نشریه علوم آب و خاک (علوم و فنون کشاورزی و منابع طبیعی)
سال نهم شماره 1 (پیاپی 31، بهار 1384)

A research was conducted in Fars province Agricultural Research Center in Zarghan area from 1999 to 2002 to determine the water requirement and crop coefficient of wheat, applying lysimeter. The results indicated that the water requirements of wheat were 720, 712 and 674 mm in the years of 1999-2000, 2000-2001 and 2001-2002, respectively. Using Penman-Monteith method for estimating reference crop potential evapotranspiration, the crop coefficients for wheat at a four-stage crop growth were 0.37, 0.64, 1.10 and 0.51, respectively. Due to the inaccessibility of the whole weather data, we tried to figure out a solution to determine wheat water requirement to schedule irrigation planning for future. In this respect, we made use of a ten-day class A pan mean evaporation and crop coefficient.

A number of researches have indicated a gradual increase in mean temperature throughout the world. Yet, there are some reports on the reduction of annual mean temperature. In this research we investigated a long-term trend of annual mean temperature in 34 synoptic stations in Iran (2 stations in cold and humid climates 14 in humid and moderate climates, 11 in Steppe climate and 7 in desert climate - following Kopen climatic division) with a minimum statistical record of 30 years by applying the minimum square-error and Man-Kendall methods (Wald-Wolfowitz method had a different result). The results confirmed a positive trend in 59% stations, while 41 % of the stations were negative for the whole time-horizon of data. Considering the significance level, 3 zones of positive, negative, and no trends for annual mean temperature were detected in Iran. However, it was hard to define a specific spatial theme for such a division. By taking another approach, we proceeded with a shared statistical time period of 1968-1998 for all stations. In this case, 68% of the stations showed a positive trend, while the remaining 32% was negative. There were some shifts in direction from one trend to another in some of the stations in the study, yet no well-defined spatial structure was reported. In contrast, at 5% level of significance, 44, 15 and 41 percentages of the stations demonstrated positive, negative, and no trend for annual mean temperature, respectively. In general the behavior was different for different climates and no specific pattern was found. So, despite the fact that some stations did not show significant trends, one may hypothesize that more regions in future will experience higher temperature values and their positive trends would be a clue for future warming.

Changing agricultural experts' attitude toward sustainability principles and perceptions is essential to create sustainable agriculture. Various studies had shown that permanent changes are not easily accessible to maintain ecological values. Therefore preparing effective information channels and precautions leading to communication system firmness are important challenges ahead. The purpose of the present research was the evaluation of caricature effects on attitude change of Jihad Agriculture Organization experts concerning sustainable agriculture in Shiraz. A Quasi-experimental research method was devised for three groups consisting of two experimental and one control group. A Pre- and a Post-test were also administered. Eighty experts from Jihad Agriculture Organization were selected in a simple randomized sampling manner. Based on research theories, questions were devised and data were collected through a questionnaire. Its validity and reliability were determined by specialists and Cronbach's Alpha, respectively. The results indicated that workshops had changed experts' attitude toward sustainability principles and perceptions and workshops with caricature had the most influences on the change of attitudes. Thus the use of caricature is significant to establish sustainable agricultural principles and perceptions in experts at local level conditions.

Public (or governmental) extension services suffer from its limitations and inadequacies to fulfill the requirements for sustainable farming practices. This study examines the aspects of practicing agricultural extension Privatization in Isfahan. The statistical sample society of the survey was the extension practitioners and technicians. Data were gathered through field questioning techniques and interpreted by the analytical methods of statistics in Isfahan province. The result of the survey method on 105 agricultural extension agents and practitioners revealed that: 1) big farmers have more interest for private extension services than small farmers, 2) the more knowledgeable the farmers, the more demand for private advices 3) pest management, greenhouse production, mechanization and market information are given priority for private advisory services. Finally, "cooperative advisory service" was found to be the most relevant structure to motivate farmers' learning and consultancy activities.

This research was conducted to measure the total factor productivity (TFP) of the rural small industries in Isfahan province comprising six types of industries: food, textile, metal, non-metal mineral, chemical, and cellulose. Among the 166 rural small industries sponsored by Jihad-Agriculture Organization of Isfahan in 2001(1380), 60 plants were selected. Cross-section information collected from the 60 plants by a questionnaire in that year confirmed the body of data for this study. The distribution of the types of the 60 selected plants followed the distribution of the types in the plant population. The analytical part of this research consisted of two sections. In the first section, the TFP of the rural small industries was established by applying Cobb-Douglas production function in which the value of the plant production was the dependent variable and the investment costs, total hours of labor, costs of raw materials, and the costs of energy and water were the independent variables. Factors affecting TFP were analyzed in the second section. The estimated coefficients of the first section and the actual data of the variables, were used to calculate the TFP for each plant. Then, another regression model was worked out in which the calculated TFPs were the dependent variable. The independent variables included the mean of the number of the employees' children, the percentage of the production employees with at least primary school level of education, annual number of the off days, dummy variable for the members of the cooperative association, and a few other variables. The results of the first section showed that the TFP of food industries was higher than that of other types of industries and there was no significant difference between the TFP of textile, metal, non metal mineral, chemical and cellulose industries. The results of the analysis for determining the factors affecting the TFP, showed that the existence of a research section in the plant, the insurance of the employees and the mean of the number of employees' children had a positive effect on the TFP. But, the level of the education of the production workers, the area of the plant buildings, and the number of the days off in plant had negative effects.

This study was conducted to determine the problems of marketing channels of damask roses and to seek appropriate solutions to enhance marketing efficiency. The results of the study revealed that traditional and industrial rose production lacked the quality demanded by the market. The efficiency index was % 92.9 in traditional and %55 in industrial production. In addition, with regard to the marketing parameters for each type of production, the share of the factors was calculated. So we can conclude that the reducing units have the most important roles in this process. According to the study, traditional units with %47.2 had a greater share compared with the industrial units (%44.5). The results have also shown that production retailer wholesalers and middlemen shares were in the lower ranks respectively. Marketing cost coefficient results showed that %70 of the retailer selling price for 1 kg of the product was related to the marketing costs. The costs for industrial units with high and low capacity were %67.7 and %65.4, respectively.

Mango is one of the most important tropical fruits grown in southeast provinces of Iran (Sistan Baluchestan & Hormozgan). Due to the favorable coastal climate conditions in the region mango is extensively grown in these areas. This experiment was carried out at the tropical fruit research station of Bahokalate in Sistan Baluchestan province between 1997 and 1998, using 8-month-old seedlings raised from local mango trees. The experiment was conducted in a split plot at randomized complete block design, with 3 replications. Grafting was made at 6 fortnight intervals between April 4 and June 19, employing three methods including side grafting, softwood grafting and shield budding. Results showed that the highest percentage of grafting success (67.2%) was obtained with grafting in April 4, and side graftings and softwood graftings generally gave higher success rates after 90 days than shield budding (side graftings 65.8% , softwood grafting 63.7% and shield budding 47.5%). After 180 days, the percentage of the grown scions and the length of those grafted in April 4 were 55% and 57.9 cm, respectively. After this period, the percentage of the grown scions and the length of the scions in the side grafting method were 65.6% and 60.6 cm, respectively, indicating better results for this method over the other two.

In this research the effect of ethinyl estradiol on somatic embryogenesis of Medicago sativa was investigated. Seeds were grown in vitro on MS medium containing 2,4-D, Kin and NAA for callus induction. Plant regeneration media with 14 different combinations of auxin, cytokinin and ethinyl estradiol were provided. Three to four-week old celli and stem or hypocotyl segments of Medicago sativa were transferred to regeneration media. Results showed that ethinyl estradiol (l mg/L) induced shoot, root and somatic embryo on calli. When the stem and hypocotyl segments were cultured on medium M12, only shoots and roots were produced with no somatic embryo. Finally, it was observed that ethinyl stradiol and auxin together could induce somatic embryogenesis and plant regeneration, while these hormones had no effect separately.

An experiment was conducted at Rasht Rice Research Institute, in 2001 to study trait relationships and to determine the direct and indirect effects of different characteristics on grain yield of rice (Orgza sativa L.). A 9x2 factorial experiment in complete randomized block design with 3 replications was used. The two factors were 9 cultivars, namely: Hashemi, Ali Kazemi, Binam, Sepeedroud, Nemat, Khazar, Taichung, Chanto, and Usen, and 2 planting patterns (15x15 cm and 30x30 cm). Significant differences were detected among cultivars, between planting patterns, and their interaction effects. The direct effect of the number of panicles/m2 on grain yield was positive and significant in both planting patterns and their combined analysis. Heading date had a positive and significant direct effect on the number of panicles/m2 in both planting patterns and their combined analysis. Only in 30x30 cm planting pattern, a positive correlation was found between biomass at heading date and the number of panicles/m2. Grain weight per plant had a direct and positive effect on panicle weight in the 3 cases studied. Also, in all the cases studied, flag leaf area had positive direct effects on grain weight per plant. Grain filling rate and effective grain filling period increased in 30x30 cm planting pattern. Native cultivars demonstrated longer latent period. Grain filling rate and effective grain filling period showed positive direct effects on grain yield in both plantings. According to the results obtained, an increase in the number of panicles/m2, rate of grain filling, and effective grain filling period would enhance grain yield. Selection for heading date, grain yield per plant, and flag leaf area would also indirectly increase grain yield.

Of all types of xenobiotics, pesticides such as herbicides play a significant role in soil and water pollution due to their widely usage all over the world. This study addresses the ability of organic amendments to enhance atrazine and metamitron degradation in two herbicide contaminated soils with contrasting textures under laboratory conditions. Soil samples were collected from surface soils with textures of sandy loam and silty clay, from northeastern part of Iran. Initial concentration of herbicides was 50 mgkg-1 soil. Contaminated soil samples were treated by manure, compost and vermicompost at the rates of %0.5 and %2 (w/w). Residual concentrations of atrazine and metamitron were determined by HPLC at the end of incubation periods of 20,40 and 60 d. Residual concentrations of atrazine were 93, 77.8 and 72.4 % of the initial concentration after 20, 40 and 60d incubation, respectively. Residual metamitron concentrations were clearly lower than atrazine. After 20,40 and 60 d., the remaining concentrations of metamitron were 5.8, 2 and 1.2 %, respectively. Organic amendments at the rates of .5 and 2 % showed similar effects on the enhancement of herbicides degradation in soils. However, no significant effect was observed between types of organic amendments. Degradation was clearly affected by soil textures. Residual concentrations of herbicides were higher in sandy loam than in silty clay soil.

To determine yield stability and to evaluate genotype interaction with environment interaction, 18 genotype of barley (Hordeum vulgare L.) and a control group were evaluated in a randomized complete block design with 4 replications in 3 successive years (1997-2000) at 10 research stations. Simple and combined analysis of variance revealed significant genetic differences between yield genotypes for grain yield. The results of combined analysis of variance indicated that genotypic and genotype were significant through interaction with environment. Therefore, different stability parameters including, environmental variance (S2i), environmental coefficient of variation (C.Vi), mean of variance of interaction (θi), interaction variance (θi), equivalence ( W2i), stability variance (σ2i), linear regression coefficient (bi, βi), mean of squares of deviation from regression (S2 di) and years within location MS for a genotype, averaging over all locations (MSy/l) were determined. Based on all the stability parameters, genotype 18 was known as the most stable one and genotypes 17 and 11 ranked lower. Genotype 5 with the highest yield was known to be the most adaptable one at fertile environments and is recommended for these locations. In addition, genotype 9 with good yield and low yield variance (1.58) and regression coefficient of less than 1 is suggested for unfertile locations.

A diallel analysis of eight bread wheat (Ttriticum aestivum L.) cultivars was conducted to determine genetic parameters and the type of genetic control for yield and yield components. The parents and their F1 hybrids were evaluated in a randomized complete block design with 3 replications. General and specific combining ability effects were estimated by the method 2 of the Griffings model I, and the genetic parameters were estimated by the Jinks-Hayman method. According to the analysis of variance, the variances of parents and crosses were significant for all of the traits, except for the fertile tillers per plant in parents and harvest index in crosses. The variance of GCA was significant for almost all of the traits. GCA to SCA ratio indicated a large additive effects for all the traits, except for the number of fertile tillers, grain yield per plant and biological yield. Darab and Chamran cultivars were the excellent general combiners for days to heading. However, Falat for plant height, Arvand for number of fertile tillers, spike length and grain weight per spike, Qods and Arvand for spikeletes per spike, Falat and Arvand for grain yield per plant and Qods and Arvand cultivars for biological yield were the best general combiners. Based upon the Jinks-Hayman method, the average degree of dominance for grain weight per spike, 1000- grain weight, grain yield per plant and biological yield indicated that these traits might be controlled by over dominance effects and other traits by partial dominance. The correlation between Yr and (Wr + Vr) for the flag leaf length, spikeletes per spike, grains per spike and 1000-grain weight indicated that recessive allels enhanced these traits. But dominant allels had their contribution to enhance other traits. The narrow-sense heritability for grain yield per plant (4%) and biological yield (14%) and harvest index (37%) was lower. However, for other traits it was more than 50%. Therefore, it can be inferred that indirect selection of grain yield through selection for yield components such as spikeletes per spike, grains per spike and grain weight per spike with high heritability and correlation with grain yield can be more effective.

This study was conducted to analyze the correlation among grain yield, yield components, duration of vegetative and grain filling periods in twelve oat (Avena sativa L.) cultivars at the Research Farm of the College of Agriculture, Isfahan University of Technology, from 2001 to 2003. A randomized complete block design with three replications was used. The correlation coefficients among the grain yield/m2, fertile tiller/m2, grain number/panicle and the duration of grain filling period were positive and significant. Among yield components, the number of panicle/m2 and the number of grain/panicle had the largest direct effects on grain yield (0.68 and 0.30, respectively). Furthermore, the duration of the grain filling period had the highest direct effect on the number of grain/panicle and the grain weight (0.82 and 0.80, respectively), which were greater than its correlations with the number of grain per panicle (0.42) and 1000-grain weight (0.35). However, its negative indirect effects through other traits reduced the correlation coefficients. The results of path analysis indicated that the number of panicle/m2 and the number of grain/panicle had the largest direct effects on the grain yield. Considering the direct effects of grain filling duration on the number of grain/panicle and the 1000-grain weight, and also the fact that most of the dry matter in oat is produced in this period, it seems plausible to use these traits as a selection criterion in breeding programs for higher yields of cultivars of oat.

Potato (Solanum tuberosum L.) has relatively weak root system and requires high nitrogen fertilizer which is costly and may pose environmental pollution. This study was conducted to compare root morphological characteristics and nitrogen uptake of some potato cultivars growing in Iran. A greenhouse experiment using a completely randomized design with 3 replications and 8 potato cultivars including: Arinda, Agria, Premiere, Diamant, Concord, Marfona, Marodana and Nevita was conducted at Isfahan University of Technology, Isfahan. Virus-free seed tubers were planted and grown up to flowering stage. The plants were then harvested and their root length (RL), root average diameter (RAD) and root surface area (RSA) were determined using a Delta-T Scan image analysis system and Windias software. Root length density (RLD), root length and shoot weight ratio (R/S) were also calculated. Dry mater production and nitrogen accumulation (total nitrogen uptake) (PNA) were also determined. Soil inorganic nitrogen was measured before planting and after harvest. All measured parameters, except RAD, were significantly (p<0.05) affected by cultivar. Large differences observed between cultivars for all traits indicated genetic diversity among the studied potato cultivars. The highest and the lowest values of RL, RLD, RSA, R/S, RDW and PNA were found in Marfona and Nevita respectively. Based on cluster analysis, cultivars were divided into four different groups. Under the condition of this study, Marfona was superior whereas Arinda, Nevita, Marodana and Agria were inferior. Due to the high differences in root morphological characteristics and nitrogen uptake among potato cultivars, plant breeders may produce cultivars with larger root volumes and high nitrogen uptake.

Data from the birth weight (BW), the average daily gain from birth to weaning (ADG) and the weaning weight (WW) of 1182, 1099 and 1099 lambs were respectively collected and applied to estimate the maternal effects on heritabilities as well as on the determination of the environmental factors. The data were collected from Shahrbabak Sheep Breeding Research Station within five year, from 1993 to 1998. The effects of the year of birth, the age of the dam and its sex on all the traits were significant. The type of birth had no effect on BW but it was significant for the other two traits. Estimates of (co)variance components and genetic parameters were obtained by restricted maximum likelihood, using single and two-trait animal models. Based on the most appropriate fitted model, direct heritability of BW, ADG and WW were estimated at 0.10± 0.06, 0.21 ±0.08 and 0.22± 0.09, respectively. The maternal heritability for the three traits was also estimated at 0.27± 0.04, 0.15 ±0.05 and 0.19 ±0.05, respectively. Direct genetic and phenotypic correlations between BW and ADG BW and WW ADG and WW were estimated at 0.85 and 0.41 0.82 and 0.48 and 0.99 and 0.99, respectively. Ignoring maternal effects in animal model caused overestimation of direct heritability. Thus maternal effects are significant sources of variation for early growth traits and their ignorance in the animal model causes inaccurate genetic evaluation of the lambs.

Vegetable crops are exposed to repeated spraying against the pests and diseases during the growing sessions. Crops such as greenhouse cucumber are usually harvested a short time after spraying, bearing a high level of pesticides with them. This fact justifies a research on this problem. This research was carried out to determine the effects of metalaxyl (a fungicide commonly used in greenhouse) residue in cucumbers grown under traditional and modern greenhouse conditions. Cucumber plants were sprayed with two different doses: 1/1 000 and 2/1000 metalaxyl in modern and traditional greenhouses. Samples were collected 1, 2, 4, 7, 10, 14, 21 and 28 days after spraying with metalaxyl. The fungicide residue was extracted, cleaned up by TLC and the final solution was analyzed by HPLC. Data were analyzed statistically by t-test (paired observations) and Duncans multiple range test. The results revealed that the amount of metalaxyl residues increased in the first four days following spraying. This amount of the residue was 10 times higher than MRL (0.5 mg/kg), while a lower level of MRL (0.5 mg/kg) was detected 21 days after the application. Results also showed that a lower dose of application left a higher residual level than the higher one. On the other hand, no significant differences (p<0.05) were found between the amounts of residues in peeled and unpeeled cucumbers. Thus, fruit peeling does not reduce the fungicide residue in cucumber. Also, there were no significant differences (p<0.05) between the results obtained from modern and traditional greenhouses. Therefore, cucumber must either be harvested before or at least 14 days after spraying with metalaxyl.

The reaction of forty two barely landraces, mostly from Azarbijan Province and a susceptible cultivar, Zarjo, was studied under greenhouse conditions in the presence of four highly virulent isolates of Pyrenophora graminea, i.e. Marand 3, Ajabshir 2, Khasseban-Tireh, and Bostanabad. The experimental design was a split-plot based on randomized complete blocks with three replications. Landraces were considered as sub-plots and the isolates as whole plots. The seeds were inoculated by the sandwich method and responses of the landraces were evaluated by the method of Mathur and Bhatnagar. The resistance of landrace #1 to the isolates of Marand 3 and Ajabshir 2 and that of landrace # 27 to the isolate of Ajabshir 2 was observed. These landraces could be used as a source of vertical resistance in barley. Landraces 6, 8, 11, 12, 13, 15, 17, 25, 27, 28, 29, 31, 33, 34, 36, 37 and 41 were classified within the range of partial resistance to partial susceptibility, which may be utilized as the sources of horizontal resistance.

A 2-year vineyard survey failed to the provide evidence that Uncinula necator (Schw.) Burr. survived winter as mycelium in dormant infected buds in Khorassan province. Ascospores of U. necator, were collected by a volumetric spore trap operating constantly in a vineyard for 55 days after the bud burst. The first powdery mildew colonies were consistently found on the leaves of the shoots (7.30 cm long) growing on the vine. Cleistothecia were found on all plant parts infected during the previous growing season. More than 35-45 % of the cleistothecia borne on the leaves and stems died during winter. Most of the ascospore discharge occurred between the bud burst and the blooming time. Ascospores were periodically released from cleistothecia on the leaves kept in vineyard from October to May, while the ascospores germinating on the glass slides germinated from October to January and then germination slowed down to zero in early March and the water content potential of ascospore cytoplasm decreased constantly during this period as well. The mass required to fracture the ascocarp wall during maturation was measured to be approximately 5g in autumn, 3g in winter and 2.5 g in early spring. The most rapid decrease in the strength of the ascocarp wall occurred during a 4-week period before dehiscence in the field. The effect of the pathogenic property ascospores on healthy leaves demonstrated their role as a primary inoculum source. Cleistothecia appear to be the principal means of overwintering of U. necator in Khorassan province vineyards.

Plant parasitic nematodes of Dorylaimida occur only in the Longidoridae. Longidorus is one of important genera in this family, which it,s species are parasite on many plants and act as a vector for some of plant viruses. From 1999 to 2001, more than 250 soil samples were collected from several localities of Iran. Nematodes were extracted, fixed (De Grisse, 1969) and mounted on glass slides in dehydrated glycerine. Using a light microscope equipped with a drawing tube, morphological and anatomical characteristics of nematodes were studied, body parts were drawn, measurements were carried out and the species of nematodes were determined. Species were compared with the original descriptions and variations reported from other regions of the world. Differences and similarities of the species with main description and closely related species were discussed. Three species, Longidorus africanus, L. iranicus and L. pisi were identified the latter species is first record for Iran. L. africanus were mainly occurred in southern regions while L.iranicus were mostly found in northern areas.

The application of solar energy for drying cereals and other agricultural commodities has been increasing lately. This is due to the fact that solar energy is free, renewable, inexhaustible and environmentally friendly. This research is a new approach for employing solar energy as the main energy source for drying purposes. The drying test rig was designed, fabricated and evaluated. The grain solar dryer is an active mixed mode type with a semi-continuous discharge system. The rig consists of six solar air collectors, a heating channel, a drying chamber and an air distributing system. Rough rice was selected as cereal grain to be dried in the dryer to evaluate the system of the drying rig. In this research the effect of mass flow rate and time of crop discharge, on the rate of crop drying were evaluated. The experiment was conducted as a factorial experiment on the basis of a completely randomized design with three replications. The first factor was mass flow rate at three levels of 0.011, 0.0066 and 0.0048 kg/m2s and the second factor was the time of crop discharge at two levels of 15 and 30 min. The dryer capacity, the amount of energy consumed (electrical and solar) during drying process, and the efficiency of collectors were also evaluated. According to Duncan's multiples range test, the effects of mass flow rate of drying air, and the interval time of discharge, were highly significant on the moisture content of discharged rough rice. The maximum efficiency of the collectors was 37.13% and the fraction of energy consumed by heating channel during the drying process, compared with solar energy, was 6-8 percent. The maximum capacity of the dryer was about 132 kg of rough rice from 11 AM to 2 PM reducing the initial moisture content from 27% to 13%. On the whole, the evaluation results indicated that the dryer could reduce the moisture content of the crop to the storage safe moisture content during appropriate time with highenergy efficiency.