Showing 401 results for Ag
M. A. Nazari, H. Shariatmadari, M. Afyuni, M. Mobli, Sh. Rahili,
Volume 10, Issue 3 (10-2006)
Abstract
Sewage sludge and effluents, as cheap sources of irrigation water and fertilizer, can supply plants with water and nutrients however, contamination of these sources with heavy metals and the possibility of human food chain contamination using these sources should be considered. In this research, the effects of industrial sewage sludge and effluents on concentration of some nurtients, heavy metals and sodium and dry matter yield of wheat (Triticum aestivum), barley (Hordeum vulgare) and corn (Zea mays) were investigated. The experiment was carried out in a greenhouse using a complete randomized design with four replication. The treatments comprised well water, well water + sewage sludge(50 tons/ha), and three industrial effluents from Iran Polyacryl factory including the cooling tower, the over flow and the factory outlet effluents. Chemical analysis showed the following results: The concentration of the elements in the sludge and the effluents were below the critical contaminating levels. The application of the treatments did not supply enough nitrogen for corn the cooling tower effluent could not supply enough nitrogen for wheat and barley all the treatments supplied enough P for wheat. None of the treatments could supply enough P for corn. The cooling tower, over flow and the factory outlet effluents could not supply enough P for barley, the micronutrient and heavy metal concentrations in the plant tissues using the effluents and the sewage sludge were higher than those for well water the dry matter yield of plants’roots and shoots was highest using well water + sludge and in comparison with the well water, effluents could increase the shoot dry matter yield.
S. S. Hosseini, E. Hassanpour, S. Y. Sadeghian,
Volume 10, Issue 3 (10-2006)
Abstract
The first Iranian hybrid monogerm cultivar of sugarbeet was developed in 2000 after an 8-year period of R&D activity. The cultivar is not only a high yielding variety but enjoys a good resistance to bolting and Sercospora. The study sought to estimate the rate of return to the public investment made to develop this variety, using the economic surplus approach. The results revealed that the investment has got an internal rate of return of 117 percent and that it has produced an exchange saving of $28.7 million. This finding indicates that the investment has been highly productive and that the field suffers underinvestment.
O. Rafieyan, A. A. Darvishsefat , M. Namiranian,
Volume 10, Issue 3 (10-2006)
Abstract
The aim of this study was to detect change of the forest area in the north of Iran between 1994 and 2001. The study area was covered by a 1:25000 topographic map (about 15000 ha) in Babol forests. The forest map of 1994 was extracted from 1:25000 topographic digital map. Landsat 7 ETM+ image dated July 30, 2001 was analyzed to produce the forest map for the end of the period. Since the evaluation of the image quality illustrated it less than ±1DN in the ETM 2, 4, 5, the rectification of the stripping distortion was ignored. There were also duplicate scan lines and sweep distortions in all the spectral bands. Orthorectification was implemented using ephemeris data and digital elevation model. Several spectral transformations such as rationing, PCA, Tasseled cap and image fusion (using Color space transformation and Spectral response method) were performed on the ETM+ data. The sample ground-truth map was prepared using GPS in 3% of the study area. In order to classify the image, hybrid classification method (digital and visual), using original and synthetic bands, was employed. At first the image was classified using maximum likelihood classifier. The most accurate map (overall accuracy and kappa coefficient equal to 94.56% and 0.89, respectively) was converted to the vector format and then it was edited on the basis of various color composites, fused images and other ancillary data. The obtained map showed overall accuracy and kappa coefficient equal to 96.39% and 0.927, respectively. The comparison of the classified map with the forest map of 1994, illustrated that 751 ha of forest area (equal to 8.2% of the previous forest area), were decreased. This includes a 417 ha increase (mostly reforested areas) and a 1168 ha decrease over the study period. The findings indicate the high potential of ETM+ data in forest mapping and change detection over the whole extent of the northern forest of Iran.
M. Falahati-Anbaran, A. A. Habashi, M. Esfahany, S. A. Mohammadi, B. Ghareyazie,
Volume 10, Issue 3 (10-2006)
Abstract
Annual medics are used for hey production, soil protection, biological fixation of N2 and green manure. In the present study, the inter and intra specific genetic diversity and relatedness of 4 diploid and two tetraploid (M. rugosa and M. scutellata) annual medics were evaluated using microsatellite markers. PCR analysis was performed on genomic DNA from individual plant and PCR products were detected using standard polyacrylamide sequencing gel. Totally twenty five polymorphic alleles were observed in the studied species. Average intra-specific genetic diversity ranged from zero (0.0) in both M. rugosa and M. scutellata to 0.114 in M. minima species, and the level of genetic diversity was similar in both M. orbicularis and M. truncatula species. Analysis of molecular variance (AMOVA) was used to partition the overall genetic diversity into within and among species, and between diploids and tetraploids. The results revealed significant (P<0.05) inter and intra-specific genetic variation. Pairwise comparisons based on Fst indicated significant differences among all of the species. Clustering analysis using UPGMA algorithm based on coancestary coefficient revealed a clear genetic relationship among species. The hypothesis on a common origin of two tetraploid species was supported by UPGMA clustering and phylogenetic analysis. The high level of Genetic diversity in spiny pod species respect to spineless pod species suggested the high importance of species with spiny pods in annual medics evolution. The findings support the usefulness of microsatellite markers for assessing inter and intra specific genetic diversity, differentiation and genetic relationships.
R. Amooaghaie,
Volume 10, Issue 3 (10-2006)
Abstract
Ferula ovina is one of forage species of Isfahan and Chaharmahal va Bakhtiari whose natural spreads are under destruction. Finding information about its seed dormancy, effective factors in the dormancy breaking and also about optimal conditions of seed germination is necessary for recovery of this plant spreads. To actieve that goal, two factorial experiments were performed in completely randomize design. First experiment was performed with 6 replications for evaluation of effect of seed age, light and cold duration factors on seed germination percentage. In the second experiment, the effect of cold duration and seed age on T50 Ferula seed was investigated in 3 replications. The results showed that one-year storage reduced seed germination percentage, but this reduction was not statistically significant. One-year-old seeds compared to freshly harvested seeds showed greater T50 which indicate the reduction of seed vigor and germination velocity. Data analysis showed that light effect was significant at 1% level. The germination rate in the light was 45.6% greater than in darkness. Therefore, Ferula seeds were positive photoblastic and their germination depended on light. Also, moist chilling had significant influence on Ferula seed germination. Moist prechilling for 7-9 weeks was the best treatment for dormancy breaking of Ferula seeds. This improved seed vigor and enhanced rate of germination but it could not replace light effect. In either situation, light was required during the germination test for optimal results. The need to cold and light may be in the direction of adaptation to ecologyical conditions naturally found in the habitat of this plant in Chaharmahal.
H. R. Bagheri, G. Saeidi, P. Ehsanzadeh,
Volume 10, Issue 3 (10-2006)
Abstract
Safflower (Carthamus tinctorius L.) is an oilseed crop and can have a considerable contribution to vegetable oil production in the country, since it has a high adaptability to different environmental conditions. This crop is grown in summer time as a second crop in Isfahan province. Therefore, this study was carried out to investigate the agronomic characteristics of the safflower breeding lines which were isolated from local populations of Iran in early spring and summer planting dates. Seven genotypes were evaluated at two planting dates, early spring (16 March) and summer (21 June), using a randomized complete block design (RCBD) with 4 replications at the research farm of Isfahan University of Technology. The results showed that the number of days to emergence, days to flowering and maturity and plant height decreased considerably in the summer planting date. However, the harvest index, seed yield per plant and seed yield per plot and oil yield increased in this planting date. Yield components were not significantly different in the two planting dates, except that 100-seed weight was significantly and considerably more in the second planting date. The average seed yield of genotypes was 2498 and 2845 kg/ha in spring and summer planting dates, respectively. In the first planting date, seed yield varied from 1876 Kg/ha, (for Kouseh genotype as check variety) to 2908 Kg/ha for E2428 line (selected from Isfshan population). In the second planting date, seed yield had a variation of 2124 to 3186 Kg/ha for the genotypes of S3110 (selected line from Khorasan population) and C111 (selected from Kouseh population), respectively. In the second planting date the check variety (Kouseh population) had a seed yield of 2965 Kg/ha. In both first and second planting dates, genotypes of E2428 and C116 (selected line from Kouseh population) had the maximum oil content in the seed, (33.9% and 32.3%د respectively). Genotype by planting date interaction was significant for seed yield and oil yield, since late planting date reduced seed yield in genotypes of S3110 and E2428, but it increased these traits in other genotypes.
G. Saeidi, A. Khandan,
Volume 10, Issue 3 (10-2006)
Abstract
The precision of evaluation for agronomic traits is very important in the field experiments to determine the genetic potential of genotypes or effect of treatments. The precision of the experiment mainly depends on the number of replications. The objective of this study was to investigate the effect of number of replications on the precision of genotype evaluation, estimation of variance components and on the heritability for agronomic traits in flax (Linum usitatissimum L.). In this study, nine genotypes of flax were evaluated for different traits, using a randomized complete block design with 8 replications. The results showed that the reduction of error variance due to increasing the number of replications mainly depended upon the type of the trait. For evaluation and estimation of heritability for number of seedlings /m2 and plant height, 3 and 2 replications were suitable, respectively. The results also showed that using more than 2 replications had no considerable effect on the prescision of evaluation, nor on the increase of heritability for days to maturity. Based upon the results, for evaluation of the number of capsules per plant, 3 or 4, and for seeds per capsules, 4 replications can be suggested. For seed yield that is the most important economic trait in flax, a relatively constant estimated mean and broad-sense heritability were obtained with 4 to 8 replicationshowever, using 2 or 3 replications over-estimated the mean of the triat (approximately 11%) and under-estimated the broad-sense heritability about 27% and 10%, respectively. With 2 replications, the estimated mean and broad-sense heritability for seed yield were 2017.6 kg/ha and 72.1%, respectively. Gain from selection for seed yield based on evaluation of genotypes with 2, 3 and 8 replications was estimated as 787, 796 and 798 kg/ha, respectively. Therefore, it seems that 2 replications can also be used for seed yield evaluation of genotypes in breeding programs of flax.
N. Etemadi, K. Razmjoo, A. Khalighi, Z. Zamani, H. Lesani,
Volume 10, Issue 4 (1-2007)
Abstract
Turfgrasses are the most important cover plants in the world. Quality evaluation of the turfgrasses is usually done by experienced evaluators using color texture, density and uniformity. The results obtained by different evaluators may be different, leading to researcher’s concern. Therefore, some quantitative methods have been used for increasing the aquracy and stability in results. In this study, three color evaluating methods including, spectrophotometery (chlorophyll content), chlorophyllmeter SPAD-502, and evaluator person, as well as leaf texture by evaluator person compared with leaf width were used for 75 populations of Cynodon dactylon L. and Tifdwarf cultivar. The results showed that there were significant differences between populations for the color and leaf texture. There were no significant corelations between measuring color by using specterophotometery, chlorophyllmeter-502, and evaluator. Use of SPAD-502 instrument for measuring leaf color of bermudagrass is not recommended due to small leaf width of this species. However, there was significant corelation between visual evaluation and leaf width in measuring leaf texture. Therefore, when no experienced evaluator is present, leaf width maybe used for measuring leaf texture.
G. Saeidi, M. Khodambashi,
Volume 10, Issue 4 (1-2007)
Abstract
This study was carried out to evaluate the yield potential and other agronomic traits of nine genotypes of flax at two different spring planting dates: April 4 and May 5, 2003 and 2004, using a randomized complete block design with three replications at the Research Farm of Shahrekord University. The results showed that the effects of planting date and genotypes were significant on all of the traits, and the genotypes had a great genetic variation. On average, the range of number of seedlings/m2, maturity, plant height, yield/plant, seed yield and seed oil content of genotypes were 306 to 464, 93.3 to 105.1 days, 28.8 to 58.2cm, 0.274 to 0.569g, 995 to 1423 kg/ha and 32.88 to 34.83%, respectively. The lowest mean of plant height and the highest mean of seed yield/ha were observed for Kordestan local population. Late planting significantly decreased the number of seedlings/m2, days to maturity, plant height, yield/plant and seed yield/ha, while this increased seed oil content. Average of seed yield/plant and seed yield/ha in the first and second planting dates were, respectively 0.506 and 0.414g, and 1598 and 811 kg/ha. Significant interaction of genotype by planting date for seed yield/ha and seed oil content was mostly due to the variation in the reduction of seed yield and increasing or decreasing of seed oil content in some genotypes in the second planting date. The genotypes had a variation of 1358 to 1784 and 632 to 1088 kg/ha for seed yield in the first and second planting dates, respectively. The local population of Kordestan had the highest mean of seed yield in both years. The results of regression analysis and also the correlation coefficients showed that the number of seedlings/m2 and seed yield/plant had the most contribution to the seed yield variation. The trait of number of seeds/capsule and number of capsules/plant were the main and most important yield components affected on seed yield/plant and due to can be used as selection criteria in selection programs to improve seed yield.
A. Jokar, M. T. Golmakany, A. Karbasi,
Volume 10, Issue 4 (1-2007)
Abstract
A dairy chocolate-flavored beverage was prepared using 55 % whey permeate and 45% whole milk. The beverage was sweetened by 3% date extract and 3% sugar. The blend was mixed with 0.7% cacao powder, 0.2 % caraginan, 0.15% vanilla , 3% skim milk powder, and 3% pasteurized cream(30%fat). Control sample was prepared by 100% whole milk without skim milk powder and cream. Both samples were heated up to 50 0C , blended by a mixer for 2 minutes, then pasteurized at 850C for 30 seconds and immediately cooled down to room temperature. Stability, pH, protein, total solids, fat and acceptability of the beverage and control samples were then evaluated. The new beverage had high acceptability.
M. Rezaei, M. A. Sahari, S. Moeini,
Volume 10, Issue 4 (1-2007)
Abstract
Qualitative indices including moisture content (M), total lipid (TL), peroxide value (PV), free fatty acid (FFA), heme iron (HI), TBA, neutral lipid (NL) and phospholipid (PL) content were investigated on anchovy fish immediately after harvesting and during frozen storage at -18 and -30°C up to 8 months (2, 4, 6, 8). Profile of their fatty acid and any possible changes were also determined. Statistical analysis of the results showed significant increase of PV, FFA, NL and significant decrease of TL, HT, PL, poly unsaturated fatty acid (PUFA) and omega-3 at each temperature rate in relation to time of storage. Based on the statistical analysis, storing of the sample at -30°C had higher lipids quality. The principal component analysis (PCA) showed that HI can be grouped with important quality indices such as PUFA and omega-3.
S.a.h. Abolghasemi, A.r. Jafari-Sayadi, S.m.a. Jalali-Hajiabadi, Z. Ansari-Pirsaraei,
Volume 10, Issue 4 (1-2007)
Abstract
To study the effects of terbutaline (a beta adrenergic agonist) on performance of broiler chickens, 21 d-old male and female Cobb broiler chicks (n=300) were randomly assigned to one of five dietary treatments containing 0 (control), 5, 10, 15 and 20 mg terbutaline per kg diet. The feed conversion ratio (FCR), feed intake and body weight gain were measuered after 3 weeks. At 42-d age, six males and six females were randomly selected from each treatment and their live weight and weights of carcass, breast, breast muscle, drumsticks, drumstick muscle and abdominal fat were determined. Terbutaline didn’t affect daily weight gain, but FCR of male chicks was reduced for 5 and 10 mg/kg terbutaline treatments comapared with the control group (p<0.05). Carcass weight and weight of drumsticks, drumstick muscle, breast, breast muscle and ratio of breast to live weight of female chicks reciving 5 mg/kg terbutaline were higher than for other treatments (p<0.05). In male chicks, the live weight and weight of carcass, ratio of carcass to live weight, drumsticks and drumstick muscle at 5 mg/kg terbutaline treatment were higher than for other treatments (p<0.05). This experiment also showed that the addition of 5 mg terbotaline per kg diet during growing period improved FCR and ratio of carcass to live weight of male chicks, increased the ratio of breast to live weight of female chicks, and increased the carcass weight of male and female Cobb chicks.
M. R. Yazdani, M. Ghodsi, S. F. Mousavi,
Volume 11, Issue 1 (4-2007)
Abstract
Cultivation of a second crop in paddy fields of Guilan province is a strategy for optimum use of land, supporting family economy and increasing oil-seed production. However, this is impeded under high rainfall and waterlogging conditions. To enhance second-crop cultivation in paddy fields, surface drainage is inevitable. The surface drainage practices should be performed with minimum costs, least time span and least variations of the land. In the present research, longitudinal surface drains were constructed with a spacing of 2, 4, 6, 8 and 10 m (depth of 20 cm), with and without 1-m lateral drains (depth of 10 cm) in Rice Research Institute, Rasht, Iran. The experiment was conducted in a complete randomized block design with three replications. Canola (Brassica napa), variety PF, was cultivated as a second crop after rice. The results showed that the effects of drain spacing on seed yield, days to maturity, number of plants per m2, and also the effects of lateral drainage on seed yield, plant height, residual N, days to maturity, and number of plants per m2 are significant (P<0.01). Highest yield (2493 kg/ha) was obtained from longitudinal drains 4 m apart, with lateral drainage drain spacing of 6 and 2 m had acceptable yields, too (2241 and 1817 kg/ha, respectively). For treatments without lateral drainage, 2-m drain spacing had the highest yield (1324 kg/ha). Considering all the expenses for drainage construction, it was found that net benefit of longitudinal drain spacing of 4 and 6 m was twice the costs. Since the rainfall in Nov., Dec., and Jan., 2000, was higher than the 20-year average rainfall of the same months, it was concluded that the results of this experiment may be recommended in the years with a rainfall less than the year 2000.
E. Khadivi Borujeni, F. Nourbakhsh, M. Afyuni, H. Shariatmadari,
Volume 11, Issue 1 (4-2007)
Abstract
Application of sewage sludge on the farmland as a source of crop nutrient had recently received considerable attention. Some management practices may be required to control the accumulation of toxic elements including Pb, Ni and Cd. Sequential extraction gives useful information on plant bioavailability of the elements. The objective of this study was to investigate the cumulative and residual effects of sewage sludge application on the chemical forms and mobility factor of Pb, Ni and Cd. Zero, 25, 50 and 100 Mg ha-1 of sewage sludge were applied for 1, 2 and 3 consecutive years in a split plot design, with three replications. Soil samples were taken from 0-20 cm at the end of the third year of application. Different chemical forms of Pb, Ni and Cd were measured. Results revealed that the soluble form (SOL) of Ni and Cd increased whereas Pb soluble form decreased with increasing levels and years of application. Exchangeable (EXC), carbonate (CAR) and organic (ORG) forms of the three elements increased as levels and years of application increased. Occluded (OCC) form decreased for Pb, Ni and increased for Cd. Residual form (RES) of Pb increased while that of Ni and Cd decreased. A gereral increase was observed for available (DTPA-extractable) concentration of Pb, Ni and Cd. Relative distributions of different chemical forms were in the following order: Pb: OCC > RES> ORG> CAR> EXC> SOL, Ni: RES> ORG> OCC> CAR>EXC> SOL and Cd: OCC> CAR> RES> ORG> EXC> SOL. The comparison of different forms of the metals showed the following orders: soluble Ni>Pb>Cd, exchangeable, carbonate and occluded Pb>Ni> Cd, organic and residual Ni> Pb>cd. Increasing the available (DTPA-extractable) concentration of the elements in such a calcareous soil showed that consecutive application of sewage sludge may increase the available (DTPA-extractable) concentration beyond critical levels. A significant corretation was observed between organic form and available (DTPA-extractable) concentration of the elements.
M. Karami, Y. Rezainejad, M. Afyuni, H. Shariatmadari,
Volume 11, Issue 1 (4-2007)
Abstract
Sewage sludge application on farmland as fertilizer is commonly practiced in many countries. Sewage sludge is rich in macro- and micro- nutrients. However, high concentration of heavy metals in sludge may cause pollution of soil, groundwater and human food chain because of uptake of toxic metals by crops. The objective of this study was to determine residual and cumulative effects of sewage sludge on concentration of Pb and Cd in soil and wheat. Different levels of 0, 25, 50 and 100 Mg ha-1 of sewage sludge were applied to the soil for four years. To study the cumulative and residual effects of the sewage sludge, applications were repeated on three fourth of each plot in the second year, on one half of plots in the third year and in one fourth of plots in the fourth year. Wheat grown in the plots, after the fourth year, soil samples from the 0-20 cm depth of the different parts of the plots were taken and analyzed. Wheat was also harvested roots, stems and grains were separately analyzed for the heavy metal concentritons. Cumulative sewage sludge application increased OM, CEC, ECe, total and DTPA-extractable concentration of Pb and Cd in soil significantly (P≤ 0.05). Residual sewage sludge in the soil also increased CEC, total and DTPA-extractable concentration of Pb and Cd significantly. Single sludge applications at different rates increased the DTPA-extractable concentrations of heavy metals. In subsequent years with no further sludge application, DTPA–extractable metal concentrations in soil decreased continuously approaching the levels in the control. However, even after four years, DTPA-extractable concentration of Pb and Cd, were still significantly higher in plots which received more than 50 Mg ha-1 sludge than control. DTPA-extractable concentrations of Pb was closely correlated with total concentrations. Sewage sludge increased concentration of Cd in roots and stems and Pb in grains significantly. Cumulative effects on concentrations of Pb in grains, and Cd in stems were more than residual effects. The results of this study show that cumulative and residual effects of sewage sludge application increased concentrations of heavy metals in soil and wheat.
M. Heidari Soltanabadi, A. Hemmat,
Volume 11, Issue 1 (4-2007)
Abstract
Studies show that excessive rotation of rice, when the grains revolve inside the milling chamber, increase the breakage. Ease of grain movement in the milling chamber could minimize this problem by utilizing screw conveyor at the first part of rotor. In this study the rotor of a conventional milling was equipped with a screw conveyor. The effects of two rotor types (modified and conventional rotors), three output rates (412, 654 and 915 kg/h) and three blade distances from the agitator (11, 12 and 13mm) were examined on indices of rice quality using a split-split plot design. In this experiment, the percentage of whole white rice and breakage, degree of milling and milling performance index were either measured or calculated. Results showed that only the effect of blade distance on percentage of breakage was significant whereas the effect of feed rate on all measured parameters was significant. In addition, the interaction effects of rotor type and blade distance, rotor type and feed rate on percentage of whole white rice and breakage were significant, respectively. The milling performance index showed that the best conditions for both rotors can be obtained at output rate of 412kg/hr and 11or 12mm blade distance from the agitator. For this adjustment, the average of percentage of breakage in the modified and conventional rotors were 20.5 and 23, respectively.
G. Mohammadi Nejad, A. M. Rezai,
Volume 11, Issue 1 (4-2007)
Abstract
This research was conducted at Rsearch Farm of Isfahan University of Technology to evaluate yield stability of 9 Oat (Avena sativa L.) genotypes and Makooi barley, to determine the contribution of each environmental factor to genotype × environment interaction, and to find the most stable yield component in these genotypes. Four Canadian cultivars and 5 Turkish breeding lines were included in this experiment. Three dates of planting (12 Oct. 31 Oct. and 21 Nov.) and three sowing rates (300, 375 and 450 seed m2) were used as 6 environments. In each environment a randomized complete blocks design with 3 replications was used. Grain yield, No. of panicle/m2, No. of seed/ panicle, and 1000-grain weight were measured. Result of combined analysis of variance showed highly significant (P < 0.01) difference among genotypes for all the studied traits. Significante differences were observed among environments for all the characteristics except for 1000-grain weight. Grain yield and its components showed highly significant genotype × environment interaction ffects. The ratio of genotype × environment interaction sum of square to total sum of square for grain yield (22.37%) was higher than other traits. Stability analysis based on regression coefficient showed that Boyer cultivar and Line No.28 with nearly b=1 and more than average yields were the most stable genotypes. Pacer cultivar and Makooi Barley had specific adaptations with suitable and unsuitable environments, respcctively. Based on deviation mean square, Boyer cultivar was the most stable one among high yielding genotypes. Tai’s path analysis of genotype × environment interaction showed that V3 genotypic component (Seed weight) was the most effective component of stability and yield. Boyer with the highest V3 score was the highest yielding and stable genotype. According to environmtntal component of path analysis, fertilization stage and grain filling period were the most sensitive growth stages to environmental conditions. Therefor, it is not effective to evaluate genotype stability according to V2 component (seed/panicle). Finally, according to the result of this experiment Boyer with grain yield of 5.8 t/ha and stable response in all environments was selected as a suitable cultivar for breeding programs or introduction for commertial production.
A. R. Valdiani, M. Tajbakhsh,
Volume 11, Issue 1 (4-2007)
Abstract
A total of 25 advanced rapeseed (Brassica napus L.) varieties were evaluated under cold weather conditions using Randomized Complete Block design (RCBD) with four replications in Dr. Nakhjavani Agricultural Research Station, 35 km North-East of Urmia the capital of West Azerbaijan province in 2000-2001. The results showed significant differences among the varieties (P ≥ 0.01) for all the phenological stages including days to germination, days to rosette completion, days to initiation of stem elongation, days to flowering initiation, pod formation stage and days to maturity. The spring varieties Sarigol (PF7045/91), Hyola 42 and SYN1 and autumnal varieties Alice, Eurol, Fornax, VDH 8003-98, Consul, Licord and Zarfam (Regent× Cobra), showed early maturity. On the other hand, Mohican, Olara, Colvert, L-1 and Akamar were late mature varieties. In fact, the most prolific varieties, DP.94.8, Zarfam (Regent ×Cobra) Cocktail, Consul and SLM046 (control variety) had the highest ability survive in the cold conditions and they completed their rosette stage sooner than the other varieties. There was positive and significant correlation between duration of pod formation stage and seed yield. Maturity date of varieties was positively and significantly correlated with harvest index, number of seed per pod, days to germination, days to rosette completion, days to stem elongation, days to flowering, and days to pod formation. Negative and significant correlations were found between days to maturity and duration of flowering and pod formation stages. It can be concluded that delay in initiation or completion of each growth stages could delay maturity of the rapeseed varieties.
M. Sabohi, Gh. Soltani, M. Zibaie,
Volume 11, Issue 1 (4-2007)
Abstract
The objective of this study was to evaluate the strategies for groundwater resources management, including competition groundwater pumping, optimal control in groundwater pumping, groundwater use and tax policy, water users' participation in groundwater pumping control, and cooperation among government and water user associations in Narimany plain located in Khorasan Province. Irrigation water demand of sugar beet growers was estimated for empirical assessment of the strategies. The results indicated that among the strategies, groundwater use and tax policy may lead growers to sustainable use of groundwater resources. Furthermore, the results showed a desirable strategy is affected by cultural, social, and economic characteristics of growers and general prevalent conditions of society. Moreover, each strategy calls for its obligations, for instance, it is necessary to have an efficient taxation system for the proposed strategy. Hence, by internalizing the external cost of groundwater overdraft (that is taxing water users) government can force them to consider the adverse effects of their decisions on other producers.
S. Mohammad Zamani, Sh. Ayoubi, F. Khormali,
Volume 11, Issue 40 (7-2007)
Abstract
Evaluating agricultural land management practices requires a thorough knowledge of soil spatial variability and understanding their relationships. This study was conducted at a traditionally operated wheat field in Sorkhankalateh district, located about 25 km northeast of Gorgan, in Golestan province, Iran. Soil samples of the 0-30 cm depth were collected right after planting at the end of autumn 2004 , 100 × 180m plot in a nested grid pattern (n=101). A 1 m2 plot of wheat was harvested at each of 101 sites previously sampled at the end of spring. Statistical results showed that frequency distribution of all data was normal. The highest and lowest CV was related to grain yield (20.40%) and pH (0.59%) respectively. Variogram analysis showed that all parameters had spatial structure and the range values showed considerable variability among the measured parameters. The ranges of spatial dependence showed a variation from 23.99m for total N up to 93.92m for K. Among the parameters, total N and ESP had stronger spatial dependence while P had the lower spatial dependence. Interpolated maps of Kriging demonstrated that crop and soil properties did not have a random pattern but had a spatial distribution. The spatial distribution of total N was similar to organic matter and also there was similarity between spatial distribution of harvest index and available P. The results demonstrated that, the spatial distribution and spatial dependence level of soil properties can be different even within similarly managed farms. Variography and Kriging can be useful tools for designing soil sampling strategies, characterizing management zones and variable application rates of inputs in the precision agriculture.
