Journal of Water and Soil Science
Year:2007 | Volume:11 | Issue:40 (B)|Papers Count:25

Fire blight caused by Erwinia amylovora, is a serious disease of pome fruits in many areas in the world which causes evaluative necrosis. Indeed, E. amylovora can invade the whole tree solely by internal progression through the host tissues. In this research, symptoms of necrotic shoots and exudates production on infected pear trees in different areas of Guilan province (Astaneh Ashrafieh, Lahijan and Kiashahr) were surveyed. Samples were taken from infected tissues of diseased trees. For isolation of bacterial causal agent, the infected tissues were crushed in pepton water, then 100ml of the extracts were cultured on Sucrose Nutrient Agar (SNA) and Luria Berthani (LB) containing Cyclohexamid antibiotic (50 mg / ml). The isolated bacteria were rod-shaped, gram negative and facultatively an-aerobic. The bacteria produced Levan on media including sucrose, but could not produce fluorescent pigments on King’s B medium. All strains made hypersensitive reaction on tobacco leaves. All isolates were oxidase, nitrate, urease and indole negative and were not able to rot potato tuber slices, produce H2S and grow in 36oC. The isolates could use citrate, acetoin, sorbitol and trehalose and their gelatin test was positive. Based on morphological, biochemical, physiological characteristics and production of a 937 bp with specific primer Ea1 and Ea2 in PCR method, the strains were identified as E. amylovora. This is the first report of the existence of this bacterium on pear fruit trees in Guilan province.

Pollination and fertilization of canola flowers are the main factors of canola seed production. In order to study the effects of insect pollinators on seed quantity and quality of three chosen cultivars of canola, namly, S.L.M., Okapi and Talaye, a split plot experiment in a complete randomized block design with four replications was carried out in Isfahan region. Main plots consisted of canola cultivars, and subplots consisted of open pollination and non-pollination by insects. Results indicated that the time to seed ripening in pollinated plots was 10.5 days less than those of nonpollinated plots. Pollination by insects increased the number of pods per plant, number of seeds per pod and weight of 1000 seeds, by 14.3%, 23.5% and 10%, respectively. Grain yield also increased by 53% in pollinated plots. Pollination decreased seed moisture percentage by 3.15%, but its effect on seed oil percentage and germination percentage were not significant. Time to seed germination of plants of pollinated plots decreased three hours. Cultivars were significantly different in seed oil percentage and time to seed germination. Talaye cultivar produced the highest amount of oil (45.5%), while Okapi produced the lowest (40.8%). There were significant interactions between cultivars and pollination in terms of seed ripening, oil percentage and moisture of seeds, and the effects of pollination was different in different cultivars.

Lots of investigation has been done in order to increase wheat yield per acre in Iran, but there is not enough study about quality of produced wheat. Bread quality in Iran has been deteriorated in recent years, mostly due to employing wheat flours of low quality. Thus the present study was conducted to find the chemical and rheological properties of four bread wheat cultivars (Omid, Rosshan, Golestani and "Kal") produced in Sabzavar region. The results indicated that the quantity and quality of "Kal" wheat gluten are more desirable in comparison to the other varieties. The rheological experiment results indicated that the Omid wheat flour is the best regarding the dough resistance coefficient and alfa amylase activity. The alfa amylase activity of all flours was low. Appropriate time for fermentation of bread dough for all flours was 75 to 90 minutes. Mixture of one to ten ratio of Roshan and Omid flour produced bread with better quality. The results also indicated that the rheological properties of "Kal" flour dough such as mixing resistance, breaking point resistance and valorimeter value are acceptable. The bakery properties of "Kal" flour are better than Rosham flour. The "Kal" variety of wheat is the same as Roshan variety and the only difference between them is the region of production and farming conditions. It shows that farming condition is one of the important factors affecting bread wheat quality.

Producing food colors from natural sources, such as tomatoes, which could be used instead of synthetic colors, is important in relation to health and safety aspects of the consumers. In this research, solvent extracting was carried out by using three non-polar solvents, including petrolium ether (bp=55oC), n-hexane (bp=60oC) and a mixture of n-hexane: ethanol: aceton (1:1:2, bp=50oC). Also, two different temperatures (room temperature and boiling point of the solvent) and three different periods of time (2, 4 and 6 hours) of extraction were tried. Using mixture of the solvents (at boiling point) for six hours showed to be the optimum conditions for extraction and there were significant differences between this treatment and other conditions for extractions. In addition to the above results, the same volumes of the solvent and samples were found to be the best ratio in comparison with the other volumes ratios. It was significant at P £.05.. The yield of color extraction from tomatoes and tomato powder was 0.14 and 0.24% (w/w), respectively. Also, the purity of the extracted color was 82.65% lycopen. The extracted color showed a good stability in sunflower oil for three months at 4oC.

Mayonnaise sauce is a nutritious food product with high caloric content, which is usually incorporated into other products as an ingredient. The product should be produced under hygienic conditions to avoid its physical and chemical deterioration along with microbial spoilage, which mostly happens due to the lack of thermal treatment. Mayonnaise is often stored for long periods at room temperature in large plastic containers before consumption. To carry out the investigation, samples of the sauce in large plastic containers and glass jars were obtained directly from a commercial producer. After preliminary quality examinations, they were allocated into 3 lots and stored at 5, 25 or 40oC for up to 6 months. They were then subjected to physical, chemical, microbiological and organoleptic tests at monthly intervals. The results showed no significant microbial growth even when kept at higher temperatures. Significant chemical changes (autoxidation), however, occurred in both containers at temperatures close to 40oC. Organoleptic examinations revealed significant changes, especially in color and emulsion stability, which were more evidenced for those stored at higher temperature. It was concluded that the storage of mayonnaise sauce in large plastic containers at higher temperatures should be avoided mostly due to deterioration through physical, chemical and organoleptic changes of the sauce.

This research was carried out to determine the optimum conditions for acidic extraction of gelatine from cattle bones. The effects of different treatments such as pH (1.8 to 2.6), temperature (60 to 80oC) and time (40 to 120minutes) on yield of extraction, gel strength, viscosity and absorption (420 nm) were measured. Coefficients of central composite rotatable design (CCRD) and regression surface response.... (RSREG) were used. The coefficients for yield, gel strength, viscosity and absorption were 0.990, 0.991, 0.998, 0.928, respectively. According to variance analysis of the data, there were significant differences between the effects of three variables (pH, temperature and time) on yield of extraction and viscosity, but no significant difference was observed between the effects of temperature and pH on gel strength and absorption, respectively. Comparisons of the averages of functional characteristics of acidic and commercial gelatin showed that viscosity and strength of acidic gelatin were higher than those of commercial one. The optimum conditions were found to be: pH=1.88, temp. 80oC and 118 min., to reach the highest yield and pH=1.88, temp. 60oC and 48 min. to get maximum strength, and pH=2.56, temp. 69oC and 118 min. to obtain the maximum viscosity and finally, pH=2.6, temp. 62oC and 48 min. for minimum absorption. Also, the results revealed that there were significant differences between trace elements content (Fe, Ca and Pb) of commercial and acidic gelatins. Although, acidic gelatin contained higher amount of the elements, but these amounts were still less than maximum values which are allowed to exist in gelatin. Amino acid compositions of both gelatins were almost identical.

In order to detect genetic variation of native fowls in Mazandaran native Fowls breeding station, blood samples were collected from 100 male and female of birds(1:11). The DNA of the blood samples was extracted according to an optimized salting out protocol. The extracted DNA was amplified through polymerase chain reaction (PCR). Of the twenty random primers (10 mer) were used in this study, fourteen yielded satisfactory PCR. The total 63 polymorphic and 77 monomorphic bands were detected for the 14 primers. The number of bands displayed for each primer ranged from 4 to 16 with 200-2100 base pairs. The highest and lowest percentages of polymorphism band were observed for primer 9 (72%) and primer 14 (16%) respectively. The band sharing frequency was calculated for each primer, which ranged from 79 to 96. The genetic similarity within population and genetic variation were estimated as 89 and 11 percentage respectively. In conclusion, the existence of high level of polymorphism after ten generation of selection may indicate the accuracy of genetic evaluation program, suitable selection strategies and also large enough effective population size in this breeding flock.

This study was conducted to investigate the effect of formic and sulphuric acids on chemical composition, dry matter (DM) and crude protein (CP) degradability of alfalfa silage and its effect on early lactating Holstein cow as three trials. In the first trial, chopped alfalfa (22 and 33% DM) was ensiled with three levels of formic acid (0.0, 15 and 20 ml/kg DM) and two levels of sulphuric acid (0 and 4 ml/kg DM). In the second trial, DM and CP degradability coefficients of silages (Treatment 1: without acid; Treatment 2: 15 ml formic acid + 4 ml sulphuric acid per kg DM) and alfalfa hay (Treatment 3) were determined using nylon bag technique in two cannulated steers. In the third trial, silages (treatments 1 and 2) were replaced with 50% of alfalfa hay in the early lactation Holstein cow diet (11 cows, 19 ± 8 days in milk). Diets were fed for 49 days. Dry matter intake, milk production and milk composition were evaluated. Blood metabolites were determined in weeks 4 and 6. Effect of wilting on pH was significant (p<0.05). Quickly degradable fraction (a) of DM was similar in both silages (0.35) but was higher (0.5) for hay rather than the silages. Slowly degradable fraction (b) of DM of the acid - treated silage was higher compared with the hay (0.39 and 0.32, respectively). Fraction (a) of CP in acid treated silage was less than the control silage and hay (0.46, 0.57 and 0.57, respectively). Fraction (b) of CP in acid - treated silage was less compared with the control silage and hay (0.41, 0.28 and 0.35, respectively). There were no significant differences between the treatments on the cow’s performance. However, time effect on milk fat and solid non-fat was significant (p<0.01). Blood glucose concentration before feeding with treatment 2 was significantly higher (p<0.01) than cows feeding with treatment 1.

In order to study the effect of corn, Ghods wheat, Falaat wheat, and triticale with or without enzyme addition on perormance and digestive tract characteristics, an experiment was carried out by using 288 male broiler chickens in a completely randomized design with 4*2 factorial arrangements for 57 days. Enzyme addition significantly decreased both feed conversion ratio of chickens fed Ghods wheat and triticale, and weight gain of chickens fed Ghods wheat. Growth performance of chickens fed Ghods wheat with enzyme was not significantly different compared with corn without enzyme. Enzyme addition decreased ileum relative weight of chickens. Gizzard and proventriculus of chickens fed Falaat wheat and triticale were heavier than those of other treatments. According to the results, enzyme supplementation showed positive effect on triticale and especially Ghods wheat based diets.

The purpose of this research was to evaluate the effect of early life nutrient restriction and subsequent intermittent lighting schedule on performance in broiler. In a factorial experiment, the effect of three levels of feeding regimes and two levels of lighting schedule were investigated using 480 day-old male Hubbard chicks. The broiler chickens were randomly distributed over two rooms consisting of 4 replicates of 20 birds for each of three treatment groups. From 3 to 12 days of age treatment groups were either allowed ad-libitum accesses, 90% or 80% to feed. From 12 days of age until 42 days of age all birds were allowed ad-libitum access to feed. The lighting schedule for day 12 onwards in one room was a 23h light (L): 1h dark (D) lighting schedule (CL) and another room with an intermittent lighting schedule (IL, 1L:3D) from 8 AM until 8 PM . The results indicated that feed intake and feed conversion ratio of birds reared in the IL schedule were significantly lower than CL, at growth and total period of experiment (p<0.01). IL schedule did not have any significant effect on mean body weight at the end of experimental period and body weight gain at total period of experiment (p>0.05). Relative growth rate and production (PI) in the IL were higher than CL schedule (p<0.01). Feed intake and feed conversion ratio of birds given 90 and 80% of ad libitum were significantly lower in comparison with control group (p<0.01). Body weight (gain) at the end of the experiment and growth period and body weight gain in birds fed 80% of ad libitum group were significantly lower in comparison with control and 90% of ad libitum groups. At 5,6 weeks and grower period EPI and relative growth rate in birds fed 80 and 90% of ad libitum were significantly higher in comparison with control. These results indicated that feed restriction and lighting program did not have any significant effect on carcass composition (protein, fat, ash and dry matter), carcass fragment percentage (except for drumstick), abdominal fat percentage, lung, heart, right and left ventricle weight and hematocrit percentage (p>0.05), but proportion of heart weight to body weight and drumstick percentage in birds fed 80 % of ad libitum were higher than the other groups (p<0.05). Lighting schedule and feeding regime did not have any interaction effect, except for relative growth rate (p<0.05). Relative growth rate in birds with feed restriction under IL schedule was higher than birds with feed restriction under CL schedule. Intermittent lighting and feed restriction had synergic, activity effect and positive effect on body weight gain and feed convertion ratio.

A total of 179,460 monthly test-day milk records (thrice a day milking) obtained from 17,946 Iranian Holstein heifers distributed in 287 herds and calved from 1986 to 2001 were used to predict breeding value of animals. Monthly test-day milk production was analysed by applying a covariance function in which the effects of herd -year -season of production (HYSOP), age at test day (covariate), additive genetic and permanent environmental effects were included. Orthogonal legendre polynomials up to order 5 (quartic) were also implemented in the covariance model to take account of the genetic and environmental aspects of milk production variation over the course of the lactation. In the present research, breeding values of individual animals based upon 305-day and monthly test-day milk yields were compared. The results indicated that ranking of ten top sires, dams as well as progenies changed as the genetic evaluation of animals switched from the traditional (based on 305-day milk yield) to the new method that was based on the covariance function. Regression analysis of average breeding value of progenies on the first year of their calving showed that the amount of genetic trend obtained from the covariance function for 305-day milk yield was greater than that of the 305-day model (11.607 vs. 3.860 Kg/year) over the period of 16 years of calving. The phenotypic trend for lactation milk yield was 92.97 Kg per year which was statistically significant. This finding indicates that a large proportion of annual increase of milk production of Holstein heifers in Iran has been due to environmental rather than genetic improvement.

The study was conducted to compare the efficiency of diets containing various levels of calcium (0, 1, 2, 3 and 4 percentage) in feeding freshwater crayfish, Astacus leptoductylus. 150 cray fish (10 individuals per tank) with mean weight of about 8-9 gram were stocked in each of 15 tanks, containing 100 L of water. In this research, The results showed that the mean values of some parameters such as weight gain (WG), weight increment rate (WIR), length increment rate (LIR), specific growth rate (SGR), biomass increment (BI), food efficiency rate (FER) and survival rate (SR) of animal fed on different diets were 0.75-1.46gr, 9.8-24.54%, 6.57-15.33% and 0.12-0.29% respectively. However, the diet with high levels of calcium (3-4%) showed the good weight and length increment, but there were no significants difference among these indices using different trial diets. The biomass of crayfish increased with increasing of calcium concentration. So, the highest biomass (11.65gr) of crayfish was observed in the diet containing calcium about 4%. Optimal calcium requirement in the freshwter crayfish was estimated about 3.4% with broken-line regression analysis. The lowest survival rate (30%) was obtained in the diet containing 2% calcium level. There were significant differences among survival rates in various experimental diets (p<0.05). These results indicate that the dietary calcium supplement is nesessary for crayfish. The diets with high levels of calcium had a good efficiency in freshwater crayfish feeding. So it is recommended to use 3-3.5% of calcium in formulated diets for freshwater crayfish.

The main objective of this study was determining the best sprinkler system and ranking total operational sprinkler systems in Isfahan province. The data was collected through 262 questionnaires completed by farmers in Feridan and Semirom cities in Isfahan province. Ranking and comparing the systems were done via criteria matrix and qualitative efficiency of objects and compromise programming. Based on the results of this study, hand-move sprinkler irrigation and then solid-set sprinkler irrigation were found to be the best systems in most of the regions. However, solid-set sprinkler irrigation was the best in some other areas. Results also showed that there were trivial differences between farmer selection in sprinkler irrigation and suitable system in the region. Also, comparison of suitable system and conventional irrigations used by farmers showed that the current systems of farmers are not usually an optimal system.

In order to manage the rangeland resources, remote sensing data is able to provide a sensible role of different cases in flora community such as biomass. The study area in SefidAb subbasin of the Lar Dam basin is located in central Alborz, where the climatic condition is semi humid and near to moderate. For the assessment of the sattelite data and their capability in estimation of the range production, Landsat-TM data with different bands was used. In this research, the field data was collected using random-systematic method in 20 sampling units of 200 plots. For geographic coordinates of the sampling units and related pixels in digital data, GPS and also existing benchmark data of the nearest points were used. Then correlation between ground data and vegetation index from different band combination was investigated and the reasonable vegetation indices were obtained. Finally, the best models were extracted for this purpose, which showed sensible relation between the field data and vegetation index. Therefore, it is possible to estimate range production using Landsat TM data related to ground control.

Northern watershed of Kouhrang River with the area of 68437 hectares is located in northwestern Chahar Mahal and Bakhtiary province within 49o54" to 50o9"E longitude and 32o83" to 32o36"N latitude. Making a balance and equilibrium between the number of ranchers, the rangeland production potential and appropriate flock size in each utilization unit is a necessary task. It is a matter of importance to determine suitable ranch size based on pastoral household but suitable household livelihood as well. The main goal of this study is to determine utilization unit size based on ecologic and socioeconomic factors for each household. Along with detecting the ranch allotments, the range capacity and its productivity potential were studied. Then, based on expenses and the revenues resulting from herdship, (on ranges), the suitable flock size for fulfillment of the household expenses regarding the range utilization periods, the suitable range size per household was determined. 10 vegetation types with 0.91 AUM per hectares grazing capacity were detected in studied area. There are 46 range allotments and some parts of other 6 range allotments in studied area with average area at 1510 hectares. Average pastoral household is 36.8 per unit range allotments. Pastoral households share at rangelands is 41 hectares now. The minimum and suitable ranch area for each pastoral household which can provide annual needs and costs is 520 hectares and 142 animal unit at a mix flock at 3 to 2 ratio of sheep to goat for a 100 – dayes grazing season. The result of this study showed that production potential at each range unit is influenced by flock size, household share on farming lands, and the household numbers on each ranch unit. Ranch unit and the livelihood level, have significant influence at 5% level on suitable ranch size per household.

In order to evaluate the capability of ETM+ remotely- sensed data to provide "Forest- shrub land- Rangeland" cover type map in areas near the timberline of northern forests of Iran, the data was analyzed in a portion of nearly 790 ha located in Neka- Zalemroud region. First, ortho-rectification process was implemented to correct the geometric errors of the image, which yielded 0/68 and 0/69 pixels of RMS error toward X and Y axis, respectively. The original multi-spectral bands were fused to the panchromatic band using PANSHARP Statistical module. The ground truth map was prepared using 1 ha field plots in a systematic- random sampling grid. Vegetative form of trees, shrubs and rangelands was recorded as a criterion to allocate the plots. A set of channels including original bands, NDVI and IR/R indices, and first components of PCA was used for classification procedure. Automatic band selection command was used to select the appropriate channel set. Classification was carried out using ML classifier on both original and fused data sets. It showed 67% of overall accuracy and 0/43 of Kappa coefficient in original data set. Due to the results present presented above, it's concluded that ETM+ data has an intermediate capability to fulfill the spectral variations of 3 form- based classes, in the studied area. Furthermore, applying complementary methods to minimize the background spectral effect is proposed for future studies.

In order to determine the reciprocal relationship between the important characteristics of soil and the growth of Haloxylon ammodendron (C.A. Mey) plant in segsi plain of Isfahan., ordination method was used. The study was performed through the stratified random sampling and the regions were separated according to the plant age and physical physiognomy, then 10 samples of Haloxylon ammodendron (C.A. Mey) of the same age were selected in each region. Meanwhile, factors such as height, canopy cover area, canopy cover perimeter, canopy cover diameter, and basal area were considered. Also, 30 profiles from viewpoint of growth situations in 10 different regions were dug. Soil characteristics such as: pH, Ec, total soluble Ca2+ and Mg2+, Cl-, CO3-, HCO3-, SP%, CaCO3%, CaSO4%, organic matter%, total nitrogen percentage, phosphorous, Na+, K+, SAR, and hardpan depth were measured. Data was analyzed using ordination method. According to the results, samples of the same age showed significant differences in plant features. Other results showed that physical characteristics such as depth of hardpan from soil surface, SP%, and chemical characteristics such as salinity, alkalinity and total nitrogen had the highest effect on qualities of this kind of plant. In other words, the results mentioned above showed the important role of Haloxylon ammodendron (C.A. Mey) in sharp increase of salinity and alkanity in its stratum.

In this investigation, the effect of seed source on the germination and survival of Acer velutinum Boiss. was assessed. Seeds were collected from 11 seed sources ( located at 20 to 2200 meter a.s.l in Mazandaran forests) and planted in a mountain nursery (Orimelk located at 1550 meter a.s.l) as completely randomized block design with three replications. The results show that the effect of seed source on germination and survival was statistically significant (p<0.01). Germination and survival rates were lower for the Pasands, Ashak and Deis sources, and the maximum seed germination was related to Lamzer site. Effect of seed sources on survival of seedling was significant too. The maximum and minimum survival was related to Lajim and Ashak, respectively. Regarding plan table seedling, the effect of seed source was significant. The maximum efficiency of seedlings has been found in Lajim, Lamzer, Parke Noor and Sangdeh sites, while the minimum range of efficiency was related to Ashak and Pasand2.

Ferula ovina Boiss. is one of grazing species whose seed germination faces certain problems. The dormancy characteristics of and optimum conditions for seed germination of this species have not been investigated so far. The present research was designed to investigate the effect of GA3 and moist chilling on seed germination of this plant. At first, a factorial the experiment in a completely randomized design with 6 replicates was performed to evaluate the factors: cold period in 0-3 °C (0,3,5,7,9 weeks), GA3 concentrations (0,500,1000 PPm) and time of GA3 (before cold, during cold, after cold). In the second experiment, the effect of cold duration and GA on T50 Ferula seed was investigated in 6 replications. The best treatment was moist chilling for 7 weeks at 3 C or 3 weeks of moist chilling together with soaking in 500 PPm GA3 solution for 12 h. These treatments significantly increased germination percentage and decreased the time of for germination by 50% (T50) compared to control. The addition of GA3, together with cold duration was more effective than its application before cold period, addition of GA3 after cold period, no further increase in germination occurred. Also increasing GA3 concentration (500 to 1000 PPm) did not have any significant effect on the percentage of germination and could not replace the total need for pre chilling. The results showed that Ferula ovina seeds display an endophysiological dormancy that can be released by GA3 and moist chilling treatment.

Selection of efficient indices is very important for detecting and measuring random, uniform and clumped distribution patterns of plants in different plant communities. To compare and evaluate indices of dispersion patterns of plants, three stands were selected in Nodushan, Yazd. A (50m*100m) area was selected within each stand for sampling. Sampling was randomly systematically conducted. Measurements and counts were made at 50 points and (1 and 2m2) quadrats which were randomly selected along four 100m transects within each sampling area. Indices of dispersion using quadrate studied in this survey include: Standardized index of Morisita, Morisita's index, Green's index, Dispersion (variance/mean ratio) index , Lloyd's index of patchiness and distance indices of dispersion including Pielou, Hopkines, T square, Eberhardt , Hines, Johnson and Zimer and Holgate indices. Results showed that T square and Holgate indices were more powerful than the other indices for detecting intensity of small-scale and tightly clumped pattern of shrubs because the two indices could distinguish between single individuals and the individuals on the edges of dense and small clumps. Johnson and Zimer index and Standardized index of Morisita (in shrublands with plant cover greater than 5%) were more efficient than the other indices for determining spatial pattern of these small clumps and single individuals. Among studied indices of dispersion, Green's index had the highest precision and with the exception of this index, distance indices were more precise than the quadrate indices.