JOURNAL OF RESEARCH IN AGRICULTURAL SCIENCE
Year:2008 | Volume:3 | Issue:2|Papers Count:15

This experiment was conducted to study the most effective morphological charactristics on rice yield with ten genotypes of rice at Rice Research Institute in Mazandaran (Amol) in 2005 on the basis of a randomized completly block design with three replications. Genotypes included eight new lines and two cultivars (Fajr and Neda) as control. Some criteria were studied such as biological yield, leaf area index in flowering stage, number of tiller, plant height, number of active leaves after flowering, flag leaf area and its effect on grain yield, harvest index and 1000-grain weight. According to the results, rice genotypes made a significant difference on grain yield, biological yield, harvest index, number of tiller, plant height and flag leaf area but had no insignificant difference on 1000-grain weight, number of active leaves and quantity of flag leaf chlorophyl. Among these genotypes, line 106 and line 104 hade the most and the least grain yield, respectively. Line 106 had a higher mean of 1000-grain weight, a larger number of active leaves after flowering, higher biological yield, shorter height of plant and greater chlorophyl in comparison to other genotypes. Considering the results of the current study it is possible to introduce some charactristics such as the biological yield, 1000-grain weight and the area of flag leaf as effective factors on rice grain yield.

An experiment was conducted in order to study the effects of drought stress on early maturity of fall safflower (LVR 51-51 cultivar) in isfahan region with water deficiency by several drought stress level (increase of irrigation period in the form of irrigation after 75, 105, 140, 175 milimeter evaporation from class A pan and cut of irrigation at the different stages at the start and of flowering and physiological maturity). Experiment was conducted in Khorasgan Islamic Azad University Research Station at the north-east of Isfahan in the method of the randomize complete block design with split plot layout during 2004-2005 years. Results showed that water deficiency by increase of irrigation period had no significant effect on the fall safflower canopy and only reduced number days to flowering (9 days), but cut irrigation was caused reduce significantly of grain thousand weight, kernel yield, grain yield and oil yield, also number days to maturity were reduce 25 and 23 days in cut irrigation treatments in early of flowering and end of flowering stages respectively, although grain yield were reduce 714 and 428 kg/ha in treatments respectively.

In order to investigate effect of nitrogen and potassium on yield and yield components of rice ratoon of Hashemi cultivar, an experiment was carried out using a factorial completely randomized black design factorial in randomized complete block design with eight treatments and three replications in region of Astaneh Ashrafiyeh (Guilan province). Treatments were 0, 50, 100 and 150 Kg N/ha from source of urea and 0 and 100 Kg K/ha from source of KCL. The results showed that the effect of nitrogen on number of panicle in m2 is significant at %5. Potassium had significant effect on yield, number of grain in panicle and 1000 grain weight at %1. The maximum yield and maximum number of grain in panicle were obtained from N100 K100 treatment. The maximum panicle in m2 obtained from N150 K100 treatment.

In order to study of limited irrigation effect on phenologic, morphologic and agronomic traits of nine sunflower hybrids, three separate experiments were conducted in a completely randomized block design at the research field of Seed and Plant Improvement Institute in Karaj. The first experiment was conducted at the optimum conditions and plants were irrigated after 60 mm evaporation from evaporation pan, whereas the second and third experiments were irrigated after 120, 180 mm evaporation from evaporation pan, class A, respectively, and those were considered as limited irrigation conditions. The results showed that limited irrigation had significant effects (p£0.01) on plant height, head diameter, seed and oil yield. The days to seed filling stage was affected by limited irrigation, but there was no significant effect on days to blooming stage. The highest seed yield was obtained from irrigation after 60 mm evaporation from pan (control) as 2932 kh.ha-1 and severe limited irrigation caused to decrease the seed yield to 500 Kg.ha-1 by %83. Hybrids had also significant differences in all traits. The Allstar had the highest yield in the limited irrigation levels (1671 and 701 kg.ha-1, respectively) and in normal irrigation condition Mehr was superior to others (3861 kg.ha-1).

In order to study the essence compositions of Galbanum (Ferula gvmmosa) in three regions Meragh, Ghalahr and Neshalj in Kashan plants were collected and extracted by water-based distillation. The dark yellow extraction was purified then identified with GC-MS. The most important components included: Alpha-pinene, Beta-pinene, Myrcene, Delta-3-carene, Limonene, Fenchy acetate and Guaiol. The most and least persent of chemical components were seen in Limonene and Fenchy acetate, respectively. The results indicated that there were significant differences among the components in different regions. The quantify of chemical components of Margh region was the highest level, while it was in Nashalj the lowest. The identified and purified components have the potential to be applied in various industries such as pharmacology industris. In addition because of varition of quality and quantity components in different regions, It is suggested that determined the kind of essences before consumption.

Chlorsulfuron is a herbicide which shows carry over effects. Their residues may damage subsequent crops presented in rotational program. Bioassay is considered a good method for detecting biologically active herbicide residues. A greenhouse experiment using cress Lepidium sativum L. as an indicator plant was conducted to detect the bioavailable residues of Chlorsulfuron (at 0-0.125 ppm) in a completely randomized design in research greenhouses of Karaj College of Agriculture, during the summer of 2006. The models of three and four parametric log-logistic described plant shoot, dry weight and height response as a function of herbicides doses. Chlorsulfuron its lowest concentration (0.025 ppm) reduced dry weight and height of cress significantly. ID20 (The Doses which caused to decrease 20% of plant dry weight) of chlorsulfuron for plant dry weight and height were 0.023 and 0.047 ppm, respectively. In general, plant dry weight and height of cress show adequate sensitivity to detected chlorsulfuron. Cress germination was not affected by either herbicide or the applied doses.

Soil and water contamination with heavy metals from steel factory is very important because of threatening the human's health. Manganese is one of the most abundant elements in the earth's crust and also is essential for plants. Nickel was considered as a toxic element in last decade but recently recommended as a micronutrient. The objective of this study was to determine Mn and Ni concentrations in soil and plants shoots around Esfahan steel company. In this research, the study area was separated in to 17 zones based on soil maps and marked 54 points were marked for soil sampling. Each point was sampled at 0-5, 5-10, 10-20 and 20-40 cm depths and DTPA-extractable concentrations of Mn and Ni were determined in soil samples. Also 162 plant samples were taken from shoots of 13 main plants species and the concentrations of Mn and Ni were determined in plant samples. The results showed that, the maximum DTPA-extractable concentrations of Mn and Ni were in the south-western and south-eastern of steel company area (129 and 4 mg/kg.soil in 0-5 and 20-40 cm layers respectively). Therefore the concentrations of Mn and Ni in soil were less than the maximum acceptable concentrations of these elements in agricultural soils (400 and 50 mg/kg.soil). The maximum concentrations of Mn in shoots of Vitis vinifera, Elaeagnus angustifolia and Oryza sativa were 272.2, 257 and 240 mg/kg.dry.matter that were higher than the natural concentrations of Mn in plant leaves (15-100 mg/kg dry.matter). The maximum concentrations of Ni in shoots of Euphorbia spp. and Vitis vinifera were 34.7 and 22.7 mg/kg dry matter that were higher than the natural concentrations of Ni in plant leaves (3 mg/kg dry matter).

Since the tendency of water and soil to salinization is a big problem in arid and Semi-arid regions, using proper management measures is necessary to deal with this problem. One of the principles of management in this regard is the conjunctive use of saline and fresh water resources. It is applied in two ways; first mixing the fresh and saline waters and the second is using them alternatively. This research was conducted to investigate the effect of three conjunction methods on soil salinity distribution in the root zone. A completely randomized block design was used consisting of three treatments and three replications in nine lysimeters. Every lysimeter was filled to 1 m depth with soil in layers having 10 cm thickness, with a bulk density of 1.46 gr/cm3. The lysimeter was irrigated five times to reach soil water to field capacity (FC=34.33%). In the first treatment (Blending), irrigation was done with a mixture of saline and ordinary waters (EC=7.5 dS/m). In the second treatment (Half-Alternate) at each irrigation event, half of the irrigation water was applied with saline water (EC=14 dS/m) and the other half with the ordinary water (EC=1 dS/m). In the third treatment (One-Alternate) irrigation was practiced with ordinary and saline water alternately (one irrigation with ordinary water and the next one with fresh water). The result shows that the average salinity of soil (soil: water ratio 1: 5) in blending, half-alternate and one-alternate experiments up to 30 cm soil depth were 6.86, 6.74 and 4.80 dS/m respectively. The result shows that the one-alternate treatment has much less salinity in top layers (0-30 cm) than other treatments. In lower depths (30-60), the blending treatment has better conditions because in this treatment, salinity was 2.2 dS/m less than one-alternate treatment. The EC value was 9.92 and 12.1 dS/m in the blending and one-alternate treatment, respectively.

Iron chlorosis is widespread and severe in horticuture and some field crops in alkaline and calcareous soils in center of Iran. In this research the possibility of using by-products of Mobarakeh Steel Complex (slag) as Fe fertilizer was investigated. This component consists of 18% Fe2O3. This pot experiment was conducted using two soils with a pH nearly 7 in Arak province. Treatments consisted of control, 1, 2, 4 percent slag mixed in with the soils, 1 and 2 percent acidified slag (pH 4.7) and FeEDDHA (5 mg Fe/kg).Tomato (cv. Ch.Flat) was chosen as a test plant. Application of 2% slag, 1% acidified slag and FeEDDHA in soil 1 and all of the treatments except 4% slag in soil 2 increased the dry matter yield significantly compared to the control treatment. Iron, manganese (Mn) and in some treatments phosphorous uptake showed the positive correlation with dry matter yield of tomato. No correlation between phosphorous and crop dry matter in other treatments could be due to the antagonistic effect between phosphorous and zinc.

This project was done to determine factor of seed born leaf blight of wheat and introducing its weeds host During a period from 1997 to 1998, the sample of wheat seeds and leaves were collected from different wheat farms in fars and kohgiluyeh & Boyrahmad provinces to identify the causal agent of wheat leaf blight. On the basis of LOPAT tests and production of fluorescent pigment on kB medium. The pathogenicity test indicated that the pseudomonas syringae pv syringae strains were the causal agent of bacterial wheat leaf blight in Fars and Kohkiluyeh and Boyrahmad provinces. Determination of seed-born of wheat were done by three methods such as liquid assay, direct plating and extraction of seed flower. The results show that in liquid assay method Pss were not isolated on KB and KBC medium. The result showed that Pss is a seed borne pathogen in wheat kernel. Perhaps as endophyte in the seeds. Among different methods used to study seed transmission of the pathogen, the colong morphology on the semi-selected KBC medium and oxidase test seemed the best method. Pathogenic strains of Pss were also isolated from annual perennial weeds such az foxtail, hairy vetch, oot grass, barley grass and Cynodon dactylon in some areas including Yasouj, Marvdasht and Sepidan.

In this study, the effects of auto-hydrolysis steam treatment on digestion kinetics of sugarcane bagasse were studied. Samples were damped so that their moisture content reached 50%, then they were steam-treated under 3 levels of pressure (14, 17 and 20 atm) and 3 levels of treatment time (120, 180 and 240s). The effects of steam treatment were evaluated in terms of dry matter loss, chemical composition of fibrous portions, sugar content, rumen degradability and in vitro gas production. Data from this experiment were analyzed on the basis of CRD statistical design (3x3) factorial model with three replications. The steam treatment significantly increased water solubility of sugarcane bagasse including water soluble sugars and decreased its fibrous portions (NDF and hemicellulose, but not ADF). Dry matter loss and sugar content were greater in longer treatment times (240s) or higher pressures (20atm) compared to shorter times and mild pressures. The least NDF, Hem and the most DML were as mach as 56.60, 11.86 and 4.55 percent respectively (20atm-240s). Dominantly, degradability and gas production traits were most improved in (20atm-240s) samples as water soluble sugar, Deg48, potential degradability, total gas production, G24 and gas production rate, as much as 29.52, 63.63, 71.10 percent; 61.85, 44.11 ml and 4.87 ml/h, respectively. Also, these samples had the least fibrous portions too (NDF, 51.60; hemicellulose, 11.89 percent). However, some traits were better in (17atm-240s) samples like washing loss. It seems that the optimal treatment results could be obtained at a steam pressure of 20 atm for 240s.

This experiment was conducted to study the nutritional effects of feeding different levels of acetic acid 5% (10, 20, 30 g/l), probiotic (0.1, 0.2, 0.3 g/l), Neomycin 20% (0.1, 0.2, 0.3 g/l) and Oxytetracycline 20% (0.1, 0.2, 0.3 g/l) by sugar syrup on the performance of honey bee (Apis mellifera L.). The experiments carried out with 14 treatments and 4 replicates for each treatment on a randomized complete blocks design in a field trial. After 105 day, the results showed that the highest honey bee populations (6142 cm2) and brood area (4452.95 cm2) related to 0.3 g/l Oxytetracycline and 20 g/l acetic acid, respectively (P<0.01). The lowest honey bee adult population (1120.92 cm2) and brood area (1274.47 cm2) related to honey syrup (P<0.01). In addition, use of 0.3 g/l probiotic increased honey production (19654 cm2) and honey syrup significantly (P<0.01) decreased that (12834 cm2). The most amount of wax production (23800.25 cm2) belonged to various levels of Oxytetracycline and the lowest amount (16291.66 cm2) belonged to honey syrup (P<0.01). The colony net weight also influenced by feeding 0.2 g/l probiotic (41.56 kg) and 0.3g/l Neomycin (25.67 kg) significantly (P<0.01). Totally, the results of present experiments showed that feeding acetic acid, probiotic and antibiotic Oxytetracycline (as growth promoters), to honey bees have beneficial effects on their performance.