JOURNAL OF AGRICULTURAL SCIENCE AND SUSTAINABLE PRODUCTION
Year:2005 | Volume:15 | Issue:3|Papers Count:21

In order to determine the macaroni waste nutritive values, 12 adult SCWL roosters were force-fed with macaroni wastes and AME, AMEn, TME and TMEn were estimated. The obtained values were 3625.43, 3634.39, 4005.05 and 3992.37 kcal/kg, respectively. In the second experiment, 720 (7 to 56-day-old)broiler chickens of the Arian strain were fed with 0, 8, 16, 24, 32 and 40 percent levels of macaroni waste (six treatments) with six replicates, using a completely randomized design. After rearing, two broilers including one male and one female were selected from each experimental unit, weighed and slaughtered and their carcass traits were evaluated. In the total rearing period, there was no significant difference between feed intakes of broilers fed the various levels of macaroni waste. The growth rate of broilers fed 16 and 24 percent of macaroni waste were significantly higher than other rations with the exception of control group (P<0.05). The best feed conversion between rations was for broilers fed 8, 16 and 24 percent of macaroni waste (P<0.05). There was not significant difference between carcass traits of broilers fed by various treatments. In conclusion, from the economical point of view, the cost production of broilers was lowered by increasing levels of macaroni waste in the rations (p< 0.05).

Root depth and spreading have an important role in drought resistance and better use of soil moisture. This experiment was conducted to study the root characters and their impact on drought resistance. Genetic material constituted of Global, Puma, Regent, Eureka and PF 7045.91 from napus species, Sonja and Parkland from rapa species and two hybrids, Hyola308 and Hyola401. The experiment was carried out under normal and water deficit conditions, arranged in randomized complete block design with eight replications. Water deficit was imposed by stopping the irrigation at 50% flowering. The results showed significant differences between two conditions as well as between genotypes with respect to most of the characters studied. Among cultivars Global had higher plant height, shoot dry weight and the number of silique than others, followed by Puma and, PF 7045.91. These three cultivars had the highest maximum root length, root volume and root thickness. Puma was able to modify its root system under water deficit condition and gained adaptive/ inducible characters to compensate drought. Maximum root length was highly and positively correlated with root to shoot dry weight ratio and root to shoot length ratio under water deficit condition. Canonical correlation analysis showed high correlation between root morphological traits and shoot related characters in normal as well as water deficit conditions.

Seed vigor decreases under unsuitable environmental conditions and this is one of the most important problems in seed formation during prematurely and preharvest periods. Good seed vigor is a desired characteristic that affects plant growth and seedling uniformity. The aim of this investigation was to study the effective factors on seed vigor of single cross hybrid 704, during periods after pollination. A factorial experiment was conducted in the form of randomized complete block design with three replications in the Field of Islamic Azad University of Fasa during summer 2000. The studied factors were water deficit and levels of nitrogen application. Water deficit levels consisted of control, early water deficit and late water deficit after flowering, respectively. Nitrogen levels were considered as control, 92kgNlha and 184kgNlha. Kernel endosperm dry weight was determined during several weeks after pollination to explain the seedling dry weight of germinated kernel. The results showed that maximum endosperm dry weight of early water deficit treatment was less than late water deficit and control by 39.70 mg and 68.27mg, respectively. No nitrogen application decreased total endosperm and pericarp dry weight by 11.48% (P<0.05). Seedling dry weight in optimum soil water deficit was less than early and late water deficit in germination initiation, but seedling dry weight of the control was increased in later weeks. Water deficit effect was greater than no nitrogen effect on seedling dry weight as early water deficit effect was 0.85 time of dry weight for no nitrogen. There was no significant difference in seedling dry weight between the levels of nitrogen application (92 and 184 kgN/ha) at 5% probability level. Regression of total endosperm and pericarp dry weight on seedling dry weight from kernel germination until harvest was significant at 5% probability level. This regression was also significant with nitrogen application. Seedling dry weight was minimum in early water deficit with no nitrogen.  

Hydrograph recession constants are required for calibration of rainfall-runoff models, base flow augmentation studies, geohydrologic investigations and regional low flow studies. Low flow characteristics of rivers have been increasingly utilized in recent years as the demand for water has increased. In this study, five different estimators of the base flow recession constant are derived and tested for Karon river in Ahwas station. The integrated moving average method, IMA (0,1,0), because of predicting values within a constant limit is not suitable for this purpose. Also existing parameter AR(2) in second-order autoregressive model is not of much necessity, so first-order autoregressive model AR(l), is enough in time series model. Covariance method and solving watershed as linear reservoir method have offered eligible and very similar results but solving watershed as linear reservoir has limitation in use. In general, regression procedures for estimating hydrograph recession parameters are generally preferred to the' time-series alternatives, and the result of covariance method is the most suitable model.

In order to investigate the effects of sorghum densities and interference periods on development, grain yield and yield components of maize, a factorial experiment based on randomized complete block design with three replications was conducted in 2002 at the Research Field of Faculty of Agriculture, University of Tabriz, Iran. Factors were: sorghum densities (4,8, 12 plants/m2) and interference periods (0,14, 28, 42 days after emergence of seedlings and also during plant life of maize). Optimum maize density was 7.8 plants/m2. In maize monoculture, the rate of plant development (except coincidence of flowering), as measured by days after sowing, was increased. However, the rate of maize development was decreased, with increasing sorghum density and interference period .Increasing sorghum density and interference periods were resulted in increasing maize plant height and decreasing yield and yield components (except number of kernels per row). Maximum maize yield losses was 38%, which occurred at the highest sorghum density and interference .At this case, maize development period increased by a week, as compared to maize monoculture. Heat requirement, based on growth degree-days, for plant development (except for coincidence of flowering) in maize monoculture was decreased, but it was increased with increasing sorghum density and interference. It was, therefore, concluded that maize yield loss could be largely overcome by minimizing sorghum density and interference.

In order to investigate the effects of sorghum densities and interference periods on maize phyllochron and leaf appearance rate, a factorial experiment based on randomized complete block design with three replications was conducted in 2002 at the Research Field of the Faculty of Agriculture, University of Tabriz, Iran. Factors were: sorghum plant densities (4, 8, 12 plants/m2) and interferences periods (0, 14, 28, 42 days after maize seedling emergence and also during plant life cycle). Optimum maize density was 7.8 plants/m-2.The results showed that the phyllochron and the time between appearance of successive leaves on a shoot was minimum in maize monoculture. With increased sorghum density and interference, the phyllochron increased, but rate of leaf appearance decreased. The vegetative growth period of maize significantly influenced by sorghum densities and interferences. The highest vegetative growth period of maize was obtained at maximuni density and interference of sorghum, and the lowest vegetative growth period obtained in maize monoculture.

Nectary of Peganum harmala (L.) is a bowel shaped structure under the ovary which produces nectar. In the present study small filter paper disks (Watman No.1) were used to collect nectar for analysis. Then its sugar content was analyzed using HPLC with isocratic elution and RI detector. Results indicated the presence of glucose, fructose and sucrose with 38.9%,33.7% and 27.5% in the unpollinated stage. Results for pollinated flowers were comparable with previous stage and were as 38.5%, 34.8% and 26.6%, respectively. Although total amount of sugars in nectar increased 100% in the pollinated stage, but the individual percentage of each sugar stayed almost the same. This study revealed that Peganum harmala s nectar pertains to hexose rich group.

To determine the general and specific combining ability of the parental lines, four restorers and two male sterility lines were selected as lines and testers, respectively. Six parental lines were crossed in a Line x Tester crossing system in 2001. Eight F1 hybrids and their six parents were evaluated in a Randomized Complete Blocks Design (RCBD) with three replications for yield and yield components. After analysis of variance, the additive and dominant variances were calculated. Generally, parents with good combining ability produce good lines in the later generations. Therefore, the basic information about the general combining ability (GCA) and specific combining ability (SCA) is valuable for breeding cultivars. The effect of GCA was significant for the number of grains per panicle, plant height and days to 50% flowering in line No.1 (IR60819R), which indicated the importance of the additive gene effects for these traits. In line No.2 (IR68749R), the effect of GCA was significant for grain yield, 100-grain weight, plant height, days to 50% flowering and grain weight. The general combining ability of two testers was not significant for all characters. The effect of SCA was positive and significant for grain yield in hybrids of IR68281A/IR60966R, IR58025A/ IR60819R and IR68281A /IR42686R. These hybrids had the highest grain yield with 8.030, 7.347 and 6.715 t/ha respectively. Therefore, these combinations are recommendable for hybrid seed production after further tests in several environments.

In this study the effects of recombinant chymosin on the proteolytic, physicochemical and sensory characteristic of Iranian white pickled cheese was compared with two other types of rennet of animal and fungi origins. For this purpose three types of rennet including recombinant chymosin (RC), animal rennet (AR) and microbial rennet (MR) were used in the production of cheese in industrial scale using equal enzyme units in identical conditions: The cheeses were then packed in 11% pasteurized brine as 250g packs. The samples were kept at 12- 14°C for the first 25 days, and they were then transferred to 4- 6° C cold room for the rest of storage time of 90 days. The water-soluble nitrogen as the index of extent of proteolysis were measured at 15 days intervals. Taste panel at the end of 90 days storage also evaluated the sensory characteristics of samples. Statistic analysis of the results showed that the cheeses made using different types of rennets were significantly different for soluble nitrogen and sensory characteristics. The amount of soluble nitrogen produced in cheeses made by MR was significantly higher than cheeses made by AR and RC. The results of sensory evaluation indicated that the cheeses produced by AR and RC were not different from each other significantly, but they were both different from cheeses produced using MR at the 1% probability level. From the flavor point of view the highest and lowest scores were given to cheese samples made by RC and MR by taste panel, respectively. At last, it was known that recombinant chymosin has favorite functional properties like animal rennet and using it in Iranian cheese was recommended.

The effect of different agricultural residues and wastes (tomato, potato, barley, sugar-cane, sawdust, and soil) mixed with cow manure at four levels of 25, 50, 75 and 100 percent, on the growth and reproduction rate of Eisenia fetida was studied in wooden boxes (0.70 x 0.50 x 0.20m). Twenty five treatments (factorial of 6 wastes with 4 levels if cow manure plus a cow manure as control) were evaluated in a completely randomized design. Effect of different factors on growth and reproduction rates were highly significant (p<0.0001). The highest growth rate of worms was attained in the mixture with sawdust at %25 level (69.48±1:13.20) and the highest reproduction rate was achieved in the tomato mixture at %75 level (74.00±8.75).Whereas the lowest growth and reproduction rate was observed in the mixture with barely (6.64±1.09 and 3.85±0.89, respectively). Earth worms reduced the dry matter and increased the ash, total nitrogen and pH (≈ 8) in the substrates. It could be concluded that adding earth worms to the organic wastes would produce suitable vermicompost for agricultural purposes.

Using the climatic forecasting has received more attention in managing drought and flooding. Nowadays, dynamic and statistical models have been established which are enabling to predict climate changes in advance. It is well known that there is a negative correlation between temperature and precipitation as well as the long term effect of temperature variation on rainfall values. Therefore, it should be possible to predict precipitation using temperature variations over time. The relationship between temperature and rainfall as well as the long term effect of temperature on the rainfall used to forecast the precipitation behavior at the Tabriz Synoptic Station. Temperature and precipitation data recorded by Tabriz Synoptic Station from 1951 to 2001 was subjected to time series models. The results not only proved the negative relationship in long term but also showed short term relationship between temperature and precipitation. The cross correlation function (CCF) graphs were drawn based on data obtained from CCF of mean, maximum and minimum temperature and precipitation over 50 years. The results also indicated that the prolonged effect of temperature on the precipitation extend approximately two months. Some equations were introduced to predict precipitation based on temperature changes over time.

In order to assess the reactions of cotton cultivars against the Aphis gossypii, a greenhouse experiment was conducted as a factorial design with six cotton. cultivars under infected and non infected conditions by using randomized complete blocks with six replications. This study was conducted at the greenhouses of Plant Protection Department, Faculty of Agriculture, University of Tabriz, Iran, in 2002. The cotton aphid was collected from Moghan cotton fields and reared on cotton cv. Varamin at 27±2°C, 60±5% relative humidity and 16:8 (L:D) photoperiod. The cotton cultivars in each experimental unit were infected at four - leaf stage with two first instar larvae. In this experiment, population density of the aphid, time required for cotton seedlings to reach from 4 to 6 and from 6 to 8 leaf stage and stem growth in infected and non infected plots of six cotton cultivars were assessed. Analysis of data showed that there was a significant difference between the cotton cultivars and also between infected-non infected seedlings for the above mentioned criteria. Interaction between cotton cultivars (4-6 leaf stage) and infection was aiso significant. The maximum decrease in stem length was observed in Rafsanjan cv. and the minimum decrease was in Zeta-2, Sahel and Mehr, respectively. The maximum and minimum population density of the aphid were observed on Zeta-2 and Sahel, respectively. It was also revealed that cv. Zeta:-2had the shortest larval period (3.83 days), the latest appearance of the winged-adults (29.66 days) and the maximum number of the winged individuals (260.5). Assessment of all the criteria showed that Sahel and Mehr were less sensitive and Zeta-2 was the most sensitive cultivars. So, it is concluded that with further studies, resistance or tolerance can possibly be found in cotton cultivars and avoid the loss caused by aphid.

In order to select a suitable insecticide to control Colorado Potato Beetle, Leptinotarsa decemlineata five biological, plant origin and chemical insecticides were compared. Treatments were Fosalon 35% (2 lit/h), Neemplus (2.5 lit/h), Custom BC-3 (1 lit/h), Jack Pot BFC (5 lit/h), B.t. Col (7 kg/h) and the control. The experiment was conducted in a randomized complete block design (RCBD) with five replicates for two years (1999-2000). Spraying was done during early larval stages of the pest. 'one day prior to insecticide application and three, five and seven days after that, number of 'survivors were counted. Results showed a significant difference among insecticides regarding mortality rate of larvae. Fosalon was significantly more effective compound by having 88.19% mortality, followed by Jac pot BFC and Custom BC 3 by 62.46, and 60.63% mortality rates, respectively. Neemplus by causing 41.07% was determined to be a less effective insecticide which was significantly different from all but B.t. Col. which caused 52.13% mortality.

Soil water retention curve is needed to describe the availability of soil water to plant, and to study modeling of water and solute transport in unsaturated soils. The direct measurement of this curve is time-consuming, difficult and costly. Recently, many attempts have been made to predict water retention curve indirectly from soil physical and chemical properties. Pedotransfer functions (PTFs) comprise the indirect methods. Predicting water retention curve and Van Genuchten equation parameters by using pedotransfer functions were the main research objectives. In current study fourty loamy soil samples (35 for prediction and 5 for validation) were randomly collected form Karaj area. Particle size distribution, bulk density, calcium carbonate equivalent and organic carbon as independent variables, were determined by the hydrometer, clod, acid neutralization and Walkly Black methods, respectively. Water retention curve for the soils were obtained, experimentally using pressure plates. The variables were separated in two groups: (1) particle size distribution, bulk density, organic carbon and calcium carbonate percentage. (2) geometric mean and geometric standard deviation of particle size, bulk density, organic carbon and calcium carbonate percentage. The most optimum combination of independent variables for estimating soil water retention curve and Van Gemichten equation parameters were selected by the regression method. The regression equations for two independent variable groups were obtained using multiple linear regression and the PTFs were compared. The results indicate that there is a significant relationship between measured and predicted values. The relationship was significant at 0.1% probability level for pointed PTFs, at 1% for n, and 5% for er of Van Genuchten predicting function. Using first group of variables for estimating soil water retention curve and Van genuchten equations parameters was better than the second group. Statistical analysis for the evaluation of PTFs indicated that GMER (Geometric mean error ratio) values were close to 1 and GSDER (Geometric standard deviation of the error ratio) values were small. The results indicate that presented functions were valid.  

The present study was initiated to evaluate the effect of climate change on phenology, growth and development of drought-stressed and non-stressed winter wheat. At first, the monthly mean temperature, radiation and precipitation were estimated for increased CO2 concentration, using two General Circulation Models (GISS and GFDL). Then the CICER model was subjected .to some modifications and re-coded in TURBO C. According to prediction of GISS and GFDL models, increasedCO2concentration will increase the mean temperature in autumn by 4.79 and 4.52, and in February and spring by 4.68 and 4.32 degrees centigrade, respectively. The mean precipitation in autumn and winter will be increased by 36 and 41%, respectively. The change in radiation will be lower, as compared to temperature and precipitation. The time pf flowering and maturity will be shortened. Therefore, the possibility of double cropping will be increased. The biological yield will increase by 50 to 67% for rain-fed wheat, and by 29 to 39% for well-watered wheat. Under non-stressed conditions, although total intercepted radiation will be diminished during the growth period, the grain yield will be increased due to higher radiation use efficiency, fraction intercepted radiation and harvest index. Under rain-fed conditions, .although the harvest index will be higher, the increase in grain yield will mainly be due to higher transpiration efficiency. The percentage of increase in water use efficiency will be higher in rain-fed condition than other condition. The need for irrigation will be lower due to diminished evapotranspiration.

Tuber yield in potato can increase by eliminating sinks like inflorescence. In order to investigate the effect of eliminating inflorescence on tuber yield and its size, five potato varieties: Moren, Agria (late maturing varieties), Pikaso (medium maturing variety), Concord, Draga (early maturing varieties) were grown in Karkaj Research Station, Faculty of Agriculture, University of Tabriz. The research was carried out as factorial experiment arranged' in a randomized complete block design with three replications. Variety and eliminating or not eliminating of inflorescence was considered as two factors. The results showed an increase of 2.5 tons/ha in tuber yield under elimination of inflorescence, however, this was not statistically significant. Eliminating, of inflorescence increased tuber size, number of leaves and number of branches which was statistically significant (p≤%1). Agria showed the highest tuber yield under both conditions of eliminating and not eliminating of inflorescence. In conclusion, elimination of inflorescence as a competing sink with tuber which increases number of leaves, number of branches and leaf area index, can increase tuber yield in potato.  

An experiment was conducted to determine the effect of different inclusion rates and degree of saturation of fat sources on true metabolizable energy corrected to zero nitrogen retention (TMEn) values in broiler chickens. Animal fat and cotton seed oil were blended in the proportions of (Animalfat: cotton seed oil): 0.25:0.75, 0.50:0.50,0.75:0.25. The three blends together with the animal fat and cotton seed oil were each added at 3, 6 and 9 percent to a basal diet. Fats were analyzed for most chemical variables (fatty acid profile, gross energy, dry matter, peroxid value, acid value, sophonification index, iodin index, unsophonification index). The experimental diets were evaluated for TMEn. From 250 day-old Arian male strains, 136 birds were selected at 18 days of age and randomely distributed in 68 cages. Each treatment was replicated four times and each experimental unit consisted of two birds. There was significant deviation from linearity in the response of dietary TMEn to added fat. Synergism, as demonstrated by the difference of determined TMEn values from those of calculated values, was substantially low, specially for the third fat blend adding at 9 percent to the basal diet. For all fats, the best regression equation (R2=0.966) can be achieved from the 3 following variables fat levels, dry matter digestibility, and oleic plus linoleum acid levels.