Showing 401 results for Ag
N. Yaghmaeian Mahabadi, J. Givi,
Volume 11, Issue 42 (1-2008)
Abstract
Gypsum affects many physical, chemical and mineralogical properties which in turn influences management, classification and sutability of the soils. This is the reason why accurate measurement of gypsum in soil is very important. In most of the soil science laboratories, the method of acetone ,in spite of its too much limitation, is being used as a standard method. The purpose of this research was to compare different gypsum determination methods and to find the most suitable one. The study areas include Jafarabad of Borkhar and Sepahanshahr.Soil samples were collected from different horizons of the studied profiles and seven samples with a wide range of gypsum content were selected. Gypsum content of the soil samples were determined by methods of acetone, sodium carbonate, resin, calcium and magnesium difference, diluted extracted sulfate, ammonium carbonate, sodium citrate and hydrochloric acid. To calculate the recovery percentage of the methods, after adding a certain amount of gypsum with known purity percentage to the soil samples, gypsum content was determined again by above mentioned eight methods. To evaluate the suitability of the methods, in addition to the recovery percentage of the methods, coefficient of variability and extent of proximity of the regression line to the 1:1 line were used. The results revealed that among the used methods, the method of sodium carbonate is the most accurate one. Resin method is ranked as the second best method and can be used in non-saline soils as another accurate method for determination of gypsum content. Sodium citrate and hydrochloric acid methods for different amounts of gypsum and ammonium carbonate method for gypsum content up to 30% are third in rank as far as their accuracy is concerned. Acetone, calcium magnesium difference and diluted extracted sulfate methods are not sufficiently accurate, because of low solubility of gypsum in water which is used as an extractant. In general, the most important determinant of accuracy of the methods is extractants of the gypsum among which the sodium carbonate has the highest efficiency.
N. Sahebani , J. Zad , A. Sharifi-Tehrani , A. Kheiri ,
Volume 12, Issue 43 (4-2008)
Abstract
Polyphenol oxidase (PPO) activities were measured spectrophotometrically in tomato(Roma VF: resistant to Fusarium oxysporum f.sp. lycopersici and susceptible to Meloidogyne javanica) roots inoculated with nematode and fungi in four biological life stages of nematode. PPO specific activity showed a significant decrease in treatments (nematode + fungi) as compared with control plants. Results showed that nematode is able to change or suppress induction of this enzyme in spite of fungal induction. Nematode in all biological stages suppressed the induction of PPO activity in tomato roots but in young adult formation stage the suppression was higher than other life stages including giant cell formation, egg-laying and penetration. Native polyacrylamide gel revealed the presence of five isozymes of PPO with Rm values of 0.26, 0.31, 0.44, 0.50 and 0.63. Isoforms with Rm values of 0.26, 0.44, 0.50 and 0.53 showed significant changes in nematode + fungus inoculated tomato plants compared to plants inoculated with fungus alone. Based on the results obtained in this study, nematode infection resulted in suppression of tomato defenses against the fungi (as secondary pathogen) and intensified the fungal disease. Five PPO isoforms with Rm values of 0.26, 0.31, 0.44, 0.50 and 0.63 were shown in native polyacrylamide gel among which the isoform with Rm value of 0.31 had a thicker band in tomato plants inoculated with nematode or fungus alone. Two isoforms with Rm values of 0.44 and 0.53 in nematode-inoculated plants were similar to the corresponding bands in the healthy control. Isoforms with Rm values of 0.26, 0.44, 0.50 and 0.53 in nematode-fungus-inoculated tomato plants showed significant changes compared to plants inoculated with the fungus alone. Nematode infection of root tissue caused suppression of PPO specific activity and induced changes in PPO isoforms with Rm values of 0.26, 0.44, 0.50 and 0.63 more significantly than isoform 0.31.
M. Falaki, H. Shabanali Fami, H. Iravani , H. Movahed Mohammadi,
Volume 12, Issue 43 (4-2008)
Abstract
The continuous rapid development of telecommunications and computer-based information technology (IT) is probably one of the biggest factors of change in agricultural extension, which will facilitate and reinforce other changes. There are many possibilities for the potential applications of the technology in agricultural extension, about which attitudes of extension professionals is highly important. The present study was conducted to assess the attitude of extension professionals which can affect the adoption of IT by extension system. The population of the study consisted of 1145 extension professionals working throughout the country in different provinces. Using a stratified random sampling technique, 241 extension experts were selected as the sample for the study. The reliability and validity of the tools of study were confirmed by a pilot study and expert judgment. The results of the study indicated that the respondents had higher knowledge on word processing softwares, windows and file management in the area of computer application. In contrast, in the area of internet application they were mainly interested in getting information from specialized sites, searching by search engines of Yahoo and Google and exchanging e-mails. Correlation analysis showed that there was a significant relationship between the attitude of extension professionals and their age, educational attainments, knowledge of IT, its application and English language proficiency. Meanwhile, there was a significant difference between attitudes of male and female extension experts towards IT.
M. Keshavarz , E. Karami ,
Volume 12, Issue 43 (4-2008)
Abstract
Drought is an unavoidable natural disaster in dry and arid regions of the world. Studies indicate that Iran with its geographical and climatic characteristics is poor in water resources. Moreover, it is estimated that in 2025, Iran should increase the water resources by 112% in order to maintain status quo. Therefore, the occurrence of drought is more prevalent in the future. This implies a real challenge for researchers to study how to manage farms during the onset of drought. Inappropriate management strategies result in loss of resources, which in turn leads to more destructive impacts of drought, consequently leading to more droughts in future. The purpose of this survey study was to identify factors influencing drought management among farmers in Fars province, Iran. A multistage stratified random sampling technique was used to select a representative sample of farmers who has experienced drought in recent years. A total of 258 farmers were interviewed using a questionnaire. A panel of experts verified face validity. A pilot study was used to assess the reliability of the measuring instrument. Cluster analysis and Structural Equation Modeling were used for data analysis. Results indicated that farmers with different social, economical, and technical characteristics chose different management strategies when coping with drought conditions. Despite farmers' efforts to manage drought, they face harsh consequences. These consequences include economic losses and degradation of farming environment. It is therefore recommended that policy makers who are involved in drought management programs learn more about farmers' drought mitigation techniques and make further attempts to increase the efficiency and effectiveness of techniques used by farmers.
E. Abdi Gezeljeh,
Volume 12, Issue 43 (4-2008)
Abstract
Based on the official statistics of industries and mines organization about 1000 tons of waste of spaghetti in spaghetti- producing plants, and around 7500 tons of waste in chickpea pre-cleaning plants are produced annually in the East Azarbayjan province. In order to determine chemical composition and metabolizable energy of the above mentioned waste, at first classified random sampling from 10% of plants was performed. Then amount of dry matter, crude protein, crude fiber, ether extract, NDF, ADF, and gross energy were measured according to AOAC (1990) procedures. The amounts of crude protein, crude fiber, ether extract, NDF and ADF, for spagettti waste were, 12/7, 0/2 , 2/4 , 1/7 and 0/1 percent, respectively, and for chickpea pre-cleaning were 30/2 , 17/8 , 8/7 , 32/3 and 22/4 percent, respectively. The waste of spaghetti was mixed with basal diet with the ratios of 0, 15, 30, 45, 60, 75, 90, and 100%. The waste of pre-cleaning chickpea was mixed with basal diet with the ratios of 15% and 45%. Then, in order to determine different kinds of metabolizable energy (AME, AMEn, TME, TMEn) of waste, 30 grams of mixed feed were force-fed to 4 adult Leghorn-type roosters, according to the method described by Sibbald. The amount of AMEn of spaghetti waste in different levels was 2915, 3535, 3937, 3643, 3728, 3671, 3687 and 3717 Kcal/kg, respectively and the amount of AMEn of metabolizable energy of checkpea pre-cleaning in two levels was 2677 and 2279 Kcal/kg, respectively. Statistical analysis showed that there were significant differences between AMEn of wastes. There were significant differences between amount and kinds of metabolizable energy in different levels. The highest amount of AME was observed to be in 30% ratio of spaghetti waste relation to basal diet. There were significant differences between amount of metabolizable energy of checkpea pre-cleaning in two levels. The highest amount of AME was observed to be in 15% ratio of checkpea pre-cleaning waste related to basal diet.
M. Rahimmalek, B.e. Sayed Tabatabaei, S.a. Mohammadi,
Volume 12, Issue 43 (4-2008)
Abstract
Genetic maps with high genome coverage are becoming increasingly useful in both basic and applied genetic researches. In the last decades, the advent of DNA markers has brought about a magnificent revolution in the production of genetic map, especially in wheat. In the present study, AFLP markers were used to saturate linkage map of 107 doubled haploid individuals produced through Fukuho _Komugi × Oligo – Culm crosses received from Japan International Research Center of Agricultural Science (JIRCAS). The framework of genetic map was used as base map for next analysis. AFLP analysis was performed with MseI / PstI as digestive enzymes. The average percentage of polymorphism with AFLP markers was around 16.6%. Data analysis was performed by computer program known as Mapmaker / EXP, Ver. 3.3. In this program, the maximum distance criterion was 50 cM and the minimum LOD equated 3. The drawing of chromosome schema for the linkage groups was performed by Draw map, Ver 1.1. In this analysis, 115 AFLP markers were divided into 10 groups in addition, some of the markers remained unlinked. The supplementary data analysis along with specific SSR markers identified the chromosome loci of the markers. Ultimately, 71.1% of the markers were assigned to genome A, 16.5% to genome B and only 3% to genome D. The AFLP markers filled 11 gaps in 7 chromosomes (2A, 3A, 7A, 2B, 3B, 5B and 7B). The low coverage of genome D was due to the limited polymorphism and its conservation in different populations. Among the chromosomes, maximum number of markers (60) was assigned to the chromosome 7A. The distribution of the markers on this chromosome was not uniform. Such a distribution was related to the grouping AFLP markers within heterochromatin region, particularly around the centromere.
M. A. Ebrahimizade, A. M. Hassanli ,
Volume 12, Issue 44 (7-2008)
Abstract
Root depth is one of the main parameters affecting soil moisture availability held within the plant root zone. This study was conducted to evaluate the trend of corn root development during the growing season in different irrigation methods with two water qualities, and distribution of roots in soil profile. The experiment was a split plot design with three main treatments (subsurface drip(SSD), surface drip(SD) and furrow irrigation(FI)) and two sub main treatments (municipal effluent and fresh water) in two consecutive years conducted in Korbal plain, Fars province. Root monitoring was carried out with the observation of soil profile root depth measurement. Samples were taken during the growing season 16 times, each with a 7 day interval. Measurement of root weight in different soil layers was carried out using monoliths of soil washed with water pressure using 50 mesh sieves. Although the longest roots were observed in plots irrigated with SSD and the shortest in FI, the final root length was not significantly affected by irrigation methods and water qualities. In this research, a model showing the trend of root length average growth was developed and tested in the experiment conditions. The average final main root depth for all treatments was 77 cm. Irrigation volume using root depth monitoring could be reduced compared to linear model, Borg & Grimes and CROPWAT model for root depth estimation. Irrigation water on the base of soil moisture deficit within the root zone in each irrigation event could be reduced when the real root depth is considered compared with the conventional general models giving a final root depth. Results showed the total dry root weight in SSD was more than that in SD and FI methods. However, water quality did not show a significant effect on dry root weight. The most root concentration in SSD was measured in depth of 20-40 cm, while in SD and FI the most concentration was in surface layer (0-20 cm). In the SSD, the roots were distributed more evenly compared with SD and FI methods. The concentration of roots in all treatments below 65 cm was not significant.
M. Tahmasbi, A. Hemmat, M. Vafaian, M. R. Masaddeghi,
Volume 12, Issue 44 (7-2008)
Abstract
For prevention of soil compaction, knowledge of allowable compression stress limit (compaction strength) in soil is important. Pre-compaction stress ( σpc) was introduced as soil compaction strength and often used as a criterion for evaluation of soil susceptibility to compaction. In this research, pre-compaction stress was measured for a sandy loam soil with plate sinkage (PST) and confined compression (CCT) tests. To prepare soil samples with different initial compactness, two soil water contents (17 and 19%db) and six pre-loading stresses (0, 25, 50, 100, 150 and 200 kPa) were used. The effects of soil water content and pre-loading stress on estimated pre-compaction stress were studied using a factorial experiment in a completely randomized design with three replications. The σpcvalues were significantly influenced by loading combination and soil water content. For PST, pre-load increase and higher soil water content resulted in higher and lower values of σpc , respectively. However, predicted σpc value increased with higher soil water content for CCT. The results also showed that the σpc predicted with PST was accurate, whereas the values obtained with CCT were 4.5 (at 17 %db) and 8.5 (at 19 %db) times higher than the applied pre-loads. Overall, the findings indicated that σpc prediction depends on the compression test, and PST could be a suitable method for soil pre-compaction stress (compaction strength) determination in sustainable soil management, i.e., soil trafficability and tillage. The PST method is also suitable to assess the effect of managing factors on pre-compaction stress.
M. Ghasemi Varnamkhasti, H. Mobli, A. Jafari, M. Heidari Soltanabadi, Sh. Rafiee,
Volume 12, Issue 44 (7-2008)
Abstract
Rice whitening is an important stage in rice milling process and improvement of the whitener machines has a remarkable effect on rice loss. To decrease the amounts of broken rice and losses, the rotor of the blade whitener was equipped with screw conveyor. To investigate the effects of rotor speed (in four levels: 600, 700, 800 and 900 rpm) and output rate (in three levels: 400, 500 and 600 kg/h) on quality of milled rice, a factorial design with randomized complete block experiments with three replications were conducted. In this study, Sorkheh variety (a medium rice variety), which is one of the prevailing varieties in Esfahan, was used. The results showed that the lowest breakage percentage (20.92%) occurred at rotor speed of 700 rpm with an output rate of 600 kg/h and the best degree of milling (6.33%) took place at rotor speed of 600 rpm with an output rate of 400 kg/h. The best rice quality (low broken rice and high degree of milling) was observed at rotor speed of 600 rpm with 500 kg/h output rate.
B. Rayegani, S. J. Khajeddin, S. Soltani , S. Barati,
Volume 12, Issue 44 (7-2008)
Abstract
Snow is a huge water resource in most parts of the world. Snow water equivalent supplies 1/3 of the water requirement for farming and irrigation throughout the world. Water content estimation of a snow-cover or estimation of snowmelt runoff is necessary for Hydrologists. Several snowmelt-forecasting models have been suggested, most of which require continuous monitoring of snow-cover. Today monitoring snow-cover patches is done through satellites imagery and remote sensing methods. MODIS have smaller Spatial Resolution and more bands in comparison with Meteorology Satellite like NOAA. Therefore, in this research we used MODIS data for creating snow cover imagery. Existence of cloud in the study area is a major problem for snow cover monitoring. Therefore, in this research snow cover area changes were estimated without MODIS data period, but with DEM imagery and regressions between temperature, height and aspect. For this purpose, on 10 Esfand when the image was suitable we estimated the snow cover area. In comparison with real image, precision of the method was confirmed.
M. Yousofi,
Volume 12, Issue 45 (10-2008)
Abstract
Freezing is one of the most important climatic factors affecting almond products in Isfahan province. Therefore, it is important to use a rapid method for assessing the resistant cultivars and wild species of these plants. Evaluation of electrolyte leakage (EL) from freezing damaged tissues of almond is an appropriate method for this purpose. In the present work, the effect of freezing on the rate of electrolyte leakage of 10 cultivated almonds (Amygdalus communis cultivars) and one wild species (A. scoparia) was evaluated in Isfahan province. The perfect and mature flowers of all samples were selected at random, and examined under natural (in nature) and artificial (in laboratory) freezing treatments in 3 replicates. All measurements were done using an Ec meter instrument and the mean of obtained data was analyzed statistically via ANOVA and Tukey's tests. In each treatment, increase in the rate of electrolyte leakage of treated samples in relation to the controls was taken as a criterion for comparison. Total Dissolved Solids (TDS) of the flowers of all samples were also measured, with an accuracy of 0.001, under natural freezing conditions. The mean of TDS was 390.8±33.5 mg/L among cultivated almonds (maximum in Safari cultivar with 439±29.3 mg/L and minimum in Kababi cultivar with 355±35.3 mg/L) and 362±55.8 mg/L in the wild almond (a little less than that of the cultivated ones). Linear regression test showed that there was no correlation between TDS and the rate of electrolyte leakage from freezing damaged tissues of the studied samples. Furthermore, the results showed that the cultivars of Tageri (with 7.47% increasing), Azar (with 19.2% increasing) and Rabie (with 22% increasing) are respectively more resistant than other cultivars under natural freezing, and the cultivars of Rabie (with 60.7% increasing), Tageri (with 67.6% increasing) and Hag Mirzaie (with 71% increasing) are more resistant than other cultivars under artificial treatment. These results are in agreement with the experimental observations in the studied area. The freezing tolerance of wild species (with 48.7% and 73% increasing, respectively) was moderate in both natural and artificial freezing treatments.
M. Amini Dehaghi, S.a.m. Modarres Sanavy, F. Fattahi Neisiani,
Volume 12, Issue 45 (10-2008)
Abstract
In order to study the effect of planting dates and genistein on nitrogen content and nodulation of three annual Medicago species (Medicago polymorpha cv. Santiago M. rigidula cv. Ragidula, and M. radiata cv. Radiata), an experimental study was conducted during 2004-2005 on the Research Farm of Faculty of Agriculture, Tarbiat Modares University, Tehran (35°43′N and 51°8′E). The factors were arranged as split-split plot in a randomized complete block design with four replications. Planting dates (February 20, March 1 and 11) were randomized to main plots and three annual medics were located in sub-plots, and genistein (0 and 20 μM) was randomized to sub-sub-plot units. Plant nitrogen contnt, nodulation and other traits were significantly different in species and M. polymorpha was better than other species in view of dry nodule weight, nodule number, nodule number in each cluster, nodule cluster number and nodule diameter. Medicago rigidula had more resistance to cold than other varieties, and its forage yield and nitrogen percentage were better than M. polymorpha. Therefore, M. rigidula may be better suited for cold zones. Twenty μmol genistein had remarkable effect on nodulation and nitrogen percentage of annual medics in comparison with control. The result showed that genistein modified negative effect of low temperature environment on nodulation and nitrogen percentage of annual medics. Nodulation and nitrogen percentage increased in all varieties at the first planting date. This finding emphasizes that genistein has a considerable effect on cold resistance establishment in varieties for improving nodulation and increasing plant nitrogen percentage in farm condition.
S. M. Naser Alavi, M. Shamsaddin Saeid,
Volume 12, Issue 45 (10-2008)
Abstract
To study the effects of plant densities and planting orientation on the seed and forage yield of sorghum, an experiment was conducted at Hossein- Abad – Shahcal village –90 kilometers south of Bam-in 2002. The experiment was a factorial with randomized complete block deisgn and three replications. The treatments were: orientation with three levels (South-North, East – West, Northeast – Southwest) and plant densities with four levels (50000, 70000, 90000, 110000 plants per hectare). Results of analysis of variance showed that planting orientation had significant effects on seed yield, weight of 1000 seeds, number of tillers, dry matter yield, length and diameter of shoot. Mean comparisons, showed that the maximum and minimum amount of the above mentioned traits except for shoot length was obtained under the North-South and East-West orientations, respectively. Significant differences were also found among densities in terms of all the mentioned traits. Results showed that increasing density decreased seed yield, weight of 1000 seeds, number of tillers and shoot diameter. The highest and lowest values (except of seed yield) were recorded for 50000 and 110000 plants/per hectare, respectively. Dry matter yield and the shoot length increased with increasing density. Based on the results of this experiment, the best plant densities to obtain the highest forage and seed yield are 70000 and 110000 plant per hectare, respectively and the best planting orientation is North-South.
A. R. Askarianzadeh, S. Moharramipour, Y. Fathipour, A. Narrei,
Volume 12, Issue 45 (10-2008)
Abstract
Cultivars or species of different plants through physical and biochemical characteristics or indirectly through food diet of host plant can influence behavioral characteristics and efficiency of a natural enemy. This investigation was conducted to determine percentage of parasitism and functional response of parasitoid wasp, Platytelenomus hylas (Hym., Scelionidae) to different egg densities of stem borer, Sesamia nonagrioides (Lef.) and effect of different cultivars on it. At the first stage, eggs of pest were separately collected from fields in three cultivars of CP48-103, CP69-1062 and CP57-614 and then percentage of parasitism in each cultivar was calculated. For determining functional response of the wasp, collected eggs from fields were reared to adult stage at 29±1 ºC, 60% of RH,. Then functional response of wasp was investigated at densities of 2, 4, 6, 8, 14, 20, 30, 40, 50, 60, 70, 80, and 90 of the host eggs for 24h. Analysis of data was done using SAS software. Results showed that egg parasitism by P. hylas in cultivars were significantly different (p<0.05). Type of cultivars influences rate of egg parasitism. Comparison of means by Duncan’s test showed that CP48-103 cultivar significantly differed from two other cultivars: CP69-1062 and CP57-614. Functional response in three cultivars was found to be a type III. Comparison of estimated parameters by Holling model in three cultivars showed that searching efficiency on CP48-103 cultivar was significantly higher than two other cultivars but CP57-614 and CP69-1062 were close to each other. Also, handling time (Th) and the maximum rate of estimated parasitism (T/ Th) on the three cultivars were different and on CP69-1062 they were significantly less than the two other cultivars.
P. Heydarizadeh, M. Sabzalian, M.r. Khajehpour,
Volume 12, Issue 45 (10-2008)
Abstract
During recent years, several genotypes have been selected from Isfahan land race Kouseh. The performance of safflower selected genotypes was studied in the field conditions, at Agriculture Research Station, Isfahan University of Technology during 2003. The experiment was carried out using a split plot arrangement according to a randomized complete block design with three replications. Planting dates (March 11, April 20, May 22 and June 23) were considered as the main plots and subplots consisted of 20 genotypes of safflower including 19 selections from Kouseh and Arak-2811 genotype. Days from planting to emergence and emergence to stem elongation were reduced as planting was delayed until the fourth planting date. Days from stem elongation to head visible was reduced with delay from the first to the third planting date, and then increased. Days from head visible to 50% flowering was reduced with delay from the first date to the third planting date, but increased in the fourth planting date. Days from 50 percent flowering to physiological maturity was increased with delay in planting. Days from planting to emergence, emergence to stem elongation, stem elongation to head visible and 50 percent flowering to physiological maturity were not influenced by genotypes. Genotype DP7 had the highest and genotype C111 and genotype DP25 had the lowest days from head visible to 50% flowering. The interaction between planting date and genotype in regard to days from stem elongation to head visible was also significant. Seed weight per plant was reduced with delay in planting date. Genotype ISF66 had the highest and genotype Arak-2811 had lowest seed weight per plant. The number of days from emergence to head visible in ISF66, DP5, C128 and Arak-2811 was affected by maximum temperature (Tmax), in genotype DP7 by Tmax2, in genotypes DP17, DP1 and C41100 by Tmin2 and in genotypes DP9, DP25, ISF28, ISF22, and C111 was affected by day length. It seems that development period from emergence to head visible was affected by temperature in the most genotypes. On March 11 planting date, genotypes had the maximum response to temperature and day length and the minimum response was observed in the fourth planting date. The genotype ISF66 had the highest seed yield on March 11 planting date. The result of this study showed that safflower should be planted in late March under condition similar to this experiment for maximum yield production.
M. Majidian, A. Ghalavand, N. Karimian, A. A. Kamgar Haghighi,
Volume 12, Issue 45 (10-2008)
Abstract
In order to investigate the effects of moisture stress, nitrogen fertilizer, manure and integrated nitrogen and manure fertilizer on yield, yield components and water use efficiency of SC 704 corn (late maturing, non-prolific and dent). In 2005, a field study was conducted in agricultural experiment station of the college of agriculture, Tarbiat Modares University. The type of design was randomized complete block with factorial arrangement and three replications. For the study, four levels of nitrogen fertilizer (0, 92, 184 and 276 kg N ha-1), integrated fertilizer (46 kg N ha-1 + 2/5 ton ha-1 FYM, 92 kg N ha-1 + 5 ton ha-1 FYM and 138 kg N ha-1 +7/5 ton ha-1 FYM ) and organic Farm Yard Manure (5, 10 and 15 ton ha-1 FYM ) along with three levels of irrigation (optimum irrigation (control), water stress 75% optimum irrigation and water stress 50% optimum irrigation) were used as treatments. The results showed maximum seed yield was produced with 92 kg N ha-1 + 5 ton ha-1 FYM and average of seed yield was 7976 kg ha-1. Maximum corn seed yield resulted when optimum irrigation water was applied and average seed yield was 7041 kg ha-1. When water stress was imposed in 50% and 75% of optimum irrigation, seed yield was decreased by 33 and 12%, respectively. The best seed yield was obtained with interaction of 5 ton ha-1 FYM and optimum irrigation. Also, maximum water use efficiency was obtained in using 50% of optimum irrigation. Maximum water use efficiency was obtained with interaction of 92 kg N ha-1 + 5 ton ha-1 FYM and imposition of water stress in 50% optimum irrigation. Results showed that adequate nitrogen fertilizer slightly increased corn seed yield under stress, and integrated (nitrogen and manure) fertilizer increased corn seed yield under stress. But seed yield greatly increased with optimum irrigation. Integrated fertilizer application increased seed yield even with severe moisture stress. Application of integrated chemical fertilizers and manure produced better seed yield and also decreased the amount of chemical fertilizers and improved soil physical and chemical characteristics.
M. Gholamhoseini, M. Aghaalikhani, M.j. Malakouti,
Volume 12, Issue 45 (10-2008)
Abstract
In order to study the effect of various amounts of nitrogen (N) and Iranian natural zeolite on the quantitative and qualitative forage yield of winter canola (Brassica napus L.) in light soil, a field experiment was conducted on research farm of Tarbiat Modares University, Tehran, during 2006-2007. Treatments were arranged in the form of RCBD with 3 replications. The experimental treatments were based on factorial various levels of zeolite (0, 3, 6 and 9 t.ha-1) and nitrogen (90, 180 and 270 kg ha-1) in urea form. Seeds of canola (Brassica napus L. cv. Okapi) were sown on October 2, and fresh forage was harvested at the time of silique formation (170 DAP). Results showed that the effect of N and zeolite on forage quantitative attributes including biomass, leaf and stem dry weight and leaf area index were statistically significant. In addition, forage qualitative traits including crude protein percentage and calcium percentage in plant mass were significantly affected by N and zeolite. Increasing application of N fertilizer caused increase in N leaching, and with increasing zeolite application, N leaching reduced. The interaction of two factors for all parameters was not significant. The most increasing effects on forage yield and quality were gained using 270 kg N ha-1 in combination with 9 t. Zeolite ha-1. More detailed studies are strongly recommended to investigate the effects of integrated application of chemical fertilizer and natural zeolite.
R. Haddad, Gh. Garousi, M. Ghannadnia,
Volume 12, Issue 45 (10-2008)
Abstract
To study the effects of different combinations of auxin (IBA, NAA) and cytokinin (BAP, TDZ) regulators, basal salts (MS, WPM, NN) and gelling agents (Gelrite and Plant Agar) on the growth and development of seedless grape explants (cv. Bidaneh Soltani), a factorial experiment was conducted based on a completely randomized design. The number and length of grown shoots were analyzed as two main characteristics. Growth regulators and salts had significant effects (at %1) on the shoot proliferation. The highest number of shoots was observed on MS salts combined with BAP (2.2 mg/l) and IBA (0.5 mg/l) on the 18th days of culture. Compared to Plant Agar, Gelrite had a better effect on the normal growth of the shoots. Based on the new shoots, combinations of MS salts and hormones may be used for micropropagation of seedless grape cultivars in the in vitro condition.
A. Ghani, M. Azizi, M. Hassanzadeh Khayyat, A. A. Pahlavanpour,
Volume 12, Issue 45 (10-2008)
Abstract
Achillea wilhelmsii Koch. is an aromatic plants belonging to Asteraceae family that has relatively wide distribution in different parts of Iran. In this study, we compared essential oil contents and constituents in two wild populations under two different ecological conditions (Fars and Khorasan Provinces, South West and North East of Iran respectively). The blooming herbs were collected and the essential oils of the samples were extracted after drying by “Clevenger apparatus”. Essential oil constituents were determined by GC and GC-MS. Our results showed that “Khorasan” population of Achillea wilhelmsii contains more essential oils than “Fars” population (0.65 and 0.2 % v/w respectively). Thirty components of “Khorasan” population that were 96.94% of total components were determined successfully and the main components were camphore(19.06%), cembrene(10%), 1,8-cieole(8.78%), alpha pinene(8.06%) and linalool (7.47%). Thirty-two components (91.98%) of “Fars” wild population were determined and the main components were isopentyl-isovalerate(9.46%), alpha pinene(8.75%), 1,8-cineole(8.70%), eudesmol(10-epi-gama)(5.56%), spathulenol(4.94%). Cembrene(10%), Germacrene B( 5.68 %) and Sabinene(4.34%) were detected in Mashhad population but not in Shiraz population. 10-epi Gamma Eudesmole(5.65%), Benzaldehyde dimethyl acetal(4.47%) and Ionone (4.29%) were detected in Shiraz population but not in Mashhad population. In conclusion, there are differences between these two populations as far as essential oils content and constituents are concerned.
S. M. Mansouri, M. Mobli, R. Ebadi, A. Rezai,
Volume 12, Issue 45 (10-2008)
Abstract
Because of many small florets and protandry, cross pollination in onion which is a biennial plant, by using polycross method for breeding is suitable and easy. To produce polycross seed, bulbs of 9 self onion genotypes were planted in the shape of equilibrium lattice design for 9 treatments with 10 replications on May 2002. To study some agronomical characteristicss, the polycross seeds produced from free pollination and original self-fed seeds (totally 18 genotypes) were planted in plots as a randomized block design with four replications. Samples were taken from each plot and different characteristics were measured. Results showed that polycross generally increased plant fresh and dry weight, plant height, percentage of off type bulbs and yield, with no effect on bulbing ratio and time to ripening. Although polycross increased most agronomical characteristics and yield in Kashan, Azarshahr and Kazeroon genotypes, in some genotypes little increase or even negative effects resulted due to interaction between genotype and polycross. With more assessment of polycross genotypes, good characteristics will be fixed and seeds with higher qualities will be produced.
