), phosphorus of serum but decreased liver fat significantly (P<0.004) and increased high density lipoprotein (HDL) of serum (P<0.02). Interactions between phytase and copper on WG (P<0.01), FCR (P<0.04), PER (P<0.03), liver copper (P<0.02) and TG of serum (P<0.001) were significant. This experiment suggests the presence of antagonistic effect between phytase and supplemental copper. Phytase enzyme improved some parameters of growth and carcass composition of common carp without supplemental copper but addition of copper to the diets with phytase enzyme impaired the improved performance of carp.
A. Sheikhi Garjan, K. Talebi, A. A. Pourmirza,
Volume 8, Issue 4 (1-2005)
Abstract
The egg parasitoids are the major natural enemies of sunn pest and application of selective insecticides is one of the strategies for conservation of natural enemies. The toxicity of five different insecticides used in cereal fields to the parasitized eggs was investigated under laboratory conditions. The insecticide solutions were made based on the recommended field rates. 3-, 5- and 8- day -old parasitized eggs were dipped into insecticide solutions.
Among the treated developmental stages (except for the fenirothion), 3- and 8- day- old parasitized eggs showed the highest and the lowest emergence percentages, respectively. Deltamethrin had maximum effect on emergence percentage whereas phosalone had the least hazardous effects. There was a significant difference in parasitism percentage between 3- and 8- day- old parasitized eggs in each of the 4 treatments, viz trichlorphon, fenitrothion, deltamethrin and esfenvalerate. Adults emerging from 3- day- old eggs parasitised less eggs than those emerged from 8- day- old eggs in fenitrothion, and trichlorphon treatments. All tested insecticides were highly toxic to the adult parasitoid, causing 100% mortality when the adults were exposed to sprayed areas at recommended rates.
S. S. Modarres Najafabadi, H. Akbari Moghaddam, G. Gholamian,
Volume 8, Issue 4 (1-2005)
Abstract
Four different species of aphids belonging to the Aphididae family in four genera were collected and identified in Rape-seed fields in Sistan region during 2000-2001. Among them, Brevicoryne brassicae (Cabbage aphid) was the dominant species with an abundance of about 89% in area. The population fluctuation of Brevicoryne brassicae was studied simultaneously on fields in Sistan region (Zahak research station and her around fields). The research was conducted on a half hectare of each farm. Thirty leaves from each field at week intervals were randomly picked up and the aphids were collected and identified at the species level. The Brevicoryne brassicae had a peak of activity in early mid March to April at temperature and R.H. ranging between 22-28ºC and 45-65 R.H., respectively. Controlled conditions indicated that the Brevicoryne brassicae has a life cycle of 6-7 days and adult female longevity is 20-31 days (25±2 ºC and 75±5 R.H.). Rearing study also revealed that this species has the ability to reproduce up to 18-98 nymphs under laboratory conditions and an apterous female gives birth to 22-93 nymphs in her life time. Samplings for recognition of predators and parasitoids were also taken at 3-day intervals. Natural enemies in fields during the two years were identified to be 5 coccinellid (Col:Coccinellidae), 4 syrphid(Dip:Syrphidae) and 2 chrysopid species (Neu:Chrysopidae). Also in Hymenoptera, 2 parasitoids (Hym: Aphidiidae & Pteromalidae) were determined.
Gh. Elyasi, Dj. Shodja, M.r. Nassiry, A. Tahmasebi, O. Pirahary,
Volume 9, Issue 2 (7-2005)
Abstract
In modern programmes of animal breeding, the polymorphisms of the milk proteins can be used as marker systems. Beta-Lactoglobulin is the major milk whey protein in the ruminants. The BLG coding gene located on ovine chromosome 3. This protein, synthesis in the mammary glands during pregnancy and the lactation stages. Studies have indicated that this protein is polymorphic in the many breeds of sheep. This is the result of a single base pair substitution in the Beta-Lactoglobulin gene that also rises to the RsaI restriction fragment length polymorphism (RFLP). The aim of this work was to analyze the genotype distribution of Beta-Lactoglobulin in sheep. Blood samples were supplied from 142 sheep of the 5 breeds (Ghezel, Afshari, Moghani, Makoii and Arkharmerino). Genomic DNA was extracted from the 200ul blood sample according to Boom et al. (1989) method modified by Shaikhayev (1995). The Gel monitoring and the spectrophotometeric methods were used for determination of the DNA quality and quantity. the Primers BLG5 and BLG3 amplified a 452 bp fragment from the exon II of the ovine Beta-Lactoglobulin gene. the Products of the amplification were recognized by the electrophoresis on the 1% agarose gel stained with ethidium bromide. The RsaI enzyme was used for restriction of the PCR products. The digested products were separated by the electrophoresis on the 8% nondenaturant polyacrylamide gel and visualized after staining with the ethidium bromide on UV transillumination. The popGen32 software (ver.1.31) was used to estimate the allele and the genotype frequencies, the Hardy-Weinberg equilibrium and dendrogram of the genetic distance. The frequency of A-allele in Ghezel, Afshari, Moghani, Makoii and Arkharmerino breeds was 56%, 34%, 36%, 53% and 48% respectively. The populations were in Hardy-Weinberg equilibrium except to Afshari breed. The lowest genetic distance was observed between Moghani and Afshari breeds and the highest genetic distance between Ghezel and Afshari breeds. The results of this study indicated that PCR-RFLP is an appropriate tool for evaluating genetic variability in sheep.
H. Ezzatpanah, M. R. Ehsani, H. Lamea,
Volume 9, Issue 2 (7-2005)
Abstract
In this research some properties of the casein micelles in the raw and pasteurized milk were studied by electron microscopy. SEM and TEM were used to evaluate the differences in acidified casein micelles of raw and pasteurized milk at the Iso Electric Point (pH=4.6). Milk samples were taken from research pilot plant of The College of Agriculture. Milk was pasteurized by the L.T.L.T. method in the same pilot plant. The samples of raw and pasteurized milk were divided into two parts. One part of raw and pasteurized milk was acidified to the Iso Electric Point of caseins (pH=4.6) by lactic acid (9%) and then sample preparation for electron microscopy was done.
According to the previous findings, results indicated that in the native pH, specially in fresh raw milk casein micelles were in spherical and individual form with the smooth surface. Aggregated casein micelles were present of acidified samples of the raw and pasteurized milk. Aggregation was the result of neutralization of electric charges in the isoelectric pH of casein and partial removal of micellar calcium phosphate. Results of both electron microscope confirmed each other and effects of heating on increasing of the casein micelle size during pasteurization were seen.
Z. Banihashemi,
Volume 9, Issue 2 (7-2005)
Abstract
The dissemination of Phytophthora spp. in the surface irrigation water was studied during 1993-94 in Marvdasht area and certain other parts of Fars province. Monthly the water samples were taken along 100Km of the Kor river 22Km up stream from the Doroudzan Dam to about 80Km down stream to Mardvdasht where Sivand and Kor rivers joined. The other sampling locations includede the Maeen river adjecent to the Dam, and the Sivand river from Dashte-Morghab to Mardasht. Few samples were also obtained from Shapour and Dalaky rivers and also from Yasouj and the Sisakht regions in Khkilueh and Boir Ahmad. The water temperature, pH and EC were measured and samples were assayed on the same day of the collection. The water sample was filtered through the two layers of the cheese cloth and about 1L was placed in a plastic container (30 × 20 Cm) 2-3C deep and 100 fresh citrus leaf disks (6mm dia) were also added and incubated at the room temprature. After 48hr, disks were collected, washed, blotted dry and plated on Phytophthora were collected, washed, blotted dry and plated on Phytophthora selective medium (PARPH). At least 50 disks were used in the 5 plates for each sample. The five to 8 boiled hemp seeds were placed on each growing colony and transferred to the distilled water, after 12hr for sporangium production. The Phytophthora species were idenified by their morphological characteristic and temperature requirement. Phytophthora spp. were present in the most rivers except the Shapour and Dalaky. The predominant species were non-popilate high temperature (above 35C) species mainly P. cryptogea and P. drechsleri. In some cases P. capcisi and the other unidentified species were also detected. Phytophthora spp. were present throughout the year but the lowest population was detected during winter months. The fluctuation of the phytophthora population and the other water microorganisms in the Kor river after shiraz petrochemical complex during the growing season was very high, but sometimes reduced to zero (perhaps due to the water pollution). No Phytophthora colonies were detected in the dam lake or in the most cases in the cement canals.
H. Naghavi, M. A. Hajabbasi, M. Afyuni,
Volume 9, Issue 3 (10-2005)
Abstract
The objective of this study was to evaluate effects of cow manure on soil hydraulic properties and bromide leaching in a sandy loam soil (coarse loamy mixed, Typic Torrifluvents). Manure was applied at 0, 30, and 60 tha-1 at three replications in a completely random design. Three months after manure application potassium bromide (KBr) at rate of 300 Kg ha-1 Br was uniformly applied on the surface. Soil bulk density, porosity, organic matter, and soil moisture at18 levels of matric potentials were determined. Soil samples to the depth of 105 cm at 15-cm increments were collected after 100, 200 and 400 mm of irrigation. Soil bulk density, porosity, organic matter content, and soil moisture at different levels of matric potential increased significantly with manure application. Manure application also significantly affected the hydraulic parameters. Bromide leaching was significantly lower in plots with manure application and the greatest leaching occurred at the zero manure application treatment. The center of mass evaluation indicated a relatively similar result with measured values.
