Applied Agricultural Research
Year:2012 | Volume:24 | Issue:4 (93)|Papers Count:14

Field experiments were conducted to evaluate the effects of different seeding dates of Berseem clover (Trifolium alexandrinum L.) on its seed and forage productions. In this study, five seeding dates in 2 weeks intervals from October 1 to November 30 during 2002 to 2003 were used. The results showed that seeding dates significantly effect on seed and forage production in 2 years of experiment. Seeding on October 1 and October 15 were the best for either seed or forage production. Differences between two years of experiment were significant. Yield production in second year was more than that of first year. Interactions between seeding date and year was not significant. Therefore, it should recommend that planting of berseem clover during October 1 to October 15 is the best date for the Mazandaran environmental conditions.

To study the effects of different soil fertilizing treatments on yield, yield component and seed mineral nutrients content in Isabgol, a glasshouse experiment was conducted in College of Agronomy and Animal Sciences, University of Tehran. In this research effect of chemical fertilizers containing N and P in three levels (chemical fertilizing treatments), cattle manure in four levels (organic fertilizing treatments), and mixture of chemical fertilizer and cattle manure in four levels (integrated fertilizing treatments) were investigated in a complete randomized block design with three replications. The results showed that fertilizing treatments had significant effect (p≤0.05) on all measured traits. Seed and mucilage yields increased with increment in rate of fertilizers applied; so the highest seed and mucilage yields were obtained by N20P10+20 ton/ha cattle manure. Mucilage percentage, seed and mucilage swelling factor were significantly higher (p≤0.05) in organic and integrated fertilizing treatments than chemical treatments and control. The results also showed that seeds N, P and K contents were positively affected by all soil fertilizing treatments.

Plasmids are genetic materials that help their host bacterial in unfavorable conditions. They have key roles in rhizobial bacteria because of the presence of nif and nod genes. The study of plasmids in rhizobial bacteria is the first step to use their useful capability in sustainable agriculture. In this study 196 isolates of Sinorhizobium meliloti isolated from the nodules of host plants (Medicago sativa cv. Hamedani) grown in different Hamadan soil samples were studied using Plasmid profiles technique. The results showed that 13 different plasmids were present among of all isolates and they were grouped in 27 different groups based on Plasmid profile pattern. Shannon diversity and similarity indices were estimated and the results showed that they are different in each physiographic unit. The results also showed that bacterial diversity affected by combination of soil characteristics not by individual factor.

It has been considered by environmental researchers and municipal managers that earthworms can used to convert organic waste and animal excreta to vwermicompost. Organic matters change markedly in the earthworms digestion system. In this study, the effect of sugar beet molasses, aeration, and soil on chemichal-physical properties and maturity of vermicompost was investigated. This experiment was carried out using nine different treatments with three replication in a completely randomized design. The results showed that total organic carbon (TOC) decreased dut total nitrogen, phosphorus and potassium increased during 100 days of incubation. In addition, nitrate concentration and available phosphorous and potassium increased in all treatment at the end of 100 days incubation. The amount of ammonium decreased noticeably. Electrical conductivity (EC) of all treatment increased but their acidity decreased. Bulk and particle density increased but total porosity of all treatments decreased significantly. Water soluble carbon (WSC), ADF (Lignin+Cellulose), NH4:NO3 and C:N (maturity indices) decreased in all treatments.

In order to estimate chlorophyll production in three wheat cultivars (Triticum aestivum L.) leaves (star, chamran and fong) by spad chlorophyll meter, an experiment carried out in agriculture farm of Shahid Chamran University in 2005. The experiment designed under factorial with a completely randomized block design with three replications, five levels of nitrogen (0, 25, 50, 75 and 100 Percent) equal 33.75, 67.5, 101.25 and135 kg/ha nitrogen were applied as basal dressing. A part of field was chosen as a reference plot that delivered all of nitrogen to produce five ton/ha grain wheat. The results showed that chlorophyll concentration in star cultivar (40.2, 42.5 and 39) was higher and in fong cultivar (37.8, 38 and 35) was lower than another two cultivars 60, 90 and 120 days after planting respectively. N1 and N5 were the lowest and the most but in cultivars star and fong were the most and the lowest respectively. N1 was (29, 25.8 and 24.1) and N5 was (38.7, 37.7 and 36.3) in star, chamran and fong respectively. So the highest readings related to star cultivar. Therefore there was a high correlation between chlorophyll concentration and nitrogen accumulation in leaves. This relationship helps to use the chlorophyll concentration in leaves and find the content of nitrogen fertilizer requirement and determine the amount of nitrogen fertilizer to apply as top-dress.

In order to study the effects of poultry manure and its incorporation systems with soil on grain nutrients cocentration of maize, a field experiment was conducted at the Ecological Research Center of Zagroos, 30 km from northeastern of Khorramabad for two consecutive years (2004 and 2005). Treatments were arranged in a split plots layout based on randomized complete block design with four replications. Two incorporation method of broiler litter incorporation with soil by furrower and disk+furrower as the main plot, and different amounts of broiler litter including zero, 10, 20, 30 Mg ha-1 as subplot were considered. The results suggested that the iron concentration of grain was much greater in the furrower treatment relative to the disk+furrower treatment. Averaged across years, maximum macronutrients and micronutrients concentration of grian were obtained by applying 30 Mg ha-1 broiler litter. However, no significant differences were found between 30 Mg ha-1 with 20 Mg ha-1 broiler litter for the nitrogen, phosphorus, manganese and cooper. The phosphorus, potassium, iron, and manganese concentration in grain for the second year was significantly greater than the first year. Thus, the incorporation of 20 Mg ha-1 broiler litter with furrower might be appropriate for increase of grain quality of maize under conditions similar to this experiment.

This research was done based on survey strategy with aim to study the effects of information sources and communication channels on adoption of “Integrated Pest Management (IPM)”. Validity of the questionnaire, as data gathering instrument, was confirmed by selected experts and Coronbach Alpha coefficient (0.87–0.79), used to confirm reliability of the questionnaire. The population of this research included all rice growers in Droudzan district. A representative sample was selected (n=90) by Cochran formula and simple random sampling method was applied to choosing the sample. According to research findings, neighborhoods, agricultural input providers, field visit of IPM was prioritized as information sources and communication channels that more used by rice growers. Calculated coefficients of correlation indicated a significant relationship between cultivated area, Level of education, being model farmer, agreement for decreasing pesticide usage rate, agreement for possibility of naturally control of pests, and usage of information sources and communications channels. Regression of variables was led to a linear equation, including visit agricultural input providers, agricultural expert, neighborhoods, field visit of IPM, cultivated area and being model farmer, explained 63% of variance of Adoption of Rice Integrated Pest Management.

In order to investigate the best Irrigation method and nitrogen application in rice cultivation an expriment was conducted in a RCBD with 3 replications. at the Rice Research Institute of Iran during cropping season of 2006 and 2007. Four levels of nitrogen (0, 45, 60 and 75 kg/ha) were splited on 3 irrigation intervals: control, 5 and 8 days interval. The result showed 5 and 8 day, irrigation interval decreased water use and increased water produtivity by 40% and 60% respectively, but no effect on yield was observed. The best nitrogen level was 60 kg/ha, using more nitrogen did not increas rice yield. Over all 8-day irrigation interval with 60kg nitrogen gave the best yield. No interaction between irrigation intervals and nitrogen levels was observed in this study.

To evaluation the adaptability and yield stability of dryland barley lines at tropical and sub-tropical dryland areas this study was performed with 20 barley genotypes in RCBD for three growing season (2002-2003 to 2004-2005) at 3 tropical and sub-tropical dryland areas. Bartelet and Hartly Fmax tests were used for detecting homogenity of error variances. Result showed that error variance for all of expriments were hemogenous at 5 and 1% probability levels. To estimation of stability and adatability grain yield of lines, Lin and Binns method (intra location variance), regresion indexes, deviation from regresion, coffiecient of location variation, coffiecient of determination (R2), and non-parametric methods such as rank and standard deviation of rank (SDR) were used. Result of combined analysis of 3 years and 3 location showed that the effects of line, line × year and line × year × location were significant at 1% probability level, while the other effects were not significant. The lines of 13, 12, 16 and 17 have the highest grain yield (3.889, 3.776, 3.763 and 3.545 t/ha, respectively). Results of stability analysis indicated that the line of 13 had higher mean rank for grain yield and in respect of standard deviation of rank line of 1 had lower SDR (2.59) followed by line of 13 (2.74). in respect of environmental variance and environmental cofieceint variation lines No. 2 and 14 detected with the at least amounts 0.36 and 19.5% respectevely. In comparing all of lines about stability parameters, lines No. 13, 16 and 17 recognized as the the best lines and finnally line 13 as the new barley line that now introduced namely mahoor.

In order to transfer resistant gene from related wild species of cotton (2n=2x=26) to commercial species (2n=4x=52), and to establish an efficient genetic broadening system, gibberellic acid and ovule-embryo culture were used. Crosses between two Gossypium hirsutum commercial cultivars (Sahel and Sephid) as a seed parents with pollen grain of Hashem Abad and Kashmer diploid cultivar (G. arboretum) have been carried out into direction. For getting mature boll, pollinated flowers have been treated with 0 and100 ppm concentration of GA3 to overcome early abscission of pollinated flowers. There was a significant difference between GA3 concentrations and crosses for boll development at 5% probability level, using Chi-square test. Highly significant differences have been observed between control and hormone growth regulator for hybrid boll setting. Maximum boll development (64%) was observed in Sephid × Hashem Abad when treated with 100 ppm GA3 after 45 DAP (Day after pollination). Only 7.5% of pollinated flowers led to develop boll in absent of GA3. Highly significant differences have been observed between 3 and 45 days old ovule-embryo culture on MS medium at 1% probability level. Direct embryo germination was observed from 45 days old embryo culture in MS hormone free medium. No significant differences were observed between tetraploid and diploid as seed parents for embryo germination. There was no direct plantlet regeneration in culture of isolated ovule less than 45 days. The seeds were not developed as well as those harvested from the self-pollinated female parents. The sterile triploid hybrid plants showed more vigorous than either parent.

Identification and determination of genetic purity of rice hybrid varieties for seed certification and control is an essential issue regarding to apply hybrid rice technology in Iran. Therefore, usefulness of microsatellite markers (SSR) for fingerprinting and genetic purity testing was investigated. Eight F1 rice hybrids and their parental lines were evaluated using 14 microsatellite markers in which 10 markers had reproducible polymorphic bands among genotypes. Totally 27 bands (alleles) produced, average number of band per primers and per genotypes were 1.92 and 1.68, respectively. Genetic purity was tested in respect of microsatellite fingerprint and polymorphic primers which detected off types seeds among F1 hybrids. Extra band(s) was also observed when the F1’s SSR products were analyzed. Null alleles were appeared in three restorer lines for RM264 microsatellite locus. Cluster analysis based on shared allelic similarity coefficient, using UPGMA algorithm, grouped the 16 rice genotypes into three main clusters, each containing 43.75%, 43.75% and 12.5% of genotypes. Overall, these results indicated there are reliable tools of microsatellite markers in DNA profiling and seed purity testing in rice varieties, especially hybrids.

Ammonium (NH3) is an important nitrogen (N) source for plants and microorganisms. Bacteria convert N2 to NH3 by nitrogenase complex in nitrogen fixation process and this NH3 is assimilated and not released. However, there are some reports that N fixation in some mutant bacteria may lead to NH3 secretion. In this study wild strains producers of NH3 through N fixation without use of any mutant, were investigated as there were few reports about them. So, NH3 production in different N fixing bacteria like Paenibacillus, Rhizobium, Azotobacter, Agrobacterium and Klebsiella oxytoca, isolated from soil and plant roots of alfalfa (Medicago sativa), lentil (Lens culinaris), bean (Phaseolus luntus), pea (Pisum sativum), wheat (Triticum aestivum) and rice (Oryza sativa) was analyzed. NH3 production was assayed with Nessler reagent from bacteria cultured in two nitrogen-free medium (with two different carbon source including sucrose and mannitol) for one week. In the next stage, three strains of Paenibacillus (E, H, SH) with the highest NH3 production were selected and by means of an innovative system, production of NH3 in three different experiments (dry biomass of bacteria without any medium, in broth medium and wet biomass of bacteria located on slant medium) was assayed until production approached none (7 week). In the last stage, NH3 production by these bacteria was compared with non-nitrogen fixing bacteria during the ammonification process. Results show that from the 35 different isolated strains, only Paenibacillus strains were able to produce NH3 during the process of N fixation and accordingly seven strains of Paenibacillus were isolated (14.2 mM at the highest). The results indicated that dry biomass of E strain of Paenibacillus produced the highest amount of NH3 in the first week (22 mM). Paenibacillus produced greater amount of NH3 and for a longer time in comparison with ammonifynig bacteria. This is a novel way for the production of free ammonium.

Investigation on the effect of variety and plant density by change of row space on some of the quantitative and qualitative characteristics of Canola (Brassica napus L.) in Jiroft region, had conducted in agricultural research center field in split plot laid out in randomized complete block design with four replications. Four plant densities (including 40, 50, 66.5 and 100 plants/m2 by change the row space including 20, 30, 40 and 50 cm as the main plot) and three varieties (including Hyola 308, 401 and Sarigol as the sub plot) had evaluated in this research. The trait consist of plant height, yield components (pods per plant, seed per pods, sub branches in plant and 1000 grains weight), grain yield by 12 percent moisture and percentage of oil yield was evaluated. The results showed that there is a significant difference between varieties in plant height, pods per plant, and seed per pods, sub branches in plant, 1000 grains weight, grain yield and percentage of oil yield. The highest performance of grain and oil yield had gained in the first density (40 plants in m2) or (50 cm planting row space) and Hyola 308 by amounts of 2393 and 1053 Kg per hectare respectively. The maximum number of grain in pods in plant took in 40 plants in m2 (50 cm planting row space). The highest amount of oil percentage was achieved from Hyola 308 with average of 44.38%.

In order to study the relationship between morphological and agronomic characteristics like grain yield in barley, and to obtain better knowledge of the effective attributes on barley yield in drought stress and non-stress conditions, an experiment was conducted at the Agricultural and Natural Resource Station of Sistan, in 2007. 81 lines of barley were examined using two 9×9 simple Lattice (stress and non-stress), with two replications. Some characteristics such as number of seed per spike, spike length, plant height, radicle length, and peduncle length had high correlation with grain yield. In both conditions, maximum variation in grain yield could be attributed to the number of seed per spike, spike length, peduncle length and radicle length. The results of path analysis also revealed the importance of the direct effect of the four mentioned characters on grain yield and affirmed the importance of number of seed per spike. Plant height, reproductive stage and flag leaf pod length had a considerable influence on seed yield variability through the mentioned components.