Journal of Agricultural Sciences and Natural Resources
Year:2005 | Volume:12 | Issue:5|Papers Count:25

In order to study the effect of plant density and supplemental irrigation on yield, yield components and protein content of four chickpea varieties in dry farming condition, an experiment was conducted in Eslam-abbad-gharb Agricultural Research Station in 2001-2002 year. The experimental design was split plot based on RCBD with three replications. Two dry farming levels (dry farming +supplemental irrigation and dry farming without supplemental irrigation), Four varieties (Bivanij, IIc482, Flip90-96 and Flip93-93) and three plant density (26, 33 and 40 plant/m2)were randomized to the main plot, sub plot and sub-sub-plot units respectively. The results showed that supplemental irrigation decreased grain protein percent (%1.59) but increased branch number (3.15), plant pod number (8.7),100-grain weight (4.05gr) and grain yield (828.67 kg/ha). Bivanij and Ilc482 varieties had the most main stem (2.68) and branch number (7.77) respectively. Flip90-96 variety was late maturity. This variety had the most protein percent (%22.96). The most plant pod number, 100-grain weight and grain yield was observed in Flip93-93 variety. Protein percent was not significantly affected by density, but by increasing plant density decreased the main stem number, branch number and plant pod number. The most grain yield (1240 kg/ha) was obtained from 33 plant/m2. Flip93-93 variety had the most grain yield under supplemental irrigation with 33 plant/m2density.  

In catchments areas which lack data for the calculation of predicted maximum flow rate of flood, one of the methmethods used is the local (Regional) analysis method. In the paper in addition to reviewing empirical evidence and historical research carried out in this regards, taking to account the number of measuring station and the frequency of measurements an attempt was made to create a logical relationship between both. After performing the required review, 11 stations were selected and their data reconstructed. Following this stage a correlation coefficient between area and floods with various return periods, a relationship for area / return period was established which was then used to determine the maximum Flood flow rate in the study area with a 99% reliability factor up to catchments with a total area of 10000 square Kilometer.  

Accumulation of sediment materials in reservoirs of dams is one of the great problems for all dams. The Voshmgir dam has encountered the problem since the beginning of the water collection. So that, now, after three decades after the start of its operation, a great part of its useful storage has been demolished. The vital and important issues of the country like watershed management, environment and the matters related to water resources development, make the removal of storage dam sediment a very important subject. Investigation of the origin, amount, place, removal and agricultural and industrial uses of the reservoir sediments of Voshmgir dam and the construction materials made from the sediments are carried out by the results of the activities and research works in the area of recognition of mineralogical, physical and chemical characteristics of the sediment. By removal of the dam resevoir sediments, the useful storage volume of the dam increases, the volume of sediments decreases and the raw materials for production of the artificial materials like brick, tile and ceramic are provided. Probable use of sediments as raw materials for construction of artificial materials through mineralogical, physical and chemical tests on the sediments of Voshmgir dam is investigated. In physical tests, the density of particles, particle size distribution and Atterberg limits were determined. In chemical test by analyzing the samples, the percentage of carbonate, sodium chloride, organic materials and loss of ignition of samples were evaluated. Finally, adobe samples which were made by traditional and pressure methods, were under the compression, bending and water uptake tests. The results were compared with Iranian 1162, German DIN 1230 and 51070 standards. The uses of these sediments for construction of artificial raw materials have been confirmed.  

  There are major and medium dams in Iran that have been already completed and they are being operated conventionally. To attain maximum benefits of them, it is imperative to regulate the reservoirs in the most efficient and judicious manner. This investigation deals with the development of an operation policy for Voshmgir reservoir located in Golestan province in Iran. This research has been aimed to serve water for irrigation purpose of Voshmgir project. Using inflow, demand and evaporation, reservoir simulation was performed. A linear programming model was developed for the reservoir to get the initial feasible solution. The developed optimization model is based on Sand SQ rules. This model was applied for reservoir simulation and optimization using 25 years historical data. Rule curves were prepared using the reliabilities 50, 75, 85 and 95 percent. A comparison was made between the currently followed operation policies and the proposed operation policy. The results showed that current operation policy is unable to supply the demand in critical months and proper precautions are not taken into account for probable future floods. The reservoir water storage in proposed operation policies showed an increased of 17 percent more than practiced policy. The average monthly supply by using the Sand SQ rules are approximately 47.63 and 49.23 percent, respectively while according to practiced policy this value is 38.7 percent.  

Time of concentration is the most important factor in choosing design rainfall of watersheds. There are several equations presented by different researchers to estimate time of concentration which are usually limited to a particular study area and it is not reliable to use them in other areas with different climatic, topographic and morphologic conditions. Due to the importance of time of concentration in estimating flood and the role of floods in damaging water structures, residential areas, etc. It is an important task to estimate it in irrigation and sewerage systems, dam construction and urban hydrology projects. In this study, 11 mountainous watersheds in Tehran, Mazandaran and Isfahan with 16.1 to 712 Km2area and main channel slope of 0.77 to 13.8% provinces, equipped with rainfall and runoff estimated using flood hydrograph and rainfall hyetograph and compared with 14 empirical equations and the calibrated equations were derived using SAS software. The study showed that all of these equations don't have sufficient accuracy for the selected watersheds except for Pilgrim-McDermott equation. Thus, to get the required accuracy, eight effective variables on time of concentration were applied for final equation and 248 new equations were derived combining these factors and omitting variables of the watershed with minimum slope. From all this, eight equations Which consist of two equations with one variable, three with two variables and three with three variables with sufficient accuracy where derived among which was the Pilgrim-McDermott equation. At least, the equations -were selected to be the best time of concentration equations for mountainous watersheds.  

A field study was conducted at Aboureihan research farm of Tehran University in 2000 to find out the effects of plant densities, different levels of nitrogen and potash on grain yield and yield components of maize (Zea mays L.). A split plot design with four replications was used in which the plant densities (6.5, 7.5 & 8.5 plants/m2) were the main plots. Each main plot was sub-divided into 9 sub-plots to accommodate the other treatments i.e. N100K0,N150K0,N2ooK0,N 100K50,N100K100,N100K150, N150K50,N150K100and N150K150. The results indicated that plant densities had a significant effect on grain yield, number of grain per ear and hundred seed weights. The maximum grain yield (14724 kg/ha) was obtained in 7.5 plants/m2.Different levels of nitrogen and potash had significant effect on grain yield, hundred seed weight and number of seeds per ear. However, there was no significant effect on number of row per ear and ear length. Results also showed that by applying NI5oK100, maximum grain yield, number of grian per ear and weight of 100 seeds can be obtained. It was concluded that treatment of NI50K100 could increase yield and yield components of maize and also applying nitrogen without potash decreased the yield and yield components of maize.  

Nitrogen is one of the most important elements needed in cereal crops especially corn and its deficiency has been seen in agronomical fields of the world. To develop and improve of husbandry in the province and due to the need of development in cultivation of dent corn alongside the forage corn different experiments should be done in order to find out the agronomical needs of this kind of crop a field. Field experiment was conducted to evaluate the effect of nitrogen fertilizer levels on grain yield and yield components of corn (Zea mays L.var.sc.704) at Chobar, Guilan province using a randomized complete block design with 3 replications. Four levels of nitrogen (0, 67,138 and 207kgN/ha) were applied. Grain yield, yield components (grain number per ear, grain weight per ear and 1000 grain weight and other related traits (hectoliter weight, and ear length) were measured. The effects of nitrogen levels on all traits were significant. Application of 207kg/ha nitrogen resulted in highest grain yield (10912.2 kg/ha), 1000 grain weight, grain weight, grain number per ear, hectolitre weight, ear length and grain weight per ear. Correlation coefficients showed that the ear length and the grains number per ear had positive and significant correlation with the grain yield. Also the use of 207kgN/ha I increased the grain weight (227.1gr), 1000 grain weight(373.7gr) and hectoliter weight(72.84kg) and showed a positive and significant correlations with grain yield.  

The experiment was conducted at agricultural research station of Gonbad during 2001 - 2002. The experiment was a factorial split arranged in a randomized complete block design (RCBD) with 3 replications. Three irrigation treatments (1- without irrigation, 2- irrigation at flowering stage and 3- irrigation at flowering and seed filling stages) and two varieties (Sarigol and Hyola 401) were as main plots in a factorial arrangement. Three nitrogen treatments (1- without nitrogen applying, 2- nitrogen applying without foliar application and 3- nitrogen applying with foliar application) were subplots. The effect of irrigation was significant at 1% level on the number of days from emergence to physiological maturity and 1000-grain weight level and on grain yield and oil at 5% level. Irrigation at flowering and seed filling stages increased grain yield, significantly, whereas there was no significant difference between non-irrigation and irrigation at flowering stage treatments in grain yield. The effect of irrigation, nitrogen and variety did not significant on oil percentage. Plant height, 1000-grain weight, grain yield and oil of Hyola 401 Hybrid were more than those of Sarigol variety. The effect of nitrogen was significant at 1% level on the pre winter growth, the number of days from emergence to flowering, Plant height, 1000-grain weight, grain yield and oil. The number of pod per plant and the number of grains per pod were affected by nitrogen application. Soil nitrogen application increased grain yield, significantly, while the effect of foliar nitrogen application on grain yield was not significant.  

Weed interference is one of the most restrictive factors in agricultural yield .This interference is often due to the allelopathic effects of the weeds. In this research, the effect of aqueous extract concentrations of root, shoot, seed, flower, stem and leaf were evaluated on germination percentage and seedling growth of the canola. A complete randomized design was employed in a factorial arrangement including wild mustard organs and totally with treatments of aqueous extracts (0%, 0.5%, 1.5%, 3.5%, 5% and 7%) each in 4 replications. First stock solution 10 %( w/v) was prepared, and then the other solutions obtained by diluting the stocks. All the different aqueous extracts decreased percentage of germination and length of radicle and coleoptile. The maximum germination was found in root extracts and minimum in leaf and flower extracts. The effect of flower extracts on length of radicle and coleoptile were more than of other organs, whereas the least effect belonged to root extract. Generally by increasing the concentration of extracts, the germination and growth were decreased.  

The beluga juveniles with 5, 10, 15, 20, 25 and 30 grams initial body weight in 6 treatments each one with three replications (N=150 fishes) were reared. The fishes transferred in 18, 2*2 m fiberglass's basins fed with concentrated feed set in a completely randomized design. The total body weight and length measured and the mortality in each basin counted and then the length and weight coefficient variation of fishes were calculated after 45 days experiment period. The mean of each parameter compared with Duncan's test. The results indicated that the fishes with 20 grams and more in initial body weight adapted better than the fishes with lower than 20 grams. Likewise the fishes with 20 grams and more initial body weight adapted to concentrated feed without any mortality.    

A lot of money is spent for the culture of juvenile sturgeon fishes, but there is not any suitable information on the symbiotic vertebrates, such as snakes, frogs, and terrapins in ponds especially in Golestan province. Therefore, 33 specimens of pond turtle were collected from culturing ponds of sturgeon centre of Voshemgir dam, Golestan province from 31/5/2001 to 21/6/2001 (21 days). The specimens then weighed and measured. All speciments were discected, then stomachs, intestines, with their contents were labled and then fixed in %4 formalin. Results of this study indicated curved carapace length (CCL) of these turtles were 50 to 180 mm (mean 126.0), weights 50 to 850 gr (mean 413.3), stomachs" wet weight 0.08 to 52.5 gr (mean 5.43), and length of stomachs 15.9 gr (mean 2.0) and 270 to 680 mm (mean 483.7) respectively. The ratio of intestine length to CCL was 1.75 to 5.7 (mean 3.95). The highest percentage of preys in relation to total swallowed organisms in stomachs were as follows: Triops concriformis %41.6, dipteran larvae %12.2, water be %6.93, water bugs %5.74, and the lowest percentage in stomachs were cockroaches, dragonfly nymphae, flies, spiders, Trichopteran larvae, Planorbis, Acipenser persicus. All of these items were determined in intestines of all specimens separately. Percentage of each of preys was determined in stomachs and intestines. Every adult female terrapin had 5 to 8 eggs, mean of their weight were 8 grams, length of them 30.8, and width of them were 19.2. only %25 of eggs hatched after 71 to 74 days (mean 72.5).  

On hundred eight specimens of juveniles of stellate sturgeon , Acipenser stellatus with average body weight of 7±lgr in six groups (5 experimental &1 control groups) were examined at Ecological Institute of Caspian sea. After determination of lethal concentration (3.7 mg/L) fish exposed to 3, 4, 5, 6 and 7 mg/L of diazinon. The LC50, 96 hr of diazinon for Acipenser stellatus calculated as 4.98 mg/L. Specimens showed abnormal behavior such as severe stress, spasm of muscles around the mouth, semicircular summing and disruption of breath activities. To study the hematological parameters, blood were taken from the fish and values of RBC, PCV, Hb, MCV, MCH and MCHC in experimental and control groups showed significant differences (P<0.05).Results from differential counts of leucocytes and lymphocytes of the groups showed significant differences (P<0.05).Inthe biochemical values of total protein and glucose of blood serum of examined groups showed significant differences (P<0.05). During the study, DO, PH, water hardness, N03, N02, EC, P04 and water temperature were also recorded daily.  

In order to study of feeding habits of Huso huso and Acipenser guldenstaedti, three earthen ponds with 2 hectars (two ponds for Acipenser guldenstaedti & one pond for Huso huso) were selected randomly. Culture period was prolonged to 31 days. The fullness index, feeding habits, condition factor (K) and growth rate (G) of the fingerlings were measured in the rearing period. Regarding of the percentage of prey abundance in the guts content of Huso huso fingerling, Cladocera (Daphnia sp.) was the primary prey (Fp>50%), Chironomidae larvae and Ostracoda were secondary prey (10 %<Fp<50%) and Copepoda (Cyclops sp.) was the occasional prey (Fp<10%). In A. guldenstaedti fingerlings at the first group: Cladocera, Copepoda and Chironomidae larvae were secondary prey degree of first to third importance respectively and Ostracoda was occasional prey. In the second group: all of the feeding organisms were as a secondary prey and on the basis of the statical analysis conducted significant differences were observed in Cladocera, Copepoda and Ostracoda in guts content. The result of observation also indicated a decrease in the growth rate and condition factor with increase of weight and length of fingerlings. Result showed the growth performance of Huso huso and A. guldenstaedti fingerlins were positive allometric (b>3) and negative allometric (b<3) respctively.  

Rapeseed is the 3rd oilseed in the world after soybean and palmoil. Recently, the production of rapeseed in Iran has greatly emphasized for enhancement of oil production. For storage of oilseeds before processing, drying of seeds to a safe moisture level is necessary. In this study, effect of moisture content at harvesting time and drying temperatures on the quantity and the quality of canola oil were investigated. Seeds at moisture level of 12, 16 and 20% (w/w) were harvested and then dried in 65,75,85,95 and 105°c to final moisture of 8% (w/w). Then parameters of total oil, acidity, Iodine value and colour of oil were evaluated. The results showed that drying of rapeseed in 85 °c and initial moisture of 12 or 16% was the best conditions for drying rapeseed without adverse effect on oil quality.  

Treatability of Paulownia wood was carried out using polymerization technique. The main aims of this study were: to determine the treability indices, the role of anatomical factors on fluid flow, flow in radial and tangential flows and comparative study of heart wood and sapwood treatability. The ends and tangential surfaces of some specimens and radial surfaces of the other samples were sealed to examine tangential and radial flows respectively. Specimen dimensions were 2.5×2.5×4cm. Monomeric styrene was chosen to impregnate the specimens. Adding the red dye to monomer before impregnation, the distribution of polymer among different ceel types examined using light microscopy. The results showed that the retention and depth penetration in tangential flow were greater than those in radial flow. No significant difference was observed between retention and penetration of sapwood and latewood. Distribution index in tangential flow was the same as in radial flow. Vessels were treated very weak in all flow directions due to blockage by tylosis; fibers were poorly treated and rays, as well as longitudinal parenchyma, were not treated at all, due to storage of food and deposited materials in their cell lumen.  

In this study design a decision-making system in integrated pest management of wheat fields in Lorestan province. Fifty fields were sampled through the province for calibration of system according to binomial sequential sampling model. In one hectare of each field moving v-shape and sampling twenty wheat plants (four samples, each sample five plants) and recording pest infestation based on present or absent of it. Sample variance of wheat pests including wheat bug, wheat thrips, wheat aphids, (in plant souper Guide), coleopteran leaf feather larves according their importance are 0.16, 0.41,0.28 and 0.19, and number of sample for each pest according K parameter respectively are 9, 10, 9 and 17 respectively. In this study Binns's method was used for calculated relationship between Ln (m) and Ln (-Ln (PL) in simple linear regression method. Line of stop sampling for wheat pest respectively are 0.25, 0.435, 0.465 and 0.176 that used for forecasting system of wheat pest and PL, PU were appreciated in wheat fields for decision making.  

Andrallus spinidens F. is a predator on a wide range of insect pests of economic important pests in fields like Naranga aenescens and chilo suppressalis. Biology, seasonal fluctuation and spatial distribution of Andrallus spinidens F. studied under laboratory(at temperatureof 23.18±1oc and relative humidity of 92.57±2% ) and field conditions by twice a week sampling using a sweep net. To study spatial distribution, sweep net and direct count methods were used to take sampling. This two methods were also compared. The incubation period was, 9:t 0.5 days. Eggs were light brown in colour and were laid in a cluster. The nymphal developmental time feeding on Naranga aenescens and chilo suppressalis larvae were 24 ±0.46 and 26.33 ±0.46 days, respectively. There were five nymphal instars. Adult insects are yellowish brown male and longevity was 9.83 and 16.3 days, respectively. Mating took 160±14.73 minutes, average number of eggs laid by a female was 241. 66±30.40. Nymphs and adults feed on prey larvae and such their body fluids. A.spinidens overwintered as an adult and there was 3 generations in a year. Spatial distribution of A.spinidens population was determined by Taylor's Power Law. Nymphs were aggregated on different rice Varieties. Aggregation indices (b) for nymphs were 2.76, 2.2 and 3.26 on Binam and Sepidroud (sweep net) and Binam (direct count), respectively. Aggregation index for adult insect on Binam (Sweep net) was 1.26 which is an aggregated distribution. This experiment showed that a sweep net sampling method was better to estimate Predator population.  

The present study was conducted to determine LC50 values of different concentrations of Steinernema carpocapsae on various larval instars and compared the efficacy nematodes on prepupa and pupa stages of beet armyworm(Spodoptera exigua).The beet armyworm were reared in the laboratory on artificial diet. The nematodes were isolated from apple orchards soil by Galleria trap and reared on last instar larvae of greater wax moth (Galleria mellonella L.). Infective juveniles (3rdstage nematode larvae) collected after emergency from the larval cadavers. Different concentrations of nematodes prepare to determine LC50values and used in bioassay tests on the leaves of sugar beet. The estimated LC50values of five larval instars of armyworm were 164,342, 396,450 and 481 nematodes per 0.1 ml respectively. The effects of nematodes concentrations ranging from 4×103, 2×104 and 4×104 nematodes per liter on prepupa and pupa stages were investigated. The percentages of mortality three concentrations were 26.6,50 and 80 for prepupa and 16.6, 23.3 and 33.3 for pupa respectively. These results indicated that prepupa stage was more susceptible than pupa stage. In addition to larval instars, we propose to use the nematodes on prepupa stage of this pest.  

Observations on the post-emergence and mating behaviors of adults of the Mediterranean flour moth revealed that the adults could not fly 15-20 min. after their wings expansion. Despite of non-feeding normally, adults fed from sucrose solution. Females were polygamous and mated 3 times. Sexual dimorphism is obvious in adults, so that, males have a smaller body and their abdomens seem elongated and rectangonal, while, females have a bigger body and before the end of oviposition period, their abdomens seem fusiform and swollen. Results of present study indicated that adding bran to the rate of 25% could increase females' fertility and also could affect some of desired aspects of mass rearing, positively. Males' longevity lasted more than that of females. Females oviposited up to 12 days, but laid most of their eggs (95%) during the first 5 days. By considering this and also mean of females' longevity (about 7 days), it is recommended that collecting eggs could be continue up to 5 days. There were high and positive correlation coefficients between weight of female 5thinstar larvae, pupae and adults, and length of females' hind tibia with number of eggs were laid by females.