Journal of Agricultural Sciences and Natural Resources
Year:2009 | Volume:16 | Issue:3|Papers Count:37

Capital is one of the most limited inputs in agriculture of Iran, which impacts creating value added process. Capital rate of return is an index of capital productivity, therefore, in this paper, capital rate of return in sub agricultural sectors by use of capital stock time series during 1959-2005 and production function technique was determined. Results show that the best form of production function for Agronomy and Horticultural sub sectors is Cobb-Douglas, for Husbandry sub sector is Transcendental and for Fishery and Forestry sub sectors is Cobb-Douglas. Results also show that average capital rate of return in Agronomy and Horticultural sub sectors, Husbandry sub sector, Forestry and Fishery sub sectors is 1.7, 3.8, 0.42 and 0.21 respectively.

Shoordareh, Aghsu and Narmab watersheds in eastern Golestan Province important with respect to the soil erosion and floodings, were selected to investigate their soil physico-chemical properties and also their clay mineralogy. Soil parent material is mainly composed of loess deposits in all the three regions. They show however, differences in climatic parameters (precipitation, evapotranspiration and temperature), and vegetation. Precipitation increases and temperature and evapotranspiration decrease from Shoordarreh to Aghsu and eventually to Narmab and natural vegetative cover shifts from scattered pasture in Shoordarreh to dense forest in Narmab. The results revealed that all the studied soil properties were significantly different in the three regions. Soil organic carbon, clay, fine silt, saturation percentage, total nitrogene, and soil available phosphorous increased by the favorable soil forming conditions in Narmab. pH, EC, sand, lime and available K significantly decreased as a result of P/ET increase in Narmab. Clay mineralogical analyses showed that there were significant differences in type and abundance of clay minerals for the three regions. Illite, chlorite and kaolinite were the major clay minerals of the loess parent material. By increasing P/ET and subsequent change in other soil properties, illite and chlorite content decreased while smectite, vermiculite and illite-vermiculite interstratified minerals increased significantly. The highest occurrence of smectite was observed in Aghsu which was probably formed from transformation of illite as a result of the leaching of K from interlayers. Vermiculite was observed in Aghsu and Narmab but with a higher abundance in Narmab mainly due to its higher stability under lower pH and alkalinity in Narmab region.

Rapid growth of population, and the consequent in creasing request for food, has resulted in the intensive cultivation and finally deterioration of natural covering of land surface, especially in forests. Soil quality is affected adversely as well. In order to study the effects of different land vegetation covers on soil quality attributes, a loess hillslope was selected in eastern Golestan province, Ghapan watershed. Four profiles in four land uses including Quercuse natural forest; Pinus plantation; Cupressus plantation and a cultivated land, were dug and studied. Samples from different horizons were collected for physico-chemical and microscopic analyses. Results showed that mean weight diameter of aggregates (MWD) was significantly different in the studied landuses and varied between 1.6 mm in Quercuse natural forest and 0.31 mm in cultivated land use. The lowest CEC, microbial respiration rate and organic carbon were 28.4 cmol kg-1, 177 mgCO2/g day and 1.32% in cultivated land use. Organic matter content in the forest area was considerably higher than that of the cultivated land use. Soil profile development studies revealed that forest soils were highly developed. Quercuse natural forest soils were classified as Calcic Haploxeralfs with a well developed argillic horizon unlike cultivated soils which showed the minimum development and classified as Typic Xerorthents. The soils of plantation had mollic epipedon and were classified as Typic Calcixerolls with moderate development. Micromorphological properties of soils can help consider changes in pedogenic processes occurring under different land covers. Formation of argillic horizon with speckled and some crystallitic b-fabric in the natural forest indicates to the high landscape stability. In contrast, crystallitic b-fabric of other land uses showed the absence of enough leaching of carbonate for the subsequent migration of clay particles. Intense erosion of the surface horizons of cultivated land use has resulted in the outcropping of the subsurface carbonate rich horizon preventing soil development.

Effect of probiotics on Rainbow trout (Oncorhynchus mykiss) larvae based on growth performance, and feed utilization (feed conversion ratio, FCR) was investigated. The 5 species of endospore bacillus, B. licheniformisi, B. subtilis, B. polymyxa, B. laterosporus and B. circulans, as a blend of probiotic bacteria, were employed in 4 concentrations for supplementation of diet. Daphnia magna was cultured in the ground ponds. The meal of Daphnia magna was used for feeding of Rainbow trout larvae.The blends of probiotic bacillus was prepared under the procedure of Protexin Co. (Iran- Nikotak). The trout larvae were fed on 10 percentage of their body weight, for 6 times a day. 15 fiberglass circular tanks with replicates for experimental and control treatments were used. This experiment was conducted in a completely random design. Trout larvae (avg 75±10mg) were fed diet (meal of Daphnia) supplemented with 1×105 (diet D1), 2×105 (diet D2), 3×105 (diet D3), 4×105 (diet D4) bacteria (CFU) per g feed for 28 days. The control diet (CD) was not supplemented with the bacteria. The results showed that in the all experimental treatments, the growth parameters significantly increased (P<0.05). Diet D1 resulted in significantly better growth, a lower feed conversion ratio and higher protein efficiency ratio (PER) than the control and other experimental treatments. No significant difference was observed between the survival rate of control and experimental treatments (P>0.05). The minimum of final body weight in control (260.32 mg) and the maximum of weight were obtained in D1 (314.02 mg).In probiotic treatments, food conversion efficiency were increased while the relative food intake significantly decreased (P<0.05). The specific growth rate in probiotic treatments was increased. The probiotic bacillus had significant positive effects on relative gain ratio, average daily growth and thermal growth coefficient. In conclusion, the experiments showed that the probiotic bacillus highly increase the growth performances and feeding efficiency in trout larvae. Furthermore, different levels of probiotic bacillus indicated different performance.

Effect of probiotics on Rainbow trout (Oncorhynchus mykiss) larvae based on growth performance, and feed utilization (feed conversion ratio, FCR) was investigated. The 5 species of endospore bacillus, B. licheniformisi, B. subtilis, B. polymyxa, B. laterosporus and B. circulans, as a blend of probiotic bacteria, were employed in 4 concentrations for supplementation of diet. Daphnia magna was cultured in the ground ponds.  The meal of Daphnia magna was used for feeding of Rainbow trout larvae.The blends of probiotic bacillus was prepared under the procedure of Protexin Co. (Iran- Nikotak). The trout larvae were fed on 10 percentage of their body weight, for 6 times a day. 15 fiberglass circular tanks with replicates for experimental and control treatments were used. This experiment was conducted in a completely random design. Trout larvae (avg 75±10mg) were fed diet (meal of Daphnia) supplemented with 1×105 (diet D1), 2×105 (diet D2), 3×105 (diet D3), 4×105 (diet D4) bacteria (CFU) per g feed for 28 days. The control diet (CD) was not supplemented with the bacteria. The results showed that in the all experimental treatments, the growth parameters significantly increased (P<0.05). Diet D1 resulted in significantly better growth, a lower feed conversion ratio and higher protein efficiency ratio (PER) than the control and other experimental treatments. No significant difference was observed between the survival rate of control and experimental treatments (P<0.05). The minimum of final body weight in control (260.32 mg) and the maximum of weight were obtained in D1 (314.02 mg). In probiotic treatments, food conversion efficiency were increased while the relative food intake significantly decreased (P<0.05). The specific growth rate in probiotic treatments, was increased. The probiotic bacillus had significant positive effects on relative gain ratio, average daily growth and thermal growth coefficient. In conclusion, the experiments showed that the probiotic bacillus highly increase the growth performances and feeding efficiency in trout larvae. Furthermore, different levels of probiotic bacillus indicated different performance.

In this research which carried out in Gorganrood within 3 months,the relationship between fish size and sperm volume, gonadal characteristics, spermatological parameters (spermatocrite, sperm density and duration of sperm motility) and hematocrit index in Rutilus rutilus caspicus of Caspian sea were investigated. Semen samples were collected from 51 kolme fish with a 5cc syringe and were immediately transported to the laboratory while were being kept on ice. With increasing in the body length, the gonadal weight significantly increased but sperm volume did not have any significant correlation with fish body length (P>0.05). Spermatocrite, sperm motility, sperm density, gonadosomatic index and hematocrit did not influenced by fish body size (P>0.05). But correlation between hematocrit index and sperm volume was significant and positive (P>0.01). With increasing in gonadal weight, sperm density significantly decreased as well (P<0.05).

This study was conducted to determine several biological characteristics such as age, growth, length-weight relationship, sex ratio, Gonadosmotic index and fecundity of immigrant population of Shemaya Chalcalburnus chalcoides in Shirud River from early April to July 2006. Age and growth determinations were made from scales from 412 fish ranging from 117.6 to 218mm total length. According to Von Bertalanffy’s growth function index, there was a meaningful difference between the growth rate of male and female fish. The sex ratio was found to be 2.4:1 (M:F) which was statically significant (P<0.05). The average length and weight in male fish was calculated as 150.6 mm and 24.7 g, respectively, whereas it was recorded at 175.7mm and 41.7g for female fish. Females (age groups II to V) were slightly longer than males (age groups I to IV). Even though, in case of length parameter there was a significant difference (P<0.05) between different sexes, however, in term of weight, no significant difference was observed between them. The peak of gonadosmotic index was recorded in May for Male fish and in early June for female fish. The average value of fecundity was calculated to be about 3900 eggs which made a meaningful correlation with body length and body weight. According to data, the egg diameters of these species were ranged between 1.05-1.17. In this study, it was concluded that, this population had greater growth factors in comparison with other population of the same species from other regions, mainly due to desirable biological parameters of Shirud River for immigration.

Diazinon is an effective insecticide for the control of herbaceous pests and one of the most commonly used pesticide in the agricultural enterprises near to Urmia Lake. In spite of this fact, no information regarding the effects of this pesticide on the survival rate of brine shrimp, Artemia urmiana are exist. In this study, the effect of 8 different concentrations of diazinon on three age groups, early hatched, 24 and 48 hours old nauplii were investigated. The experiment was carried out on the basis of completely randomized design, with five replicates. The results showed that age and different levels of diazinon insecticide have significant effect on the survival rate of nauplii (P<0.01). The age group of 48 hours old has a high sensitivity to different levels of diazinon and the difference among average mortality rate of this age group with early hatched and 24 hours olds was significant (P<0.05). Slope of dose-response curves also supported this phenomenon. 24 hours LC50 obtained from Probit Analysis for groups early hatched, 24 and 48 hours olds were 9.6838, 9.6320 and 1.8389 mg/L respectively. It is concluded that relative mortality rate in interval low concentrations was greater than consecutive high concentrations (P<0.05). High larval development and metabolic rate are probably reasons that can explain the sensitivity of 48 hours old group as compared to other two age groups.

This study was conducted to evaluate the quality of different mineral- vitamin premixes in performance of laying hens. This experiment was performed with one hundred and ninety two Hay-line W-36 laying hens from 70 to 80 weeks in a completely randomized design. Experimental groups were include ration without using of mineral-vitamin premixes (control), and three brands of mineral-vitamin premixes including Aras Bazar, Tolidaru and Darosazan. For 10 week. There were not significant differences in performance and egg quality among experimental groups (P>0.05). The overall results of the present study indicate that it's possible to remove dietary mineral and vitamin supplements from laying hens diets in late laying period without any adverse effects on performance and egg quality.

The experiment was conducted to determine protein digestibility total excreta collection method of soybean (SBM), canola (CM) and sunflower (SFM) meals by conventional addition method (CAM) included with intact and caecectomized adult cockerels. The apparent and true digestibilities of protein values were significantly differente for soybean canola and sunflower meals (P<0.05). The means values of apparent and true digestibilities protein was 85.53, 86.71, 82.03, 83.02, 83.40 and 84.90 percent respectively. The caecectomy of cockerels apparent and true digestibilities of protein were decresed in caecectomized birds as 2.78 and 2.94 percent for soybeab meals, 3.11 and 3.29 percent for canola meals and 3.06 and 3.31 percent for sunflower meal. Therefore, the effect of caecectomy on digestibility of protein in adult cockerels is dependent on the compositions of the meal assayed. However, caecetomised and intact cockerels had not differences for amount of EEL and ENL excretion.

The influence of PMSH and HCG on reproductive performance of Atabay breed ewes in breeding and non-breeding seasons was investigated. For this purpose, two experiments were conducted at breeding and non-breeding seasons. At each experiment, 30 Atabay ewes with initial live weight of 28±1.5kg and age of 2.5±0.45 year were randomly allocated into three equal groups. After estrous synchronization, using intramuscular progesterone administration following treatments were studied: Group 1 (control); ewes that received only saline, Group 2; ewes that received 1000 IU of PMSG, and Group 3; ewes that received both PMSG (1000 IU) and HCG (500 IU). The percentage of ewes showing estrus was similar in breeding season for all groups (P>0.05) while in non-breeding season, a higher percentage of ewes of group 3 showed estrus (P<0.05). Conception rates in groups 1, 2 and 3 in non-breeding season were found as 80, 90 and 100 percent, respectively (P<0.05), while pregnancy rates were not significant in experimental groups in breeding season. Gestation period and parturition period were shorter for groups received gonadotropins than control group in both seasons (P<0.05). At this study, single birth rates were significantly lower for ewes in group 3 than other groups in both experiments but multiple birth rates were higher for group 3 than groups 1 and 2 (P<0.05). Lambing rate in breeding season for groups of 1, 2 and 3 was 90, 80 and 140 percent (P<0.05) respectively, while it did not significantly differ between experimental groups in non-breeding season. Results of this study showed that oestrus response, conception rate, gestation period and single birth rate did not affected by season but parturition period for breeding and non-breeding seasons was 22.6 and 27.5 days, respectively (P<0.05). In addition, multiple birth rate and lambing rate were higher in breeding season (P<0.05) than non-breeding season.

Today's trend to use and production of low/free fat products was increased. Pre-drying of fried products is one of the ways for reduction oil uptake. In this study, the effect of pre-drying at three times (10, 20 and 30 minutes) on amount of oil uptake and quality attributes of produced French fries from three potato varieties of Golestan province (Agria, Kenebek and Satina) was investigated. Results showed that three potato varieties had different amounts of oil absorption which Agria and Kenebek varieties with 14.24 and 14.11% of fat content had the highest and lowest amount of oil absorption respectively. In Agria variety, pre-drying lead to increase of oil uptake in compared with control samples, in this variety blank sample and 10 min pre dried sample with 14.27 and 20.72% oil absorption had the lowest and highest amount of oil absorption respectively (P<0.05). In Kenebek variety fat content of blank sample was 14.11%, pre-drying decreased oil uptake in compared with control samples and increased texture and color of potato stripes (P<0.05). Pre-drying decreased oil uptake of Satina variety stripes too and amount of oil uptake decreased with increase of drying time. Our results reviled that in Satina variety, the highest and lowest amount of oil absorption related to blank sample and 30 min pre dried sample with 11.46 and 6.83% fat content had respectively (P<0.05). Pre-drying increased dry mater content, color and shearing force of stripes in compared with control samples in three studied variety (P<0.05).

With increase of consumer conscious, demand for low or free fat products has been increased. In recent years researches for reducing oil absorption were increased. Coating of foods before frying is one of the methods for reducing oil uptake in fried products. In this study the effect of coating with hydrocolloids on amount of oil absorption and quality attribute of potato stripes were investigated. Results showed that coating with hydrocolloids due to their barrier properties, lead to decrease in water loss of strips during frying and by respect to the role of water in control of oil uptake, amount of oil in coated samples were less than blank sample. Among different studied gums, mixed of pectin and carboxy methyl cellulose 1% and xanthan 1.5% with 3.40 and 3.43% had the lowest amount of fat content. Xanthan in all concentration lead to oil reduction. The highest amount of coating pick up was related to xanthan, carboxy methyl cellulose, guar and pectin gums, respectively. The highest decrease in water loss during frying was observed in xanthan and pectin and the lowest was observed in different concentration of guar gum. Coating with hydrocolloids in compared with blank sample lead to increase in moisture content of French fries. By this respect the highest and lowest amount of moisture content increase, were 0.35 and 0.16 which related to xanthan 1% and guar 1%, respectively.

The aim of this study was to identify lactic acid bacteria of Lighvan cheese, as a first step towards the development of a starter culture, which would allow the making of a safe and uniform product from pasteurized milk. Fifty four typical colonies of lactic acid bacteria (LAB) were selected out of 480 isolates from samples of Lighvan cheese. Isolates were identified by biochemical test. Accordingly they were classified into 6 genera: Lactobacillus, Enterococcus, Streptococcus, Pediococcus, Leuconostoc and Lactococcus (55.5, 11.11, 9.25, 5.55, 3.7 and 1.85% respectively and 12% of isolates were unidentified). L. agilis (13 isolates), L. plantarum (8 isolates) and entroccoci of faecium group (5 isolates) were prevalent species in product. Other identified Lactobacilli included L. maltaromicus (4 isolates), L. paracasie subsp paracasie (2 isolates), L. intestinalis (1 isolate), L. salivarius (1 isolate) and L. acetotolerance (4, 2, 1, 1 and 1 isolate respectively). Also isolates of Strepoccocus thermophillus (2 isolate), Streptococcus downei (1 isolate), Streptococcus oralis (2 isolates), Enterococcus Faecalis (1 isolate), Leuconostoc mesenteroides subsp dextranicum (1 isolate), Leuconostoc. Mesenteroides subsp. mesenteroids (1 isolate), Pediococcus inopinatus (2 isolates) and P. pentosaceus subsp intermedius (1 isolate) were identified. The results of this study suggest that an adequate starter for production of Lighvan cheese may be composed of strains of L. agillis, L. plantarum, Enterococcus faecium group and species of Lactococcus and Luconostoc.

One of the most expensive stages of malting process is kilning. The aims of kilning are limiting biological growth, reduction moisture content and generation of color and flavour. Application of microwave drying because of high processing efficiency and energy can be desirable. In this study two varieties of barley namely Sahra and Dasht, were used to investigate the influence of temperatures (40, 55,70 and 85oC) and type of dryer on physico-chemical properties of malt such as diastatic power, cold water extract, hot water extract, color and pH were measured. Analysis of variance was performed using SAS software and the means were compared using LSD test at 5% level. Results showed that diastatic power, cold water extract, hot water extract and pH reduced and colour increased. The best temperature to produce enzymatic and non enzymatic malts was 55 and 85ºC respectively. Results of combined hot air (55oC)-microwave drying showed that with increasing power from 100 to 300W, quality characteristics of malts revealed similar pattern to hot air drying.

The effects of some natural compounds on shelf-life of pear fruit were studied. For this, mallow mucilage edible coating and thymus essential oil were used. Thymus essential oil in two concentrations of 250 and 400ppm were applied. Mucilage was added to Thymus as 20 percent of total weight (w/w), to understand the interaction effects. Fruit decomposition, consistence, TSS, pH, total acidity, flavor and weight reduction percent were measured on different periods of storage duration including; 0, 20, 40, and 60 days. Results indicated, fruit decay decreased and firmness increased as essential oil or in mixture with mucilage was applied. Further, total soluble solid in those fruits treated with thymus essential oil increased, as the shelf-life duration extended. Application of mallow mucilage led to better fruit water conservation in comparison with control. This treatment cause more firmness and decrease of total soluble solid. None of treatment could not affect titrable acidity and pH. Application of thymus essential oil as an antioxidant caused less fruit color disappearance and strengthened the fruit flavor. Using thymus essential oil in two concentrations decreased peroxides activity and consequently inhibited fruit enzymatic browning.

To evaluate the effect of papain enzyme on kilka myofibrillar proteins, the target proteins extracted in 10mM phosphate buffer and 0.6M NaCl solution. The hydrolysis conducted at 40-80 centigrade degrees, 5-90 min, and 10-300TU/g protein of enzymatic activity using central rotable composite design (CRCD) with 4 replications at central point, and 5 levels of each treatment. Degree of hydrolysis increased 7 times by increasing in enzyme activity from 10 to 300TU/g protein. Degree of hydrolysis increased up to about 60 centigrade degrees and stayed almost constant there after. Reaction temperature did not affect peptide chain length (PCL). PCL was a quadratic function of time and enzyme activity. The diversity of PCL was 10-80 in all samples (P<0.05). The shortest peptides obtained at higher temperatures or longer reaction times. According to the results partially hydrolysis of fish myofibrillar proteins improves its functionality.

The current major cultivars grown in Iran [Okapi(O), Hyola 401 (H), Zarfam (Z), and Talayeh (T)] were supplied from the production areas [Khorasan Razavi (K), Golestan (G), Mazandaran (M), Tehran (T), and Fars (F) provinces], and their oil fractions were extracted after drying. The oils were composed of 7.2-8.0% saturated fatty acids, 61.7-67.4% monounsaturated fatty acids, and 23.6-29.3% polyunsaturated fatty acids. Except for the oils from Z-T and H-G cultivars with peroxide values of lower than 1.2 meq/kg, the oils from the other cultivars had peroxide values of higher than 2.0meq/kg. The highest and lowest iodine value was found for the oils from T-K (109.6), and O-K (104.2) and H-G (104.8), respectively. Unsaponifiables matter content ranged from 3.4% (O-K) to 8.6% (H-G). The oil samples were contained 1.6% sterols on average. The oils from Z-K and O-K cultivars had the greatest tocopherols content (793.4 and 765.1 ppm, respectively), and the lowest contents were found in the oils from T-F (573.6 ppm) and H-M (556.0 ppm) cultivars. Phenolics, wax and total polar compounds contents were in the ranges of 23.8 ppm (T-F) and 127.3 ppm (H-M), 5.6% (O-K) and 10.8% (Z-T), and 2.2% (O-K) and 13.0% (T-F), respectively. The oil samples had densities, viscosities and refractive indices of 806.1-820.0 kg/m3, 96.3-104.2 cP, and 1.464765-1.467888, respectively. Oil/oxidative stability indices were according to the following order: H-G = Z-T > O-K > Z-K > H-M = T-F > T-K.

A suitable grazing system should be arranged based on the physiological characteristic of range plants. An investigation was conducted to determine the trend of changes in total nonstructural carbohydrate reserves during growth development in three grasses of crested wheatgrass (Agropyron cristatum), pubscent wheatgrass (Agropyron trichophorum), and intermedia wheatgrass (Agropyron intermedium) at Golestan National Park. The mean annual temperature and mean annual precipitation of the study area are 9oC, and is 304 mm respectively. The elevation of study area is 1660 m. To relate carbohydrate reserves to the rate and stages of growth, leaf length, height, and the pheological stages of 10 plants of each species were measured during growth period. Then, total nonstructural carbohydrates (TNC) in the storage organs of root, crown, and rhizome were determined by using Anthrone reagent. Results showed that the concentrations of TNC in storage organs were significantly different between three species (P<0.05). The changes of TNC in different phonological stages were significantly different in storage organs of three species (P<0.05), with exception in the root of A. trichophorum. With the progression of growth, TNC in the crown of A. cristatum and in the rhizome of A. intermedium indicated increasing trend. The concentration of TNC in crown of A. cristatum and in root and rhizome of A. intermedium were minimum at vegetative growth stage. But such reduction happened for crown of A. trichophorum during head stage. The reduction of TNC was occurred in certain phonological stages, especially in flowering and seed ripening which may be related to environmental factors. In stages of low carbohydrate reserves, the species may not be able to recover the loss of photosynthetic tissue. Therefore, variation in carbohydrate reserve cycles of species indicate their different responses to frequency, intensity, and season of defoliation.

This study was examined the suggested grazing systems in Range Management Plans through an assessment. This research carried out in 2007 at Semnan province. The statistical population of the study consists of all experts in Natural Resources Administrative Offices and all pastoralists that exploit/own selected ranches. The sample size (30) was determined based on stratified random sampling method and Cochran formula and distributed in each stratum (District) according to their weight (total Range Management Plans). Descriptive result showed that the average rank of suggested grazing systems is 2.57 that means the suggested grazing systems in Range Management Plansr prepared for Semnan province are located at week or fair level. The other results showed that there are significant differences between experts’ opinion and pastoralists’ opinion on the suggested grazing systems. There is a significant and positive correlation coefficient between survey factors and respondents’ opinion about suggested grazing systems. The stepwise regression showed that X5 variable (the content of prepared Plans) is the first and the most important variable in the correlation (R2=0.77).

To determine preference values of important range species in steppe rangelands of Yazd, direct time observation and bite-count techniques were employed in a mixed local herd. For each technique, 9 sheep and 9 goats were marked and chased for 15 minutes in three periods of grazing. The time of forage consumptions and the number of bits taken from seven important range species were recorded in three periods of grazing. To determine the range species composition based on production and canopy cover, 1-m2 plots were used. Factorial experiment in completely randomized design was used to compare preference values of seven important range species for each species of animal in three periods of grazing by using the recorded time and the counted bits. In both techniques, the variation of preference values of range species was similar for sheep and goat. Similarity of preference values for sheep and goat were above 80% and there were not significant differences in two methods (P<0.05). The precision of both techniques (direct time observation and bite-count) were same. In general, both techniques used during the grazing period had the similarity of 75%. As far as bite-count could be done with least available facilities, so this method is preferred to the direct time observation.

In this research, effect of four fungicides including: Carbendazim, Thiophanate Methyl, Thiabendazole and Rovral T S in levels: 0.1, 0.32, 1, 2.62, 6.91, 18.42 and 50 ppm against the spore germination of four isolates of Ophiostoma novo-ulmi, aggressive causal agent of Dutch elm disease, on Malt Extract Agar (MEA) 2% in vitro studied in RC Design. Carbendazim and Rovral T S fungicides with mean of 62.57% and 37.88% had highest and lowest inhibition effect of spore germination among fungicides, respectively. Also, EC50 values for Carbendazim, Thiophanate Methyl, Thiabendazole and Rovral T S were calculated 0.728, 0.785, 2.228 and 4.808 ppm, respectively. The isolates had also significant difference at probability levels of 5% and 1% for tolerance rate to different fungicides levels, so that Onu4 isolate with 55.76% and Onu3 isolate with 53.04% were the most susceptible and tolerant, respectively. Potential using of these fungicides in order to control Dutch elm disease have been discussed in this paper.

In order to determine demographic parameters of the melon aphid, 20 wingless adults were reared separately in 10×60 mm leaf cage on cucumber leaves in a growth chamber at 26±2oC, R.H. of 65±5% and a photoperiod of 16L:8D. The highest life expectancy (ex) value was 12.8 days in early emergence and the lowest was 1 day during 21 days of adults life. Intrinsic rate of increase (rm) and net reproductive rate (Ro) values were 0.471 and 49.256, respectively. The mean generation time (T) was 8.27 days and the population of aphid was doubled (DT) within 1.47 days. Female aphids were able to multiply 27.03 times per week (rw). Adult longevity was 13.8±1.09 days and mean number of offspring produced per female was 49.05±2.32 and mean number of females per female per day (mx) was 3.22±0.59.

The predatory mites of family Macrochelidae live in different edaphic habitats and can play an important role in soil biodiversity. A faunistic survey was carried out to identify the mite of the family Macrochelidae in Guilan Province, northern Iran, during two years of 2007 and 2008. An identification key was also provided for Guilan Province machrochelid mites. Eight species from two genera were identified totally. The lists of identified species are as follows. One and two asterisks above the species name mark the species which have been recorded for the first time from Guilan Province and Iran, respectively: Holostaspella bifoliate, Macrocheles recki, M. merdiarus, M. peniculatus, M. muscaedomesticae* M. peniciliger, M. robustulus and M. glaber.

Granary weevils and specially meal’s louse are one of the most important factors in destruction of granaries (meal), in both quality and quantity .To examine the efficiency of non-chemical ways against the Tribolium castaneum, the influence of various doses of gamma ray on adult insect was studied. The experienced insects were reared in controlled situation (temperature 27±1˚C, humidity 65±10%, light period 8:16) and after gamma radiation, they were kept in the same mentioned situation. Due to the primary tests, the extent of experienced dose for growth period of young-adult and mature-adult insects were determinated. Then the gamma effects on the insects were studied. Young-adult and aged-adult insects exposed to amount of special dose death registered of observe after one day. The probit analysis showed that, the amount of killer-dose for 50 percent of their population in the young-adult and aged-adult levels were 1495.30 and 1671.64 Gy. In order word, shining of the 1671.64 Gy of gamma ray can destroy. They most resistant point in this insect’s life is the adult level that is controllable with 2400 dose against all level of life in this pest. To find the effect of radiation on meal quality, the quantity of necessary amino acid in meal before and after radiation was studied. Analysis the collected observations showed that radiation doesn’t have any negative influence on quantity of amino acid in meal and actually in helps to increase the quantity of phenylalanine acid considerably.

With due attention to the Dissemble of lateral function of environment, specification of these functions and estimates it, has high importance in national economic. In this study for estimate of valuation of environmental amenities in Abasabad touring region in Behshar, recreation value is estimated in the year 2007, by using contingent valuation method (CVM) and effective ingredients be determined by Logit model. One hundred forty questionnaires are investigated by stochastic sampling among visitors. Hence, be said to visitors, bid of 1000 rials, for low bid, 2000 rials for middle bid and 3000 rials for high bid. Early be said first bid and if it not accepted by visitors, then be said lower bid price and if it accepted then be said upper bid price. The results show that variables of individual income, household's income and educations had positive effect on visitor's willingness to pay (WTP) for using of environmental amenity. Variables of individual age and distance had negative effect on amount of individual willingness to pay. Amount of individual willingness to pay for using of environmental amenity in Abasabad touring region estimated and it was equal to 2200 rials. Ultimately Mean annual willingness to pay for per family is estimate 95040 rials.

Artificial neural networks (ANNs) was used to estimate daily global solar radiation at a weather station lacking any measured Rs values based on the measured Rs values at another station with similar climate. The accuracy of ANNs was compared with that of six other models developed for estimating Rs including FAO-56, Hargreaves-Samani, Mahmood-Hubard, Bahel, Annandale, and Bristow-Campbell models. The weather data was selected from Karaj and Shiraz weather stations having arid and semi-arid climates, respectively. The weather data of Karaj station, where daily global solar radiation was measured, was used to train ANNs and Shiraz data was used for validation. ANNs generated daily global solar radiation estimates with higher degree of accuracy as compared with all the other models used with the input parameters of maximum possible sunshine hours and daily extraterrestrial solar radiation, which both depend on latitude and day of the year, and actual sunshine hours with root mean square error (RMSE) of 2.34 Mj m-2 day-1 and correlation coefficient (R) of 0.94 (at 1 percent significant level). In case actual sunshine hours was not available, Annandel and Hargreaves-Samani models with locally calibrated empirical parameters and ANNs with minimum and maximum air temperatures and extraterrestrial radiation as input parameters gave the best results.

Snow Water Equivalent (SWE) is one of the important parameters in climatic and hydrologic studies and knowledge on SWE values is essential for supplying, season floods control and water providing for human consumptions use. In this research, first, correlations between SWE and corresponding elevation were determined using different regression relationships and then the best equation was selected based on correlation coefficient (r). In the next step, based on the equation and using GIS, spatial distribution of snow water equivalent was determined and its local map was developed. Finally, the results were evaluated using the map of exact observed data which was interpolated by ordinary Kriging geostatistical model. The results indicated that the best correlation relationships between SWE and elevation were polynomial non-linear, logarithmic non-linear and linear regressions (P value<0.05), respectively. Also, the results showed a strong corresponding between the SWE mapping which was developed by polynomial non-linear method and the interpolated map and decreasing elevation from west to east of the study area, SWE value extremely decreased.