نشریه علوم کشاورزی و منابع طبیعی
سال شانزدهم شماره 1 (پیاپی 71، فروردین و اردیبهشت 1388)

Noting to the importance of enhancement of coefficient agricultural mechanization through investment in agricultural machinery, a study was conducted using survey data of 573 farmers in Khorasan Razavi province. We applied Tobit model and Heckman's two stage method in order to determine factors influencing investment and the amount of capital invested in agricultural machinery. Marginal effect of variables in Probit model showed that farmer’s experience and education levels, acreage, availability of bank credits, own capital, using chemical fertilizers and ownership had positive effect, but age, achievement to rental machinery had negative effect on investment in agricultural machinery. Meanwhile, the results of second stage of linear regression showed the farmer’s education and experience levels, using chemical fertilizers, family labor, acreage, cost of harvesting, own capital, availability of bank credits and ownership had positive effect, whereas age, using leguminous in crop pattern, and achievement to rental machinery had negative effect on the amount of capital invested in agricultural machinery. Keeping an eye on these findings, in order to improve the coefficient of mechanization, a policy package including farm machinery leasing through subsidized credit, establishment of agricultural mechanization bank, land consolidation, creation the sense of ownership and application of proper extension systems is suggested.

The main purpose of this study was to investigate socio-economic factors affecting contribution of rural women and their impacts on family income in the Divandarreh County in Kurdistan Province of Iran. This applied research was done based on survey method. The statistical population includes all married women farmers (N=1770) living in the rural areas of Divandarreh County of Kurdistan. A sample of 177 women was selected by the use of “proportional stratified random sampling” method. A questionnaire was designed and employed to gather the required data. A panel of experts verified its content validity. A pilot study was initially conducted to determine the reliability of the questionnaire. The data were analyzed by SPSSwin11.5. The results showed that there was a significant and positive correlation between rural farmer's women contribution in family income and number of child, value of rural farmer's labor, level of participation in financial decision making of family, educational level, and social believes. The result of multiple regression showed that variables consisting number of child, value of women farmer's labor, participation in financial decision making of family, educational level, and social believes could explain 67% of the variation in the level of women farmer's sharing of family income. In addition, the results of path analysis showed that number of child a participation degree directly and value of rural farmer's labor, educational level and social believes were indirectly affected dependent variable.

This survey research was conducted to investigate facilitative attitude of extension practitioners and analysis related influencing factors. The statistical population of the study consisted of 2961 extension practitioners working in different provincial extension deputies of ministry of Jihad-e-Agriculture. Using Cochran's formula, 232 extension practitioners were selected as sample using multi-stage method. Content validity of the questionnaire confirmed by a panel of Extension Experts and Faculty members of the University of Agricultural Extension and Education. Calculated Coronbach Alpha coefficient as indication of questionnaire’s reliability for scale of facilitative attitude was equal to 0/90. The data was analysis with SPSS software. According to research findings, the most of respondents (58%) have a fairly facilitative attitude. The result of the multivariate regression indicated that 50% of facilitative attitude as dependent variable variance explained by the five independents variables that involved in linear equation, including: field visits, taking course in facilitation field, collaboration in research-extension projects, job record, and record of membership in cooperatives and local organizations. Through a path analysis diagram, direct and indirect effects of these independent variables on facilitative attitude were indicated.

The main purpose of this research was to analyze opinions of kiwifruit growers in west of Mazandaran province in respect to factors influencing on changing cropping pattern from Paddy and Citrus Culture to Kiwi fruit. The statistical population includes all 7867 Kiwi fruit growers living in village areas of west Mazandaran in Iran. A sample of 150 Kiwi fruit growers were selected by the use of “proportional random sampling” method. A questionnaire was used to collect data. Content validity of questionnaire was approved based on viewpoint of an expert panel. Cronbach's alpha was used to measure reliability of the index measuring factors influencing changing cropping pattern from paddy and citrus culture to kiwi fruit” that it,s extent was 0.90 and showed that mentioned variable had high reliability. According to factor analysis economic advantage, management of cultivation activities, accessibility credits facilities, compatibility with local agronomic culture conditions, irrigation management, labour and social pattern were recognized as the seven main factors that affect changing cropping pattern from paddy and citrus culture to kiwi fruit in the study area.

In this study brine with light, moderate and heavy concentrations (10%, 18% and 26%) in two ambient and refrigerator temperatures (16 and 4 ˚C) were used for salting Mahi sefid. The fish was weighted at 8, 16, 24, 32, 40, 48, 56, 64 and 72 hours intervals after weighting and brining. The end of salting process determined with the cease of fish weight changes. Then the fish was smoked in a traditional smokehouse with cold-smoke and after that analyzed immediately. Experiments were carried out with factorial method in completely randomized design at significant level P<0.05. The results showed that counter-effect of brine concentration and temperature on content of total volatile basic nitrogen, tiobarbituric acid and quality score of taste was significant P<0.05. Comparison of averages showed that minimum contents of moisture, pH, peroxide value and total volatile basic nitrogen were in 26% brine concentration, that they were 46.21%, 6.70, 19.44 mmol o2/kg lipid and 72.33 mg per 100g sample respectively. Also maximum contents of ash, salt, fat in dry weight, protein in dry weight and tiobarbituric acid were in 26% brine concentration, that they were 13.09, 16.17, 6.23, 39.92 and 0.24 mg malondialdehyd per kg respectively. In sensory analysis smoked products that salted in 26% brine concentration had higher quality scores, in order to their quality score of taste became equivalent very good. In summary the smoked product that was salted in 26% brine concentration had better quality.

We investigated the morphology, age and growth of Capoeta capoeta gracilis in Zarrin-Gol Stream of the Golestan Province of Iran during October 2007. One hundred specimens of Capoeta capoeta gracilis were sampled for which the length range was measured to be between 39.9-149.8 mm. The 0+ year age group was the most frequent (59%) and the 3+-4+ age groups were the least frequent classes (1%). The longest specimen was 149.8 mm in total length. Fish in age group 0+ had significantly larger inter orbital eye length in comparison with the fish in age groups 1+ and 2+ (P<0.05). Fish in age group 2+ had significantly smaller head length and head height than the fish in age groups 0+ and 1+. Instantaneous growth of the fish at the age 3+ was very much lower the than the younger age groups. We determined a negative allometric power length-weight relationship for the species as W=0.00003×L2.822 (r2=0.91). The Von-Bertalanffy equation coefficients were determined at.

This experiment was carried out to examine the effect of temperature on egg incubation period, exogenous feeding onset, growth and survival of Persian sturgeon, Acipenser persicus larvae. Experiment was conducted in groups A, B and C at three ranges of temperature (14.5±0.6, 16.3±1.2 and 20.5±1.4 °C, respectively). After fertilization, eggs were placed in the incubation tanks with the same density. Larvae were fed with Artemia urmiana nauplii after absorption of yolk sac, from external feeding time to the fifteenth day after hatch. Data were analyzed at the end of the experiment. The least time for egg incubation was observed in group C (113/3 h). Fish weight was not statistically different on hatching time. But mean body weight was significantly different between groups at the external feeding time and on the 15th day after hatch. Fish in group C had the lowest and the highest weight on external feeding time and 15th day after hatch (38±0.1 and 95±7 mg, respectively). The period of internal feeding and initiation of external feeding was affected by temperature. The longest and the least time for exogenous feeding onset were observed in groups A and C (13.6 and 7.3 days, respectively). Growth parameters in group C were higher than the other treatments. Also, larvae in group B showed the highest survival. The results of this study showed that water temperature has important effect on hatching time, exogenous feeding time, growth factors and survival in Acipenser persicus larvae as increase of temperature caused to increase of growth and decrease in hatching time and exotic feeding onset time.

A 60-day feeding trial was conducted to examine the effect of dietary Ergosan on growth performance, survival and blood cells changes in beluga, Huso huso juvenile. Ergosan as algal product containing 1% alginic acid supplemented at 0, 2, 4 and 6 g/kg diet (diets A, B, C and D, respectively). Each diet was fed to triplicate groups of Beluga with the initial body weight of 41.7±1.8 g at 10 days intervals (1-10th, 20-30th and 40-50th with non-supplemented diets and 10-20th, 30-40th and 50-60th with supplemented diets). Control group fed with non-supplemented diet during the experiment. Fish fed with respective diets based on 5% body weight. Water temperature was 24.3±2.3 °C. Photoperiod was adjusted at 13 Light /11 dark. Growth indices in the fish fed with supplemented diets were significantly higher than the control group (P<0.05). Feed conversion ratio (FCR) in the fish fed diets B, C and D were significantly better than the control group (P<0.05), while PER was not different among groups. Survival was not different among all the treatments (P>0.05). Also, use of Ergosan resulted in significance differences in lymphocyte percentage, while there were no statistically significant differences in hematocrit, monocyte and myelocyte percentages, hemoglobin concentration, number of erythrocytes, total leukocytes, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. Neutrophils and eosinophils percentage in the control group was higher than the fish fed with supplemented diet (P<0.05). These results indicated that dietary Ergosan affect some growth and haematological parameters in great sturgeon, Huso huso juvenile.

In this study effects of extenders on motility of spermatozoa (pooled semens from 3 male) of the ship sturgeon (Acipenser nudiventris) were investigated. Optimum ionic content (Na+, K+, Ca2+ and Mg2+), pH and buffer content (tris, tris-hcl, hepes) of activation solution as well as the optimum dilution rate and osmolality were determined. The results show optimum motility characteristics of spermatozoa in buffered solutions tris-hcl 30 mML-1 containing 12.5, 1, 7 and 15 mML-1 Na+, K+, Ca2+ and Mg2+, respectively, at dilution rate 1:100 and pH 8.5. At osmolalities of 68-94 mOsmol Kg-1 the spermatozoa motility was partly inhibited but the motility of A. nudiventris spermatozoa is inhibited by high osmotic pressure (133 mOsmol Kg-1 or more). The results of the present study demonstrated that various parameters such as ion concentration (Na+, K+, Ca2+ and Mg2+), osmotic pressure, pH, buffer content and dilution rate. affect the motility duration of ship sturgeon spermatozoa. K+ concentration in combination with osmotic pressure controlled spermatozoa motility in ship sturgeon. In conclusion Na+, Ca2+ and Mg2+ counter the inhibitory action of K+ and bivalent cations (Ca2+ and Mg2+) are more effective than Na+.

During the study, which was conducted to determine fish species diversity in coastal areas of the Gomishan wetland on the basis of twice per season from autumn 2006 to summer 2007, 13555 specimens belonging to 15 species and 8 families were caught. Total diversity and frequency of species and frequency of each species were different among the seasons. Atherina boyeri was dominant in spring, summer and winter, Gambusia holrooki in autumn. Alburnus albulnus had the lowest quantitative abundance in the study area. Out of six Gobiid fishes, Neogobius fluviatilis and Bentophilus stellatus showed the highest and the lowest abundance respectively. In the coastal areas of the Gomishan wetland, the highest Shanon and diversity indices were observed in winter, the highest richness index in spring and the highest evenness index in winter.

For evaluation of cultural common carp some water physicochemical aspect including ionic composition (Na+, K+, Ca2+ and Mg2+) and organic (total protein, glucose and cholesterol) and their correlations with heamatocrite indicator, growth and survive within 7 months on 15 ponds (10 hectar) in Dikjeh area of Gonbad in Golestan province in iran were investigated. The range of water ionic composition were included (0.99-26.30 Mmol/l) Na+, (0.60-14.20 Mmol/l) K+, (0.68-24.62 mgr/dl) Ca2+ and (0.87-12 mgr/dl) Mg2+, also the ranges of water organic composition were measured (0.2-0.73 gr/dl) total protein, (0.86-85.41 mgr/dl) cholesterol and (0.68-105.8 mgr/dl) glucose. The results of pearson were showed that there were significant correlation between water Mg2+ with length, weight (P<0.01) and fish biomass (P<0.05), Ca2+ with weight and fish biomass (P<0.05), Na+ with length and weight of fish (P<0.01), K+ with fish biomass (P<0.05), total protein with length, weight (P<0.01) and fish biomass (P<0.05), cholesterol with heamatocrite (P<0.05) and water glucose with length (P<0.05) and weight of fish (P<0.01). So, between water ionic and nonionic parameters with growth and survive significant correlation was showed. There for with management and regulation this factors in suitable culture range are caused growth and survival increasing in common carp.

In this study, fish burgers of fish surimi from carp (Cyprinus carpio) were investigated for quality changes during refrigerated storage. Proximate composition (moisture, fat, protein content) and chemical quality parameters (peroxide value, thiobarbitoric acid, free fatty acid and heme iron) of fish burgers were studied for a period of 30 days. Sensory evaluations (appearance, odor, flavor, texture and general acceptance) were carried out for several times throughout the experiment. For the samples stored in refrigerate peroxide value, thiobarbitoric acid, free fatty acid increased while heme iron decreased. Sensory evaluation indicated excellent-to-good attributes at 5 days and good-to-acceptable at 8 days. Based on this assessment, 8 days is determinated to be the shelf life of fish burgers stored in refrigerated.

An experiment was carried out to compare the effects of ewe milk with commercial milk replacer and starter dirt with different levels of concentrate on the growth, feed intake and rumen development of suckling lambs. Thirty Dalagh breed male lambs were separated from their mothers at 3±1 days of age divided into 6 groups (5 lambs per treatment) and were fed with 6 treatments for 90 days age. Treatment consisted of 2 fluid feed (ewe milk and milk replacer) and 3 starter diets (diet 1: 100% concentrate, 2: 67% concentrate and 33% alfalfa hay, 3: 33% concentrate and 67% alfalfa hay). Lambs were fed ewe milk or milk replacer in 2 per day and starter diet 3 per day and their intake were measured. Data were analyzed as a randomized completely blocks design according to 2×3 factorial method. The end of experiment 18 lambs (3 per treatment) were slaughtered, stomach harvested, emptied, washed with water and rumen development characteristics were measured. Data for growth, feed intake, rumen development parameters were analyzed as a randomized completely block according to 2*3 factorial design. Results showed the average of daily weight gain (ADG), dry matter intake, feed efficiency, ratio rumen weight to stomach weight (percent) and rumen wall thickness (RWT) in lambs fed ewe milk and milk replacer did not show significant differences, but means of papillae length (PL), papillae width (PW) and papillae density (PC), were differences statically significant and higher on lambs fed ewe milk (P<0.01). Feeding starter diets affected on ADG (P<0.05), PL, PW, RWT and PC (P<0.01) and higher on lambs fed starter diet with 100% concentrate. This experiment demonstrated that lambs could be reared with milk replacer, without any problem on the growth, feed intake and rumen development. Feeding starter diet with high levels of concentrate on suckling lambs resulted in high growth and good rumen development.

Data collected of lambs born from 1982 to 2006 in herd number one of Baluchi Sheep of Mashad Abbass Abad Sheep breeding station were used for the analysis. Animal breeding values were predicted using univariate analysis based on animal model. Genetic, phenotypic and environmental trends were estimated by regression of mean breeding value, mean phenotypic value and difference between phenotypic and breeding values on year, respectively. Total genetic progress of 22 years for birth weight (BW) and 24 years for weaning weight (WW), 6-month weight (6W), 9-month weight (9W) and 12-month weigh were 0.011, 1.488, 2.066, 2.062 and 2.034 kg, respectively. Genetic trend for BW, WW, 6W, 9W and 12W were 0.7±0.06, 55±1, 72±2, 77±2 and 88±3 gr per year, respectively. The phenotypic trends for BW, WW, 6W, 9W and 12W were 4±1, 3±9, -11±11, 15±11 and 118±14 gr per year and environmental trends estimates for respective weights were 3±1, -52±8, -83±9, -62±9 and 29±12 gr per year, respectively.

At this study, the possibility of barely grain substitution with crude olive cake in Dalagh lamb fattening was investigated. 28 male Dalagh lambs with mean initial live weight of 30±1.1 kg were allocated into four groups with 7 lambs each in a completely randomized design. Lambs were fed four different rations for 93 days. The first group (control) was fed a commercial concentrate, but the second, third and fourth groups were fed a concentrate that barely grain was replaced by olive cake at 33, 66 and 100 per cent, respectively. Rations were similar in nutrient. At the end of experiment, five lambs from each treatment for the study of some carcass characteristics were slaughtered. The final live weight, dry matter intake, daily gain, feed conversion, hot and cold carcasses weight differed significantly between treatments (P<0.05). The results showed that the high level of olive cake inclusion (100 percent substitution) decreased (P<0.05) dry matter intake and also feed conversion and consequently resulted in low daily gain, final weight and carcass weight. The medium level of olive cake inclusion (33 and 66 percent) resulted in a significantly higher (P<0.05) feed conversion and daily gain compared to the control. There were no differences among groups in percentage of hot and cold carcasses, hand weight, fat-tail weight and fat-tail percentage. Feed cost per kg based on dry matter for diets 1 to 4 was 1010, 962, 905 and 859 Rials, respectively. In addition, feed cost per each kg carcass with considering daily gain and carcass performance for diets 1 to 4 was 20804, 15182, 15172 and 20840 Rials, respectively. The results of this study suggested the possibility of administration of up to 66 percent of olive cake to the concentrate for lamb fattening, considering the positive effects on the feed conversion, daily gain and carcass weight and also reducing production cost.

The present study aims to investigate the effects of different sources and levels of prebiotics (Aspergillus Meal, Mannan Oligosaccharide) in broiler chickens diets on the growth performance such as feed consumption, weight gain, feed conversion and carcass composition such as the percent by weight of edible and inedible parts on the basis of bird’s live weight. At the beginning of the study 280 day-old male broiler chickens Ross 308 were allocated to seven treatments and four replications in a randomized complete block design. Treatments were 1) 0%, 2) 0.10% AM in the starter period and 0.05% in the grower-finisher period, 3) 0.20% AM in the starter period and 0.10% in the grower-finisher period, 4) 0.30% AM in the starter period and 0.15% in the grower- finisher period, 5) 0.10% MOS in the starter period and 0.05% in the grower-finisher period, 6) 0.20% MOS in the starter period and 0.10% in the grower-finisher period and 7) 0.30% MOS in the starter period and 0.15% in the grower-finisher period. Sources of AM prebiotics had higher feed consumption than Sources of MOS prebiotics in the starter period (P<0.05). AM prebiotics had higher weight gain than MOS prebiotics in the finisher period (P<0.05). AM prebiotics had a better feed conversion than MOS prebiotics in the finisher period (P<0.05). The prebiotics levels and sources of prebiotics did not influence the percentages of net carcass, intestines, breast and thighs but MOS prebiotics had a higher level of liver percent than AM prebiotics (P<0.05). Control treatments had a lower abdominal fat than other treatments (P<0.05). On the whole, Sources of AM prebiotics, showed a better performance than sources of MOS prebiotics.

An experiment was conducted to evaluate the effect of enzyme on performance and carcass quality of Arian chicks. The broiler diets were based on corn, barley and wheat. Seven hundred twenty straight run broilers were randomly allocated to 8 dietary treatments in a CRD design with 3 replicates and 30 birds per each. The experimental diets were based on corn, corn with enzyme, barley with enzyme, wheat with enzyme, corn and barley with enzyme, corn and wheat with enzyme, barley and wheat with enzyme, corn, barley and wheat with enzyme. Birds received feed and water ad libitum throughout the experiment. Body weight, feed intake, feed conversion ratio and mortality were measured at the end of starter, grower and finisher periods. Carcass characteristics, digestive tract weight and length were determined at the end of the experiment. The results of this experiment showed the significant differences in body weight and feed intake at all periods (P<0.05). Feed conversion ratio was significantly affected in starter and grower periods (P<0.05). Breast meat and thigh yield did not differ but carcass yield was significantly different between barley with enzyme and corn and barley with enzyme treatments and livability was significantly different between corn and wheat with enzyme and corn, wheat and barley with enzyme treatments (P<0.05). The gizzard, liver, pancreas and abdominal fat proportion to live body weight were not different among treatments. Duodenum, jejunum and ileum weight but not length were significantly different among treatments (P<0.05). The result gives an impression that adding enzymes to these cereals has been shown to improve performance to levels at least as high as those obtained with corn based diet. It is indicated that the negative effects of anti-nutritive factors in the diets on the performance of broiler were overcome by addition of enzymes.

In this survey was determined medicinal, pastural and rare plants species of Astaneh Mianband, Located in Damghan. Analyses of the flora of this region show that, there are 242 vascular plants species in 38 plant family. The results of this study show that, in total, about 93 medicinal and 149 pastural plant species into 141 Hemicryptophyte, 30 Chamephyte, 40 Therophyte, 31 Phanerophyte and Nano phanerophyte exist in this area. From the view point of regional elements plants of This region include 3.8% cosmopolitan, 17% Euro-Siberian and Irano-Turanian and Mediterranean, 1.45% Euro-Siberian and Irano-Turanian and Saharo-Sindian, 9.7% Irano-Turanian and Mediterranean, 10.2% Irano-Turanian and Saharo-Sindian, 2.42% Euro-Siberian and Irano-Turanian and Mediterranean and Saharo-Sindian, 3.8% Irano-Turanian and Mediterranean and Saharo-Sindian, 19.4% Euro-Siberian and Irano-Turanian, 28.6% Irano-Turanian, 1% Euro-Siberian, 1.63% Saharo-Sindian and 1% Mediterranean determined. Furthermore, threatened species have been analysed according to the IUCN criteria. The most important criteria for determination of the rare species categories have been evaluated. On the basis of this study, four categories of rare species so called endangered, Vulnerable, lower risk and data deficient are determined and list of these species have been presented, this study show that, there are in total, 47 threatened plant species in this area.

watering points are from the most effective factors that influence grazing distribution in rangelands. Where other limiting factors such as slope, height and soil have no variation, forages utilization by livestock is limited by distance from watering points. In this research, the effects of livestock overgrazing on vegetation of a critical area around livestock watering point were investigated in a flat and arid rangelands in Chahe-Nou of Damghan, Iran. In ordet to determine of degraded area around watering points, the importance value of two species of Peganum harmala and Artemisia sieberi in 8 geographic directions were analysed by using ANOVA and Duncan's multiple range test. The association of two species of Pe.ha and Ar.si was studied using Chi-squer test. Transects of 1.5 km were laid out in 8 geographic directions around watering point and samples were taken systematically. Each 100 m of one transect was considered as block. In each block, four quadrats of 4 m2 were plotted to measure canopy cover percentage, density and frequency of both species. Results showed that importance value of Pe.ha was not significant for all transects (P>0.05) but the importance value of Ar.si was significant (P<0.05). There were negative association between the two important species of Pe.ha and Ar.si. It can be concluded that the intensity of grazing was concentrated within 500 meters around watering point which can be considered as critical zone. The results also showed negative impact of overgrazing on vegetation structure, which may indicate the necessity for a monitoring program livestock grazing and watering points in these rangelands.

Acer L. or Maple belongs to Aceraceae or Sapindaceae. A. sacharum is potentially valuable as a source of sugar and the other species in this family are used in wood industrial products. Despite its economic importance, it constitutes species that raise many taxonomic and evolutionary questions. The systematic of this assemblage are further complicated by the fact that generic and specific circumscription within the family is considered to be highly artificial by many taxonomists with species delimitation primarily due to lack of enough morphological traits. Presence of unidentified and hybrid species, numerous synonymous and influences of environmental changes on morphological traits, as well as usage of different diagnostic characters for species identification, leaf polymorphism, have further complicated the confusion over species grouping in this genus. This work was initiated with the objective of morphology to: Identify taxa and establish their relationship and compare these results and data with other researches. Thus, we observed 63 morphological reproductive and vegetative characters from stem, leaf, flower and fruit and cluster analysis (Bray-curtis distance and single linkage) was done. Results showed that A. platinum and A.cappaducicum had the most similarities. Ordination analysis (Principle coordinate analysis) showed that Acer species distinct from other species (Koelreutaria paniculata Laxm, Dodonea viscosa (L) Jacq. based on first coordinate. These findings are consistent with earlier phyllogenetic and rRNA in several studies. Also A.negundo distinctness from other species at the first of cluster showed it is the basic species and this regard has opined by other phyllogenetic studies.

Peanut (Arachis hypogaea), is one of the most susceptible host crops to Aspergillus flavus invasion. In order to find of relation between chemical compositions of peanut with its resistance to Aspergillus flavus, four different peanut cultivars namely Goli, Mahalli, India and China were collected from Golestan province. After measurment of chemical compositions, for each 20 g antisepticised peanut, 2×106 cfu∕ml Aspergillus flavus spore were added and were placed in the incubator for 8 day at 26 °C. The values for the chemical composition of peanuts are as follow: moisture: 3.33-3.56%, protein: 20.02-24.28%, lipids: 44.77-55.26%, oleic acid: 43/16-59/33%, linoleic acid: 25/19- 36/84% Ash: 1.98-2.43% and sugar: 3.56-4.53%. Goli and Mahalli had the least whereas India and China had the greatest susceptibility to the A. flavus in the end of 8th of incubation, respectively. Furthermore, it was observed that Goli cultivar had least whereas India cultivar had greatest rate of aflatoxin B1 production, respectively. There was a significant correlation between the fungus growth rate and chemical composition of peanut, with the increase in resistance, protein and oleic acid content increased and fat and linoleic acid content decreased significantly. Content of Ash and sugar did not show positive relationship with the resistance to Aspergillus flavus.

Button mushroom (Agaricus bisporus) is the most widely cultivated and consumed mushroom in the world but preservation methods are necessary to extend shelf life of fresh mushroom. Drying is one of the most important methods to increase the shelf life of high moisture products. Since mushrooms are very sensitive to temperature, choosing a proper drying method is very important. In this study the effect of osmotic dehydration in different concentrations (10, 20, 30 and 40% w/w) of sucrose solutions, temperatures (30, 40, 50 and 60 C) and different mushroom-solution ratio (1:10, 1:15 and 1:25) on kinetics properties of mushroom slices during 5 hours was studied. The results showed that the moisture content of samples decreased with increasing of temperature and sucrose concentration, while Brix increased. Depending on applied treatments, final moisture content and Brix of mushroom slices after osmotic process were in the range of 47.6-87.9% and 7.4-46.7 respectively. Kinetics curves of moisture content and Brix were also obtained during osmotic dehydration process. It was also observed that concentration of osmotic solution is the only effective factor on rehydration ratio of dried mushroom slices.Keywords: Button mushroom; Osmotic dehydration; Brix; Rehydration

Temperature is one of the most important environmental factors affecting physiological characteristics of fungi. Effect of temperature on growth, spore and Cerato-ulmin production of Ophiostoma ulmi (4 isolates) and O. novo-ulmi (6 isolates), causal agents of Dutch elm disease, was studied. MEA 2% was used to estimate rate of daily growth and Zentmyer`s liquid medium was used to estimate spore and Cerato-ulmin production rates. Each experiment was carried out in 3 treatments of temperature including 22±1, 27±1 and 33±1 °C. The results showed that effect of temperature on growth and Cerato-ulmin production was more perceptible than spore production. The O. novo-ulmi isolates had the most daily growth and Cerato-ulmin production in 22±1 °C. For the O. ulmi isolates, the most daily growth and Cerato-ulmin production were recorded in 27±1 and 33±1 °C, respectively. However, the most spore production for each of the isolates of two species occurred in different temperatures. Spore-production ability of causal agent, with regard to importance of its spread by spore within xylem vessels of elm trees, could be considerable and discussable.

The highest profit is the ultimate goal of any farming firm. The management of machine replacement (specifically tractor) is one of the most critical factors for achieving this goal. Therefore, accurate prediction of tractor repair and maintenance costs is a must. The objective of this research was to predict tractor repair and maintenance costs using neural network and regression methods and comparing their performance for these predictions. The study was conducted using empirical data on 60 two-wheel drive tractors from Astan Ghodse Razavi agro-industry. The results indicated that both neural network and regression models have high rather accurate prediction of repair cost but the performance of regression model in comparison with neural network model for prediction of oil and fuel costs was very low with much less accuracy.

This main purpose of this paper is to response to these questions: First; whether is relationship between social capital and environmental responsible behaviours? It also tries to answer the question of “what is the relationship between social capital and environmental responsible behaviours regarding to three different geographical places (i.e. Gilan,Mazandarn and Golestan). The study was carried out by survey method and 750 urban citizens (of Gilan, Mazandaran and Golestan) have been selected as sample of the study. Proportionate stratified random sampling method was used to select the samples. Questionnaire was the main instrument for data collection which has designed by the Researchers. The survey results a significant relationship between social capital and environmental responsible behaviours. It also indicates that there is a significant relationship between main elements of the social capital and environmental responsible behaviours. Consistence with previous research, the relationship between social capital and environmental responsible behaviours varies geographically. The results of the research can be applied for promotion and development of environmental responsible behaviours and this requires improving social capital and it's dimensions like Trust, Participation in local community and increase the network relationship between social groups first.

In this study, with measuring water uptake in different soil layers, the role of different parts of root system in crop water supply during water stress conditions is characterized. Four cylindrical lysimeters with 25 cm diameter and 100 cm height were filled with clay loam soil. Soil columns were separated to 4 layers with 3 cm sand layers. Subsurface irrigation was applied with water stress patterns (decreasing number of layers which were irrigated from subsurface). Sand layers in each column which were preventing soil moisture exchange, could characterize the real role of each sub-layer root in water uptake when surface layers were under water stress. In this study root water uptake equation is corrected for water stress condition with presenting a compensation factor. With this corrected equation root water uptake in soil layers under water stress condition is investigated. The results showed that corrected equation determined root water uptake better than other equations in some conditions. Compensation factor is dependent on a plant factor (), that was determined with inverse optimization technique from root water uptake data in each lysimeter (it is calculated as 1.1, 1.87, 2.23 and 2.38 for lysimeters 1, 2, 3 and 4, respectively). This factor increased with increasing water stress severity.

There is a lack of information about erosion, sediment transport and sedimentation in our country and usually there is a significant difference between computed and measured data. Due to this fact that the rivers always is under erosion, the study of sediment transport is very important in river hydraulic and geomorphology. Sediment transport phenomenon is one of the important processes which influence many of the hydraulic and river structures, and one of the biggest problems for using water recourses in the world. In this study, artificial neural network was used as an effective way in order to estimate suspended sediment load in Doogh river in Golestan province. The flow discharge in present day, past day and hydrograph situation were used as input parameters, while the suspended sediment load was used as output parameter. The MLP neural network with tangent sigmoid activation function was used for training the network. The results show that the artificial neural networks estimate the suspended sediment load more accurately (R2=0.98, RMSE=0.015, NASH=0.97) than available method such as rating curve method with and without data classification.

Drought is one of the natural phenomenons that its prevention is not possible yet. This problem shows the importance of drought monitoring and creating a drought warning system. In this research to investigate drought frequency the Standardized Precipitation Index (SPI) for monthly and yearly periods were applied. For this reason, the precipitation data of meteorological stations of Golestan province were obtained from the authority. After some statistical tests such as: homogeneity and outlier test, monthly precipitation data of 26 stations for 30 years period (from 1976-77 to 2005-06) were selected. The SPI values for any months and any years were calculated and the drought situations were determined. The results show that in all periods and all stations the normal category has the heist frequency. Meantime, in any time periods there were more than one drought situations in the province. Moreover, the results show that the frequency of extreme events (sever drought and sever wet condition) in the semi-arid regions of the province is higher than humid regions. While, according to the SPI index these frequencies should be the same for all regions. On the other hand side, the frequency of wet and dry conditions (not extreme events) for the arid regions of the province is less than humid regions. Whereas, according to the SPI categories these frequencies should be the same for all regions.

During 1999-2001, a faunistic study was carried out in order to collect and identify the thrips species on soybean fields in Golestan province, northern Iran. A total of 14 species in 8 genera belonging to 3 families were identified. Thrips tabaci with 71% relative abundance and 45.5% relative frequency was the predominant species that is distributed in all of the soybean fields of Golestan province.

This experiment was conducted in order to compare the effect of feed form (pellet vs. mash), dietary nutrient density and metabolizable energy (min vs. max requirement) on performance of broiler chicks. For this purpose, growth response of eight hundred Ross 308 male broiler chicks was evaluated in a completely randomized design with a factorial 2×2 arrangement (2 factors including pelleted form and dietary nutrient density each at two levels), and eight replicates for each treatment. A number of 25 birds were allocated to each treatment. Results of this experiment showed that high level of nutrient and metabolizable energy density and also feed pelleting significantly increased weight gain (P<0.05). Feed dietary nutrient and metabolizable energy density affected feed intake in the first and third week of ages (P<0.05). Increasing of dietary nutrient density did not affect feed conversion ratio, but pelleted form of feed significantly improved feed conversion ratio during whole period of experiment (P<0.05). Birds fed with pelleted diet had higher mortality than those fed with mash diet. Dietary nutrient density had no effect on meat yield cost, but pelleted of feed resulted in decrease of meat yield cost. The result of experiment showed that feeding birds with pelleted diet and high level of nutrient and metabolizable energy would improve performance of broiler chickens.

In recent years, doubtful symptoms of virus diseases had been seen in extensive cucurbit fields of Golestan province. Therefore in summer of 2007 sampling of cucurbit plants (pumpkin, watermelon, melon and cucumber) with symptoms of mosaic, deformation, blistering of leaf and fruit for the identification of WMV was down. For the disease identification and its distribution, serological method DAS-ELISA was used. This research results showed that 28 of 153 collected samples, in DAS-ELISA reaction, were positive and other were negative. The most of percentage of WMV contamination have been seen in Golestan province in melon (39%) and the least was in cucumber (7%). Also the results of warermelon mosaic virus distribution in province showed that the most contamination was related to Bandar Gaz (40%) and the least related to Gonbad and Aliabad (7% in any one). This is the first report of WMV existence in Golestan province.