Journal of Agricultural Sciences and Natural Resources
Year:2004 | Volume:11 | Issue:3|Papers Count:20

To evaluate the effect of seeding rate on forage and seed yield for two species of beard wheat (Triticum avesticum var. Tejan) and durum wheat (Triticum durum var. Stork) in rainfed system, an experiment was conducted in Bahnamir region at Mazandaran province in 2000. The design was arranged as split plots with the wheat species assigned to the main plots and seeding rates of 130, 180 and 230 kg/ha as the subplots. The plants were harvested at vegetative growth stage (before booting) for forage and at the end of the physiological maturity for seed production. The durum wheat (Stork cultivar) in both vegetative and the end of the physiological maturity growth stages produced significantly more biomass than bread wheat. As seeding rate increased the more biomass was harvested, however, the seed production decreased in both species. The durum wheat was significantly more sensitive to increment of seeding rate in response to seed production. The maximum seed yield for durum wheat was obtained at seeding rate of 130 kg/ha while bread wheat showed no significant response to seeding rate.

The effect of foliar application of copper and zinc on grain, oil, protein yield, and seed quality of canola (OKP variety) were studied in Dashtkar region of Bardsir, 65 km south -west of Kerman. Copper and zinc solutions being sprayed twice (first in stem elongation and then in early flowering) in 16 treatments, each with different amounts of copper (copper sulfate), in four levels: Cu1 (0 kgCu/ha), Cu2 (0.15 kg Cu/ha), Cu3 (0.30 kg Cu/ha), Cu4 (0.45 kg Cu/ha) and zinc (zinc sulfate), in four levels: Zn1 (0 kgZn/ha), Zn2 (0.80 kg Zn/ha), Zn3 (1.60 kg Zn/ha) and Zn4 (2.40kg Zn/ha), using factorial experiment with split block design in three replications. The results showed that the effect of Zn levels and Cu-Zn interactions on pods/plant, seed, oil and protein yield were significant (p<0.1%). Whereas, Cu3Zn4 treatment made maximum increase. The results indicated that Zn3,Zn4 and Cu2 treatments had the most effect in increasing seed oil and protein (%). However Cu3Zn4 treatment, increased seed oil (%), seed Zn and Cu concentrations.

Nutrient deficiency diagnosis and uptake limitation of nutrients at different phosphorus and zinc fertilizer application rates for dryland wheat were studied. Experiment was set up in a completely randomized block design with 4 rates of phosphorus (0, 50, 100 and 150 kg/ha P2O5)and 4 rates of zinc (0, 10, 20 and 30 kg/ha Zn) in factorial arrangement with three replications in field of Dryland Research Institute station (Maragheh) for three years (1995-1998). Data were compared at different methods (DRIS and correlation between nutrient ratios and grain yield). The results showed that the correlation between nutrient ratios and grain yield was effective than DRIS method. Mn was most critical nutrient to increase grain yield compared to other nutrients. For the nutrient balance, between Mn and other nutrients, the ratios N/Mn, P/Mn, K/Mn and Fe/Mn should be less than 660, 29, 420 and 2.8 respectively. In contrast, the ratios of Mn/Zn, Mn/Cu and Mn/B should be more than 2.5, 10 and 9 respectively. It can be concluded that correlation method is best fitted to the nutrient balance and increased grain yield. As indicated by this method, the above mentioned ratios are required for nutrient balance and highest grain yield.

The effects of subsoiling and irrigation frequency on potato yield were evaluated during 2000- 2001 growing season at Tajarak Research Station of Hamedan province. In this study, two tillage methods consisting of I)Conventional tillage using moldboard plow to a depth of 20-25 cm and 2) moldboard plowing + subsoiling to a depth of 35-40cm , and three irrigation frequencies (3,6 and 9 day irrigation intervals), were used. A split plot design within a randomized complete block design with three replications (tillage method and irrigation regime were assigned to main plot and sub plot, respectively) was used. The effect of subsoil loosening on soil resistance was evaluated by determining cone Index at two stages (after of the first and middle irrigation). At end of growth season (harvesting time), potato yield and some of the quantitative and qualitative factors of potato consisting of tuber size, tuber number per plant, tuber weight per plant and the percentage of deformed tubers were measured. The result showed that subsoiling caused marginal reduction in soil strength beneath the 25cm surface layer. No significant differences in yield were observed between subsoiled and unsubsoiled plots. The effect of irrigation regime on potato yield was significant (p<0.06) and 3-day irrigation interval treatment had higher yield than the other two irrigation treatments (6- and 9-day irrigation interval). The results indicated that irrigated crops such as potato for which water requirement is supplied in short intervals, it may not necessary to loosen the soil by subsoiling under conditions similar to this experiment.

In order to determine redroot pigweed and barnyard grass economic damage threshold in dry bean an additive experiment was conducted at experiment. station of Ferdowsi University of Mashhad. The type of design was completely randomized block (CRD) and experimental treatments included three levels of redroot pigweed densities (4,8,12 plant/m2) and three levels of barnyard grass (10,20,30 plant/m2) that planted at fix density of bean(20 plant/m2) pluse weed free check in each block. For determine of weeds competitive indexes used from regression model. Results from experiments data and regression model showed that redroot pigweed is more competitive than barnyard grass and their economic damage threshold was 0.04 and 0.22 respectively. But whit respect 90 percent in control efficacy the amount of economic threshold in both weeds was zero.

One of the natural enemies of aphids is green lacewing, Chrysoperla carnea (Steph.), which in biological control programmers is usually released in egg stage. In this way, predators of egg have an important effect on the efficacy of egg releasing. To compare the effect of ant, Tapinoma simrothi K. as a generalist predator on the efficiency of lacewing, this experiment was conducted in three treatments of egg releasing methods included chrysocard, chrysobag and egg released mixed with sawdust each in 5 replications. Each replication included a potted ornamental cabbage plant, Brassica oleracea L. infected with cabbage aphid, Brevicoryne brassicae L. Fifty eggs were released in each replication. After 24 hours the remained and healthy eggs were counted. The results showed that in chrysobag all eggs were healthy, but in chrysocard 35.6% and in sawdust method 59.6% were healthy, respectively. The results indicated that the chrysobag method protects eggs better than other methods.

In an investigation for possibility of using natural compounds which are safe for human instead of hazardous antifungal agents for control of contamination in food stuff, the inhibitory effects of various concentrations of thyme, savory, mint, lemon, galbanum and eucalyptus oil on the growth of aflatoxin producing strain of Aspergillus parasiticus was studied. The results showed that among 6 tested essential oils, thyme and savory oils have been most inhibitory effects respectively and other essential oils in tested concentrations could not have sufficiently inhibitory effects on Aspergillus parasiticus. Although more researches needs for determination the exact amount of effective dose between 0-200 p.p.m thyme and 200-400 p.p.m savory but we can hope to use thyme and savory oils as safe and certain antifungal agents instead of hazardous synthetic materials.

In study fungi in rhizospheres of field crops and fruit trees collected from different parts of Iran, seven fungi were identified as follow: Endogone pseudopisiformis, a saprophite fungus from phylum Zygomycota, Archaeospora frappei ,Enfrophospora infrequens, Glomus coremioides, G. microcarpum, G.rubiforme and Scutellospora pellucida from phylum Glomeromycota, all these fungi are new for Iran mycoflora. Morphological characteristics, mycorrhizal associations and distribution of these fungi are illustrated.

In order to evaluate the influence of temperature and precipitation on formation and development of soil in forestry regions of Elburz Mountains northern Iran, three different climatic conditions namely udic-thermic, xeric-mesic, and udic-mesic were diagnosed. In each climate one unit of mountain physiography with parental calcareous material were selected. Then, to determine macro-and microorphological, physico-chemical and clay mineralogy characteristics, the necessary soil profiles were also considered in various situation and direction. Field and laboratory studies showed that udic-mesic area contains deep soils with mollic epipedon and clay cutans (argillan) accumulated on the walls of voids. With increasing soil depth, the amount of clay cutans was also increased. Relative occurrence of clay minerals was montmorillonite, illite, vermiculite, ciyorite and kaolinite, respectively. In xeric-mesic areas the solum was thick and organic matter of surface horizon also were low. Only a few amount of calcite in form of microcrystals (calcite) have been accumulated on the walls of voids. The relative occurrence of clay minerals was illite, chlorite and vermiculite, respectively. However, in udic-thermic areas, due to high rainfall and temperature, calcite were leached and clay were moved downward. Clay cutans (ferri-argillan) were observed on the walls of voids from shallow depth which were maximized in depth of 78 cm. Relative occurrence of clay minerals were illite, vermiculite, montmorillonite, chlorite and kaolinite, respectively. Depth increasing enhances the relatic amount of montnorillonite.

In this data consisting of 1382 records of birth weight (BW), 1367 records of 3 month weight (3MW) and 1263 records of weaning weight (WW, 4 month weight) from the Sanjabi sheep, collected from the animal research center of Mehrgan in the Kermanshah city over the period 1369 to 1377. Average and standard deviation for birth weight, 3MW and 4MW were respectively estimated 4.58±0.67, 23.46±4.90 and 26.71±5.41. For estimating genetic and phenotypic parameters, (Co) variance components the animal model DFREML packages were used that the most suitable model for studied traits included fixed effects of year of birth , age of dam, sex of lamb, type of birth and month of birth(except BW) and random effects for the direct and maternal addative genetic effects and maternal permanent environmental effect. Direct heritability and maternal heritability were estimated 0.1, 0.096 (BW), 0.21, 0.11 (3MW) and 0.14, 0.12 (WW) respectively. Direct addative genetic correlation between BW with 3MW, WW and 3MW with WW were estimates 0.68, 0.603 and 0.755 respectively Phenotypic and environmental and correlation were estimates between BW with 3MW,WW and 3mw with WW (0.391,0.31), (0.311, 0.292) and (0.597,0.556) respectively.

The identification of hydro logically homogenous regions is a primary step in many of regional flood frequency analysis techniques. This study was carried out to determine the most important climatic and physical factors, which influence the watersheds in the east and northeast of Iran. The data of flood peak discharges and the characteristics of 16 basins in the study area were used. At first, test of the selected regional distribution function (Log Pearson type III) was fitted and instantaneous peak discharges in different return periods were calculated. Independent and significant variables were selected using factor analysis method such as: basin area, mean elevation, drainage density and annual average rainfall. These variables explained 87.82 per cent of total variances. Hydrologic homogenous regions were also distinct using cluster analysis method. Comparison of the calculated RMSEs in two basins showed low errors among grouped regions.

In this research, Snowmelt Runoff Model (SRM), which is based on degree-day method, was used to study the runoff generation in Mahabad basin. In order to incorporate the distributed aspects of snowmelt process, the Mahabad basin was divided into four elevation zones. The inflow to Mahabad dam is measured at two gauging stations located upstream of the dam. In this region there is one temperature measuring station located in Mahabad City. Seven raingauge stations exist in the basin. Extrapolation method was used to find the temperature in the other zones of the basin. To obtain precipitation for the other zones, extrapolation and interpolation techniques were used. In order to calculate the flow due to snowmelt and rainfall, fourteen parameters were calc1ilatedfor each of the elevation zones. These parameters were later used as the input to the model. Area and hypsometric elevation of basin and elevation zones are the basin characteristics, and temperature, precipitation, snow cover area and measured flow discharges are the input variables, and runoff coefficient, degree-day factor, temperature, laps rate, critical temperature, rainfall contributing areas, recession coefficient and lag time are the input parameters to the model. Defining the values of these parameters, the model simulation was carried out. The computed and measured hydrographs were plotted. Comparison of the hydrographs was made through visual inspection, the coefficient of determination R2, and principle of continuity. The R2 value and the percent of volume error worked out to be 0.85 and -3.79% respectively. Results show that the accuracy of the model is acceptable.

Sediment yield isn't usually estimated by interpolation methods; because of lacking of enough rivers concentration data. So the most common method to estimate mean suspended sediment load (SSL) is using sediment rating curve (SRC) in combination with discharge data classified as extrapolation methods. There are different methods for determination of SRCs equation and processing flow data. In this research we estimate the SSL in 17 hydrometric stations with 18 extrapolation methods to evaluate the accuracy and precision of them. These methods classified to 6 groups of SRC estimation and 3 types of flow data. In addition we computed the actual SSL on the basis of intensive sediment concentration data in Ghazaghly station using interpolation method. Comparison of results showed that the "Mean loads within discharge classes- Daily discharge" method has good agreement with actual load and therefore selected as the standard method. Finally differences among 17 methods are comprised and evaluated with standard one in other 16 stations. The results showed that FAO, Nonparametric, Parametric, and Fitting one line methods haven't good agreement with standard method. Also Flow duration method underestimated SSL about 14%.

Study of the sediment movement in rivers to understand accurate hydraulic behavior and river morphology, is an important issue in river engineering Based on transport mechanism, bed material load is divided into suspended load and bed load. There are many empirical and semiempirical equations to estimate bed load now. But complication of sedimnent transport phenomenon arised from the reaction of hydraulic and sediument parameters caused that, these equations cannot predict sediment transport rate accurately. So the evaluation and choosing the best methods to estimate rivers bed load by comparison of calculated and measured data are very important. In this article, sixteen equations are studied to estimate the bed load of Zarringol River in Golestan province. Then calculated and measured data by Helly-Smith sampler are compared and the results are analysed graphically. At the end, the best methods to calculate Zarringol river bed load discharge are proposed.

A3x4 factorial experiment was conducted for 51 days to determine the effect of diets containing different levels of protein and fat on growth of fingerlings Iranian sturgeon (Acipenser persicus). Twelve different diets were formulated with 3 levels of protein (45,50 and 55) and 4 levels of oil including fish oil and san flower oil (0.5 ,4 , 8 and 12).1188 iranian sturgeon fingerlings with initial body weight (IBW) of 1.1±0.2 gram, after adaptation to the experimental conditions were selected and stocked randomly into 36 fiberglass tanks (100 water volume) at 35 fish per tank. Two ways analysis of variance showed that percent body weight increase (%BWI), specific growth rate (SGR), protein efficiency ratio (PER), food consumption ratio and productive protein value (PPV), content were significantly (P<0.05) affected by deferent protein and fat level. Fishes fed on diets No.8 (containing 50% protein and 17.2% lipid) showed the highest increase body weight in percentage, the best specific growth rate, best protein efficiency ratio and lovest food consumption ratio. The protein, lipid, dry matter and ash content of fish were significantly (P<0.05) different by the diet. Thus the highest amount of dry matter, crude protein, and crude fat was found in the fingerlings fed by diets No.7 & 8 are not significantly difference from each other. Based on the findings of the study, 50% dietary crude protein-from a good quality source-is recommended for the optimum growth of Iranian sturgeon fingerling. More over the rate of needed lipid for optimum growth of fingerling 17.2% was recommended.

This study was conducted to determine composition and abundance of macro benthos in marine shrimp culture ponds. Two salt water ponds with an area of l.2ha each and water depth 1.8m were used in this study during 3 months of summer in 2002. Sediment was sampled using by an Ekman grab covering a surface area of 225Cm2 monthly from entrance, central and out let sections and in each area 3 times. Samples were immediately preserved with 10% formalin. In the laboratory; each sample was seived through a 500 micron mesh screen to retain macro benthos. With a binocular microscope, all organisms were counted ami identified according to major taxonomic groups. Water quality parameters such as temperature, pH and salinity were measured weekly. For determining alkanity and percent of total organic matter (TOM %) monthly and grain size totally, sediment were sampled distinctly. Sediment analysis for composition and abundance of macro benthos revealed the presence of 3 groups namely; Arthropoda (crustacea, insecta), Mollusca (gastropoda, bivalvia) and Annelida (polychaeta) that mollusca group was dominant in 1 and 2 ponds with 87% and 71.4% abundance respectively. In this group, gastropoda was dominant with 90% in each ponds. The composition and abundance of macro benthos differed in different months in each pond. Soil alkanity did not significantly differ between two ponds and in first pond in different months, but it significantly differed in second pond. Also the percent of total organic matter did not significantly differ in two ponds, but it significantly differs in different months. Grain size consisted of coars and medium sand, silt and mud that quantity of them differed in two ponds and different locations, too. The range of temperature, pH and salinity were30.67-36.3°c, 8.23-8.77 and 42.67-56 ppt in first pond and were 31.67-36c, 8.37-8.8 and 41.67-56ppt in second pond respectively.

Ecological and population dynamism on Bovidae family in Golestan National Park was accomplished on the Ovis ammon arkali, Capra aegagrus, and Gazella subgutturosa by field observations and non-parametric statistics tests (such as Kruskal-Wallis and U-test). The conclusions revealed that Almeh, Darreh-Khoshk, and Dagermanly regions were similar in Urial density; and the best Urial population (namely population structure and rate of increase) is in center of park, whereas eastern populations in park are very fragile and young (because of hunters and easy access of violators); also with study of 17 Urial carcasses became manifest that the most hunting occur by Leopard (7 cases) and then by Wolf (3 cases) but 24% of Urials be hunted by this two main hunters and remainders of mortality occur by violators and natural factors. Natality of wild Goat was similar in four regions (Chonde-Abbas, Adam-Chagheran, Dagermanly, and Toonel-Aghsou). life expectancy and generation time was 5 years, r=0.135, sex ratio was 2 male to 1 female, and moderate annual duration was 0.78; so that Wild Goat populations in Golestan National Park with a view to generation time, annual duration and sex ratio are similar; means effects of human and natural factors on the population are similar. Gazelle's population in Golestan National Park was contained: r=0.156, generation time 3.7 year, and life expectancy in males was 0.4 year greater than females. No significant differences were between Gazelles herd. Kid's survival in autumn was less than spring season (at 95% level).

Collection and identifications snails of paddy fields in side river of the Babolrood has been investigated in 1999-2000. Seven stations (Rostaye-Anarestan Babol, Rostaye-Kashtaleh Babol, Zir-pole Mohammad Hassan Khan Babol, Darzi Nagib Babolsar, Armich Kolaye Babolsar, Miandasht Babolsar, Zir-pole Bozorg Babolsar & Masab Babolrood) were chosen in the length of about 88 kilometers. The out comes of this survey lead to identification of 15 snail species belonging to 8 genera and 7 families. The main characteristic for identification were selected as the shape, size of shell, dextral and sinistral position of the shell, operculum, aperture, radula, renal ridge and reproduction system. Out of identified species, 14 species, 8 genera and 5 families were categorized from sub-class Pulmonata, while only one species (Valvata piscinalis) recorded under sub-class Prosobranchiata. The number species of planorbidae (Planorbis planorbis, Planorbis carinatus, Planorbis intermixtus, Gyraulus euphraticus, and Gyraulus convexiusculus) was more in comparison to the others, whereas Lymnaea truncatula and Lymnaea stagnalis (Lymnaeidae) were observed their importance in medical and agricultural aspects respectively. Among the station surveyed, maximum and minimum 14 and 5 species were recorded in Rostaye Anarestan Babol and Masab Babolrood, respectively. These 2 stations are 50 kilometers away from each other. Planorbis intermixtus, Planorbis carinatus, Gyraulus euphraticus, Gyraulus convexiusculus, Pomatias rivular and Lymnaea pereger were reported for the first time from Mazandaran province. Identification key for collected snail fauna also reported in this investigation