Showing 43 results for Ahmadi
Masoud Ezzat-Ahmadi, Hamdollah Kazemi, Mohammad Reza Shakiba, Mostafa Valizadeh,
Volume 2, Issue 2 (summer 1998)
Abstract
Effect of different times and levels of nitrogen fertilizer application on growth and grain yield of spring wheat cultivar “Ghods” was studied during 1993-1994 growing season at Karkadj, Agricultural Experiment Station, College of Agriculture, University of Tabriz, using a split plot design with three replications. Main plots were assigned to five levels of N fertilizers (0, 40, 80, 120 and 160 kg/ha) and subplots to five times of applications [all of N fertilizer at planting (T0) 1/2 at planting + 1/2 during tillering stage (T1), 1/2 at planting + 1/2 during heading stage (T2), 1/3 at planting + 1/3 during tillering and 1/3 at heading stages (T3) and 1/4 at planting + 1/4 at tillering + 1/4 at stem elongation and 1/4 at heading (T4)]. Results showed that different levels of N applications affected grain yield and biological yield significantly, while the effect of split application and also N levels × times of application interaction on these two traits were non-significant. Growth stages of wheat were not significantly affected by different N Levels and times of application. Dry matter accumulation, leaf area index, and crop growth rate, in response to growing degree days during growing season, increased when higher levels of N fertilizer were applied. Leaf area index and crop growth rate initially increased up to anthesis and then decreased. Crop growth rate decreased to zero level at soft dough stage and then became negative. Variations in relative growth rate and net assimilation rate, in relation to growing degree days, decreased when different levels of N fertilizer were applied at early part of growing season it was maximum while at later growth stages decreased and finally became negative, Times of N application and level × time interaction during growing season did not affect the growth indices significantly.
Mahmood Alichi, Ali Asghar Ahmadi,
Volume 3, Issue 1 (spring 1999)
Abstract
The effectiveness of Buprofezin (40% SC) and Pyriproxifen (10% EC) on the mortality of nymphal stages and fecundity of cottony cushion scale was investigated under glasshouse conditions. The LC50 of IGRs was also determined for the first nymphal stage. Two applications were conducted at intervals of 1 day prior to introduction of crawlers and 42 days after infestation. The results indicated that Buprofezin was superior to Pyriproxifen in suppressing the growth and development of crawlers. The mortality of first instars was determined 28 days after the first application. Although the total mortality of second instars due to Pyriproxifen was higher than that by Buprofezin, but the cummulative mortality of 1000 ppm treatment was estimated to be 100% in both experiments after 42 days. The effect of Buprofezin on incomplete molting of nymphs and its ovicidal activity showed a decreasing rate in third instar nymphs survival and fecundity of cottony cushion scale in relation to different concentrations of the IGRs, but it never reached 100%. Meanwhile the 1000 ppm concentration of Pyriproxifen in the same treatments brought about complete mortality to third instar nymphs and inhibited adult and egg formation due to imbalanced juvenile hormone activity. However in 1 ppm concentration of Pyriproxifen, a noticeable increase in fecundity of cottony cushion scale was observed.
Latifeh Ahmadi, Mehdi Mirza,
Volume 3, Issue 2 (summer 1999)
Abstract
Biological activity and making use of sage essential oil in different industries depend on the chemical composition of the essential oil which is itself affected by several factors. In order to study the quality and quantity of the essential oil during growth stages, samples of the plant were gathered. The essential oil was extracted through steam distillation from the different plant parts separately. Volatile parts were analyzed with GCMS instrument. The study showed that the quality and quantity of the chemicals from different parts of the plant were not the same: Alpha-thujone and Beta-thujone as two important compounds were the lowest in the leaves of sage at flowering stage (1.2%, 3%, respectively). The study also showed that the quantity of Camphor (2.9%), Cineole (2%), Alpha-thujone (6.4%) and Beta-thujone (1.6%) in the essential oil of aerial parts of the plant were lower than the international standards (33%, 10%, 16% & 2%, respectively).
S. Yarahmadi, S.r. Mirai Ashtiani, R. Ebadi, G.h. Tahmasebi,
Volume 5, Issue 2 (summer 2001)
Abstract
In this study 130 honeybee colonies in 4 locations (Damavand, Tehran, Qum and Karaj-Savojbolagh) were sampled to determine the phenotypic correlations among 9 morphological and 3 production traits. The morphological traits were length (FL) and width (FB) of fore wing, cubital index (CI), length of hind leg (HL), length of probosics (LP), slender index (SI), length (WL) and width (WT) of wax mirror, distance between wax mirror (WD), index of wax mirror (IW) and corbicular area (CA). The production traits were honey yield (WH), pollen gathering (WP) and wax: production (WW). Data were subjected to analysis of variance, phenotypic correlations, stepwise regression and path coefficient analysis. Results of phenotypic correlations demonstrated that correlations between FL with FB (0.65), WL (0.361), WT (0.261), HL (0.555) and LP (0.257), WH with WP (0.300), WW with WH (0.560) and CA with WH (0.234) were significant (P≤0.01). FB with WH (r=0.204) was also significant but there was no significant correlation between CA and WP. Results of stepwise regression and path coefficient analysis showed that whereas morphological traits were settled as independent variables, much of the corresponding changes in production traits remain uninterpreted. In spite of the significant correlations among several morphological and production traits, body measurements alone are not suitable criteria to select colonies for high productions of honey, pollen and wax.
A. Rezaizad, B. Yazdi Samadi, M.r. Ahmadi, H. Zeinali,
Volume 5, Issue 3 (fall 2001)
Abstract
To determine the relationships between yield and its components, and to find the direct and indirect effects of yield-related traits on soybean yield, 240 genotypes were grown in the Research Station, College of Agriculture, Karaj, Iran, in 1997-98 using an augmented design. The study of correlation analysis showed that number of seeds per plant and seed yield per plant had the highest significant correlation coefficient (r=0.92). Other significant correlation coefficients were found between biomass per plant and yield (r=0.86) and between number of pods per plant and yield (r=0.67). Results of stepwise regression analysis revealed that number of seeds per plant, seed weight, and number of seeds per pod were the three major traits affecting seed yield in soybean. However, path analysis showed that only two of the three above-mentioned traits, namely, number of seeds per plant and seed weight, are quite important for soybean selection programs. Stepwise regression analysis was used again, omitting number of seeds per plant, which showed that number of pods per plant, seed weight, plant height and number of days to 90% maturity, are important contributors to yield. Path analysis, this time, revealed that the correlation effects to plant height and number of days to 90% maturity on yield is due to the indirect effects exerted through other traits. It is concluded that three traits, namely, number of seeds per plant, seed weight and number of pods per plant have notable effects on soybean seed yield.
A. Ahmadi Iikhchi, M. A. Hajabbassi, A. Jalalian,
Volume 6, Issue 4 (winter 2003)
Abstract
Cultivating rangeland to be shifted to crop land farms commonly causes soil degradation and runoff generation. This study was conducted to evaluate the cultivation effects on runoff generation and soil quality. The experiment was performed in a rangeland and a 40-year cultivated land located at two slope positions (back slope and shoulder) of a hillside in Dorahan, Chaharmahal & Bakhtiari Province. A 60±5 mm.hr-1 rainfall intensity was simulated by a rainulator. Organic matter, mean weighted diameter, saturated hydraulic conductivity, collected runoff and sediments were measured. The differences between the means were tested using T-test. Results showed 35, 53 and 8% increases in the organic matter, mean weighted diameter, and saturated hydraulic conductivity in back slope, respectively. The increases in these parameters in shoulder position were 39, 60 and 33%. The values for runoff and sediments in back slope were 3 and 8 times greater than in other similar positions while the values in the shoulder position were 11 and 55 times greater than the same values in other positions.
O. Farhadian, M. R. Ahmadi,
Volume 7, Issue 3 (fall 2003)
Abstract
Oval fertilization and survival rates at incubation stage form the most important issues of concern in rainbow trout hatcheries in Iran. Hatchery managers tend to use the best method in fertilizing the ova in order to obtain the highest survival rates. A survey of common fertilization methods may help to determine the best one. In this study, the ova from two groups of 3-5 year-old and younger than 3 years broodstocks were fertilized employing dry and semi-dry methods in normal water and dry and semi-dry methods in fertilization solution. The experiment was carried out in a completely randomized design as a 422 factorial arrangement and with two replicates.
The analysis of final results indicates that the highest survival rates of eggs and larvae were obtained in semi-dry fertilization. These rates significantly increased when fertilization solution was used (P<0.05). Moreover, the survival rates of eggs and larvae of 3-5 year-old broodstocks were higher than those of younger than 3 years. On the other hand, type and methods of fertilization showed no significant differences with degree-day (sum of heat) at developmental stage but the age of broodstocks made significant differences with degree-day from fertilization to the first hatching stage (P<0.05).
J. Niazi, H. R. Fooladmand, S. H. Ahmadi, J. Vaziri,
Volume 9, Issue 1 (spring 2005)
Abstract
A research was conducted in Fars province Agricultural Research Center in Zarghan area from 1999 to 2002 to determine the water requirement and crop coefficient of wheat, applying lysimeter.
The results indicated that the water requirements of wheat were 720, 712 and 674 mm in the years of 1999-2000, 2000-2001 and 2001-2002, respectively. Using Penman-Monteith method for estimating reference crop potential evapotranspiration, the crop coefficients for wheat at a four-stage crop growth were 0.37, 0.64, 1.10 and 0.51, respectively. Due to the inaccessibility of the whole weather data, we tried to figure out a solution to determine wheat water requirement to schedule irrigation planning for future. In this respect, we made use of a ten-day class A pan mean evaporation and crop coefficient.
A. Ghane, M. R. Ahmadi, A. Esmaili, A. Mirzajani,
Volume 10, Issue 1 (spring 2006)
Abstract
Present study investigates macrobenthic invertebrates and their community structure in Chafrood river to classify and assess the study sites regarding the environmental anthropogenic factors. Along a 9 km distance, 8 study sites were selected, and macrobenthic were monthly sampled using a surber sampler (1600cm2, 250 μ mesh net) with 3 replicate at each station. Collected samples organisms were fixed with 4% formalin and laboratory process including sorting, identification and enumeration of the animals were preceded. During the study 73 benthic taxa were identified which were dominated with aquatic insects larvae especially orders Diptera and Ephemeroptera. The maximum and minimum total abundance was 2335 ind.m-2 in station #2 and 1639 ind.m-2 in station #4 respectively. Benthic animals' frequency data were summarized to community structure metrics including total richness, EPT richness and ratio of EPT frequency to Chironomidae family. A Shannon- Winner diversity index and Hilsenhoff family level biotic index was also determined for each studied station. Result of cluster analysis for stations, based on the community structure metrics and diversity index, was in accordance with the station classification using biotic index and both classify the affected stations at the same group.
H. Arzani, M. Jangjo, H. Shams, S. Mohtashamnia, M. A. Fashami, H. Ahmadi, M. Jafari, A. A. Darvishsefat, E. Shahriary,
Volume 10, Issue 1 (spring 2006)
Abstract
Range suitability and its grazing capability are the most important criteria in rangeland analysis and monitoring. Determination and monitoring of factors affecting on range suitability and diagnosis of them are important .All range ecosystem components affect range suitability. Which among them physical and vegetational factors, forage production, water resources and sensitivity to erosion were considered. The objective of this research was to determine range suitability of Lar, Dasht bakan, Ardestan, Siahrood rangelands to design a model for sheep grazing. This study was carried out in four regions, two of them (Siahrood and Lar) located in Alborz mountain chain, Ardestan in center of Iran and Dashtbakan in Zagros mountain chain. According to the results among physical factors, slope remoteness of watering points and sensitivity to erosion had more effect on grazing capability than vegetation factors. In Siahrood watershed aboundancy of poisonous plants, high slope, transient watering points and non resistant formations were limiting factors. High slope, sensitivity of soils and stones to erosion, kind of exploitation in Lar watershed affected range suitability. In Ardestan watershed, low range productivity, presence of invader plants, erosion, remoteness of watering points are major limitation of range suitability. In Dasht Bakan factors including slope, elevation, dispersion of water resources and transient water resources were limited grazing capability. In land evaluation each land utilization type has certain land use requirement and each land unit has certain land qualities. Utilization of rangeland based on grazing capacity, range readiness and recreation of degraded rangeland can improve suitability of rangelands in the studied areas.
J. Niazi Ardekani, S. H. Ahmadi,
Volume 10, Issue 4 (winter 2007)
Abstract
In this paper, the effect of irrigation water salinity levels on seed germination, dry matter weight of seedlings at eight-leave stage, and the salt tolerance of 8 rapeseed cultivars was investigated. Relative yield reduction in saline and non saline conditions, salt sensitivity index and Van Genuchten-Hoffman methods were used to determine the salt tolerance of the cultivars. Results showed that the effect of different salt levels, cultivars and their interactions on germination and dry matter weight of seedlings was significant at 0.01(the higher the salt level, the lower the germination and dry matter). Also, using the Van Genuchten-Hoffman method, the irrigation water salinity corresponding to 10%, 25%, 50% and 90% reducts in germination and dry matter of seedlings were determined. Statistical analysis showed that a single cultivar gives different responses to salinity during growth stages and it may be tolerant in one stage, but sensitive to salinity in another growth stage. In this research, ACSN1, Falcon, and Shirali in germination stage and ACSN1, Falcon, and Cobra in seedling growth stage were salt tolerant. The three cultivars Oyerka, Global, and Ceres and the next three Shirali, Global, and Oyerka were sensitive to salinity in germination and seedling growth stages, respectively. Finally, the ACSN1 and Falcon cultivars were introduced as salt tolerant, and Oyerka and Global were considered as salt sensitive.
J. Ahmadi, S.f.orang, A.a. Zali, B. Yazdi – Samadi, M. R. Ghannadha, A. R. Taleei,
Volume 11, Issue 1 (spring 2007)
Abstract
Generation mean analysis (GMA) was used to study the type of gene action and inheritance of grain yield and its components. Generation mean analysis with joint scaling test was performed. This research was conducted at research farm of college of Agriculture at the University of Tehran. The parents and their progenies ( F1, F2, BC1 & BC2) in three mating groups ( Sardari × 7007, Sardari × 7107& 7107 × 5593) were produced and planted using a randomized complete block design with four replications for each mating group. Of four replications in each experiment, two replications for drought and two replications for non-drought condition were used. The eight traits which were evaluated included grain yield, plant height, plant weight, tiller number, spike length, grains per spikes and 100 grain weight. Most of the genetic parameters including mean (m), additive (d), dominant (h), additive × additive [i], additive × dominant [j], and dominant × dominant[l] effects were significant. However, all gene effects were not significant in all traits.The dominant gene effect was the most contributor factor to inheritance of the majority of traits. For the majority of the traits, additive gene effect was significant, but its magnitude was less than dominant gene effect. Also the dominant × dominant[l] epistasis was more important than additive× additive [i] epistasis. The degree of dominance in most of traits indicated the predominance of dominant gene effects.
M. Saeidi, A. Ahmadi, K. Postini, M. R. Jahansooz,
Volume 11, Issue 1 (spring 2007)
Abstract
Soil moisture is one of the most important determinants of plant’s seed germination, emergence and finally yield formation in arid and semi-arid zone (e.g. IRAN). In such a situation, the selection of a cultivar resistant to drought is the most important task. In this regard, a research at three levels (Farm, Greenhouse, Laboratorial) was conducted to study 10 genotypes with three improved background including: Improved Indigenous(II) genotypes (Sardary, Roushan, Omid), Improved Indigenous Foreign Crossed (IIFC)(Azadi, Falat, Qods) and four Indigenous lines (IL)(5593/2-3, 6452-6, 5806-3, 7007/2-6). On the basis of our data with decrease of osmotic potential, seed vigor with high speed and slope in different genotypes decreased. In -0.8 MPa level of osmotic potential, Omid, Azadi and 5593.2-3 genotypes had the highest and Sardary, 5806-3 and Falat genotypes had lowest seed vigor. In -1.6 MPa level of osmotic potential seed vigor of all genotypes severely decreased and in this level of osmotic potential, no significant difference was observed among genotypes. The greater correlation between seed germination, vigor and emergence percentage in farm situation was obtained but the correlation between all germination characteristics in laboratory and farm situations with yield was not significant. Orthogonal analysis shows that II genotypes have greater seed vigor in comparison with other groups of genotypes, but did not show any significat difference among the three groups. The percentage and rate of germination.
A.r. Khanahmadi, Gh. Rahimi, A. Nejati-Javaremi, S. Esmaeilkhanian,
Volume 11, Issue 40 (summer 2007)
Abstract
In order to detect genetic variation of native fowls in Mazandaran native Fowls breeding station, blood samples were collected from 100 male and female of birds (1:11). The DNA of the blood samples was extracted according to an optimized salting out protocol. The extracted DNA was amplified through polymerase chain reaction (PCR). Of the twenty random primers (10 mer) were used in this study, fourteen yielded satisfactory PCR. The total 63 polymorphic and 77 monomorphic bands were detected for the 14 primers. The number of bands displayed for each primer ranged from 4 to 16 with 200-2100 base pairs. The highest and lowest percentages of polymorphism band were observed for primer 9 (72%) and primer 14 (16%) respectively. The band sharing frequency was calculated for each primer, which ranged from 79 to 96. The genetic similarity within population and genetic variation were estimated as 89 and 11 percentage respectively. In conclusion, the existence of high level of polymorphism after ten generation of selection may indicate the accuracy of genetic evaluation program, suitable selection strategies and also large enough effective population size in this breeding flock.
A. M. Amini, A. Ahmadi, A. Papzan,
Volume 11, Issue 41 (fall 2007)
Abstract
The purpose of this study was to assess characteristics of and reasons for farmers’ disagreement on implementation of land consolidation projects. Part of needed information was collected through questionnaire and interviewing 75 farmers in 6 unsuccessful villages in Kermanshah and Lenjanat region and also visiting some performed and ongoing projects. Other part of information was obtained by questionnaire and interviewing 44 experts involved with performing the project in Jahad Agricultural offices. Fragmentation of properties were measured by Januszewski fragmentation coefficient. Correlation coefficient and comparison of mean were used to analyzed the information. The results showed that disagreement of farmers is the most important obstacle for progress on land consolidatin projects, which accounted for farmers. In Lanjanat, these farmers have a better land structures in respect to size and fragmentation of parcels. In both rejoin reasons for farmer’s disagreement are divided in three groups: logical-justified reasons, logical-unjustified and illogical. Mediation, preference and legislative force are the three interactive methods to satisfy these farmers. To decrease disagreements and promote land consolidation in the two regions, following suggestions are offered: education and extension, correcting the technical and adminestrative methods of land consolidation and legal and judicial supports to implement the projects.
A. Ahmadi, A.m. Amini,
Volume 11, Issue 42 (winter 2008)
Abstract
The purpose of this research was to study factors on farmer’s request to land consolidation projects and also consolidation’ adventages in utilization units. The data of this study was collected through completing questionnaires and interviewing 34 experts connected with administrating of land consolidation projects in agricultural offices and service centers in Kermanshah township and Lenjanat region in Isfahan. Data was also collected through visiting some performed and performing projects. The results showed that in Kermanshah land consolidation improves the technology, farm management and land more than other production factors. In Lenjanat it improves technology and farm management in comparison with other factors. In both regions the aplicant villages of the projects have a larger ownership and more fragmentaed parcels than other villages. Moreover they have younger exploiters, more educated and less in number. It is also notworthy that these regions obtain more extention education, are nearer to agricultural offices, and have closer relation with extention agents.
A. Moradi, A. Ahmadi , A. Hossein Zadeh,
Volume 12, Issue 45 (fall 2008)
Abstract
Drought is a major factor limiting growth and development of crops such as mung bean (Vigna radiate (L.) wilczek) in arid and semi-arid regions of the world. This study was conducted to investigate the effects of different timing and severity of drought stress on physiological traits of mung bean and its relation to grain yield. A field experiment was carried out during 2004 growing season at Experimental Farm of Agriculture College, University of Tehran, Karaj, Iran. The treatments were laid out in a Randomized Complete Block Design (RCBD) with three replications. Plants were exposed to moderate and severe water stresses at either vegetative (VS) or reproductive stages (RS). Physiological traits were measured at the end of vegetative and the middle of pod formation. Generally water stress reduced leaf net photosynthesis rate, stomatal conductance and leaf relative water content at different growth stages. The effects of RS treatments were more severe than that of VS one. Severe VS treatment increased photosynthetic water use efficiency, whereas RS treatments decreased it significantly. However, leaf area index and total dry matter were more responsive in VS compared to RS treatments. VS treatments did not affect harvest index, while RS treatments reduced it significantly. Drought stress also reduced grain yield by 9 and 49 % (relative to control plants) in severe VS and severe RS treatments, respectively. Therefore irrigation is critical during reproductive stage mainly because of the higher demand for photoassimilate. It is concluded that to maximize mung bean grain yield in arid and semi-arid areas, appropriate watering should be practiced across all phenological stages in general, and during reproductive stage in particular.
A Ahmadi, M Jodi, A Tavakoli, M Ranjbar,
Volume 12, Issue 46 (fall 2009)
Abstract
The objective of this study was to evaluate some morphological characteristics associated with grain yield potential on 20 bread wheat cultivars under two irrigation and drought stress conditions. The experiments were conducted at Research Farm of Agriculture College, University of Tehran, Karaj during 2001-2003. Twenty bread wheat cultivars were planted as subplots within each irrigation main plots in randomized complete block design with 3 replications. Drought stress was imposed at the end of flowering, and plants were re-watered when they showed signs of wilting, particularly during the morning. The results showed that the interactions between cultivars × year and cultivars × irrigation were significant for the grain yield. The cultivars showed significant differences in grain yield under drought stress condition in 2001-2003. Roshan, M-79-4 and Alvand in 2001-2002 and Azadi, Marvdasht and M-79-17 in 2002-2003 were most productive under drought stress condition, whereas C-79-12, MV-17 and Shahpasand in 2001-2002 and M-79-4, Roshan and Nicknajad in 2002-2003 performed visa versa. Correlation between grain yield and measured traits under irrigation condition was different from drought stress condition, suggesting that grain yield controlling mechanisms operate differently under these conditions. Drought stress caused a reduction in 1000 seed weight of cultivars. High 1000 seed weight and high grain number per ear were accompanied by high grain yield in drought stress and irrigation conditions, respectively. In the present study, clear relationship between grain yield and ear length was not observed.
Sh Mohammad Nejad Kiasari, M Safaee, Sh Nourozi, H Ahmadian, A Mataji,
Volume 13, Issue 48 (7-2009)
Abstract
Determination of suitable species is the most important factor in success of forestation in unfavorable conditions. One of the least costly and the shortest ways for introduction of adaptable species in an area is recognition of the plants that grow naturally. The objective in this study was to find out the effects of protection and water spreading operations on the quantitative improvement of Greek Juniper seedlings. In this study, the areas of water spreading station (Research station of Poshtkoh Water spreading) and an area in western section of water spreading station (an area as control) along the Poshtkoh watershed were chosen. The research was performed on counting of Greek Juniper (Juniper excelsa) in each of two areas. The ratio estimation method was used in a randomized systematic design in strips with the width of 50 meters and 200 meters apart for registration of qualitative parameters of Greek Juniper (Juniper excelsa). The total surface of areas was 600 ha and inventory with intensity of 16 percent has been done. This study showed that in spite of the less number of Greek juniper trees per ha in the station (0/104) in relation to the number of Greek juniper trees per hectare out of the station (0/666), the number of the Greek juniper seedlings in the station was eight times (8.34) more than the number of the Greek juniper seedlings out of the station. As to the effect of protection and water spreading operations on natural growth and increase of number of Greek Juniper seedlings in the station, forestation using this species in this area is recommended.
M Ahmadi, M Bahrani,
Volume 13, Issue 48 (7-2009)
Abstract
A study was conducted in 2007 to investigate the effect of nitrogen fertilizer rates (0, 30, 60 Kg ha-1) on some agronomic characteristics, seed yield and oil percentage in three Sesame(Sesamum indicum L.) cultivars (Dashtestan, Darab 14, and Zarghan) in Kaki region (Bushehr Province). The type of design was completely randomized block with factorial arrangement and three replications. Nitrogen(N) fertilizer had a very significant effect on agronomic characteristics, such as number of capsules in the main stem, number of capsules per plant, branches /plant, biological yield, seed yield ,and oil percentage, but had no effect on 1000 seed weight. There was no significant difference between the application of 30 and 60 Kg of N fertilizer ha-1 with respect to harvest index. Seed yield increased as N rate increased, but each cultivar had a different response to different rates of nitrogen. Dashtestan and Zarghan had superiority over Darab 14 with respect to overall agronomic properties such as response to fertilizer and early maturity, but from the qualitative point of view, Darab 14 produced higher percentage of oil.
