JOURNAL OF AGRICULTURAL SCIENCE AND SUSTAINABLE PRODUCTION
Year:2007 | Volume:17 | Issue:3|Papers Count:20

Abutment as a hydraulic structure is used in river training, river bank protection and agricultural land conservation. In spite of protecting river banks, abutment may face with scour phenomenon due to flow concentration particularly at the abutment nose. In order to investigate the effect of contraction ratio, some experiments were conducted using short wing-wall abutments. The experiments were carried out in a clear-water condition at three different V/Vc values namely 0.9, 0.95 and 0.98. The results showed that relative dimensions of scour hole, including upstream length, downstream length and width of hole, decreased about 7, 36 and 24 percents with increasing canal contraction, respectively. Maximum scour depth occurred at the contraction ratio of 0.16 and beyond this limit, there was a reduction of up to 21.5 percents at the maximum scour depth. Maximum scour depth was also 3.27 times of the abutment length. Therefore, it may be concluded that in order to avoid contraction effect in a model abutment, the L/W ratio should be less than 0.16, otherwise scour depth decreases in respect to maximum scour depth.

Last studies showed that income fluctuations of pistachio producers are high and unpredictable. Those studies indicated that systemic risk of pistachio yield is low and so insurance plans are useful for reducing pistachio yield variability. But, there is no study with regard to measuring factors influence on willingness to participate in pistachio insurance program in Iran. In this study, using a multi stage random sampling method and interviewing 300 Iranian pistachio producers, the factors influence on participation in pistachio insurance program was investigated. Legit model and analysis of variances were used in this way. The results showed that the factors such as farmer's education, the age of pistachio trees, quantity of consumed water and chemical fertilizer, farmer's debt, pistachio yield, high risk aversion and risk acceptance coefficients, having information about pistachio insurance pilot program, and off-farm works have a negative effect on participation in Pistachio fair insurance. In contrast, producer's age, low risk aversion, risk acceptance and risk neutrality have positive influences on demand for fair insurance. At the end, some recommendations, such as area yield crop insurarice, reforming farm credit system, elimination of premium subsidy, were made to increase pistachio producers' participation in insurance program.

In this research the possibility of application of rock phosphate along with Thiobacillus bacteria phosphate solubilizing microorganisms, organic matter and sulfur on corn was studied. This experiment was carried out as a randomized complete block design with 15 treatments and four replications in Karaj Soil and Water Research Station. The treatments consisted of : T1= Control(without phosphorous fertilizer); T2=Triple superphosphate (200 kg ha-1); T3 = Rock phosphate (RP) (400 kg ha-1); T4=Rock phosphate + elemental sulfur (S) (500 kg ha-1 ); Ts= T4= Thiobacillus inoculants (Thio) (1 kg ha-1 T6= T5+ Phosphate solubiling microorganisms (PSM) (l kg ha-I); T7=Ts+ organic matter (OM) (500 kg ha-1); Ts=T6+0M; T9=T4+OM; T10=T4+ PSM; T11= T10+OM;T12= T3+PSM; T13=T3+OM; TI4=T13+PSM and T15= OM. At the end of growing period plants were harvested and yield, yield components, soil available phosphorus and Zn, Fe, Cu, Mn and P uptake by corn were measured. Results indicated that there weren’t significant differences between treatments for wet forage yield. The highest yield (76858 kg ha-1) was obtained from T7. There were significant differences among treatments for ear weight and length, and the highest ear weight and length were obtained from T14 (416. 46 gr and 23 cm respectively). The highest and lowest concentration of phosphorous in the corn grain belonged to T7 (which was significantly different from the control) and T14. Respectively the highest concentration of Fe was obtained from T12 which was only significantly different from T2, T3 and T4. The highest amount of manganese and cupper concentration belonged to T15 and T2. The highest soil available phosphorous was obtained from T10 (9.7 mg. ka-1).

Oilseed rape with spring and fall types and wide adaptability to different climates such as temperate and cold regions, can be used to expand oilseeds cultivation in Iran. Among new oilseed rape genotypes wide variability have been reported in seed yield, yield components, oil percent and growth characters related to productivity. The genotypes including greater numbers of silique in plant, usually have higher seed yield. The aim of this study was to evaluate new oilseed rape genotypes based on some growth characters related to productivity, seed yield, yield components and oil percent. The study was based on randomized complete bolock design with 23 oilseed rape genotypes in four replications. The experiment was carried out in Agricultural Research and Natural Resources Center of East Azarbaijan (46°and 2" E, 37° and 58" N) during 2003-4. Results indicated significant differences among genotypes in rosette diameter (at the time of reaching mean air temperature below base temperature,5°C), silique numbers per plant, 1000 seeds weight, seed yield and oil per cent. Cluster analysis of genotypes based on studied traits, resulted in three groups. Modena, Dexter, Syn-4 genotypes had higher amounts of seed yield and oil percent, and were in clouded in the same group. Their seed yield was 5006, 5172 and 4776 Kg/ha and their oil percent were 48.5, 47.5 and 46.5, respectively. It seems that these genotypes can be used to extend oilseed rape cultivation in East Azarbaijan and similar areas.

Oilseed rape (Brassica napus L.) is the third largest oilseed crop in the world. The quality of oil derived from oilseed rape is determined by its fatty acid compositions. An undesirable characteristic of oilseed rape is a relatively high level of linolenicacid (C18:3), which is easily oxidized leading to rancidity and a shortened shelf life of the oil. Previous attempts to reduce the linolenic acid levels in oilseed rape oil through breeding have been impaired by complex genetics and strong environmental sensitivity of this trait. Bulked sergeant analysis was employed to identify RAPD and ISSR markers associated with linolenic acid in a doubled haploid population segregating for linolenic acid content. Based on analysis of individuals DH lines, five markers, which had associated with linolenic acid, were identified. Markers UBC153550, UBC528660 and UBC5381650 accounted for 19, 18 and 14% of the genetic variability of linolenic acid, respectively. Marker UBC5381650 was then converted to a SCAR marker for easy selection. Markers UBC153550, UBC528660 and UBC5381650 and SCAR marker identified in this study suggested as the useful markers for detecting of low linolenic acid genotypes in oilseed rape programs.

Heritabilities, genetic effects and influence of line x year interaction were studied on important fatty acid compositions with doubled haploid lines derived from T099-5318-20x DH12075 in 2002 and 2003 growing seasons. Results showed that effects of line and line x year interaction were significant for all fatty acids. Genetic correlation coefficients were mostly significant among different fatty acid compositions. A negative correlation was observed between palmitic acid and stearic acid as well as palmitic acid and oleic acid. Palmitic acid covrelated positively and significantly with linoleic acid while its correlation with linoleic was not significant. Results of heritability for different fatty acid components showed that heritability was intermediate for all fatty acids and ranged from 0.44 for satiric acid to 0.48 for oleic and linoleic acid.

In order to investigate the quantitative characters of mungbean (Vigna radiata (L.) Wilczk) cultivars, a field experiment was carried out on 1999 in the Research Field of Department of Agronomy and Plant Breeding, College of Agriculture, University of Shahid Chamran, Ahvaz. The experiment was conducted in a randomized complete block design (RCBD) in factorial arrangement with four replications. Plant spacing at four levels 15, 20, 25 & 30 cm within row (densities of 133333, 100000, 80000 & 66666 plants/ha, respectively) and three varieties Partow, VC-1973A and 1-62-32were used. During the growing season , plant height was measured six times from each plot, Also in the physiological maturity stage, grain yield and first pod height were measured. The results showed that among cultivars, 1-62-32have the highest grain yield (1723.33 kg. ha-1), plant height and first pod height (the most suitable for mechanical harvest) while Partow have the lowest grain yield (1438.64kg. ha-1).The highest (1713.44kg. ha-1) and lowest (1378.58kg/ha) grain yield observed in plant spaces of 20 and 30 cm within row, respectively. From 65 days after planting till maturity stage, 1-62-32 had the highest and VC-1973A the lowest plant height. The highest and lowest plant height observed in plant spaces of 15 and 30 cm within row, respectively. With the increase of plant density, relative growth rate, crop growth rate, plant height and first pod height was increased.

In order to determine the superior tomato local populations cultivated in West Azarbaijan, an experiment was conducted using randomized complete block design with four replication sat Kahriz Station during 2004.Thirty local populations of tomato selected from 140 local populations of West Azarbaijan along with three check verities, namely Koral, Petoearly-CH and Fauna were evaluated. During the growth season eight descriptive characters including sun scald, blossom end rot, fruit cracking, leaf density on stem, plant size, fruit firm texture, fruit size uniformity, fruit shape and 19 quantitative characters including days to flowering, days to first harvest, days to 50% fruit ripping, number of florescence on main stem, number of flower in the florescence, fruit set, length of main stem, number of lateral branch, number of fruit per plant, fruit length, fruit width, number of seed in fruit, fruit soluble content, fruit pH, vacuole umber per fruit, fruit per carp thickness, yield per plot and fruit weight per plot were recorded. Results of analysis of variance indicated significant differences among genotypes for all of the studied character sat 1% level of probability. Yield per plot showed positive and significant correlation with days to fruit ripening, fruit weight and fruit pH, whereas its correlation with number of fruit per plant and fruit soluble content was negative and significant In most of the genotypes, fruit peri carp thickness was relatively high. Fruit weight in the genotypes ranged from 175.4 g in landraces number 1647 to 38.85 g in landrace number 1717. Fauna check variety with 88.78 tha-1 and local populations of 1650and 1748 with 87.24 and 86.14 tha-1, respectively, showed the highest fruit yield. Whereas the minimum fruit yield was observed in the population number of 1717 with 59.66t.ha-1.

A split plot experiment (using RCB design) with three replications was conducted in 2004 at the Research Station of the Faculty of Agriculture, University of Tabriz, Tabriz, Iran, to determine the best developmental stage of three pinto bean cultivars (COS16, Khomain and Talash,) at which maximum seed vigor is attained under different irrigation regimes (11, 12 and 13-irrigation after 60, 80 and 100 mm evaporation from class A pan, respectively). Analysis of variance of the data indicated that maximum seed weight, seed germinationrate and minimum electrical conductivity of seeds were not significantly different among seeds produced under different irrigation conditions. However, these traits were significantly affected by the genotypes. Maximum seed weight of Khomain was significantly higher than Talash and COS16, while maximum seed germination rate of this genotype was lower than that of other two genotypes. Minimum electrical conductivity was lower for seeds of Khomain, compared to seeds of Talash and COS16. However, this difference between seeds of Khomain and COS16 was not significant. Changes in seed vigor during development and maturity showed that mass maturity and maximum seed vigor under h occurred earlier, compared to other two irrigation regimes. Mass maturity (end of grain filling period) under 11 and 12 conditions achieved at about 1270 growing degree-days (GDD) after sowing for Talash and 1210 GDD after sowing for COS16 and Khomain. Mass maturity of all genotypes under 13 occurred at about 1160 GDD after sowing. Under all irrigation regimes, seed vigor increased, with increasing seed weight. However, at later harvests, seed vigor slightly decreased, due to seed deterioration. Maximum seed vigor as measured by germination rate and electrical conductivity of seed leachates, was attained at about mass maturity and 60 - 180 GDD after that, respectively.In general, it was concluded that high vigor seeds of pinto beans could be produced at about or sometimes after mass maturity, when seed moisture contents about 16-25%.

In order to determinate morphological and physiological traits associated with yield improvement in rapeseed, two field experiments were conducted with 16 cultivars during 2004-2005 and 2005-2006 in Fars province (Arsanjan). Experimental design was randomized complete block with 16 treatments and four replications. The results indicated that Talayeh and Hayolla308 in both years had the highest and the lowest grain yield, respectively. Harvest index, number of pods per plant, plant height, leaf photosynthesis rate in flowering stage and stomatal conductivity in flowering and pod formation stages, were significantly correlated with grain yield. The length of sowing to flowering period also had significant correlation with grain yield. In summary the results showed that increasing harvest index, number of pods per plant, photosynthesis and stomatal conductivity during flowering and reducing plant height had positive role in increasing rapeseed yield and can be used in breeding programs for increasing the grain yield.

An investigation was undertaken to provide linear and non linear models with and without intercept to estimate fat-tail and abdominal fat weight based on blood fat components and to predict the fattening capability derived from body weight and external body measures using 57 Lori ram lambs aging 60-75days. Trunk length (X1), body height (at shoulders:X2), Breast height (X3), rump width (X4), fat-tail circumference (X5), heart girdle (X6), muzzle dimensions (at 3 cm above nasal openings: width (X7), height (X8), circumference (X9), scrotal diameters (X10), scrotal circumference (X11) and live body weight (X12) were recorded at commencements well as at the close of fattening trial (70 days). All lambs were slaughtered to gather the data on cholesterol, triglycerides, HDL, LDL level in blood along with fat-tail and abdominal fat weight at 70th days. The most precise estimation for fat-tail weight was achieved by a linear and without intercept, model consisting of (X19), (X13), (X14), (X15), (X16) and (X17) variants with R2=0.973. To estimate the abdominal fat weight a nonlinear, and without intercept, model including (log X13),(X193)and (log X13) found to be the best (R2=0.969). Accuracy of a model containing (X39), (logX12), (X6) and (X113) was maximum for prediction of live body weight at the close of fattening period (R2=0.996). Finally, a nonlinear model without intercept consisted of (log X5), (X39), (X30.5) and (X123) was of the highest reliability to predict the feed conversion ratio (R2=0.97).

Bacterial disease of fire blight caused by Erwinia amyovora, as one of the important and serious diseases of poem fruits, has caused economic losses to such trees in some regions of Iran in recent years and still is spreading in the country orchards. In an experiment, with two chemical and biological methods, the disease control was evaluated under field condition in East Azarbaijan province. For chemical control, Bordeaux mixture and in biological control, bacterium Erwinia herbicola (Pantoea agllomerans) were used. In case of fire blight severity on pear trees, there were significant differences between treatments. Treatment of four stages of oil sprays had the highest disease severity (75.375%) and treatment of four stages Bordeaux mixture with oil sprays had the least disease severity (1.875%) on pear trees. Disease severity for biological control was 20.625%. Fire blight bacterium population size was significantly different among treatments. Oil sprayers at four stages together with sprayer had the highest population size of pathogen and oil sprayers at four stages along with Bordeaux mixture had the least population.

In order to identify the biodiversity of plant parasitic nematodes in some area of Tabriz (under cultivation of vegetables and turt), a total of 104 soil and root samples were collected during 2004- 2005. Plant parasitic nematodes were extracted and processed to be transferred to glycerin. Microscopic slides were prepared and nematode species identified based on their morphological and morphometrical characters in comparison with those given in literature. Among the identified species, eight species belonging to four different genera in cricocenemids were recognized. The identified species were, Criconema mutabile (Taylor, 1936) Raski & Luc, 1985 (Teragon and turfgrass rhizosphere), Criconemoides informis (Micoletzky, 1922) Taylor, 1936 (Kohlrabi and turfgrass rhizosphere), Criconemoides mongolensis Andrassy, 1964 (Teragon rhizosphere), Mesocriconema antipolitanum (de Guiran, 1963) Loof & De Grisse, 1989 (Beet, Penny-royal, Tomato, Fenugreek and turfgrass rhizosphere), Mesocriconemacurvatum (Raski, 1952) Loof & De Grisse, 1989 (Dill, teragon and turfgrass rhizosphere), Mesocriconema xenoplax (Raski, 1952) Loof, 1989 (Turfgrasrhizosphere) Paratylenchussimitis Khan, Prassad & Mathur, 1967(Turfgrass rhizosphere) and Paratylenchus mexicanus Raski, 1975 (Teragon, and Lettuce rhizosphere ). The latter species is new record for nematode fauna of Iran. Grouping of the species based on morph metric characters with another recorded populations from Iran as well as foreign population, was carriedout by claster analysis.

In order to collect and identify the astigmatic soil mite fauna of fields and orchards in Khalatpoushan Research Center, Faculty of Agriculture, University of Tabriz, Iran, a faunistic study was carried out during the year 2006. In this study, a total of two families, six genera and nine species were collected and identified. Between two families, Acaridae and Glycyphagidae had the highest and lowest numbers, respectively. However, genera Tyrophagus oudemans and Blomia oudemans had the highest and lowest numbers in total collected speciemens, respectively. Also, among identified species, Tyrophagus putrescentiae Schrank, 1687, and Blomia freemani Hughes, 1948,had the highest and lowest numbers,respectively. Those genera and species which have been indicated with * are the first records for East Azarbaijanprovince. Collected families, genera and species are as follows:Glycyphagidae: Blomia*freemani* Hughes , 1948, Acaridae: Suidasia nesbiti* Hughes, 1948, Caloglyphus rhizoglyphoides (Zachvatchin, 1937), Tyrophagusneiswanderi Johnston and Bruce, 1965, T putrescentiae Schrank, 1781, T longior Gervais 1844, T similis Volgin, 1999, Rhizoglyphus robini Clapared, 1869, Tyroborus lini Oudemans, 1924.

Trichogramma brassicae Bez. is one of the most important species of Trichogrammain Iran. Fundamental ecological studies on local populations of this species are needed for a successful biological control of hosts. In this study, some biological parameters of the parasitoid were compared on two host species, Anagasta kuehniella and Plodia interpunctella for two generations.All the experiments were carried out at 24±1°C, 65±10% RH, and 16L: 8D. Pre-adult developmental time of females was similar on two hosts, as it was estimated as 9.66 and 9.60 days on A.kuehniella and P.interpunctella, respectively. In the case of males it was slightly longer than females as it was 11.29±0.19 and 10.15±0.16 days at the same hosts. Differences between generations were also negligible both in males and females. Longevity of adult female was 15.32±1.08 days on Anagasta that was significantly longer than Plodia with a mean of 9.17±1.02 days. It was also longer in 2nd generation, as it was measured 10.82±1.07 and 14.39±1.17 days in two successive generations. This period in males, was very shorter than females and was estimated 3.95±0.29, and 5.03±0.24 days on Anagasta and Plodia, respectively. Differences between males in two hosts were significant. Total eggs laid at lifetime by a female were significantly more on Anagasta with an average of 79.17±5.55 than Plodia by a mean of 46.15±4.32. Rate of adult emergence was more in Plodia eggs (0.82±0.02 at average) than Anagasta (0.77±0.01 at average).Sex ratio (percent of females) in Anagasta with an average of 0.61±0.02 was more than Plodia with a mean of 0.52±0.02 and declined with senescence of mothers. These results revealed that Anagasta has been a more desirable host than Plodia for Tbrassicae.

Onion is one of the major field crops in East Azarbaijan province. Application of various insecticides has led to a disturbance in natural balance of insect fauna of onion fields and it has provided a condition for out breaking potential pests, such as onion psylla (Bactericera tremblayi). This study during 2005- 2006 indicated that the pest overwinters as adults on the host plants or under debris within or at edge of the fields and begin their activity on the mid March. The hibernated insects feed on new emerged leaves of the seed plants and lay their eggs on them and make their first generation. The adults obtained from the first generation migrate to the new cultivated fields and then lay their eggs on new emerging leaves in a row. These leaves deform and curve on the same directions the egg masses. The eggs hatch in 6.4±0.6 days and the nymphs pass through five instars. The developmental time of nymphs was 18.93±1.53 days. The adult life span was 30.67±6.74 and 36.87±4.24 days for males and females, respectively. The preoviposition period was evaluated 5.13±0.52 days. Each female laid 480.27±77.09 eggs in her life span. The pest can produce more than four generations year. According to the literature, the biological and ecological characteristics of this insect as a pest have not been studied yet. Therefore, this study appears to be a new work in Iran and in the world.

Wheat take-all, caused by Gaeumannomyces graminis var tricid, has been observed in recent years in different areas of Iran. Current biocontrol studies have confirmed the effectiveness of the Trichoderma species against many fungal phytopathogens. In this study, biocontrol effects of Trichodermaisolates were evaluated against take-all pathogen. Five isolates of T virens T65, T virims T90, T virens T96, T virens T122 and T koningii T77 were used as isolates that were screened by antifungal tests against take-all pathogen in laboratory and three isolates of TrichodermakonongiopsisT149, T brevicompactumT146 and TrichodermaviridecensT150 were used as random selection. Also, Trichodermin B and Subtilin as commercial products of biocontrol and mustard flour as organic agent that control common bunt were used in order to evaluate biocontrol effects against take-all in greenhouse. In dual culture tests, five isolates namely T65, T90, T96, T122 and T77 covered and overgrowth the colony of the pathogen. This is followed with hyphal coiling (mycoparasitism) for isolates of T65, T96 and T90. In culture filtrate and volatile metabolite tests, all of the isolates differently reduced mycelial growth of take-all pathogen. In greenhouse tests, TreatmentsT96, T65, mixture of eight isolates and Trichodermin B, showed more biocontrol effectiveness than other treatments which reduced 25- 55 percent disease severity,and increased 27-59 percent dry weight of shoots and 23-58 percent dry weight of roots than infected control. Seed treatment was more effective than soil treatment. Based on shoots and roots dry weight, all of the treatments showed significant differences than positive control (p<0.05)and reduced 21-37 percent shoots dry weight and 27-44 percent roots dry weight in the best biocontrol effectiveness against disease to be prompted by biocontrol effects of T96, T65, mixture of eight isolates and trichodermin B.