JOURNAL OF AGRICULTURAL SCIENCE AND SUSTAINABLE PRODUCTION
Year:2007 | Volume:17 | Issue:1|Papers Count:21

Almond is a horticultural product which is one main non-oil expoits in Iran and its export faces f1uctuation consistently during past years. This study was carried out to examine export comparative advantage of Iranian almond, investigate the change during 1970-2002, and evaluate the a comparative advantage of Iranian almond in competition with other famous countries in its trade and production. The information needed were data of several time series for production and export which was obtained from FAO and export comparative advantage RCA & RSCA were measured. The results indicated that although during 1970-2002 Iranian almond had export comparative advantage in accordance with the standard criteria, but it has fluctuation and decreasing trend. RCA decreased from 222.71 to 4.10 during this period. Thus Iran's position at international market decreases gradually. Regarding the comparative indicators, the almond comparative advantage of USA, Spain, and China were lower than Iran. There was a negative correlation between RCA of Iranian almond and RCA of USA almond. This showed that USA almond is the most important export competitor of Iranian almond. USA could catch Iran's share at international market using modern technologies. Regarding the almond supply function indicated that domestic production, whole cost index. foreign exchange rate inf1uence on iran's exports. Insistency index of export income for almond was 37.2 which showed that Iranian export income of almond had high fluctuation during the past period.

To investigate the role of managerial capabilities of onion farmers in Ghoghan Azarshahr county, East Azarbaijan of Iran, on yield augmentation, a sample of 105 manager-farmers were randomly selected. To gather more planned data, a well- designed and pre-tested questionnaire were completed through personal interviewing. The capabilities of farmers were measured by qualitative scale of weak, medium and strong. Questions were based on reviews of theoretical and applied literature. Data were analyzed using some descriptive statistics and also Spearman's correlation and multiple regression methods. The results showed that there were significant positive correlation between the capabilities of farmers and their levels of onion yields. The correlation coefficient of planning, organizing, conducting, controlling, innovation, representing strength with relevant agencies, technical, commercial, financial- management and accounting abilities as correlated with onion yield were 0.50, 0.50, 0.45, 0.33, 0.49, 0.49, 0.55, 0.66, 0.42 and 0.18, respectively. However, results of stepwise regression analyses showed that commercial, technical, and organizational abilities, with determination coefficient of 0.506 appear to significantly determine the variation in onion yield. Thus, the extension of managerial science and experience within the farmers to alleviate the yield gaps is recommended. This new approach would be cheaper and more efficient.

Rice is a strategic agricultural product in Iran. Rice was a major agricultural commodity imported in Iran for the past two decades. This study evaluates the effects of agricultural policies on production of the major rice groups (quality long-grain rice, high-yield long-grain rice, quality medium-grain rice, and short-grain rice) in Gilan and Mazandaran provinces. For this purpose, rice production cost statistics by Agricultural Ministry during 1994-2000, was used. A policy analysis matrix (PAM) is an effective tool to measure the impact of government policy on the private and social profitability of economic activities. The results of this study indicated that most of rice producers earned positive private profits (profits in market price) at current agricultural policies. However, all of producers had negative social profits (profits in shadow price). Accordingly, protection of rice is positive but resource allocation is not effective and it has negative effects on national income.

In order to study the effects of training system (number of main limb) and bearing pruning (severity of pruning) on yield and quality of peach fruit, an experimental design was carried out as factorial combination of three factores including, two peach cultivar (Anjiri and Mahalli), three number of limbs (3,4, and 5 limbs), and three severity of pruning (1/2, 1/3, and 1/4 cutting back of bearing shoots) based on randomized complete blocks with three replications. Results indicated that effect of year on yield per tree and per hectare was highly significant (p£0.01). Effect of cultivar was only significant on fruit weight and canopy extention rate. Fruits obtained from the local cultivar (mahalli) with average weight of 107.79 gr was heavier compared to the Anjiri cultivar (71.20 gr), but total soluble solids( TSS) of Anjiri (%19.28) was higher than local cultivar (%16.28). Effect of severity of pruning on weight of fruits, TSS and length of shoots was significant (p£0.01).The highest rate of TSS (%18.70), fruit weight (96.97 gr), and vegetative growth (68.06 cm) was obtained from more severe pruning. Effect of limb number was significant on all of traits except for TSS and shoot growth. The best quality fruit was obtained with the lowest number of limbs. The highest fruit weight (116.07gr) and vegetative growth of shoots was obtained from the local cuttivar in 1/2 severity pruning. The highest TSS was observed in Anjiri cultivar for both years. In conclusion, we recommend a relatively heavy pruning for both regulation of productivity and better fruit quality.

The effect of planting date and nitrogen levels on corn forage yield and relevant characteristics to quality (Var.SC704) was studied during 2003 at Nazlou Agriculture Research Station, Fac. of Agric Univ. of Orumiyeh, by using of split plot design based on randomized complete blocks with four replications. The treatments composed of nitrogen at four levels (0, 80, 160 & 240 kg/ha) in main plots and three planting dates (12 May, 22 May, 1 June), in subplots. The cob dry matter, leaf weight, stem and leaf-sheath weight, tassel and ear weight, leaf/stem, grain/cob, grain yield, harvest index, ear percentage, crude protein yield of forage, and biological yield were measured. The result showed that planting date and nitrogen level significantly affected the studied traits with the exception of harvest index and leaf steam ratio. Under the empirical conditions of this experiment it appears that first planting date and 240kg of nitrogen use is optimal for production of highest quantity quality of corn.

In this research, the effects of the planting arrangement on the seed yield, its components, seed oil percentage and certain agronomic properties of safflower (Carthamus tinctorius L.) in Gogan (Located in East Azarbaijan Province) during 2002-2003 were studied. The space between rows was 15, 30, 60 centimeters and the distances between the plants in a row were 5, 10, 15 centimeters, respectively. Genotypes were IL111, Kj818 and Arak-2811. The experiment was factorial based on randomized complete block design with three replications. During the growing season different characters such as plant height, number of branches per plant, number of capitulums per plant, number of the seeds per capitulum, seed yield, harvest index, 1000 seed weight, and seed oil percentage were measured. Analysis of variance showed significant differences among genotypes for number of the seeds per capitulum, number of capitula per plant, 1000 seed weight, plant height and seed yield. The planting arrangement had significant effect on number of capitulum per plant, number of seed per capitulum, and seed yield. The plant spaling of 15 cm within row resulted in the highest yield. Arak-2811 with 4.34 tons of seed yieldlha was the highest yielding genotype. It seems that extending safflower cultivation to medium and poor soils of localities near Ourmieh Lake (e.g. Gogan) will be useful for obtaining an acceptable yield.

Cultivation of salt tolerant plants like madder (Rubia tinctorum L.) at saline soils not only may lead to acceptable yield, but also helps soil reclamation and may lower salinity intensity. A greenhouse experiment was conducted to evaluate the effects of salinity sources and levels on growth and solute composition of madder. A factorial experiment was carried out in randomized block design with three replications at Yazd Agricultural and Natural Resources Research Center. Treatments included three salt sources (NaCl, Na2SO4, and NaCl+Na2So4) and six salinity levels (0, 4.5, 9.0, 13.5, 18.0 and 22.5 dS/m). The results showed that plant shoots and roots damages were significantly (p£0.01) sever by the mixture of NaCl+Na2SO4 than by NaCl and Na2SO4 alone. Increased salinity decreased plant number, weight of shoots and roots dry matter, and leaf area per pot regardless of salinity sources. Leaf free proline concentration also increased by salinity. Foliage sodium and potassium contents resulted from sodium chloride increased and decreased by rising salinity level, respectively. Critical salt tolerant level for madder was determined to be nearly 14.0 dS/m of soil saturation extract.

To evaluate the effects of water limitation and plant density on yield, some yield components, and seed oil content of safflower, a field experiment was conducted at Research Station, Faculty of Agriculture, University of Tabriz, Iran. Experiment was arranged as split plot factorial based on RCBD with three replications. Four irrigation regimes based on phenological stages viz I1= control, I2= irrigation up to R3 stage, I3= irrigation up to R2 stage, and I4= irrigation up to RI stage was considered as main factor. Combination of three varieties of safflower (V1 = Padideh (L.R.V51/51), V2 = Zarghan279, and V3= Varamin 295) and two densities (D1 = 20 and D2= 40 plants.m-2) were considered as sub factors. Data analysis of variance showed that irrigation regimes, cultivar and its interaction with irrigation regimes, as well as plant densities, had significant effects on grain yield. There was no significant difference between two irrigation levels (I1 and I2) with respect to seed yield of Zarghan. Oil percent was not affected by treatments and Zarghan produced the highest seed and oil yield. Hundred seed weight of Zarghan and Padideh was not statistically different but, they had significant difference with Varamin. D1 produced the highest number of capitulum/m2. In general, Zarghan was better than other two cultivars in h having highest seed and oil yield, and suitable use of water. However, the highest petal yield was obtained for Padideh in I2D2 treatment combination. Varamin which is burless and therefore suitable for petal harvest, having no significant difference with other cultivars in h, obtained the second rank in petal yield.

In this research, Phenotypic and genetic parameters were estimated for five persistency criteria of milk yield. The criteria included, the maximum production of all test-day records per lactation divided by the related mean, standard deviation of all test-day records of complete lactation, the percentage of daily milk retained from the peak to the end of lactation, the ratio of latest test-day yield record to the mean of all test-day yield records and a criterion which derived from estimated lactation curve factors in incomplete Gamma function. Data set comprised 36487 records of first lactation milk yields of Holstein dairy cattle of Iran with at least eight recorded test-days per lactation. Estimated heritabilities based on the univariate models were 0.32 for 305-days milk yield, and between 0.0469 to 0.0819 for persistency criteria. Estimated heritabilities based on the multivariate models were changed a little in comparison to univariate models. Genetic correlation between persistency criteria and 305-day milk yield were between -0.6124 to 0.6617. Genetic correlation between persistency criteria were between -0.9265 to 0.9988. Phenotypic correlation had similar trend to genetic correlation. The result showed that genetic correlation between milk yield and some persistency criteria were favorable for selection and breeding programs.

Nitrate is one of the most important pollutants in the nature. Entrance of high amounts of nitrate to the body creates some disorders such as methemiglobinemia and cancer. To estimate nitrate dietary I intake of Ardebil citizens, compound samples of various food materials were taken from several shopping places at different times, and nitrate concentration was measured. For determination of food consumption amounts, data were collected from 50 families (240 persons) by filling of questionnaires and average nitrate dietary intake was then, calculated. Nitrate dietary intake for Ardebil citizens was 6.16 mg/ kg. day. This value was much higher than the allowed amount of dietary intake (ADI) for nitrate by WHO/FAO (3.7 mg/kg.day). This result showed the potential risk of nitrate for people's health. Leaf vegetables constituted approximately 60 percent of total nitrate intake and lettuce, spinach and fresh vegetables had the highest nitrate concentration. With regard to high consumption rate of bread and relatively its high nitrate content, it is necessary to find the origin of nitrate in this food material. Conducting more research about the origin of nitrate in different food sources and establishing a reference laboratory for permanent control of nitrate in food is being recommended.

Hazelnut has high nutritional value because of high oil content, essential fatty acids, sterols, antioxidants, and minerals. Monounsaturated and polyunsaturated fatty acids and sterols have major roles in reducing LDL in coronary heart disease. In this study, fatty acids, sterols, and vitamin E of extracted oils from hazelnut samples, collected from different areas in Iran (Moghan, Qazvin, Fendeglo and Roodsar) by chromatographic methods. Oil content of hazelnut samples were % 52- 55. Fatty acid and sterols compositions of the oil samples were analyzed by GC. The extracted oils contained fatty acids such as oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), palmitic acid (C16:0), stearic acid (C18:0), arachidic acid (C20:0), and eicosenoic acid (C20:1). The results showed that oleic acid was predominant followed by linoleic acid. Among samples, hazelnuts from Qazvin and Fendeglo had the highest oleic acid (%80.6) and linoleic acid (%19.4), respectively. b-Sitosterol, stigmasterol, campesterol, cholesterol and D5-avenasterol were also determined in all of the extracted oil samples by GC. The highest content of sterols in oil samples were b-sitosterol (1502 ppm), campesterol (98 ppm), stigmasterol (23 ppm), in Moghan variety and D5- avenasterol (115 ppm) in Fendeglo variety. a-tocopherol was also determined by HPLC in all oil samples in which varieties of Fendeglo and Moghan had the highest (477.5 ppm ) and lowest content (323.8 ppm ), respectively.

There is high interest for low calorie diet foods. Sunflower pectin which is naturally occurring low methoxyl pectin can be used to produce jelly products (i.e. jelly, jam and marmalade) over a wide pH range, with small amount of sugar in the presence of calcium ion. In this study, pectin extracted from sunflower heads, was used to formulate different low calorie apple juice jellies. Experiments were conducted using completely randomized factorial design using pectin (0.5 and 1%), sugar (10, 35 and 50%) and calcium chloride (10, 30 and 50 mg/g pectin), at three pH levels (2.5, 3.5 and 4.5). The results indicated that there was a significant difference between texture (hardness and brittleness) and organoleptic properties of the apple jellies obtained from different levels of pectin and calcium chloride. Sugar level had significant effect on sensory properties of jellies, but it had not significant effect on textural properties.

The efficacy of some new insecticides in comparison with two organophosphates, phosalone, and azinphosmethyl, were studied against codling moth Cydia pomonella L. in Orumiyeh apple orchards during 2003-2004. The experimental design was randomized a complet block with 4 replicates and 10 treatments as: acetamiprid (Mospilan SP 20) at the rate of 500 ppm, indoxacarb (Avaunt SC 150) at 300 and 450 ppm, lufenuron (Mach EC 50) at 1000 ppm, hexaflumuron (Consult EC 10) at 750 ppm, phosalone (Zolone EC 35) at 1500 ppm, fenpropatrin (Danitol FL 10) at 1000 ppm, thiacloprid (Calypso SE 480) at 300 ppm, azinphosmethyl (Gusathion EC 20) at 2000 ppm and check (water). Each plot consisted of three apple trees. The percent of efficacy was calculated based on the total infected and uninfected fruits for each plot. Results show that the differences of experimental treatments are significant at 1% level. Comparing the means revealed that there was a significant difference between all insecticides and check at 5% level, so all insecticides were effective against codling moth in comparison with the check. The efficacy of thiacloprid at 300 ppm, fenpropatrin at 1000 ppm and acetamiprid at 500 ppm was similar to azinphosmethyl at 2000 ppm, and their differences were not significant at 5% level. The hexaflumuron at 750 ppm and two 300 and 450 ppm doses of indoxacarb were in a separate group and because there was a significant differece at 5% level between this group and two standard insecticdes, azinphosmethyl and phosalone, then these compounds were not as effective as above mentioned organophosphates against codling moth.

A faunistic study was carried out during 2005 in alfalfa fields of south west of East Azarbaijan (Sardrod, Khosroshahr, Oskoo, Kandovan, Maragheh, Bonab, Ajabshir, Gogan, Azarshahr) in order to collect and identify the edaphic astigmatic mites. This survey was resulted in identifying the following two families, eight genera and 11 species. Species indicated with * are new records for the alfalfa fields mite fauna of East Azarbaijan. Histiostommatidae Krantz, 1978: Histiostoma feroniarum Du four, 1939 , Acaridae Latreille 1802; Suidasia sp.; Tyrophagus perniciosus Zachvatkin, 1991; T.similis Volgin, 1949; T. neiswanderi Johnston and Bruce, 1965; T. brevicrinatus Robertson, 1959; T. putrescentiae Schrank, 1781; Tyroborus lini Oudemans, 1924; Rhizoglyphus robini Claparede, 1869; Aleuroglyphus ovatus Troupeau, 1878; Acarus tyrophagoides Zachvatkin, 1941. Family Acaridae, genus Tyrophagus and species T. putrescentiae had the highest numbers among all collected speciemens. However, the genera Aleuroglyphus Zackvatkin, 1935, and Caloglyphus sp. both had the lowest percentage among nine studied areas. Among 11 recognized species, T. putrescentiae and A. ovatus with 44.58% and 0.3%, respectively, had the highest and lowest percentage which were collected from Khosroshahr, Oskoo, Azarshahr, Gogan, Kandovan, Ajabshir, Bonab, Maragheh (T putrescetiae) and Kandovan (A. ovatus). Also, among all nine studied areas, Khosroshahr with 28.79% and Gogan, Sardrood with 0.6% of all identified mite species had the highest and lowest numbers, respectively. All specimens were deposited in Acarology collection, Department of Plant Protection, Faculty of Agriculture, University of Tabriz.

A total of 109 fungal isolates were collected from the wheat fields in various regions of Lorestan province, during 1994-95 and in a complementary survey in 2003-04. All isolates were recovered from samples having crown and root rot symptoms. Of these, 45 isolates belonged to Fusarium and the remaining belonged to other fungus genera. Fusarium verticillioides, F. proliferatum, and F. equiseti had the higher frequencies with 62.2, 4.5, and 4.5% of the isolates, respectively. Fusarium avenaceum, F. semitectum, F. sambucinum, F. chlamydosporum, F. lateritium, F. acuminatum, F. subgulatinans, F. reticulatum, and Fusarium sp., were the least frequents. Among other fungi, isolates of Bipolaris hawaiiensis, and B. sorokiniana comprised 18.4 and 13.8 % and Rhizoctonia solani comprising 1.8 % were the most and the least frequents, respectively. The species F. reticulatum, Fusarium sp., Bipolaris hawiiensis, Alternaria triticina, and Curvularia senegalensis isolated and their pathogenicity was confirmed for the first time from the root and crown of wheat in Iran. Pathogenicity of F. lateritium and F. subglutinans on wheat is also reported for the first time.

The sweetpotato whitefly, Bemisia tabaci(Genn.) (Hom: Aleyrodidae) is a major pest of field crops, vegetables and omamentals in Iran. Economic losses caused by the pest may be through viral transmission, excretion of honeydew or by direct damage to the plants. The infested leaves containing nymphs and pupae were collected from cotton fields in Darab, Qom, Saveh, Gonbad, Gorgan, Varamin, Garmsar, College of Agriculture, Orsoiieh and Rafsanjan (Kerman) and Shooshtar. Experiments were conducted on cotton Gossypium hirsutum L. (Varamin 76 variety) in a growth chamber under 24±2°C, 55±3% RH and 16:8 (L: D) photoperiod. Random amplified polymorphic DNA was used to detect genetic diversity in 11 Bemisia tabaci populations in 2001. In this study five decamer primers were used in the amplification reactions. All the primers produced polymorphisms. All together 71 RAPD markers were found. The amplified DNA fragments were in the range of 200 to 3000 bp. The Jaccards and Nei's similarity coefficient and Euclidean distances were used to generatea dendrogrambased on unweightedpair - group method with arithmetic averages (UPGMA). The cluster analysis divided the genotypes into six clusters. The clusters were at 1) Darab 2) Shooshtar 3) Orsoiieh genotype 4) Rafsanjan 5) Varamin 6) Garmsar, Saveh, College of Agriculture, Qom, Gorgan and Gonbad. To confirm the above phonogram, cluster analysis based on biological traits using Euclidean distance method and the UPGMA algorithm was used. It was found that both techniques produced similar results. In both cases, no relationship was observed between genetic and geographical diversity. The clusters based on RAPD markers correlated fairly well with classification scheme based on biological traits. This study suggested that RAPD can be a useful technique to study DNA polymorphism in Bemisia tabaci.

In order to evaluate the effects of Menthol (94-96%) and Thymol (99%) on varroa mite and their comparison with the effect of a chemical drug as prizin (Comaphus 3.2%), experiments were conducted in cold region of dehbakri Kerman province during years 2000 to 2002. Thirty two honeybee colonies were divided into 8 treatment groups, each with four replications in a completely ranodomized design. The groups were treated for 28 days with comaphus (Perrizin), crystal menthol (94-96%) 20, 35 and 50 treatments, Thymol (99%) 0.25., 0.5., and 1 g/lit, in 50% sugar syrup, and control (without any miticide). The effects of treatments on the honeybee queen death and worker mortality were also studied. The percentage mite mortality due to experimental treatments was determined using the sticky board method. Total mite mortality in the treatment over the 3- years period was 85.86% in the perizin group, 68.57% in Thymol 1 g/lit, 65.78% in Thymol 0.5 g/lit , 62.06% in crystal menthol 20 grams, 45.68 % in crystal menthol 35 g/lit , 45.37% in crystal menthol 20 grams, 45.34% in Thymol 0.25 g/lit, and 5.97% in the control. Mite mortality percentage was higher in the perizin group than in all of other treatments and control. But none of the Thymols, 50 grams of crystal menthol 35 grams of crystal menthol differed significantly from one another. There were not any queen deaths or noticeable adult and brood worker mortality in the treatments. Therefore, due to the lack of significant differences between above mentioned treatments, low expenses, and lower probability of new resistance, use of crystal menthol (35 grams) against Varroa destructor in the honeybee colonies of cold regions, such as rehbacri was suggested.