Agricultural Sciences and Technology
Year:2005 | Volume:19 | Issue:2|Papers Count:25

In order to study of advanced barley lines, 19 genotypes of barley (Hordeum vulgare L.) with one control were evaluated in 3 years (1998-2000) at 10 locations. These trials were carried out in the form of a randomized complete block design with 4 replications. In order to introduce stable line (s), several non-parametric measures including mean of rank, standard deviation of rank, yield ratio index and the 4 methods proposed by Tennarasue were used. Analysis of variance for each environment (year and location combination) and combined analysis of variance for year combinations and three years were accounted. The results of analysis of variance for each environment showed a significant difference between genotypes in some environments. The main effects of genotype and environment and genotype ×environment interaction were significant, indicating yield fluctuation and difference among yield cultivars in various environments. Overall, genotypes 5 and 17 were distinguished as stable and genotype 13 and 7 as unstable. Non-parametric methods of mean and standard deviation of rank are preferred, because they were easy for calculation and conformity with yield of stable cultivars.

Sugar beet is one of the most important crops in Iran. The potential yield and its limitations can be estimated using a simple model and long-term weather information. The present study was aimed to develop a simple model for sugar beet. The model will simulate the phenology, development and senescence of leaves as a function of temperature. The biomass accumulation is simulated as a function of solar radiation interception, temperature and CO2 concentration. The growth of root is dependent on the developmental stages. Soil water balance including transpiration, evaporation, downward growth of root and infiltration were also simulated. The model uses a daily time step and readily available weather (maximum and minimum temperatures and rainfall, and sunshine hours and/or solar radiation) and soil information. The model was tested for Iran. The simulated average yield and its range were similar to observed yield (root mean square error was equal to 11.7 Mg h-1). It is concluded that this model can be used to study the effect of climatic factors on yield.

During 2001-2003, a survey was carried out to identify injurious living factors to Pistachio trees in the natural forest of Khajeh, kalat. To do this, each year from late march until late october a weekly or biweekly sampling program was conducted. To sample, a variety of methods including direct collection, shaking the foliages, knockdown and light trap were used. In some cases, the immature stages were reared to adult. During this period, a variety of insect and mite specimens were collected and identified. Among them, frequency and activity of three species be longing to the order of Lepidoptera were was more observable than the other pests. They are as follows: Gelechia cuneatella Douglas, (Gelechiidae), Nephopterix minimella Amsel, Pyralidae), Arimania komaroffi Ragonot, (Pyralidae). The first two species are reported from pistachio trees for the first time and are new for Iran. The 3rd species which already has been reported from Iran is new for Khorasan province. All of these species are important defoliators of pistachio trees in region. Some aspects of their biology such as seasonal activity and the number of generation of each species was studied.

The secondarily homothallic life cycle of white button mushroom which results in scarcity of uninucleate basidiospores (homokaryons) in its progeny, is the most impediment for genetic improvement of its strains. With respect to uncertainty of fruiting test and nonexistence of specified morphological criterion, in two recent decades scientists have used molecular markers as a fast and certain criterion for screening of homokaron isolates. In this study, RAPD markers have been used for identification of homokaryon isolates. Results showed that RAPD markers could discriminate homokaryons and heterokaryons based on number of bands. The number of band in homokaryons significantly reduced compared to those of heterokaryons. Results also showed that cluster analysis based on average of band number could separate homokaryon and heterokaryon isolates in two distinct groups.

Secondary metabolites have an important role in adaptation of plants to their environment and are the main sources of pharmaceutical materials such as alkaloids. Many of these compounds are produced through chemical synthesis for many years, while most of them obtained from natural resources due to their complicated structures. Production of secondary metabolites via tissue culture has some advantages over traditional methods. Alkaloids are first synthesized in roots and then transported to shoots and leaves. Hairy root cultures could be employed artificially to produce these metabolites. Hairy roots could be induced using Agrobacterium rhizogenes. In this research, explants of leaves and shoots of Datura. stramonium were inoculated with A .rhizogenes strain A4 in B5 medium. The nature of transgenic hairy roots was examined using PCR with specific primers for ro/B and ro/C of T-DNA. Growth and rate of alkaloids of transformed hairy roots were compared with normal ones using a completely randomized design. Rates of hyoscyamine and scopolamine alkaloids were measured through HPLC machine. The results indicated that the growth of transformed hairy roots was stable over time and their yield was more than three folds of that of normal ones. The results of HPLC showed that the rates of alkaloids did not change in transformed hairy roots compared to those of normal hairy roots. As a result, it is concluded that the presence of Ri plasmid in transformed hairy roots increases the content of hyoscyamine and scopolamine alkaloids.

Agricultural production inherently incorporate risk. In the processes of decision making risk is on of the most important factors on the adoption of new technology. The main objective of this study is to investigate the impacts of different factors on the production risk of irrigated and rainfed cumin in Khorasan province using generalised stochastic formulation and cross section data for 1378-79. The results indicated that the application of improved seeds decrease the production risk of irrigated and rainfed cumin, the fertilizer has an negative effect on production risk of irrigated cumin and the effect of tillage cost is negative on the production risk of rainfed cumin.

The antagonistic effect of some bacterial strains against Fusarium moniliforme the causal agent of collar and root rot of rice were investigated. Two hundred sixty six bacterial strains were collected from rhizosphere of infected plants from Rasht, Lahijan, Foman, Anzaly, Talesh and Astara in the Guilan Province. Antagonistic ability of 13 strains of these bacteria (8 Gram negative and 5 Gram positive) were demonstrated by using the dual culture method. According to the results of biochemical and morphological trials, the Gram negative bacteria were identified as Pseudomonas fluorescens and Gram positive was as Bacillus cereus. In determining the effects of volatile metabolites produced by antagonistic bacteria, all strains, inhibited growth of Fusarium moniliforme in vitro conditions. Culture filtrate and antibiotics produced by these strains inhibited growth of the pathogen. All P. fluorescens strains produced siderophore on King's B contained 5, 50 and 100 µmol FeCI3 which inhibited growth of the Geotrichum candidum. The bacteria colonization experiment showed that F21, F15 and F23 strains increased their populations on rice root system by 2.28, 2.27 and 2.23 CFU logarithm. Effecte of fungicides Benomyl and Rovral T.S on strains of antagonistics bacteria indicated that these fungicides had no effect on strains when used in 1000 ppm.

The purpose of the present study was to investigate the practical applications of alternative lighting programs as intermittent lighting at high or low intensities on the incidence of leg disorders and performance of broiler chickens. Eight hundred and sixty four day-old male and female broiler chicks (Ross breed) were randomly placed in 24 floor pens, sex separately (12 pens per sex, 36 chicks per pen). In the first 2 days of the trail, all chicks were subjected to continuous lighting [23h light (L):1h dark (D), CL] at a light intensity of 20 lux at bird height. After 2 days, chickens were subjected to an intermittent [1h light (L):3h dark (D), IL] or continuous [23h light (L):1h dark (D), CL] lighting programs combined with two different light intensities (high or 30 lux versus low or 8 lux). According to the obtained results, birds reared at IL showed significantly higher final body weight than their CL counterparts (P<0.05). Sex differences in final body weight were observed so that males were heavier than females (P<0.05). Lighting programs or light intensities did not significantly affect cumulative feed intake whereas they had significant impact on FCR. The results showed a significant reduction in FCR for broiler reared under IL and low light intensity (P<0.05). The intermittent lighting schedule significantly (P<0.05) reduced abdominal fat deposition of both male and female broilers but light intensity programs did not significantly affect abdominal fat pad content. Effects of lighting programs or light intensity schedules on mortality and bone ash percentage were not statistically significant. Intermittent lighting combined with low light intensity program, in addition of enhanced production efficiency and lowering the cost of electricity, resulted in lower room temperature. From the practical point of view, this may be used as an efficient management technique for raising broiler during hot season in tropical and subtropical regions.

Isabgol due to its mucilage in seeds is very important in pharmaceutical industry. A field experiment was conducted in Mashhad during 2001-2002 growing season to study the effect of sowing date and seed rate on growth, phenology, yield and yield components of isabgol(Plantago ovata Forsk). Treatments were arranged in a split-plot design with three replications. Main plot consisted of five sowing date (6Nov, 6Dec, 5Mar, 4April, 5May), and sub plot consisted of four seed rates (4, 8, 12, 20 kg/ha). Results showed that duration of phenological stages decreased as sowing date was delayed. The effect of sowing date on morphological characteristics such as plant height, spike length, leaf and tiller number per plant was significant, but increasing seed rates had no significant effect on these characteristics. However, spike length was significantly influenced by sowing date and seed rate. Yield components such as number of spike per plant, number of seed per spike, number of seed per plant and 1000 seed weight decreased as sowing date were delayed and seed rates were increased. LAI and total dry mater increased by increasing seed rate and decreased by delaying in date of sowing. LAI was maximum in reproduction stage. Both seed rate and sowing date had significant effect on isabgol seed and biological yields. Maximum seed and biological yields were obtained in the third sowing date and they were reduced as sowing date was delayed. Both 1000 seed weight and harvest index were not significantly influenced by these treatments. Quality characteristics, which studied, were swelling factor, husk percent and mucilage percent. Sowing date had no significant effect on quality characteristics. However, highest quantity and quality of  mucilage gained at third sowing date.

Two experiments were carried out to test the effects of alfalfa particle size and functional specific gravity on chewing activity, digestibility, rumen kinetics, and production of lactating dairy cows fed corn silage based rations. In experiment1, using the in vitro method, water-holding capacity, insoluble dry matter, hydration rate, and functional specific gravity changes were determined in alfalfa hay (varying in particle size) and corn silage. Reduction of particle size increased bulk density, functional specific gravity, and the rate of hydration and decreased water-holding capacity of alfalfa. In experiment 2, nine mid lactation Holstein dairy cows fed total mixed rations, containing three sizes of alfalfa hay (with geometric mean 7.83, 4.04 and 1.14 mm) were used in a replicated 3 ×3 Latin square design. The diets contained 20, 20, 35, 7, 7.5, 10, 0.3, 0.1 and 0.1 % of DM alfalfa, corn silage, barely, soybean meal, beet pulp, wheat bran, DCP, vitamin premix and salt, respectively. The geometric means of rations were 3.34, 2.47 and 1.66 mm in long, medium and fine alfalfa treatments, respectively. Reduction of particle size increased daily NDF intake (kg), but decreased the proportion of physically effective factor and physically effective NDF in the ingested rations. Reduction of particle size increased the functional specific gravity of rations, intake of DM, but reduced digestibility of NDF and ash. Reduction of particle size decreased ruminal mean retention time, but increased the ruminal particulate passage rate. Milk and FCM yield was not affected by treatments. The rumen pH, total chewing activity, rumination, eating time and milk fat were reduced as particle size decreased, but milk protein increased. This study showed that reduction of forage particle size increased bulk density, functional specific gravity, hydration rate of alfalfa hay and was the most influential factor affecting DMI, milk composition and chewing activity but had minimal impact on digestibility and milk production.

This investigation was conducted to evaluate the effects of the osmopriming on seed germination of rapeseed, under water stress condition. The design of the experiment was a factorial completely randomized design (CRD) with three replications. The experimental factors were three rapeseeds cultivars, (Cobra, SImo46 and Okapi), three levels of Osmopriming (0, -3, -6, -9, -12 and -15 bar) and three levels of water stress (-5, -10 and -15 bar). At the first stage seeds were immersed in one level of Osmopriming treatment for up to 48 hours at room temperature. Then the seeds were distilled by water for 24 h at 30°C and subjected to water stress treatments for two week. The results showed that Osmopriming technique had a significant effect (p<% 1) on seedling parameters including: dry weight of seedlings, length of radicles and plumules, rate and period of germination. The upper levels of osmopotential had more inhibition effect on plumula growth than the lower levels of osmopotential. Means comparing showed that the most and least rate of germination was obtained by Okapi and Cobra hybrids, respectively. Under water stress conditions Okapi hybrid had longer radicle, more lateral roots and higher proportion of root to plumule then the other cultivars. Thus this cultivar was more resistance ant to water stress.

To study the effect of crop rotation on composition, density and distribution of weed population, a field experiment was conducted at the collage Agricultural, of Ferdowsi University of Mashhad Experimental Station during spring 2003. Different rotations in three experimental parts of the field were: 1) corn silage-barley silage, 2) chickpea-barley silage and 3) cumin-barley silage. Weed species identification and weed density were measured in 0.5m ×0.5m quadrates. Samples were taken based on systematic methods by using grids of 12.5m ×12.5m, 11.5m ×11.5m and 5m ×10m respectively, depending on the shape of each part. Sampling was done in two stages: a) before post emergence herbicide treatment and b) three weeks after application of herbicide. Weed density in barley silage was very low; however, there were highest and lowest densities in cumin-barley silage and corn silage-barley silage rotation, respectively. On the other hand, weeds in field had patchy distribution. The patchiness is the basic character for site-specific weed management. The results indicated that weed density and composition is influenced by crop species and management practices. Therefore, with proper crop rotation, and suitable weed management, we can overcome the weed problem by using minimum amount of herbicide.

Rice breakage in paddy milling is an important cause of crop loss in Iran. In this regard, an experiment was conducted at the Rice Research Institute of Iran to study the effects of two engineering factors (the rotor speed of rice Jet Pearler and air flow) and the effects of two varietal factors (kernel shape and inlet grain moisture content) on rice breakage. Rotor speed at levels were: 600, 700, 800, 900 rpm and for air flow at two levels: without and with air flow. Three levels of grain moisture content were adapted as: %8-9 , %10-11 and %12-13. Three rice varieties of Khazar (long grain), Binam (medium grain) and Gharib (short grain) were selected for the experiment. Results showed that as rotor speed increased, the amount of rice breakage, first decreased and then increased. Breakage of Khazar variety was more than Binam and that of the binam variety was more than Gharib variety. Amount of rice breakage increased with increasing moisture content. Introduction of air flow into rice during milling resulted in a significant decrease in kernel breakage. Thus, airflow is an important factor that should be considered in design of frictional whiteners. Results of statistical analysis of the data indicated that the best combination of rotor speed and grain moisture content for all three varieties was 800 rpm and %8-9, respectively. Different regression equations were developed to predict percent breakage of rice, for two conditions (with and without air flow). The best and simplest models were two second order equations having three variables of: pearler rotor rpm, grain moisture content, and kernel slenderness ratio.

In this research, 8760 records of dairy cattle of a farm (with two herds) in Guilan province were studied. Effects of season, year, sex of calf, lactation number, herd, milk yield (first 150-day) and age of cow on reproduction performance were evaluated. Means of days to first service (DFS), days open (DO), service per conception (S/C) and calving interval (Cl) were 86.64±0.34 days, 124.57±0.63days, 2.17±0.02 time and 409±0.71 days, respectively. Effect of season on reproductive factors was significant (P<0.01). Reproductive performance in autumn and spring was maximum and minimum, respectively; also the year effect was significant (P<0.01). Effect of lactation number on reproductive factor was significant (P<0.05). Effect of age was significant on DO, DFS and Cl (P<0.01), However its effect on S/C was not significant (P>0.05). Effect of milk yield on DFS and S/C was significant (P<0.01). Effect of sex of calf on reproductive performance was not significant (P>0.01). The results of this study suggest that, Holstein cows of Guilan province have the most suitable reproductive condition in lactation number 3 and autumn calving. Also milk yield (first 150-day) has significant effect on days to first service and service per conception.

Ruminal disappearance and intestinal protein digestibility of various feeds including forages (alfalfa hay and silage, corn and whole barely silages, and wheat straw), grains (barley and corn), by-products (sugar beet pulp and wheat bran), protein sources (soybean, cottonseed and fish meals) and whole soybean (Sahar and Williams varieties) were evaluated using the in situ mobile nylon bag technique (MNB) and three-step (38T) in situ/ in vitro enzyme procedure. Total tract protein disappearance of wheat straw was significantly less than the other forages (P<0.05). Intestinal protein digestibility of barely grain determined by MNB and 38T (0.74 and 0.83, respectively) was significantly (P<0.05) higher than corn grain (0.63 and 0.75, respectively). Mean total tract protein digestibility of soybean meal determined by MNB and 38T (0.87 and 0.92, respectively) was significantly (P<0.05) higher than cottonseed meal (0.78 and 0.77, respectively) and fish meal (0.80 and 0.81, respectively). Intestinal and total tract protein digestibility of roasted whole soybeans were significantly (P<0.05) higher than non-rosasted seads. The coefficient of determination (r2) for the relationship of intestinal protein digestibility between the mobile nylon bag technique and three-step procedure was 0.94.

To study of chemical composition, mineral contents and protein quality of meat and bone meal, six composed samples were provided randomly in one month length from a meat and bone meal producing plant. The average values of chemical composition in meat and bone meal, based on proximate analysis, were:moisture 6.1, crude protein 38.1, ether extract 20.6 and ash 23.1 percent. Mean values of gross energy and acid detergent fiber were 5338 kcal/kg and 11.1 % respectively. Mean contents of major elements: Ca , P , Mg , K , Na and Cl were equal to 5.4 , 3.4 , 0.24 , 0.58 , 2.9 and 3.36 percent respectively. Trace elements of Mn, Zn, Fe, and Cu were equal to 62.4, 67.1, 1001.4 and 135.1 mg/kg respectively, on average basis. For evaluation of protein quality a nitrogen-free diet and seven semipurified diets containing 10% crude protein from meat and bone meal and fish meal origin were fed to 160 male Arboracres chicks from 8-17 days. The experiment was conducted in randomized completely design with 4 replicate of 5 chicks. Protein efficiency ratio (PER) and Net protein ratio(NPR) showed significantly differences(P<0.05) among meat and bone meal samples and varied between 1.28-2.04 and 2.20-2.80 respectively. The values of PER and NPR in meat and bone meals were significantly (P<0.05) lower than the corresponding values in fish meal. Percentage of tibia ash showed significantly differences (P<0.05) among meat and bone meal samples and varied between 32.64- 38.31 %. The highest values of tibia ash percent were observed in samples of meat and bone meal which contained high levels of Ca and P. The levels of uric acid in blood serum, as protein quality response, showed significantly differences (P<0.05) among meat and bone meal samples and were generally higher than that in fish meal.

The effect of urea nitrogen fertilizer and sodium nitrate on the growth of fungus Trichoderma koningii compared with two species of Fusarium culmorum and F.graminearum causal agent of wheat head-blight disease. In this investigation various parameters such as comparison of the colony growth, spore production and chlamydospore in a single and dual cultures studied. In addition, the effects of urea nitrogen and sodium nitrate on the fungal colony growth were measured by colony diameters in single and dual cultures. Mycelial colony growth rate of Trichoderma under effect of urea fertilizer in 1g/I and 2g/I was significantly increased when compared with two species of F.culmorum and F.graminearum. But this growth rate in nitrogen condition significantly decreased by Trichoderma, when compared with control. While both species of Fusarium in the above condition showed significantly (P<0.05) an increase on the fungal growth rate when compared with control. Species of F.culmorum with increasing of urea fertilizer concentration significantly increased in growth rate of mycelial in comparison with control 48h after incubation. Application of urea on chlamydospore production by Trichoderma indicated a significant reduction seven days after culture. But, had a little effect on macroconidia reduction of F.culmorum. But neither species of Fusarium produced chlamydospore on urea media nor in 1gr or 2gr per liter. Trichoderma koningii in both conditions of amended media with urea fertilizer and sodium nitrate was able to parasitize both species of Fusarium.

Lentil (Lens culinaris Medik.) as one of the most important members of the Fabaceas plays fundamental role in the nutrition of the people in developing countries due to its high percentage of protein. Since it is very necessary to determine diversity among the available germplasm, 220 accessions in the seed bank of Agricultural College of Ferdowsi University of Mashhad were studied. The accessions were cultured on the basis of augmented design in fall of 2002. 16 different morphological traits were evaluated among them. On the basis of yield, 64 accessions were assessed for genetic diversity. Using Random Amplified Polymorphic DNA (RAPD) analysis was assessed the genetic variation. In this regard, a total of 9 random primers were used to generate RAPD bands determine genetic variation of accession, using genetic distance analysis. Out of the 9 primers, the OPL-19 showed the highest efficiency in discrimination of accession analysis to reveal phylogenetic relationships among the accessions. A wide range based on morphological data were 0.58 - 2.6 and based of molecular data were 0.21 - 0.96. Based on morphological traits, two genotypic groups were distinguished at %90 similarity level, however, on the basis of molecular data, 11 genotype groups were differentiated based on %90 dissimilarity level. Diversity index of morphological traits was ranged from 0.36 for number of two seeded pods to 0.83 for number of seeds per plant. The index of genetic variation was %80, showing that there are high genetic variation among accessions. Furthermore the data suggested that there was correlation of %83 between RAPD and morphological matrix. So it seems that the RAPD method is an effective tool for genetic analysis of lentil germplasm.

High temperature treatment of milk for cheese processing would inhibit or delay the enzymatic effect during milk coagulation .On the other hand due to denaturation of soluble proteins, the yield of product increases with elevating of pasteurization temperature. In this research, the effect of various pasteurization temperature (72 °C at 15 sec and 75, 80, 85 and 90°C at 60 sec.) and addition of CaCI2 (0.05, 0.1 and 0.15 g/l) on rennet clotting time (RCT), fat in dry matter (FDM), moisture in free fat cheese (MFFC) , yield, dry matter (DM), weight loss and organoleptic properties of Iranian white cheese were evaluated. The results statistically analyzed and showed that the optimum pasteurization temperature of raw milk for Iranian cheese processing regarding the keeping quality and high productivity of Iranian white cheese is 80°C at 60 sec. with adding 0.1- 0 .15g/I CaCl2

To evaluate date production efficiency of producers in the cities of Barn and Jiroft, frontier software was applied. For collection of data 190 date producers were interviewed. Different rypes of efficiencies were calculated. Results indicated that, on the average, an increase in plantation area (land use) would lead to higher- technical and economic efficiencies. However, the highest allocation efficiency belongs to those date producers who had one to three hectare of land, specifically 62 percent. Producers with less than one hectare had an allocation efficiency of 57 percent. Date Producers who had more than three hectares of land had an efficiency of 52.2 percent. Furthermore optimum application of inputs was investigated. The study showed that date farmers, in general, were faced with shortage of capital but were using other inputs more than they needed.