Showing 1573 results for on
A. Alizadeh, A.g. Ghorbani, G.h. Haghnia,
Volume 4, Issue 4 (1-2001)
Abstract
In order to compare the effect of drip and furrow irrigation methods with different quantities of water (50%, 75%, and 100% of the amount of water evaporated from class A pan evaporation during irrigation intervals) on yield and quality of tomato, an experiment was conducted on a silty loam soil in Mashhad Agricultural Research Station. The experimental design was a factorial trial with completely randomized blocks and. four replications.
The results showed that the highest yield (51 t/ha) was obtained from the treatment of drip irrigation with 100% water application. This amount was 4.5 tons higher than the yield from furrow irrigation treatment. Deficit irrigation by 25 and 50 percent decreased total yield by 34.7% and 67.95% in the drip irrigation method and by 27.57% and 64.29% in the furrow irrigation, respectively. Water use efficiency in drip irrigation was two times higher than that in the furrow treatment. Quality and chemical composition of the fruits were not significantly different in the two irrigation methods. Increasing the water deficit, however, increased the amount of soluble solids of the fruits.
M. Arsalanbod,
Volume 4, Issue 4 (1-2001)
Abstract
Consumption of goods and services by households is an important index of their level of economic welfare. State of consumption distribution among households is an important index of equity in economic welfare. In this research, two important dimensions of consumption distribution have been studied: 1) Trend of changes of consumption distribution between Iranian rural and urban households 2) Changes of consumption distribution among households within rural and urban areas in different provinces. Secondary data were used in this research from rural and urban households surveys of expenditure and income for different years.
The results show that the ratio of urban household expenditures over rural household expenditures during 1965-96 has had a decreasing trend, though the gap is still high. To compare consumption expenditure distribution changes within rural and urban areas in different provinces, the data for the two years of 1986 and 1996 have been used. The results show that countrywide the Gini coefficients in 1986 and 1996 in rural areas were higher than those in urban areas in rural areas the coefficients were 0.458 and 0.421 and in urban areas 0.430 and 0.403, respectively, which indicate a decrease of 8.08 and 6.28 percent, respectively. Among the rural areas of 24 provinces, the Gini coefficients of 9 provinces increased and those of 15 provinces decreased from 1986 to 1996. This is while the comparison for the urban areas in the same provinces and for the same period indicates that the Gini coefficient of 6 provinces increased but that of 17 provinces decreased. No change occurred in the case of Tehran Province.
H.r. Rahmani, M. Kalbasi, S. Hajrasuliha,
Volume 4, Issue 4 (1-2001)
Abstract
Soil as the third major component of our environment is exposed to different kinds of pollution. Lead has been recognized as a factor in environmental pollution. Pollution of soil and plants along the highways and roads by Pb from automobile exhaust gases has extensively been reported as the most important pollutant source in the environment. This research was carried out to determine the degree of soil pollution along the following highways: Rasht-Anzaly (Anzaly area), Kelachay-Ramsar (Ramsar area), Tehran-Karaj (Karaj area) and Isfahan-Tehran (Delijan area). In each location a transect of 100 meters long, perpendicular to the highway axis, was selected for sampling. Soil samples at different depths were taken from different distances from the highway and analysed for some physical and chemical characteristics and total Ph content by 5M HNO3 extraction.
Results indicated that the total Pb content of soil decreased exponentially with distance from the roadside. Total Pb content of soil decreased sharply with depth in all highways except in one area indicating that Pb was retained in the surface soil and that its movement down to the deep soil was slow. Total Pb content of soils was highly and directly related to the traffic volume.
M.r. Salavati, A. Arzani, A.f. Mirlohi, A. Bankehsaz,
Volume 4, Issue 4 (1-2001)
Abstract
This study was conducted to evaluate the responses of Iranian commercial genotypes of maize (hybrids and their inbred lines) to callus induction and plant regeneration, using mature embryos. Twenty five genotypes comprising of 12 inbred lines, 11 single cross hybrids, 1 double cross hybrid and 1 composite cultivar were used. Mature embryos of the genotypes were plated on MS and N6 media. Callus induction rates were evaluated using relative growth rate of callus (RGR), callus fresh weight (CFW), callus dry weight (CDW) and callus growth rate (CGR).
The results indicated that genotypes highly varied in both callus induction and plant regeneration. IL8 inbred line, SC7 (IL4×IL8) and SC9 (IL6×IL10) hybrids had the highest callus production capacity (based on CFW and CDW), whereas the highest RGR and CGR were obtained for ILl inbred line and SC9 hybrid. The estimated heterosis based on superior parent showed the highest heterosis for CFW, CDW, RGR and CGR in SC9 hybrid. Genotype × medium interactions for CWD, RGR and CGR were significant. For instance, SC9 hybrid on MS medium and IL8 on N6 medium produced the highest CGR. There was a significant difference between the observation periods [8, 12, 16 and 20 days after planting (DAP)], so that CGR was the least at 8 DAP and increased gradually till 16 DAP, but declined afterward. CGR had a range of 0.51 in IL8 inbred line to 0.74 in SC9 hybrid. Comparisons of the genotype for plant regeneration percent indicated that ILl and IL10 inbred lines as well as SC2 and SC4 single cross hybrids had the highest regeneration rates. Considering plant regeneration as a critical and genotypic dependent factor, it can be concluded that ILl and IL10 inbred as well as SC4 (IL4×IL5, ‘single cross 301’), SC2 (IL2×IL3, ‘single cross 704’) and SC7 hybrids are recommended for use in tissue culture-based breeding programs in maize.
M.z. Nouri-Delawar, A. Arzani,
Volume 4, Issue 4 (1-2001)
Abstract
This study was conducted to evaluate the response of 18 rice (Oryza sativa L.) genotypes to callus induction and plant regeneration from immature embryo culture, using three media (MS, LS and N6). To evaluate callus induction rate, the following criteria were used: callus diameter, callus fresh weight and callus dry weight. Percentage of callus water content was also measured. After transferring the produced calli from the induction media to a regeneration medium (MSR), percentage of plant regeneration was evaluated.
A highly significant difference was observed among genotypes for both callus induction and plant regeneration (P<0.01). In callus induction phase, “Nemat” and “Cheram-2” cultivars were superior for callus diameter, having 4.83 and 4.6 mm callus diameter, respectively. “Nemat”, “Cheram-2”, “Sepidrood” and “Taroum” cultivars as well as “33IRCTN91” and “IRFAON-30” lines were significantly superior to other cultivars for callus fresh weight. Among the genotypes “Nemat”, “Zayandehrood”, “33IRCTN91” had the highest percentage of callus water contents. Based on plant regeneration, “33IRCTN91” line and “Anbarbo”, “Nemat”, “Cheram-2” and “Taroum” cultivars showed highest rate of plant regeneration from callus. Significant differences were observed among media. While MS and N6 media did not showed any significant differences for callus diameter, callus fresh weight and rate of plant regeneration, they were superior to LS medium (P<0.01). According to percentage of callus water content, MS and LS media ranked the best and the most inferior medium, respectively. In the present study, MS and N6 media were considered as suitable in vitro culture media of rice immature embryos. Among genotypes, “Nemat” and “Cheram-2” cultivars were ranked the best for both callus induction and plant regeneration. Also, the used Japonica rice cultivars were superior for percentage of plant regeneration. The calculated correlation coefficients between traits showed a non-significant correlation between callus induction and plant regeneration, which, in turn, indicated that these traits were independent.
F. Zarmehr, J. Pourreza, A.h. Samie,
Volume 4, Issue 4 (1-2001)
Abstract
This experiment was conducted to determine the requirements of vitamin supplement and available phosphorus in broiler chickens from 42 to 56 days of age. In a completely randomized design, with a 3×3×3 factorial arrangement, 270 one-day-old commercial broiler chicks were divided into 27 groups (replicates) with 9 treatments, 3 replicates and 10 chicks in each group. Each of the nine diets was given to each treatment from 42 days of age. Levels of vitamin supplement were 0.5, 0.25, 0% and available phosphorus levels were 0.27, 0.22, 0.16%. Diets were isocaloric and isoprotein. Group weight and feed consumption of each replicate were determined after 42 and 56 days of age and daily gain, daily feed consumption and feed conversion were calculated. Percent of carcass components and tibia ash were determined.
Results indicated that removal of vitamin supplement from 42 to 56 days of age did not have any significant effects on daily gain, daily feed consumption, feed conversion, live weight, viscera, abdominal fat, carcass weight, wings, neck and back bone. Also, reduction of available phosphorus did not have any significant effect on daily feed consumption, feed conversion, live weight, viscera, abdominal fat, carcass weight, breast meat, femurs, wings, neck and tibia ash. Interaction between vitamin and phosphorus were significant for daily gain, daily feed consumption, live weight, wings, neck and tibia ash (P<0.005) and were highly significant for breast meat, femurs, and back bone (P<0.00l).
E. Rowghani Haghighi Fard,
Volume 4, Issue 4 (1-2001)
Abstract
Whole corn plant was ensiled in 70 gr minisilos for 60 days to evaluate the effects of addition of two levels of Cellulomonas uda bacteria (0, 1.2×105 and 2.4×105 cfu per gr of fresh forage) on fermentation and chemical composition of silage. The experiment was arranged as a completely randomized design. The silos were opened after 3 and 6 days of fermentation. The criteria measured included dry matter (DM), pH, organic matter, water soluble carbohydrates, crude protein, cell wall (NDF), acid detergent fiber (ADF), hemicellulose, cellulose, and ammonia-N contents.
Both levels of bacteria significantly decreased the pH of silages after 3 days (P<0.05). The final pH of silage with the higher level of bacteria was significantly lower, indicative of a greater fermentation of cellulose in this silage. Addition of bacteria resulted in a non-significant increase in the level of final residual water soluble carbohydrates. Final silage ammonia-N concentration was less than 0.8% of dry matter in all silages and was not affected by bacterial treatment. The ADF content was decreased by 11.9% in the silage containing the lower level of bacteria and by 1.8% in the silage which contained the higher level of bacteria. The NDF content increased in the control silage and that with the lower level of bacteria but decreased by 3.6 gr Kg DM-1 in the silage with the higher bacterial level. Hemicellulose contents increased in all silages but cellulose contents decreased by 9.38% (control), 17.37% (low bacteria) and 12.49% (high bacteria) in the control and bacteria-treated silages, respectively. The results indicated that the addition of 12×105 cfu Cellulomonas uda per gr of whole fresh corn plant was effective in increasing residual water soluble carbohydrates, reducing NDF and hydrolyzing cellulose of whole corn plant.
L. Mosharraf Boroujeni, J. Keramat,
Volume 4, Issue 4 (1-2001)
Abstract
Recent restrictions on the use of artificial food colours have prompted extensive research on natural pigments as suitable substitutes. The red beet Beta vulgaris L. has been found as a suitable source of natural red pigment since beet powder and concentrates can conveniently be used in food products. In this research, hot and cold extractions of randomly selected red beets were used after preparation and blanching. The extracts were filtered and passed through a column of Amberlite XAD-7 resins after adjusting the pH to 2.5. The adsorbed colour compounds were extracted from the resins by eluting the column with acidified alcohol. The solvent was removed by vacuum rotary evaporator and solid colour was obtained, using a freeze dryer.
Physicochemical properties of the solid colour were determined by measuring ash and sugar contents of the solid colour. Also, its purity and stability were investigated under different conditions.
The amount of ash and sugar were negligible. The highest stability was observed at a pH value of 5 under cold and dark storage conditions. The purity of the solid colour was determined by scanning in the range of visible wavelengths and preparative TLC. The result showed that purity of the colour as a hundred percent betacyanins. The yield of production was calculated as 2.7 g powder per kilogram of beet. The colour was used in producing ice cream and frozen sherbets, which showed to be a suitable replacement for artificial colour carmoisine. Also the production cost of the colour was as low as less than 0.1 percent of that of ice cream or frozen sherbets.
S. Saboory Halestani, S.h. Dokhani, G.h. Kabir, R. Shokrani,
Volume 4, Issue 4 (1-2001)
Abstract
Four cultivars of olive, Kalamata, Marri, Zard and Fishmi were obtained from Roodbar town and treated with two methods, natural and controlled fermentation with Lactobacillus plantarum as a starter culture at 25°C for 100 days. HPLC analysis experiments were conducted during the whole study period. A higher level (1.08% w/w) of total acidity was produced in Fishmi cultivar especially in the natural fermentation (0.8-1.1 g lactic acid/ml) than in other cultivars. Individual organic acids were determined by HPLC. Quantitative changes of organic acids in olives showed (P<0.0l) an increasing pattern of lactic and acetic acids during fermentation, but decreasing levels of malic and citric acids were revealed. The highest level of lactic acid (1.1% w/v) was observed in Zard cultivar and the type of fermentation had no effect on acid production. Malic and citric acids gradually disappeared during 50 days of fermentation period and this change was faster for citric acid during controlled fermentation. Malic acid did not follow this pattern.
K. Zibai, B. Hatami,
Volume 4, Issue 4 (1-2001)
Abstract
The efficiency of singular and joint usage of third larval instars of ladybeetle, Hippodamia variegata (Goeze) and green lacewing, Chrysoperla carnea (Steph.) was studied against cotton aphid, Aphis gossypii Glover on cucumber plants in greenhouse.
The predator-prey ratio of 1:30 reduced the population of pest significantly. Singular and joint usage of predators, however, was not significantly different. The predator-prey ratio of 1:90 reduced the population of host significantly but the treatment with larvae of both predators and the treatment with only ladybeetle larvae were not significantly different. However, only the treatment with lacewing larvae was significantly different from the two above-mentioned treatments.
Y. Rezaenejad, M. Afyuni,
Volume 4, Issue 4 (1-2001)
Abstract
Due to high production of organic residues such as sewage sludge and compost, land application is probably the best way to prevent accumulated residues in the environment. However, the risk involved in the land application of organic residues should be evaluated prior to the assessment of their economic and fertilizer values. The objective of this study was to evaluate the effect of organic residues on soil chemical properties, yield and uptake of heavy metals and nutrients by corn (Zea mays L.). The study was a randomized complete block design with three replications with four treatments including cow manure, sewage sludge, municipal compost and inorganic fertilizer.
The organic amendments were applied to the plots at a rate of 50 t ha-1 and inorganic fertilizer treatment consisted of 250 kg ha-1 ammonium phosphate and 250 kg ha-1 urea.
Organic amendments significantly increased soil organic matter content, EDTA-extractable Fe, Zn, Cu and Pb and plant available P, K, and N. Uptake and concentration of nutrient in corn grain and shoots were significantly affected by treatments, whereas Cd and Pb concentrations were the same among the treatments. Cow manure and sewage sludge treatments had the highest and compost had the lowest corn silage and grain yields. Overall, the results indicated that cow manure and sewage sludge had a high fertilizer value and led to heavy metal concentrations in soil as well as corn tissues which were much lower than the reported standards.
T. Sohrabi, A. Hosseini, K.h. Talebi,
Volume 5, Issue 1 (4-2001)
Abstract
During recent years, worldwide concern has been focused on the potential for contamination of surface waters and ground waters by agrochemicals in runoff and soil water from irrigated fields. Given this perspective, it is very important to correctly evaluate the levels of different agrochemicals in water, both from human toxicological and environmental viewpoints and to develop management strategies for reducing agrochemical loads to acceptable levels in the environment. The main objective of this study was to assess the qualitative changes of tailwater due to the use of agrochemicals and thereby to determine contamination loads. Four farms (A, B, C and D) were chosen in the Foumanat region in the F2 unit in 1996. The areas of these fields ranged from 0.22 to 0.6 ha having a number of unequal successive basins with variable inflow and outflow rates.
A quantitative analysis showed that the tailwater ratio in farms A, B, C and D ranged from 2 to 64% during the irrigation season. The outflow water was classified as C3S1. The changes in qualitative factors were not significant and did not follow any certain pattern during the irrigation season. The changes in SAR, EC, Cu, Zn, B, P, K and DO in the inflow and outflow waters were also insignificant. After fertilizer application, the increase in nitrogen concentration in the outflow was significant. The average pollution loads in the inflow and outflow were about 1618 and 1476 kg/day/ha, respectively. The remaining load in the rice fields was about 142 kg/day/ha, which was meaningful at 1% level. The fifth farm (E) located in Lahidjan was sprayed with diazinon. Water samples were analyzed each day for diazinon residues for 10 days after application. Sample analysis showed that the concentration of the insecticide was 93.08 mg/l immediately after application and gradually reduced to 0.98 mg/l ten days after spraying.
K. Mohammadi,
Volume 5, Issue 1 (4-2001)
Abstract
In this paper, a numerical solution is presented for one-dimensional unsaturated flows in the subsurface. Water flow in the subsurface, however, is highly nonlinear and in most cases, exact analytical solutions are impossible. The method of reference-operators has been used to formulate a discrete model of the continuum physical system. Many of the standard finite difference methods and also the finite volume method are special cases of the method of reference-operators. Unlike elementary finite difference methods, the method of reference-operators may by used to construct finite difference schemes on grids of arbitrary structure. A one-dimensional model was developed to predict the soil-water suction (negative pressure head) and water content in a vertical column of a layered soil. The model was verified against some available analytical solutions and experimental results and, in all cases, it showed good agreement.
S.a. Khatoonabadi, A.m. Amini, A. Mirzaali,
Volume 5, Issue 1 (4-2001)
Abstract
Experience has shown that all centralized planning, policy-making and decision-making which presuppose exclusion of public participation have never been successful in achieving their objectives. The goal of this research is to determine the driving and preventive factors of herders’ participation in rehabilitation designs of Aghghala ranges in Gorgan Province. The research method was direct observation in which measurement techniques were used. A questionnaire was used to divide the sample society into two categories: the experts who design the range management system, and the local herders.
Results obtained from this investigation showed that according to the experts training, economic, planning and social parameters have the greatest effects on local herders’ participation while the herders maintained that planning, economic, training and social parameters have the greatest effect on decreasing their participation.
S. Ayoubi, A. Jalalian, J. Givi,
Volume 5, Issue 1 (4-2001)
Abstract
Qualitative land suitability evaluation is based on the physical parameters affecting the yield agricultural crops. The socio-economic factors are not considered in such evaluations. This study was carried out to assess the qualitative land suitability for irrigated wheat, barley, maize and rice in northern Baraan. Five soil series and 25 different phases were first delineated. Land utilization types commonly practiced in the region with intermediate input levels were considered. Physical requirements of the crops were determined and ranked using the available information. FAO framework and the proposed method of Sys were used for the evaluation. Qualitative evaluation was carried out according to both simple limitation and parametric methods by comparing land and climatic characteristics with crop requirements.
It was shown that in addition to climatic factors, soil salinity, drainage and some soil physical properties such as texture, gravel and lime are the most limiting factors. Land physical suitability for rice production was very low in most land units. The results from physical evaluation by parametric method were very close to those from the simple limitation approach.
A. Abtahi,
Volume 5, Issue 1 (4-2001)
Abstract
The effect of soil salinity on plant growth is due to two factors, namely, increase in osmotic pressure of soil solution and the ionic composition of salt. The present experiment was conducted to obtain information about the response of pistachio (Pistacia vera L.) to salinity and ionic composition of the salt. Salinity with different relative composition of sodium chloride and sodium sulfate were applied to two pistachio cultivars, Fandoghi and Badami. Yield (dry matter of leaf and shoots produced in each pot) of plants were compared by the analysis of variances method of F and Duncan tests.
The yields of the cultivars were significantly different (P≤0.01) with Fandoghi cultivar producing less shoots and leaf and, consequently, lower total dry matter. Increasing the salinity level decreased the plant growth. Leaves were more sensitive to salinity. Increasing the ratio of sulfate salt alleviated the depressive effect of salinity such that when salinity was 100% sodium sulfate, the dry matter yield of shoots was 1.5 times and that of leaf was 1.7 times higher compared to the treatment where salinity was 100% sodium chloride. Leaf was more sensitive than shoots and, therefore, it showed a more positive response to chloride decreasing.
J. Mohammadi, J. Givi,
Volume 5, Issue 1 (4-2001)
Abstract
This study aims to evaluate land suitability for irrigated wheat in Falavarjan region (Isfahan) using the theory of fuzzy sets. This method differs from the usual land evaluation procedures in its use of weight for different land characteristics and in its method of determining land suitability index. The results were compared with those from parametric land evaluation method. The correlation between land indices and observed yield was higher for the fuzzy set method (r=0.35) as compared to the parametric method (r=0.14). The higher relationship given by the fuzzy set method illustrates its potential usefulness and applicability to land evaluation.
A. Mirlohi, M.a. Hajabassi, S.j. Razavi, E. Ghanaati,
Volume 5, Issue 1 (4-2001)
Abstract
Soil loss due to erosion is a common problem in most parts of Iran. Reduced soil organic matter and lack of proper agricultural management have intensified the problem in recent years. Conservation tillage systems are becoming more widely used in corn production in other parts of the world because of soil losses due to wind and water erosion and energy inputs. Changes in tillage methods, however, create different environments for the germination, development and maturation of corn plants. Most corn hybrids have been selected and developed under conventional tillage systems but these hybrids mayor may not be well adapted to both systems. This study aims to evaluate the performance of five locally grown corn hybrids under zero and conventional tillage methods. The experiment was conducted for 2 years on a plot of land specified for this study. Experimental design was a split plot with randomized complete block arrangement and four replications.
Seedling and juvenile plant growth were not affected by tillage method and were similar for all hybrids. Plant dry matter was affected significantly by the cropping system and was lower in no-till method. Plant leaf area index and stem diameter reduced significantly in the no-till system. Reduction was greater in the second year of the experiment. Also grain yields were significantly different among years, tillage method and plant genotypes. Yield reduction was highest in the second year of the experiment under no-till cropping system. There was no interaction between tillage method and corn genotypes, indicating that, usually genotypes perform similarly with regard to grain yield under both tillage methods. The results suggest that corn production under no-till system in Isfahan is probably associated with yield reduction.
M. Shivazad, A. Seidavy,
Volume 5, Issue 1 (4-2001)
Abstract
An experiment was conducted in order to study the possibility of compensatory growth by changing dietary nutrients concentration in the female Arian broiler chicks using a completely randomized design by means of standard and diluted diets. By standard diet is meant diet recommended by Arian’s guide catalogue and by diluted diet is meant the diet used in Iran broiler farms. However, both diets contain the same nutrient/energy ratios. Chicks in the seven treatments received in their starter, grower and finisher stages standard and standard and standard, standard and diluted and diluted, diluted and standard and diluted, diluted and diluted and standard, diluted and standard and standard, diluted and diluted and diluted, standard and standard and diluted respectively. Furthermore each treatment contained three replicants and each replicant contained 30 chicks. This experiment was conducted in autumn using 630 female Arian broiler chicks for eight weeks.
It was concluded that weight gain of chicks receiving standard diets during all stages of their growing period was the same as the chicks receiving diluted diet during their starter period and standard diets during grower and finisher periods. Feed consumption and feed conversion ratio of these treatments were statistically lower than other treatment groups. Furthermore, production index and percentage of mortality was better than other treatment groups. Likewise, viscera% and abdominal fat% remained significantly constant in all treatment groups. But the cost of feed per unit of live body weight was lower in the treatment receiving diluted diets in all three stages of their growing period.
A. Foroozandeh, A.h. Samie, G.r. Ghorbani,
Volume 5, Issue 1 (4-2001)
Abstract
The objectives of this study include the determination of the growth potential of Naeini lambs when fed with diets varying in energy and protein concentrations and also an investigation of the influence of level of energy and/or protein intake on carcass characteristics and composition. Ninety Naeini weather lambs (initial live weight 29.89 ± 2.9 kg) were used in a 92-day feeding experiment. Animals were blocked to each of nine dietary treatments. Diets contained either 2, 2.25 or 2.5 Mcal ME/Kg DM and 11.7, 13.2 or 14.7% CP diets were fed in a 3 × 3 factorial arrangement in randomized complete blocks.
Lambs fed with high energy diets consumed significantly more feed (P<0.05) than lambs given the medium (ME) or low energy (LE) diets. The average final body weight and daily weight gain for lambs fed with HE, ME and LE diets were 41.4, 38.3, 34.5 Kg and 162, 124, 74 g/d, respectively, which were significantly different (P<0.05). Feed conversion ratio in HE group was significantly lower (8.3) than ME (10.4) or LE (14.3) groups. Energetic efficiencies and protein efficiencies were better for HE than for ME and LE diets. Increasing dietary energy significantly (P<0.05) improved energy and protein efficiencies of the diets. Dressing percentage, lean meat and eye muscle depth were significantly (P<0.05) improved with increasing levels of energy in the diet, but also increased dissectible fat. No significant changes were observed in bone percentage and body ash due to any changes in dietary energy. As the protein level of rations increased, feed conversion ratio and carcass meat percentage increased, but carcass protein percentage decreased.
