JWSS - Journal of Water and Soil Science

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In order to determine the effects of number of irrigations on stages of development, yield, and yield components of cumin, an experiment was conducted in 1993 - 94 growing season with a randomized complete block design and four replications. The location of the experiment was Isfahan University of Technology Research Station in Shervedan Field. The irrigation treatments were: I1- Irrigation after planting I2- Irrigation after planting and at the stage of full standing of plants I3- Irrigation after planting, full standing of plants, and anthesis and I4- Irrigation after planting, full standing of plants, anthesis, and beginning of grain filling stage. The stages of development (from emergence to anthesis) occurred simultaneously in all treatments. However, the water deficit in I1 and I2 caused the plants to reach their physiological maturity 5 days sooner than the other two treatments. The time intervals between anthesis and physiological maturity in I4 and I3 treatments were 12 days and 5 days longer than those in the other two treatments, respectively. The grain yield of I1 and I2 were approximately 60% of I3 and no significant difference was observed between the grain yields of I1 and I2 treatments, nor between I3 and I4 treatments. The grain yields in I3 and I4 treatments were about 1742 and 1800 Kg/ha, respectively. The number of umbels per plant, the most important grain yield component, was greater in I3 and I4 than the other two irrigation regimes, but the number of seeds per umbel and 1000-seed weight of I3 and I4 were lower than that in I1 and I2 treatments.

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This experiment was carried out to determine the relationship of plasma triglycerides and carcass dry matter with abdominal fat. One of the problems of broiler is carcass fatness, especially abdominal fat due to rapid growth of broilers which is not the consumer preference. Six hundred one-day-old commercial broiler chicks (Lohman) were divided into 40 groups, 15 chicks per group. Each one of the 10 experimental diets, in which barley was substituted for corn at levels of 0, 5, 10, 20 and 40%, was fed to 4 groups of chicks for 56 days. All diets were isoenergetic and isonitrogenous. Rice hulls was used to make diets isoenergetic. At days 42, 49 and 56, one male and one female were selected from each pen and after blood sampling, the birds were killed, eviscerated and percentages of carcass and amount of abdominal fats were measured. Blood samples were used to determine plasma triglycerides, cholesterol and total lipids. The results showed that increasing abdominal fat reduced carcass moisture content. Correlation between abdominal fat and plasma triglycerides was positive and significant (p<0.05). Correlation between abdominal fat and carcass moisture was negative and significant (P<0.01). The regression equations indicated that abdominal fat can be estimated from plasma triglycerides and carcass moisture content. The equations also indicated that using several parameters for estimating abdominal fat is better than single parameter estimation.

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Short-term changes (5 years) in canopy cover, species composition and forage production were studied under protection from grazing and grazed condition in 19 range sites in Fereydan region, Isfahan province. In this study, density, canopy cover and forage production data were obtained from quadrates inside and outside exclosures in the spring of 1983. These parameters were studied again in 1988 and compared with the previous data. Results indicated that species diversity in these range sites was relatively high up to 212 plant species were identified. Sixteen, 8.5 and 75.5 percent of these species were classified into I, II and III palatability classes respectively. After five years, comparison of inside and outside exclosures indicated an increase in the density of species of I, II and III palatability classes by 138.8, 120.8 and 51.5 percent inside exclosures, respectively. Density of all species had increased by 62 percent as a result of 5-year protection from grazing. Species composition data as canopy cover were used to construct 3 dendrograms to investigate the similarity among range Sites. Assuming 32% similarity as the threshold level, 19 range sites were classified into 10 vegetation types in 1983. After 5 years, these vegetation types decreased to 8 and increased to 11 under protection from grazing and grazed conditions, respectively. The average forage production inside exclosures was almost twice as much as in grazed sites (600 Vs. 315 kg/h). Three groups of range sites were recognized according to the time requirement for rehabilitation by grazing protection. The first group was improved considerably by the end of the 5-year protection Period. The second group improved relatively within five years of grazing exclusion. The third group did not improve by 5-year grazing protection and needed much longer protection period or some other range rehabilitation practices.

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Sorghum grain is an important cereal to be cultivated in tropical and sub-tropical areas. The extension of its cultivation and application in animal and poultry diets may reduce the need for imported corn. In order to determine the nutritive value of sorghum, 36 sorghum grain (SG) varieties and one type of corn were grown at the same location. The grains were analyzed for their nutrient composition. Results from of proximate analyses showed that the ash, crude protein (CP), phosphorous (P) and acid detergent fiber (ADF) contents of SG were 1.72±0.54, 11.6±1.18, 0.34±0.03 and 8.35±3.93, respectively. The ether extract (EE) of SG was lower than Iranian and imported corns. Iranian corn had higher amounts of CP (10.7%), EE (5.9%) and CF (3.3%) than the imported one (7.8, 4.2 and 2.25). Tannin contents of low and high SG varieties were 0.021% and 0.998%, respectively. The apparent and true metabolizable energies (AME and TME) of SG were decreased due to increasing the tannin contents. The values of TME_n (3853, 3771 and 3213 Kcal/kg) showed significant differences (p < 0.05) among low, medium and high tannin sorghum (LTS, MTS and HTS) varieties. However, in comparison with the SG, the corn had higher amounts of TME (3853, 3771 and 3213 VS. 3947 Kcal/kg). LTS had the highest AME (3453 Kcal/kg) among all the grains, while there were no significant differences (P > 0.05) between MTS (3458 Kcal/kg) and the two corn grains (3406 Kcal/kg).

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Seven Iranian and foreign cultivars of rice were crossed in a half-diallel. Parents with F2-generations were transplanted in a randomized complete blocks design with 3 replications and evaluated for length to breath ratio of paddy and brown rice, head rice and crust, grain yield, percent of head rice and broken rice, amylose content, gelatinization temperature and gel consistency. The ANOVA table showed significant differences among genotypes, general combining ability effects for all traits and specific combining ability effects for length to breath ratio of paddy and brown rice, percent of head rice and broken rice, so representing additive and non-additive effects in genetic control of the traits involved, respectively. The graphical analysis of the results showed partial dominance for length to breath ratio of paddy and brown rice, grain yield, amylose content, gelatinization temperature and gel consistency. Because of additive gene effects, genetic advance from selection would be high for these traits. The genetic control of brown rice weight is complete dominance, and for weight of head rice and rice crust weight over dominance involved. So, genetic advance by selection for these traits would be poor. In the genetic control of higher length to breath ratio of paddy and brown rice, brown and head rice weight, grain yield and amylose content recessive genes are involved. Domsiah for higher to breath ratio of paddy and brown rice and Sepidrud for brown and head rice weight had the most recessive genes. IR28 for higher grain yield and Sepidrud for less crust weight had the most recessive genes.

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In a completely randomized design, 600 commercial day old broiler chickens were used to study the possibility of replacing corn with barley. Each of 10 experimental diets in which corn was replaced with barley at levels of 0, 5, 10, 20 and 40 percent, with and without tallow, were given to 4 replicates of 15 chickens each. At 42, 49 and 56th days of age, one male and one female from each pen were killed. Body weight gain, feed intake and feed conversion ratio were not affected by different levels of barley at 42th day of age. Increasing the level of barley had not effect on body weight gain at 56th day of age. Feed conversion ratio improved slightly due to addition of 4% tallow to the diets containing different levels of barley. Abdominal fat was increased due to added tallow in males and females. Increasing slaughter age increased abdominal fat in both sexes. Difference in abdominal fat in females was more than males.

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The production and acreage of corn in Iran and in Fars Province, in particular, are expanding at an increasing rate. The impacts of this event was studied by a risk programming model (MOTAD). The results indicated that the optimal cropping patterns with corn had less variance than the optimal patterns without corn in all income levels. The results also showed that with the introduction of corn into cropping pattern, the use of land and water were increased, but the rate of increase in the use of land was more than the rate of increase in the use of water. By determining risk - aversion coefficient for the sample farmers, their sensitivity to corn price changes were studied. The results indicated that the relationship between corn and wheat is complementary but it is competing with barley, sugarbeet, cotton, cucurbits and legumes.

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Limited time for crop residue decomposition and complete seedbed preparation in double-cropping necessitates reduced tillage which is associated with its shortcomings. Information about seedbed preparation aspects in double-cropping of wheat and mungbean in Isfahan is lacking. For this reason, the effects of various seedbed preparation methods on growth, seed yield and yield components of mungbean (experimental line 1-61-16) were studied in a wheat-mungbean double-cropping system during 1996 at the Agricultural Research Station, Isfahan University of Technology. Two residue management treatments (burned and nonburned) along with four tillage systems: moldboard plow, disk, khischee and no-till were laid out in a strip plot design within a randomized complete block design with four replications. Improved establishment and plant growth conditions associated with burning residue treatment significantly increased plant density, above ground plant weight, number of nodes per branch, plant height, number of pods per main stem and per square meter, number of seeds per pod on main stem and on branches, number of seeds per main stem, seed yield, biological yield and harvest index. Higher plant density in this treatment resulted in significant reduction in the number of branches and number of pods per branch. Desirable conditions for establishment and growth in disk and moldboard plow treatments significantly increased plant density, above ground plant weight, number of pods per main stem and per square meter, number of seeds per pod on main stem and on branches, number of seeds per main stem, seed yield, biological yield and harvest index. No-till treatment produced the least results in respect to the above traits. The results indicated that burning residues with disk tillage system might be an appropriate seedbed preparation method under conditions similar to this experiment.

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This study was conducted to evaluate the capability of reversed-phase high performance liquid chromatography (RP-HPLC) of wheat (Triticum aestivum L.) storage proteins, and their genetic variability in different winter and spring isolines, cultivars and landraces. Gliadin proteins were extracted from the flour of five randomly selected seeds of each genotype. In this method, Nucleosil C18 300 A column (250×4.6 mm ID), equipped with a guard column and acetonitrile containing TFA as mobile phase was used.

All selected conditions for RP-HPLC such as suitable velocity and resolution were sufficient to achieve the objectives of this study. Under these conditions, the number of gliadin components by RP-HPLC analysis was more than electrophoresis subunits. In addition, quantitative results of RP-HPLC facilitated the data analysis. Also gliadin analysis by RP-HPLC had a high potential in detecting rye (Secale cereale L.) genes, so that the presence of ω-secalins in the genome of Falat variety was easily detected. Therefore, it was concluded that RP-HPLC analysis of gliadin proteins is as efficient as electrophoresis, and could even replace it in some cases. The result of cluster analysis for gliadin polypeptides indicated the gradual increase of genetic variation from isolines to landraces. Generally speaking, among the landraces, Ali Abad, Aghda, Sefid Bafghi, Ghermez Bafghi, Shahdas and Sorkheh had greater genetic variations.

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Designers of hydraulic structures are often faced with the problem of estimating flood frequencies at stream sites, where little or no flow information is available. A regional regression model is widely used which relates physical and climatological parameters to flow characteristics. In this study, a new method is used which is based on the station-year technique and combined records for several stream-flow gaging stations to make a single composite sample. This method, named ‘hybrid’, was proposed by Hjalmarson and Thomas (1992). It was applied to a group of records from 17 apparently homogeneous stream gaging stations to determine regional flood frequency equations. The study area consists of two adjacent basins, Gavkhoony and North Karoon in the central part of Iran. Using area and mean elevation of the catchments as the most important criteria in relation to peak discharge, the interactive process of the hybrid method was performed, resulting in two-parameter models of regional flood frequency. The performance of the hybrid method was evaluated by comparison with the regional relations determined from a multivariate regression. The comparison revealed that the accuracy of the hybrid method was significantly better than the regression method for low return periods.

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In order to study the genetic and environmental variability of morphological and phenological characteristics and also to gain a better understanding of the morphological basis of yield variation in soybean, an experiment was conducted at Research Farm, College of Agric., Isfahan University of Technology, in 1996. The experiment was arranged in three augmented designs with 285 lines and 5 control varieties. There were highly significant differences among genotypes for all the characteristics studied. The phenotypic coefficients of variability were greater than the genotypic ones for all the traits although the differences for most of them were small. The highest phenotypic and genotypic coefficients of variation, in order of magnitude, were obtained for number of pods per plant, days to flowering, plant height, height of the lowest pod, and number of lateral branches. Heritability estimates and the percent of genetic improvement for these traits and seed weight were high but for seed yield per plant were low. The lowest coefficients of variability were related to number of seeds per pod and days to germination. The results of stepwise regression analysis indicated that the maximum variation in seed yield could be attributed to the number of pods per plant, number of seeds per pod, and 100-seed weight. Factor analysis in addition to emphasizing the importance of yield components, resulted in four factors which determined 97.34% of yield variation. These factors which were indicators of physiological sink and source, with respect to the traits contained, were named as photosynthetic sink, plant architecture, fixed capital, and weight, respectively. In general, it was concluded that in order to improve soybean cultivars, selection should be in favor of plants with stronger structure, higher number of leaves, nods and pods per plant, and higher seed weights.

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Combining herbicides for controlling broadleaf weeds and grasses in wheat farms has not been studied under Isfahan environmental conditions. Thus, this experiment was conducted in 1995-96 at the Agricultural Research Station, Isfahan University of Technology, in order to investigate the issue. In this study, 2,4-D+MCPA (U46 Combi Fluid 6), bromoxynil, metribuzin, diclofop-methyl and tralkoxydim and their combinations in 11 treatments plus weed-free and weedy checks were evaluated using a randomized complete block design with 4 replications. Goldbachia laevigata and Avena fatua were the dominant weeds. Cirsium arvense and Convolvulus arvensis were of less importance. Efficacy of bromoxynil on annual broadleaf weeds was higher than 2,4-D+MCPA, while 2,4-D+MCPA was more effective on perennial broadleaf weeds. Diclofop-methyl and combination of bromoxynil with tralkoxydim were the most effective on A. fatua, while differences between treatments containing diclofop-methyl or tralkoxydim on decreasing A. fatua numbers were non-significant. The most and the least visual damages to wheat plants were caused by metribuzin and bromoxynil, respectively. Wheat yield was not significantly affected by treatments. However, the highest yield was obtained by tralkoxydim + bromoxynil treatment, which produced the lowest total dry weight of weeds at terminal spikelet and heading stages of wheat. The results obtained here indicate that combination of bromoxynil with tralkoxydim might be the best treatment for the control of all annual weeds under conditions similar to this experiment. But if perennial broadleaf weeds and wild oat are dominant in the field, combination of 2,4-D+MCPAwith diclofop-methyl might be preferred.

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In order to study the genetic variation among local varieties of onion in Iran, an experiment was conducted in the Research Center, Faculty of Agriculture, Tabriz University. Sixteen populations were evaluated for agronomic characteristics and also total seed proteins via SDS-PAGE. Cluster analysis and principal component analysis were used to group the onion populations under study.

 Analysis of variance showed significant differences among varieties for leaf color, leaf length, texture tightness, onion yield per plant, and number of edible layers. No significant differences were observed for the number of twin onions, bulb diameter, and onion dry weight. Hamadan (98-148), Arak (98-95, 98-96, 98-97, 98-103), and Zanjan (98-223) populations acquired the highest onion yield per plant. The significant differences between populations for the majority of characteristics proved the existence of genetic variation in the Iranian onion germplasm. The results from cluster analysis for agronomic characteristics were the same as those from the cluster analysis for the onion yield per plant. The 16 populations were divided into 4 groups. Cluster analysis for the electrophoresis banding pattern resulted in two groups, which was not similar to the dendrogram of agronomic traits. Using principal component analysis, the first principal components determined 97.57% of the total variation. Onion yield per plant was the most important trait in the first principal component and onion dry weight was the second trait in the rank.

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Soil structure maintenance and stability is an important index indicating sustainable soil management. In this regard, components such as soil moisture and organic matter affect soil compactibility during farm machinery trafficking. Soils in Central Iran are commonly very low in organic matter (OM) and thus susceptible to compaction. This study was conducted to measure the effects of soil moisture content and manure application on soil compactibility. A randomized complete block design with four blocks (replicates) with the treatments nested (split-block) into the blocks was used in the soil (Typic Haplargids), located in Isfahan University of Technology Research Farm (Lavark). One-year aged manure treatments 0, 50, and 100 t ha^-1 were incorporated into soil up to the tillage depth (20 cm) by a heavy disc. After five months (July-November), a two-wheel-drive tractor Universal Model U-650 was passed through the field at soil moisture contents of plastic limit (PL), 80% PL (0.8PL), and 60% PL (0.6L), either once (P1) or twice (P2). Bulk density (BD), cone index (CI), and soil sinkage (S) were measured as indices of soil compactibility and trafficability. Adding manure countered the effects of load and wetness on BD and CI, significantly. There was a significant difference between the effects of 50 and 100 t ha^-1 of manure on BD but not on CI. Manure application reduced soil sinkage at high moisture contents (PL) but increased it at low moisture contents (0.6PL). Adding manure also reduced the BD and CI of subsoil. Repeating the passage of tractor (P2) increased compaction significantly. The significant increase in BD and CI did no occur at 0.6PL. When no manure was applied even at 0.6PL, there were limitations for trafficability, whereas this limit for 50 t ha^-1 treatment was reached at 0.8PL. Results from this study indicate that the manure application at a rate of 50 t ha^-1 reduces soil compactibility and increases soil moisture trafficability range.

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This experiment was carried out to study the effect of ionophore drugs (Salinomycin, Lasalocid and their combination) on the performance of broiler chicks. Also their relationship with methionine (three levels) was evaluated. 1215 one-day-old commercial broiler chicks (Arian) were divided into 81 groups, 15 chicks per group, and tested in a completely randomized design with a 3×3×3 factorial experiment and three levels (0/0, recommended and 1.5 times recommended) of drugs and three levels (0.0, 1% and 0.2%) of supplemental methionine.

The results indicated that these drugs reduced body weight gain significantly (p<0.05) at 21 and 56 days of the experiment. Decreasing feed consumption and increasing feed conversion was significant (p<0.05) due to Lasalocid supplementation. Increasing drug level significantly (p<0.05) reduced body weight gain and feed intake and feed conversion was increased at 21 to 42 and 0 to 56 days of the experiment. The effect of supplemental methionine on body weight of 42 days (P<0.05) and feed conversion at 21 to 42 and 0 to 56 days (p<0.01) were significant. The interactions between drug type and drug level on body weight gain, feed consumption and feed conversion were significant (p<0.05). Lasalocid significantly (p<0.05) increased water intake. Drugs did not affect litter moisture and mortality. The results showed that Salinomycin was better than Lasalocid. Also supplemental methionine was not effective in compensating for the growth depression caused by ionophore drugs.

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In 1996 and 1997 pistachio orchards in Isfahan Province were surveyed to determine the presence and damage levels by Eurytoma plotnikovi Nikolskaya and Megastigmus pistacia Walker. In order to investigate seasonal population fluctuation of E. plotnikovi, larval, pupal and adult stages were monitored in three orchards. In each orchard, 200 nuts with more than 50% infestation to overwintering larvae were dissected and examined twice weekly. In 1997 in one orchard, at intervals of one week, 100 randomly selected fresh nuts were examined to determine oviposition trend and damage development. In this field, the biology of the pest was also compared to developmental stages of pistachio trees. In most orchards visited, E. plonikovi was present and was the dominant species in relation to M. pistacia and its damage varied between 0.8-75%. In 1997, start, peak, and end of pupal stage were observed on April 4th, May 7th and May 21st. Start, peak and end of adult emergence occurred on May 4th, May 18th and June 4th. In two other orchards, almost a similar trend was observed. Start, peak and end of oviposition were also observed on May 18th, May 28th and July 2nd. Development of pistachio tree was divided into nine stages and the above mentioned dates were compared to that.

E. plotnikovi had one generation every one or two years. Only one egg was found in each infested fruit and first stage larvae had a long prefeeding period. The use of the information obtained from this study in the management of these pests is discussed.

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Mutual understanding among officials and followers has been a point of concern in behavioral management. Natural resources extension which, from the very first step, is concerned with the exploration of practical problems is in serious need of an atmosphere of mutual understanding between agents and clientele. In this research, attention was drawn toward the measurement of mutual understanding between executives and nomads regarding nomads’ problems in utilizing natural resources and breeding cattle in Isfahan Province. For this purpose, initially, understanding between nomads and natural resources administrators (extension agents and specialists) regarding their respective problems were measured and compared. The research population of the study consisted of two groups. The first, involved 32 administrators, extension agents and specialists, and the second, 75 nomad families. Two different questionnaires were developed for the study as research instruments in which 52 items regarding nomad problems were included. Each part of the population was asked to rank the items accordingly. Then, some nonparametric tests such as Kruscall Wallis and Mann Whitny U tests were applied to compare the mean rank for each item within and between the two groups.

Results showed that the administrators and nomads had different attitudes in only two of the 52 items. Administrators had no statistically significant different attitude in 52 problems. Eliminating the discriminating items, the attitudes in only two groups were compared and results showed that they had no significant difference in the remaining 48 items. Therefore, extension agents can follow these problems based on their mean rank priority in their developmental projects. This method of data reduction and understanding field constraints can be applied to the studies dealing with planning agricultural and/or natural resources development projects through extension education.

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In order to find the critical period of weed control, the best time of weed control beginning (i.e. herbicide application time), and the length of weed control period (i.e. herbicide persistency) in corn, field experiments were conducted in Bajgah and Kooshkak in Fars Province in 1995 using a randomized complete block design with 14 treatments and four replications. Treatments consisted of different times of weed control beginnings (20, 30, 40, and 50 days after corn emergence), different duration of weed control periods (10, 20, and 30 days), a weedy check, and a weed-free check during the period of corn growth.

 In Kooshkak, a 10-day duration of weed control period had significantly lower corn yields than 20 and 30-day periods. In Bajgah, a 10-day weed control period had significantly lower corn yields than a 30-day period. Time of weed control beginning was not significant at both locations however, the interaction between beginning time and the duration period of weed control was significant. It appears in both locations that a minimum 20-day control period at the initial stages of corn and weed growth, and a minimum 30-day control period before corn pollination are necessary to prevent corn yield losses. In order to prevent corn leaf area decline at both locations, a 20-day weed control period until 40 days after crop emergence is necessary.

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Diallel crosses of six breeding inbred lines of corn (Zea mays L.) were used to estimate combining abilities, heterosis and some other genetic parameters for yield and some of its components. Parents, 15 F1 crosses and 4 filler genotypes, were evaluated in a 5×5 simple lattice design. For all the traits studied, except seed length, the efficiency of lattice design was less than one. Therefore, data were analysed as a randomized complete block and after eliminating the filler genotypes, Grriffing’s method 2 with mixed B model was used in the genetic analyses.

General and specific combining ability (GCA and SCA) mean squares were statistically significant for all traits studied. The ratios of GCA to SCA mean squares were greater than one for all traits, except for the number of seed rows per ear, indicating the importance of non-additive gene effects in their genetic control. Low heritability estimates and degrees of dominance lower than one were further evidence of the presence of non additive gene effects for all the traits studied, except for the number of seed rows per ear. Therefore, production of single cross hybrids in order to take advantage of non-additive gene effects is of prime importance for grain yield, number of seeds per ear row, l00-seed weight, seed length, ear length, and comb percentage. For genetic improvement of number of seed rows per ear, selection methods for parental lines will be more efficient. In the hybrids studied, number of seed per ear row and l00-seed weight played a more important role in the observed variations in yield. In general, hybrids 4×5 and 5×6 with high SCA for number of seed per ear row, l00-seed weight and grain yield were considered favorable for the conditions of this study.

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Obtaining high seed and oil yields of sunflower requires coincidence of vegetative and reproductive stages of growth of the plant with suitable environmental conditions via selecting appropriate planting date. Since the suitable date of planting for sunflower cultivars under Isfahan environmental conditions was not determined, this experiment was conducted in 1996 at the Agricultural Research Station, Isfahan University of Technology. In this study, five dates of planting (April 27, May 12 and 27 and June 12 and 29) and three open pollinated sunflower cultivars (Record, Vnimik 8931 and Armavirec) were evaluated using a randomized complete block design with split-plot layout in three replications. Date of planting was considered as the main plot and cultivars were randomized in the sub-plots.

Number of seeds per head (SH), l000-seed weight (SW), seed oil percent (SOP) and, consequently, yields of oil (OY) and seed (SY) were significantly reduced as planting was delayed. Reduction in these traits were considered to be related to the coincidence of vegetative and reproductive growth stages with higher temperatures prevailing at later plantings. Vnimik 8931 had higher SH and SW, and thus produced higher SY. This cultivar had lower SOP than Record, but produced higher OY than Record due to its higher SY. Armavirec was ranked the least for the measured traits, except for its SH that was slightly higher than that of Record. SH was the most contributing trait to the increase in SY, and SY was the most determining trait for the increase in OY. Date of planting by cultivar interactions for SH, SY and OY were significant. Nevertheless, the highest amount of the measured traits were obtained with Vnimik 8931 at the first planting date.