Agricultural Sciences and Technology
Year:2001 | Volume:15 | Issue:2|Papers Count:23

In order to examine salinity tolerance and efficiency of biological nitrogen fixation (BNF) of Sinorhizobium meliloti, isolates of the bacteria were sampled from several saline regions of Iran. Then isolates were subjected to salinity treatments of 0,1,2 and 3%, sodium chloride using a solution culture medium. After 5 days, the growth of the bacteria were measured and evaluated, and the bacteria were classified from sensitive to tolerant. In experiment 2 sensitive to tolerant bacteria, and alfalfa cultivars, Ranger and Gharayunjeh, were treated using Johnson nutrient solution (without nitrogen) in Leonard method with salinity treatment of 0, 0.1, 0.3 and 0.5% sodium chloride to evaluate the efficiency of BNF in the isolates. Results showed that nodule numbers in 0.1 % sodium chloride were higher than control. However, in higher concentrations of sodium chloride (>0.1 %) the number of nodules decreased with increasing the salinity. Also, root and shoot decreased with salinities higher than 0.1 %. The greatest nitrogen content of root and shoot were obtained with isolates 18 and 19 and the lowest ones were observed in isolates 18 and 22. Results showed that there is no good correlation between EC of the bacteria inhabitant and the salinity tolerance of the bacteria.

The amount of anthoncyanin content and methods of color recovery from saffron petals were investigated. Results indicated that total anthocyanin of saffron petal was 6.87mg/gr on dry basis which is considerable in comparison with other sources. The most effective system for extraction of color was achieved by using 0.1 N Hcl as solvent with extraction time of 2 min. This natural color can be used in some acidic foods and beverages (pH<4.5) as red color.

In four separate experiments, ecophysiological characteristics of a wide range of Iranian wheat cultivars were studied during 1377 and 1378 growing seasons. In the first trial, 12 bread wheat cultivars released during the last 44 years were studied under the same agronomic practices. In the second trial, 6 cultivars selected from the first trial were planted under the recommended agronomic practices for maximum attainable yield of each cultivar. In the third trial, the same 6 cultivars were grown with wild oat at the density of 80 plant/m2 and managed as mentioned for the second trial. The fourth trial was similar to the second one, but the planting density was set at optimum (recommended), 33%, and 66% higher than optimum. Result of the first two trials showed that there has been an increasing trend in yield of wheat cultivars associated with the year of their release. There was a positive and significant correlation between grain yield and harvest index (r=0.65 and 0.93 for the years 1377 and 1378, respectively). Competition ability of wheat cultivars has also been enhanced in the course of their release as it was evident by a higher yield, a lower weed biomass, and a greater competitiveness index (Cl) of the new compared to the old cultivars when infested by wild oat. Increasing plant density above the recommended level optimum led to a yield reduction in all cultivars, but this yield reduction was not significant. It was concluded that during the last 50 years, wheat cultivars have been improved for higher grain yield and better inter-specific competition ability. However, intra-specific competition ability of cultivars was not changed significantly.

The effect of intestinal micro flora on endogenous amino add excretion and amino acid digestibilities in feedstuffs, were studied by adult hy-line roosters (egg-type). In the first experiment, amino acid excretion values were determined by 16 intact and 16 cecectomized roosters and the resultant data were analyzed by a single variance analysis (t-test). The difference in amino acid excretion values (mg/bird/48 hr) between intact and cecectomized roosters for methionine and triptophane were 0.34 and 0.09 that were not significantly different, but all other reported amino acids were significantly different (P<0.01). In the second experiment, amino acid digestibility values in feedstuffs were determined by cecectomized roosters, because ceca had a significant effect on amino add excretion. Six roosters were assigned to each feedstuff and the obtained results were compared with others. It was found some differences in true amino acid digestibility values that may reflects the difference among feedstuff varieties and processing methods. The mean true digestibility values of 18 amino acid for corn, wheat soybean meal and sunflower meal were 89, 83, 81 and 82% respectively, that have a little difference with the results of others.

The quantification of protein in four mammals’s milk including cow, buffalo, sheep and goat using lowry method based on the measurement of the color intensity formed during reaction between phenolic amino acids and folin-phenol reagent by spectrophotometer at 750 nm, showed highest amount of protein in sheep and lowest in goat’s milk. The results of quantification of different fractions of caseins in above milk samples using Agarose Gel Electrophoresis (AGE) technique showed maximum amount of α-casein in cow’s milk with corresponding minimum β-casein fraction. The highest amount of β-casein was found in goat’s milk with corresponding minimum α-casein. No significant differences were observed in κ-casein fractions in four different kinds of milks.

The effects of inputs application on cotton risk was studied by a general stochastic production function. The results showed that chemical fertilizer and pesticides are risk-increasing and acreage (Land) is risk-decreasing. Therefore reduction in consumption of chemical fertilizer and pesticides due to lowering input subsidies or environmental considerations will not increase cotton risk.

In this study 3983 body weight records from 1068 ewes during 1989 to 1999 from the Station of Improvement of Bakhtiari sheep, breed were used to study of factors affecting the ewe body weight and optimum ewe size. Least-squares means (±s.e) of body weight of ewe at mating, lambing, weaning and shearing were 56.80(±0.12), 68.40(±0. 16), 56.66(±0.16) and 60.08(±0.14) kg; respectively. Effects of mating year and age of ewe on body weights were highly significant (P<0.01). Body weights increased with increasing age of ewe, reaching a maximum at 5 to 6 years and thereafter remained fairly constant. Estimation of genetic parameters of body weight at mating were: direct heritability 0.73(±0.02), maternal heritability 0.146(±0.02), total heritability 0.459 and genetic correlation between direct and maternal additive genetic effects -0.70. Ewes ranging in body weight at mating from 55 to 65 kg had the maximum productivity. However, it could be concluded that in order to increase productivity, body weights of ewe at mating should be improved to 60±5kg. In the first step we should improve environmental factors (e.g. management, nutrition,...) and then select within breed. It seems that selection within breed can make a major improvement in body weight at the time of mating but it is expected that genetic progress in body weight at the time of mating may impose some restriction on selection due to negative correlation between direct and maternal values.

The yield advantage and inter-specific completion were studied in corn-soybean mixtures. Species monocultures and all combinations of 3 corn densities (5.5, 7.5 and 9.5 plant/m2) and 3 soybean densities (23, 33 and 43 plant/m2) were plants in a complete randomized block design with factorial arrangement and 3 replicates. Topping treatment on corn was conducted at soft dough stage and data analysed as a split plot design where topping were allocated to main plots. Ignoring the soybean density, increase in corn density to 9.5 plant/m2 led to an increased corn grain yield in mixture. The highest grain and biological yield of soybean was obtained in mixture with medium corn and low soybean densities (7.5 and 23 plant/m2, respectively). Corn topping led to a increase in corn grain no. per row and 500 grain weight of soybean. However, the other yield components of species were not significantly affected by this treatment. Reciprocal yield models showed that in corn intra-specific competition and in soybean inter-specific competition were the main determinates of grain and biological yield. That is corn was the dominant species of mixture. When corn topping was conducted the effect of each corn plant on grain and biological yield of soybean was respectively, equivalent to 9.37 and 9.14 soybean plant. However, this equivalency in control treatment was increased to 11 and 13 soybean plant, respectively. That is, corn competitive ability decreased after topping. This result was confirmed according to completion indices. Land Equivalent Ratio (LER) of mixtures increased with increasing spices density in mixture. Corn topping was also led to an increase in LER so that the highest LER in topping and non-topping treatments were 1.215 and 1.078, respectively.

An experiment was conducted to evaluate the effects of different levels of N on forage yield and silage quality of three sorghum cultivars. The sorghum cultivars Viz: Speed feed, Jumbo, and Syahzan, a native strain, were cultivated in four levels of N fertilizer (0, 50, 75, and 100 Kg/ha). Their yield and quality were compared in a Completely randomized block design with split - polt layout and three replications. Seeds were hand sown in a density of 20 plant/m2 in late spring 1997. The CP, CF, Ash and pH content of the harvested plants were measured by the appropriate procedures. Laboratory silages were made from the harvested and chopped plants with DM content of 18.9 to 22.2 in a polyethylene 20 liters containers for 6 weeks in ambient temperature. Nitrogen application of 100 Kg/ha produced the highest forage dry matter as well as silage production in Syahzan cultivar. Jumbo cultivar significantly produced the highest forage and silage dry matter than the other cultivars (14 and 13.5 tons DM/ha), respectively. There was a significant difference (p<0.05) among cultivars for protein component, crude fiber percentage and ash content. The native strain (Syahzan) and Speed feed produced highest protein percentages and protein yield as well as the highest crude fiber, respectively. Ensilage caused an increase in protein, crud fiber and ash content for all cultivars.

Disposal of large quantities of animal waste is becoming a serious and costly environmental problem. Recently, research programs have been initiated in using earthworm to break down organic wastes. Vermicompost which is resulted from earthworm to break down organic wastes. Vermicompost which is resulted from earthworm activities on organic wastes is an important and valuable source of plant nutrients. The aim of present work was to determine the effects of vermicompost on the growth characteristics of tomato under greenhouse conditions. The effects of three levels of chemical fertilizer and five levels of vermicompost on root and shoot growth, fruit weight and the number of tomato were investigated. The results showed that chemical fertilizer and vermicompost had a significant effect of root and fruit weight and number of tomatoes. In 100% vermicompost treatment. fruit weight and fruit number, shoot and root weight were respectively three. four, five and nine times more than control treatment. The effect of vermicompost application was much higher on root than shoot growth, the results also showed that the enriched vermicompost with the highest level of fertilizer led to a greater root and shoot weight. The vermicompost by fertilizer interaction had no significant effect on fruit number. However, fruit weight as well as root and shoot growth were significantly affected such an interaction.

In this research for standardization of milk protein, five treatments (five milk with different dry matter ordinary milk use in cheese making as control treatment and control milk with 1 %, 2%, 3% skimmed milk powder and 10% water as four other treatments) were selected and it is noticeable that fat/solid-non-fat ratio was retained constant, the influence of different concentration of milk dry matter on Iranian white cheese yield and protein contents was investigated. Present treatment were analysed by using complete randomized block design with factorial test and for comparison the mean, the Duncan’s Multiple Range test (p=%1) was used. The results of this research showed that using the dry matter, indicated a significant increase in cheese yield and fat in dry matter content, whereas fat content of whey declined.

The objective of this study was developing a simple mechanistic model for bambara groundnut to predict crop performance at both potential and water limited conditions. An agrometerological model "BAMunt" driven by solar radiation, temperature, rainfall and atmospheric humidity was developed to simulate the growth and development of the bambara groundnut at a range of locations. When water is not limiting, BAMunt predicts light-limited growth as a result of intercepted radiation and conversion of radiation into dry matter. A separate module calculates the depth of the root front and the extractable water amount to predict water-limited growth. Our results show that the model predictions are reasonably close for both light and water limited production. In most cases, simulated pod yield was similar to observed yield which ranged from 2.6 to 28.4 gm-2. Similar results obtained in comparison between observed and simulated shoot weight with range of 78.8 to 535.8 gm-2. The reasonable agreement obtained showed that the model could be a good starting point to provide a generic model for a range of underutilized crops.

The purpose of this study was to examine economical and technic factors inf1uenceing in adoption of sprinkler irrigation technology among the farmers of Ham province. This study utilized a descriptive survey research methodology. The population for the study was census of all farmers who adopted and have the sprinkler irrigation systems on their farms (N =60). The questionnaire developed by the researchers. Content validity were established using a panel of experts comprised of three agricultural and extension education faculty members at the Tarbiat Moddaress University. Further, the questionnaire was validated by three agricultural officer of Ilam province. A reliability analysis conducted and Cronbach’s alpha were reported 0.83 percent. The results of the study showed that: There was a significant relationship between farmers" adoption of sprinkler irrigation technology and "personal characteristics (except age, education and land situation)"; and economic factors. There was no relationship between adoption and technical factors.

Agricultural extension & education has an important role in agricultural development. It is one of the vital part in each agricultural development project and program. The role of agricultural extension & education in the development of agricultural Moshia which is an special form of agricultural cooperative is also important. The main objective of this descriptive research is to identify the role and to analyse the current situation of agricultural extension & education in these Moshias which have been organized in Birjand area since 1359. From 48 Organized Moshia in this area, 37 Moshias which were active for three recent years, were selected. These Moshias have 567 members and 200 members or 35% were selected randomly for the study. In order to obtain the related information and data, two questioners were provided. One for each Moshia and another for every selected member. The results show that the average land ownership per-Moshia was 141.5 hectares and land per member was 9.15 hectares. The mean of the members age was 40.14 years, while illiteracy rate among them was 51 %. Seven different government organization and departments have offered educational programs for the member of the Moshias. The kinds and the contents of the programs have been different and the duration of the classes was from half of a day to 90 days. Group and mass methods of education was used and in the 16 Moshias there was a kind of farm-demonstration. Seventy percent of the members listened to the radio, but only 15% watched TV. According to the results about 70% of the educational programs have been useful and effective. In order to improve the traditional agricultural practices, which is still common in the Moshias, and a better use of scarce natural resources, the development of extension education programs is necessary and highly recommended.

In order to investigate the genetic of morphological traits in 121 genotypes of lime, red and pinto beans. and grouping of genotypes for use in plant breeding, and experiment was conducted as a simple lattice design at the Research Station of Agriculture College of Isfahan University of Technology, in 1997. High variability was observed among genotype for all the studied characters. The phenotypic coefficients of variability were greater than the genotypic ones. For all the traits. Cluster analysis on the basis of quantitative traits detected 7 groups and identified that genotypes of lima, red and pinto beans were not greatly differ so that they were distributed in all the groups. Analysis of variance revealed a highly significant differences between clusters for all the characters studied. Genotypes of group 7 had the highest yield and mid-maturity date. The genotypes of groups 1 and 6 because of having maximum dissimilarity, were distinguished suitable for crossing in order to make use of more variability. The first two canonical variables which justified 82.2 percent of the variation, demonstrated that day to maturity, main stem length, length of lateral branches and number of nodes in the main stem and lateral branches had a considerable contribution to the discrepancies among groups. Principal components analysis was performed for all of the genotypes and separately for lima, red, pinto, determinate and indeterminate genotypes showed that in all of them 4 components justified more than 78.4 percent of the total variation. But different traits contributed differently to each principal component.

Orchard plant production can be regarded as a productive sector in policy in agriculture. Limitation of resources necessitate optimal utilization of them in production processes based on a sustainable system. Risk avoidance of farmer has caused over utilization of the resources and therefore, unsustainability. Therefore a sustainable system based on proper use of these resources is needed. On this respect a survey was made in 1378 an 112 grape production farms in Khorasan province. Results showed that most of these farmers are risk avoider and there is a considerable gap between optimal and real utilization of resources. Social and economic factors associated with this unsustainability are discussed.

To evaluate the chickpea cold tolerance for fall planting in highland regions of Iran an experiment was conducted at the College of Agriculture Experimental Station, Ferdowsi University of Mashhad. 530 accessions of Mashhad Collection Chickpea (MCC) were planted during the fall of 1997-98 and 1998-1999 growing seasons. Seedlings were counted thirty days after emergence and also after winter. In 1997-98 and 1998-99, 42% and 61 % of accessions were found to be very cold tolerant (rate 1) and/or tolerant (rate 2). Cold severity and duration in 1997-98 were higher than those in 1998-99. In two years 64 accessions jointly were rated one and/or two, from which 30 accessions were selected on the basis of survival. From the selected accessions, nine accessions survived 100% in both years, 16 accessions have 100% survival in one year and more than 75% survived another year, and five accessions had more than 75% and less than 100% survival in both years. Amongst of 30 accessions numbers of 11 and 19 were desi and kabuli type, respectively. Most of the collected accessions were in seedling stage and had a semi-erect growth habit before the onset of cold in winter. The results indicated that there were some cold tolerance accessions in MCC and introduction of cold tolerance cultivars for fall planting seems possible.

An experiment was designed to examine the responses of the store lambs to different inclusion levels of urea treated whole crop wheat (UWCW) in grass silage (S) based rations, in particular their effects on feed intake, growth and carcass characteristics. A well preserved UWCW was mixed with grass silage to replace, 100, 75, 50, 25 and 0.0 percent of forage dry matter. All forages were fed ad libitum with 450g concentrate per day to lambs (30kg live weight) over 16 weeks. The highest and the lowest DMI were obtained in diets, 4 "W25" and 1"W100", respectively. The ME concentration in the diets increased with decreasing level of WCW. The lowest ME and CP intake were found in diet 1 "W100" and the highest MEI and CPI were observed in diets 4"W25", control "Sl00", and 2"W75". DLWG and FCR were improved in lambs Fed diets 4 and 1. The lambs which consumed diets 4 and 2 showed greater cold carcass weight, whereas the lowest killing out percentage was observed in lambs were fed on diets 1 and 5 however, the highest killing out % was recorded for diet 2. These results show that UWCW is not a suitable forage for feeding alone, WCW therefore, should be mixed with other forage for feeding to animals.

In order to study the effects of light intensity and quality on the rate of development and dry matter distribution of redroot pigweed (Amaranthus retorflexus L.), which is an important weed in the most parts of summer crop fields, and experiment was conducted at the University of Guelph, Canada. Controlled environment conditions were used for simulating different light treatment, that may occur in a natural crop-weed system. Different light treatments were three combinations of low and high PPED and RIFR levels. Some quantitative and morphological traits such as total dry matter, branch number, plant height, leaf area and allocated dry matter percent to each parts of plant were measured. Also reproductive development stages like as initiation of floral primordium, initiation of flowering and initiation of seed set were determined. The results showed that low PPED significantly decreased total dry matter, branch number, plant height, leaf area and rate of leaf appearance. Physiological indices such as LAR and SLA also were significantly increased by low PPFD. However, results were different under low PPFD and R/FR treatment. The initiation of floral primordium was delayed at low PPED with high R/FR in comparison to full sunlight treatment. This delay was partly compensated by Low PPFD and R/FR. Remarkable increment of plant height and allocation of more dry matter into the main stem under low PPFD and R/FR treatment indicates the role of spectral light quality in growth and development of red root pigweed and confirms it’s high adaptation ability under crop-weed interference.

Records of milk production and pedigree information of Mahdasht dairy herd from 1994 to 1998 were used to survey the factors that influence economic traits and evaluated environmental factors and genetic parameters. Respectively. The total milk yield, peak production, days in milk, days open and calving interval were 6782±1006(kg), 32±6(kg), 290±31 (day), 121±52 (day) and 390±46 (day), respectively. The total milk yield, days in milk and calving interval were affected by days open (P<0.05). The best days open was 80 to 110 days. The effects of year and month of calving were significant on days open (P<0.05). The Heritability of days open was 0.06±0.03. The additive genetic correlation of days open with total milk yield, peak production, day in milk and calving interval were 0.19, 0.1, 0.13 and 0.87 and phenotypic correlation were 0.08, 0.3, 0.1 and 0.66, respectively.