Journal of Agricultural Sciences and Natural Resources
Year:2008 | Volume:15 | Issue:6|Papers Count:39

A 3-year field experiment was conducted to compare fruit quantity and quality of Thomson navel orange (on flying dragon rootstock) under four microirrigation systems. The experimental design was complete randomaized blocks with four treatments and six replications. The treatments consisted of four microirrigation systems: Microjet, Bubbler, two and three in-line drippers. Trees were irrigated during spring and summer seasons when tensiometers indicated the soil tension of 50 kPa. The amount of applied water in each treatment was measured by water meter. In middle November, fruites of one tree per replication were picked and the yield of trees were measured. Then, 25 fruits per tree were randomly separated and peel thickness, diameter, length, weight, TA and TSS were measured. Trunk diameter and canopy volume were measured in Mar. 2003-2005 and Nov. 2005. Comparison of means showed that the yeild of trees in microjet and two drippers irrigation were significantly higher than bubbler and three drippers systems. The yeild of trees in two drippers and microjet treatments was 16.6 to 19.2% more than bubbler and three drippers. Irrigation systems had no significant effect on the vegetative growth of trees and fruit peel thickness, diameter, length, weight, TA and TSS.

The present research in this regard has been done with the aim of identifying and examining the extension mechanisms effective on the risk management of wheat Production in Khorasan Razavi Province. This study is of the survey kind with a population of around 19536 farmers who produce wheat of Khorasan Razavi Province, have been involved in cultivation of water wheat in the agricultural year of 2005-2006, and have done the farming operation under the supervision of experts. From among this population, 400 farmers were selected by using stratified sampling method with proportionate scale and studied. In order to obtain information from interview, questionnaire tool were used and its sustainability was approved by Cronbach's Alpha coefficient. The results of the research showed that the most threatening risks of wheat production according to their priority include natural and economic risks and the most important strategies used against them according to their priority include technological and financial strategies. The results factor analysis showed that in stage identifying wheat production risks, abundant and group mechanisms, in stage assessment of wheat production risks effects, individual and group mechanisms and using indigenous organization, in stage identifying strategies and tools, group mechanisms, designing radio and TV program, in stage appropriate methods of selecting tools and risk management sterategy, individual mechanisms and utilizing indigenous knowledge, and in analyzing decision making process, individual and group mechanisms with emphasis on indigenous knowledge are effective on the management of wheat production risks.

The purpose of this research was to investigate communication factors influencing attitudes of farmers' application of soil conservation practices in the Karkhe and Dez Wtershed in Khusestan Province of Iran. The study consist of all farmers in Karkheh and Dez watershed in Khuzestan (N=394), of which 82 is selected through proportionate stratified random sampling technique (N=82). The study was a descriptive–co relational, survey research. A questionnaire was designed and employed to gather the required data. A panel of Agricultural Extension and Education experts verified its content validity. The scale of attitude of the questionnaire was proved to be reliable as Cronbach Alpha Coefficients was equal to 0.74. A pilot study was initially conducted to determine the reliability of the questionnaire. Findings in the study indicated that a majority of the farmers have positive attitude toward adoption of soil conservation practices. The results showed there are a significant and positive correlation between farmers' attitudes towards application of soil conservation practices and rate of use Cosmo politeness, organizational and mass resources and channels of communication. The results of factor analysis of communication factors data showed that the most important factor was the Cosmo politeness resources and channels .According to regression analysis level of using Cosmo politeness, organizational and mass resources and channels of communication were found to have contributed to the increase of positive attitudes of farmers toward application of soil conservation practices.

Identification of susceptible areas to landslide occurrence is one of the basic measures to reduce the possible risk and hazard management. The main aim of this research was to compare applicability of two statistical landslide hazard zonation models (valuing information and valuing area accumulation) in the Shastkalate forest, Gorgan, Golestan province. By using fielding works, the occurred land slides in the study area were gathered and rectified by GPS. The occurred land slides map was generated using GIS software. By review of previous works and field works, the seven following factors were recognized as primary effective factors on the landslide occurrence: altitude, slope, aspect, rainfall, geology, distance from fault, and distance from hydrographic network. After preparing the map for above-mentioned factors in GIS, these maps were crossed with the occurred landslide map. Landslides amounts and their areas were computed in each class. After determining the rate of each factor (element), land slide zonation was performed in GIS by statistical models i.e., valuing information and valuing area accumulation according to area density and the weighted quantitative amounts. The efficiency of output results of models was assessed by DR and QS indices. The results of DR index showed that both models had better functioned to recognize the hazard classes with high danger than ones with low danger. The results showed that in the study area that was analyzed by QS index, the valuing information model with QS=1.039 had relative desirability than the valuing area accumulation with QS=0.45.

The knowledge of effect implement forest management systems on regeneration density and species diversity is very important and essential for conservation and forest sustainable devlopment. The effects of shelterwood system (stands 25 and 45 years old or stand 1 and 2) were detected on regeneration density and species diversity and were compared with natural stand in the Loveh forest (Golestan province). Systematic random network was established with dimensions 60×60 m and 60 plots were measured. Then all data including species, DBH and implement regeneration information saplings complete lower and greater than 1.30 m hieght were recorded. Results showed that regeneration density have significant different (on level 99% probability) in the natural stand with managed stand (stand 1 & 2). Hense it was observed maximum density saplings in managed stand (25 year). Results also showed that stands have significant difference in the richness indices and Simpson’s hetrigenity indices. This acount is lower compared to managed stand but it is increase opposite eveness value (Smit- Wilson). Species diversity was higher than these in managed stand due to reduced canopy cover and establishing on ligth-demanding species.

Knowledge of forest structure and its complications are very important and necessary in forest management. The aims of this study was to investigate structure in unmanaged Oak stands and were compared with managed stands including 25 and 45 years practiced stands (Shelter wood system) in the Loveh forest, north of Iran. In this study 45 plots were selected with dimension 50×50 m with systematic randomness layout. Then all of tree variables measured and recorded including: species name, DBH, total height, trunk height and diameter of the canopy. The results showed that unmanaged stand have difference significant (P<0.003) with 25 and 45 years managed stand in DBH, basal area, density, total height, trunk height and canopy area. Unmanaged stand has maximum DBH (56.4 cm) while 45 years practiced stand has minimum DBH (22.5 cm). Basal area (44.57 and 20.77 m2) and height (22.6 and 18.12 m) were influenced respectively. Also 45 year-old and natural stands have account density maximum and minimum (521 and 230 per hectare). Natural stand is including maximum canopy area with (218.5 m2 / hectare) and 45 year-old its have a minimum canopy area (98. 7m2 / hectare). Generally, results showed that density trees in stands with canopy area have relationship reverse.

Soil quality as a concern for sustainable global development was defined to conserve soil productivity and water, air and human health under sustainable land uses. Soil quality investigations are needed to provide information for management and regulatory decisions. Soil quality indicators usually are used to assess soil quality in an ecosystem. This study was conducted to evaluate the effects of three crop rotation systems in paddy soils of Dasht-Sar district, Amol, Mazandar province. Three adjacent sites which managed over 8 years similarly were selected. The study area located 8 km far away of Amol in Mazandaran province. Soil sampling was performed on a regular systematic pattern in three selected plots with 100 in 15 m dimensions and in depth of 0-30 cm of soil in forty locations. Statistical Results showed that frequency distribution of most data was normal. The lowest CV% was related to pH. Analysis of Variance (ANOVA) and comparison test showed that there were the significant differences in soil quality indicators between understudy crop rotation systems. Results of multivariable regression analysis revealed that soil respiration and microbial biomass carbon had high correlation coefficients with soil organic matter and MWD. Overall results indicated that the rice rotation with legumes such as bean and clover over a long time improved soil quality in compared to rice-follow rotation.

Salinization and sodification of soils is one of the major problems in arid and semi-arid regions with shallow water table. Preparing soil salinity map for site-specific management is an important issue, since excess of soluble salts in the soils root zone can provide problems to the plant growth. Study area is located in the northeast of Aq-Qala. For preparing soil salinity map, samples of 100m*100m grid pattern in 784 points from 0-30 cm soil depth were taken. Electrical conductivity from soil saturation extract (ECe) was measured. Analysis of data and preparing ECe map were carried using a Geographic Information System (GIS). The results were indicated that, ECe of study area is 9-32 dSm-1. According to the soil salinity map, soils were classified in the three ranges: 9-15, 15-24 and 24-32 dSm-1. The results were indicated that the soils of study area were affected by salinization and sodification due to excessive evaporation of shallow saline water-table. While, soils in southlands is the more salinity than northlands, due to shallower water-table. Therefore, site-specific management and increasing the water table depth in study area suggested as main method to prevent of soil salinization and sodification. In this study preparing soil salinity map was aim for site-specific management and reclamation of soils in study area.

Biofertilizer effects were investigated on soybean seed vigour produced under water deficit stress conditions. Experiments were conducted under field and laboratory conditions. Filed study was done as a split factorial in RCBD and laboratory experiment was conducted as a factorial experiment in CRD with 4 replications. The seeds were evaluated by standard germination test. Experimental factors were biofertilizer (Bradyrhizobium japonicum, Bradyrhizobium japonicum+Pseudomonas fluorescens and Bradyrhizobium japonicum+Glomus mosseae), cultivar (Zalta Zalha and line Clark×Hobbit) and water deficit stress (irrigation after 50 [normal irrigation], 100 [mild stress] and 150 [intense stress] mm evaporation from pan class A, in parents field). Results showed that water deficit stress had negative effect on soybean field seedling emergence and seed vigour. Under field conditions, co-inoculation of B. japonicum and P. fluorescens with seed were effective on cumulative emergence rate in water deficit stress levels. Co-inoculation of B. japonicum and P. fluorescens with seed cultivars were effective on primary field emergence in water deficit stress levels. Under laboratory conditions, Application of biofertilizer had significant effect on germination prcentage and coefficient of velocity of germination, but interaction of cultivar and biofertilizer was differed under stress conditions. Inoculation of Zalta Zalha seed with Bradyrhizobium japonicum increased coefficient of velocity of germination percentage in normal irrigation conditions, but in mild stress condition using of Bradyrhizobium japonicum and Pseudomonas fluorescens or Glomus mosseae increased seed germination. Inoculation of Clark×Hobbit seed produced under mild stress conditions with Bradyrhizobium japonicum and Pseudomonas fluorescens increased germination percentage. Germination percentage, primary root length, primary shoot length and cumulative emergence rate had significant and positive correlation with primary field emergence.

In a two-year study, above-ground dry matter accumulation in canola (Brassica napus), and its relation with harvest index and seed yield were evaluated under vast environmental conditions. The experiment was a randomized complete block design arranged in split plot, conducted at Agricultural Research Station of Gonbad. It was arranged in two conditions, i.e. supplemental irrigation and rainfed. Two cultivars of spring type canola (Hyola 401 and RGS003) as subplots were grown at five sowing dates as main plots. The sowing dates were 6 Nov., 6 Dec., 5 Jan., 4 Feb. and 6 Mar. In both years, the mean above-ground dry matter in supplemental irrigation was more than that of rainfed conditions. The amount of rainfall at flowering and seed filling periods in 2005-6 was less than that of in 2006-7. This resulted that the efficiency of supplemental irrigation to increase above-ground dry matter and seed yield in 2005-6 was considerably more than that of in 2006-7. The increase of air temperature at late sowing dates caused significantly decreases in above-ground dry matter, harvest index and seed yield. Delay in sowing date led to critical periods of flowering and seed filling coincided with terminal high temperature and drought, which resulted in decrease in the number of days to flowering and physiological maturity stages. The amount of accumulated above-ground dry matter (except seed) at physiological maturity stage in Hyola 401 and RGS003 cultivars was 6290 and 6140 kg/ha in 2005-6, and 5795 and 5804 kg/ha in 2006-7, respectively. So the seed yield superiority of Hyola 401, compare to RGS003, was mainly due to higher harvest index, and there was not any considerable difference between two cultivars, for accumulated above-ground dry matter except seed.

Genetic characterization and classification of germless are very important in breeding programmers. In this study 46 Citrus genotypes of Iran were classified based on data obtained from microsatellite marker banding pattern, using the Complete Cluster analysis. In this research nine pair of SSR primers generated a total of 54 alleles. The CAC33 with 9 alleles had the highest and TAA17 with 4 alleles had the lowest number of alleles among the SSR markers employed. The number of heterozygote varieties varied from 21 in TAA27 and 43 in TAA17 loci. The highest PIC value was related to TAA15 (PIC=0.782) and the lowest was for TAA27 (PIC=0.412). Cluster analysis divided the genotypes into 3 clusters. The genotype Kc36 was very similar to Kc43 and both of them were grouped in the same cluster and the least similarity with other types was related to the genotype Kc41. Also (Citrus maxima), (Citrus medica) and (Citrus reticulata) were placed in three groups. Based on results obtained from this experiment, it was inferred that among the studied SSR marker employed, TAA41, CAC15, CAC19, TAA15, TAA33, CAC33 and TAA1 revealed high distinct polymorphism. From the result of this study we suggest that these markers can be used for detecting genetic variability on Citrus germplasm.

This study investigated some hematological response and healing of experimentally wounded carp with injection of vitamins A, C, A+C and AD3E under laboratory conditions at temperature of 17-18oC, in order to improve the healing process in skin lesions. Ten treatment groups of fish (body weight 120±20g) were injected with 10000, 20000, 50000 IU vitamin A/KgBw, 200, 500, 1000 mg vitamin C/KgBw, 20000 IU vitamin A and 500 mg vitamin C/KgBw, 1ml vitamin AD3E (contains: 5000 IU vitamin A, 10000 IU vitamin D3, 20mg vitamin E)/KgBw, 50mg oxytetracycline/KgBw and one group without any injection as control. We also used 50mg oxytetracycline injection/ kg bw on all treatments. Wounded tissues and blood were sampled in 0, 5, 10, 15, 20, and 30 days after making the incision. During the 30-day period of wound healing, except in differential leukocyte counts, there were no statistically significant changes in hematocrit, total erythrocyte and leukocyte counts. There were also no histological differences among all treatments. Histological analysis revealed all treatment incision site healed 30-day at the same rate. Therefore, injection of vitamins did not improve wound healing in common carp under the conditions of this study.

A survey has been done to determine some biological characterictics of eggs (including diameter, surface, volume, surface to volume) and hydrated egg (including diameter, surface, volume, surface to volume, yolk sphere, pervitelline space and yolk sphere to pervitelline space) in 90 migratory population of wild common carp at 3 treatment (initial, middle and end of broodstock migratione time) in 2005 to 2006. Rang of egg diameter and its surface to volume were 1.2mm to 1.75mm and in hydrated eggs were 1.55mm to 2.15mm which was significant (P<0.05) at broodstock migration times and was minimum at the end of migration time and was maximum at initial migration time. Yolk sphere to perviteline space ratio in hydrated eggs and in wild common carp broodstock was calculated 1.64 which definitely yolk sphere was larger than pervitelin space. The difference between Effect of broodstock migration time on yolk sphere to perviteline space was significant (P<0.05) and was larger in initial cycle. Becase, the larger eggs in initial migration time, have longer metabolic rate.

In this study, the effect of vitamin C injection on resistance promoting of common carp, Cyprinus carpio juveniles against doses of theront of Ichthyophthirius multifiliis was investigated. Average weight of fish was 36.5±14g. Required theronts were obtained according to Wahli method from infected ornamental fish. There was 24-hours interval between injection, and exposed to theronts. This experiment was carried out in 13 treatments include: 15 fish per each group, control (without injection vitamin C and challenge with theront), fishes were not injected and exposed to 3 levels of theronts in 250-5000-20000 per fish, 9 treatments with different levels of vitamin C, 200-500-1000 mg/kg BW, and challenged by different dosages of theronts, 250-5000-20000 per fish under in vitro condition (25-28oC). The results showed positive effects of vitamin C injection, 500 and 1000 mg/Kg BW, on reduction of mortality rate, but injection of 200 mg/KgBW had no effect on mortality rate. Also, high mortality rate was observed in higher levels of theront concentrations. Mortality range was between 0% (control and 250 theronts) and 100% (without injection vitamin C and challenge with 5000 theronts, without injection vitamin C and injected by 200 mg/Kg BW and challenge with 20000 theronts).

The tubercles of teleosts are induced by several sex hormones and fall off shortly after spawning. During this study which was carried out in Gorganrood for 3 months, the correlation between secondary sexual characters and fish size with gonadosomatic Index and spermatological parameters (spermatocrit, sperm volume, sperm concentration and duration of sperm motility) of Mahisefid Rutilus frissi kutum kamensky 1901 was investigated. 10 samples semen of Mahisefid was gathered with 5cc syringes and immediately were transferred to laboratory with ice flask and based on the number of their breeding tubercles divided to 3 categories: tubercles>100 (1 treatment), 80-100 (2 treatment), and tubercles <80 (3 treatment). With increase of head tubercles, total length (P<0.05), sperm volume (P<0.01) and gonad weight (P<0.05) was increased. But duration of sperm motility, spermatocrit, sperm density and gonadosomatic index were not influenced with the number of head tubercles (P>0.05). The results of Pearson test indicated that head tubercles with total length, total weight and gonad weight (P<0.01) and sperm volume (P<0.05) was correlated significantly. But no significant relationships (P>0.05) were found between gonadosomatic index with sperm parameters and fish size.

Salinity is one of the environmental stresses that impose a reduction or delay in germination and supress establishment and growth of both halophyte and glycophyte plants. This research was carried out to estimate the salinity resistance of four Eucalyptus species: Eucalypus sargentii, E.occidentalis, E. salubris and E. globules at germination phase and seedling growth phase. Five NaCl level (0, 50, 100, 150 and 200 mM) treatments were used in three replication in a factorial experiment design based on completely randomized plots. Radicule length, plumule length, vigour index germination percentage, germination speed and germination index were estimated at germination and seedling stage. Pigments (total chlorophyle, chlorophyle a, b and carotene), soluble sugar, prolin, amas, leaf area, relative water content, water saturation different, specific leaf area and leaf water content per unit leaf area were measured in growing stage on six mounth plant. Increased of salt stress leds to increased prolin, soluble sugar and decreased of pigments and growth parameters in four species. The highest quantity for vigour index and germination speed respectively belonged to E. occidentalis and E. salubris. In growth stage E. sargentii had highest quantity in total chlorophyll, chlorophyll a, carotene, prolin, soluble sugar and leaf area. The lowest quantity in germination and growth stage was belonged to E. globules.

Salinity is one of the most serious threats to yield reduction of crop and resulted to depletion of natural vegetation in many parts of world especially in Iran. Sesbania aculeata is moderately salt tolerant and may be utilized as forage crop for reclamation in semi-saline lands. The objective of the present study was evaluation of salt tolerance in Sesbania aculeata and investigation of the roles of potassium nutrition in salt effects alleviation. Plants were cultivated in greenhouse with Hoagland nutrient solution in sand culture. The experiment were conducted in completely randomized deign as a factorial. Factor one was salinity treatments including 0 and 100 mM NaCl and factor two was potassium treatments including 1, 2.5, 5, 10, 15, 20 and 40 mM K+. The plants harvested after 2 months treatments. The identified parameters were included fresh and dry mass, Na+ and K+, concentration and biochemical parameters including chlorophyll a and b, soluble sugar, amino acids content and peroxidase activity. The results indicated salinity reduced plants growth and decreased relative water content and imposed ions imbalance in plants tissues. Increase of salinity in root medium resulted to increment of Na+ and Cl- concentration and decrease of K+ and K+/Na+ ratio. Also, Salinity induced marked increase in peroxidase activity. Potassium treatments without salinity could be divided to 3 parts including critical, luxury and toxic nutrition. The optimum of plant growth was achieved in 1 mM potassium treatment without salinity and potassium toxicity in 40 mM K+ treatment caused increase in peroxidase activity and amino acids content and decrease of soluble sugar and consequently resulted to lower growth. In critical potassium nutrition (1 mM K+), Na+ and Cl- toxicity caused increase in peroxidase activity that resulted to relatively the lower growth under salinity. Salinity was intensified potassium toxicity (40 mM K+), decreased soluble sugar, increased peroxidase activity and consequently induced drastic growth reduction. The highest growth of plants under salinity was observed in 2.5 mM potassium nutrition. The results indicated that salinity enhanced potassium demand in Sesbania aculeate up to a threshold.

The demand for low/free fat products increases by increasing in diseases related to edible fat. Chips and fast foods are very popular among peoples specially child’s and young peoples. It's contained high level of fat and so can be harmful for its consumers. Production of highly quality low fat chips is a way to increase of society health. Coating before frying reduces oil uptake in fried products. In this research the effect of four hydrocolloids Guar, Xanthan, Carboxy methyl cellulose (CMC) and Tragacanth gum at different concentration on oil uptake and sensory properties of produced chips was evaluated. Results showed that CMC 1%, Xanthan 0.5%, Guar 0.3%, Xanthan 1% and Tragacanth 1% with amount of oil absorption 21.220, 21.757, 22.383, 24.840 and 26.740 percent had the lowest amount of oil uptake respectively and uncoated chips (blank sample) and coated with Tragacanth 2% had the highest amounts of oil absorption (P<0.05). In sensory evaluation, the highest and lowest quality related to coated chips with Tragacanth 2% and uncoated chips, but by regard to results of oil absorption and sensory evolution, best one was a sample coated with CMC 1% and Guar 0.3%.this sample significant differences in sensory properties with Tragacanth 2% (P<0.05). In sensory analysis all coated potato chips in compared to blank sample get high score and nobody didnt distinguish coated sample with uncoated one (P<0.05).

In this study, the effect of "Osmodehydrofrozen" fruits on sensory, physical, chemical and microbiological properties of yoghurt and its quality during storage was evaluated. The experiment conducted in two stages. At the first stage, the fruit percentage, type and addition time (before and after of fermentation) was determined, the results indicated that yoghurts which contained 10% apple or 13% strawberry which was added after fermentation had better quality. Because of high osmotic activity of apple, the synersis value was lower in apple yoghurt. According to osmotic activity in both fruits, the synersis value was very lower than fruit yoghurts which contained untreated fruits. Taste value was higher in strawberry yoghurt and texture and mouth feel values were higher in the yoghurt with high percentages of fruit. The results of second stage (quality evaluation during storage) indicated that storage had significant effect on pH, acidity, synersis, taste and texture (p<0.05). No mold and yeast grew in samples containing apple and Coli forms disappeared after 7 days of storage. In samples which contained strawberry, yeasts grew and coli forms disappeared after 7 days of storage.

Internal and external accumulation of ethylene is considered as one of the most significant causes of post-harvest losses in cut leafy vegetables including lettuce and cabbage. Ethylene is an important factor in the ripening of fruits and is naturally produced in most plant tissues. Its production and accumulation during the storage can cause serious damage to the stored vegetables such as lettuce and cabbage. It plays a significant role in shelf life and can cause a marked increase in respiration rates and enhanced senescence. In vegetables and cut flowers, accelerated aging and the initiation of ripening can occur following exposure to ethylene at concentrations as low as 0.1ml/l. As senescence begins, spoilage due to indigenous bacteria can be augmented. In the presence of ethylene, vascular tissue browning is formed in the cut edge of lettuce and cabbage. Another symptom of the presence of ethylene is the appearance of brown dots and patches on the leaves. Removal of ethylene therefore is expected to increase the shelf life of the harvested lettuce and cabbage. This study was conducted to investigate the effect of removal of the ethylene using Potassium Permanganate coated nano zeolites from the storage. Potassium Permanganate and Zeolite based Nano-Molecular Filters were used in ETH 1500 machine (Bioconversion). One cultivar of lettuce and one cultivar of cabbage were used in this experiment: the Iceberg lettuce and Chinese cabbage. The experimental design was Factorial in Complete Block Design (CBD) with four replications. The two factors were the presence or absence of the machine and the kind of vegetable (lettuce and cabbage). Commercial traits affecting the marketing and shelf life of lettuce i.e. pH, texture (firmness), colour (Chroma, Hue angle and lightness) appearance and the reduction in fresh weight were measured at the beginning of the experiment (day 0) and every 7 days after that until 21 days of storage. Results showed a significant difference in the measured traits in lettuce and cabbage cultivar between the presence and the absence of the ethylene absorbing machine. Comparison of the means showed that in Chinese cabbage after 21 days of storage, significantly higher texture firmness (208.83N), color brightness (%63.21), and visible quality (3), and significantly lower reduction in fresh weight (%2.945), pH (6.42), and the cut edge vascular tissue browning (3.38) were observed in presence of the ethylene absorbing machine in comparison with the control treatment (no ethylene absorption). Similar results were obtained for Iceberg lettuce after 21 days of storage. These results indicate that using nano zeolite particles coated with potassium permanganate in a machine circulating the ethylene containing air, prevents weight loss, reduction in firmness, spoilage and increase shelf life and the quality of stored lettuce and cabbage variety.

Morphometrical variance and host preference of two isolates of root-lesion nematode Pratylenchus vulnus, extracted from apple and maple trees, were analysed. Studies of morphometric characters (population cultured on carrot disks) with MVSP-32 software (UPGMA method and euclidean similarity coefficient) and also analysis of variance showed that number of variable characters is higher among the female nematodes than the male ones. Characters were grouped into three categories (high variability, higher than 70%, medium variability, between 50% to 70% and low variability, less than 50%) according to a percentage of inter-population variance. In the female nematodes, head-vulva distance and overlapping amount indicated the least variability in the two isolates. However, Body Width and Anal Body Width were the most variability. Host preference of maple (Acer velutium and Acer cappadocicum), olive (Olea sp.), corn (Zea mayes) and soybean (Glycine max) were evaluated for these isolates. Acer velutium and Acer cappadocicum were good hosts for both isolates. In the soybean plant, Reproductive factor (Rf) was less than 1 and therefore that is not regarded as a host, although nematode penetrated in the root. In the corn and olive plants was observed no penetration of nematode in the roots, therefore these plants were considered as non host plants. The results of this research demonstrated morphometric variability and high host preference in the Iranian isolates of Pratylenchus vulnus.

The present research was carried out for comparison of xylem vessels diameter and some anatomical attributes relation with it at Ulmus minor and U. parvifolia as the important factors of host-resistance to Dutch elm disease. In this experiment, in addition to estimate of vessels diameter, indexes of percentage of vessel transactional area, percentage of vessels greater than 100 micrometer and rate of relative theoretical hydraulic conductance were calculated in the second and third year rings for these two elm species. The results showed that significant difference at probability level 1% was among the calculated indexes of these elms, so that U. minor had the less vessels but with more diameters than U. parvifolia. The percentage of vessel transactional areas and vessels greater than 100 micrometer were calculated for U. minor more than U. parvifolia. The relative theoretical hydraulic conductance index was also received significantly for U. minor higher than U. parvifolia. Totally, being of these significant differences among cited anatomical indexes for U. minor, susceptible to Dutch elm disease, and U. parvifolia, resistant to Dutch elm disease, could be affected to indicate agent or agents of host-resistance with respect to Dutch elm disease, that were discussed in this paper.

Sclerotinia stem rot (SSR), caused by Sclerotinia sclerotiorum, is one of the most damaging diseases of canola in many areas of the world, including Iran. The relationship between disease incidence (I) and severity (S) is an epidemiologically significant concept, because incidence is quicker and easier to measure than severity. It is generally perceived that measures of incidence are often more accurate, precise, and reproducible than measures of severity, but severity is often considered a more important and useful measure of disease intensity than incidence for certain objectives. The I-S relationship of SSR of canola was studied in Golestan province, northern Iran. Statistical analyses were performed on three factors: fields, location/year combinations, and all data collected for the final model. For the first factor, allometric (ln transformation of I and S) model had the best fit, but in the second factor, the slope of linear and ln models at the Gonbad location was significantly different from three other locations (Gorgan, Ali Abad, and Kalaleh). Final models were evaluated based on R2, SEEy and residual plots of regression analysis of raw and back-transformed data. Based on these criteria, final models were of allometric family, both in Gonbad (S=(0.526) I (1.2)) and three other locations (S=(0.82) I (1.073)).

Cone penetrometers are devices to determine the soil penetration resistance at different depths and the results can be used in many varied applications such as construction, military and agriculture. In this research, cone index - depth measurements of a developed tractor mounted and a hand push (model SP1000) cone penetrometers were compared and evaluated. In both systems, a cantilever beam transducer and a photocell sensor were used to measure the soil resistance and depth, respectively. The penetration tests were conducted on two type soils at two plots. On each plot, 10 points were randomly selected and both systems were tested. The hand push penetrometer data were collected in a digital memory and was given to a computer. However, the results of tractor mounted cone penetrometer were recorded by an x-t recorder. The results of experiments indicated that coefficient of correlation for plowed and stubbly soils were R2=0.97 and R2=0.96, respectively. Based on t-test results, there was no significant difference between cone indexes for both systems at 5% level of confidence. Therefore, with respect to advantages of tractor mounted cone penetrometer, it is suggested to use in soil strength researches.

Particle discharge from a flat bottom hopper has been performed employing a Discrete Element Model with Multi-sphere particles. A flat bottom hopper of 100cm width has been prepared using 3-dimensional particles in a vertical layer. Particulate assemblies comprising 5000 particles of equal volume but different aspect ratios ranging from 1 to 4 have been created using some non-overlapping spheres in order to investigate the effect of particle shape on bed structure and flow characteristics of particles. The particles all generated and deposited in an upper section with almost the same hight and flow started by removing the orifice. The results showed a distribution of solid fraction within each bed, with the closest distribution to the normal distribution for the beds of elongated particles. The localised densely packed areas have been separated by voids caused by bridging of particles in the beds. Simulation results on silo discharge showed that the behaviour of beds of spherical particles was quite different from that of non-spherical particles. Spherical particles moved individually during flow and rolled over each other, resulting in a lower resistance to shear with a fluid-like flow, whereas elongated particles exhibited a stronger shear due to interlocking between particles, resulting in a flow, like a breaking continuum. This unique behaviour of spherical particles caused a higher flow rate than non-spherical particles. The formation of arching has been also simulated by the DE model. A qualitative correlation between the frequency of arching and aspect ratio has been recognised.  More arching occurred as the aspect ratio of particles increased. Due to this behaviour of non spherical particles their observed flow rate was less than that of spherical particles. It can therefore be concluded that the results obtained from the DEM models with spherical particles cannot be generalised to real material comprising non-spherical particles.

Vegetation dynamic concepts and models play an important role in the new paradigms of the rangeland science, but historically, their development have been remained abstracted and theoretical. Rangeland health concepts and methods provide a relatively suitable analytical and practical framework for applying these theories in the field. To make succession investigation feasible, we have used the chronosequence succession's concept to change time dimension into spatial dimension. Then, the Rangeland Health Assessment (RHA) protocol was applied to rank sites for their health as compared to those of the references area. After grouping sites based on their similarity in health rank and using ecological threshold, the catalogues of state, transition and threshold model of the study sites were provided. Then states, transitions and thresholds were interpreted. It was recognized that grazing intensity is the most important factor in health decline of sites and transition between states. 

The earth work is usually regarded as one of the most expensive activities in engineering practice, yet the methods used in the consulting engineers do not provide the required accuracy and is very time consuming with regard to the computational time. In this paper a new method has been proposed for determining the earth work volume which was based on employing an irregular triangular mesh. The project line level is also optimized by using the method of Newton-Raphson. Comparison between the results of the proposed method and the traditional one for a case having an analytical solution indicates that the proposed method improved the accuracy by a factor of 3. Therefore, applying the proposed method not only increases the accuracy of earth work volume computation, which directly influences the project expenditure, but also determines the optimum project line level based on the earth work volume.

This research was aimed to study the effect of Eucalyptus Camaldulensis tree age (4, 6, 8 years old) on the chemical components for pulping industry. Chemical analyzes were performed for each age group three times and the results of chemical components were compared with each other. The percentages of cellulose, hemicellulose, lignin, extractives and ash for 4 year old trees were 37.9, 34.41, 23.7, 3.22 and 1.05 respectively and for 6 year old trees were 41.08, 30.7, 25.39, 4.62 and 0.81 respectively and for 8 year old trees were 41.9, 29.53, 26.86, 6.03 and 0.54 respectively. Finally because of having more cellulose and less ash, the 8 year old trees could be better for pulping industry.

The present study aims at introducing and recognizing the forest types and their overall evaluation in Daalaab region, Ilam province. In order to recognize forest types in this region, first, the existent types upon map were specified based on physiognomic observations in nature, Then 60 plot (1000m2 for each) were specified by using methods of height gradient inventory and our given factors including Crown Cover were measured within them. The separation of types boundary was done based on Crown Cover percent of dominant species within plots and finally three types named Quercus brantii, mixed type (Quercus brantii–Pistacia atlantica-Acer cinerascens), and Daphne mucronata- Amygdalus orientalis types were recognized in the region. It is important to note that the change of forest types in relation with the changes of elevation from sea level, gradient, and somewhat direction is significant, so as we see, Quercus brantii type is prevailed in elevation ranges from 1300 to 1600 meter from the sea level and as the gradient and the elevation from the sea level increases, tree and shrub types prevail. The mixed type is found in elevations range from 1600 to 2000 meter from the sea level and in higher heights, more than 2000 meter, the Type of Daphne mucronata-Amygdalus orientalis is formed in which one can see diffused monotrees of Acer cineracens.

This research aims to introduce computer software, called FANOOS V1, for optimizing the production lines of wooden furniture in a typical factory. At the first, the necessary information was collected and classified through observation, study and experience. Then, the relevant algorithm was prepared by employing the language programming, design software as well as database software. Finally, the interrelations among the sections of the algorithm were defined. The prepared software contains the main process lines and their subsections. Also, it has capability to guide the production process in different sections. Furthermore, the existence of software in the production lines may lead to reduction of the production time in amount of 30 to 50 percent compared to the traditional methods.

Urmia Lake is one of the largest habitats of artemia which is located at Northwest of Iran. The larvae of artemia contain different fatty acids as well as EPA &DHA which are essential for feeding of fishes and crustacean larvae. These fatty acids are useful against disease and pigments production. The aim of present study was to investigate the quantitive variation of fatty acids of decapsulated cysts artemia in Urmia Lake which stored for nine months after production. For this study some low- hatching Artemia urmiana cysts were selected, purified, then decapsulated by chemical materials. They packed in cans after drying. These cysts stored at +4 to +10 oC for nine months and their fatty acid profiles were analyzed during five intervals. Analysis of data showed significant outcome (P£0.05) for C18:1n9, C20:0 and C20:5n3 (EPA) and non-significant for the rest of fatty acids (P>0.05).