Year:2007 | Volume:13 | Issue:3|Papers Count:28

Effect of two kind of mulching in which dark and transparent polyethylene were used and also the density of planting of autumnal cucumber culturing was studied in experiment that carried out in Lorestan agricultural research center in 2001. In this experiment the distant between the planting rows (1.5 and 2m) were used as the main plots and the three levels of mulching were used as the subplots. The distance of plants at the rows (20, 30 and 40cm) was used as 3 levels of sub-subplots and so the experiment was carried out as split-split plot with 4 replications. The results showed no significant differences between all the measured characteristics as the distance between the rows were decreased. But differences between all the measurements of planting characteristics affected by different mulching system were statistically significant at I% level except the effect of mulching on cucumber fruit weight that the differences were statistically significant at 5% level. Yield under transparent mulch 356% and under dark mulch 287% were increased as compared with that without mulching. Reduction of distance between the rows From 2 meter to 1.5 meter resulted no significant differences in bare ground treatment as the data obtained were statistically analysed.

The purpose of this research was to measure the tendency of student's toward agriculture majors and also to help agricultural higher education planners. Therefore, this study considered practical in which survey and correlational methods were implemented. Statistical population included all students at the bachelor level who were majoring in agriculture in two provinces of Lorestan and Hamadan (N=2000).A random sample n=125 were selected. A questionnaire was used to gather data. Both descriptive and inferential statistics were used to analyse the gathered information. The questionnaire were validated and reliability gained (.84) through an implication of a pilot test. Descriptive results of this study showed that 55 percent of respondents were male and 45% were female. Only 12 percent of students were living in village. The findings of the study showed that student's interest toward majoring in agriculture was moderate. However, their interest significantly increased after entrance to the agricultural college. Results of this research revealed that about 89 percent of the undergraduate students had positive attitude toward majoring in agriculture (21%=moderate agreed, 68%=entirely agreed). However, only 11 percent of them had negative attitude toward majoring in agriculture fields. Analytical finding of this study showed that there is significant statistical relation between gender as independent variable and the students' attitude as dependent variable. There was also significant relation between two variables of living location (village and city) and students' attitude. The findings showed that there was no significant difference between attitude of Azad University's students and attitude of Public University's students toward majoring in agriculture fields.

In order to identify the plant ecological groups and determining their distribution pattern with physiographic factors, research was carried out in an area of 124 hectare at the altitude of 80-1200 meter from sea level, in south of Boushehr province. Study area selected by experimental methods and fieldwork. For identifying and classification of vegetation cover, 248 grid permanent plots by determining minimal area with 256 m2 for tree-shrub layer and 64 m2 for herbal layer were chosen on the basis of Braun-Blanquette combined cover abundance scale. Sampling was carried out at last part of growing season(Feb. and Mar. 2002) in two distinct layer (tree-shrub layer and herbal layer).Clustering analysis was done using TWINSPAN for identifying plant ecological groups. GIS application used for mapping plant ecological groups and Digital Elevation Model (DEM). Comparison between plant ecological groups and slope, aspect and elevation maps showed that there exist a significant relation between vegetation and elevation, so that from foot of mountain up to 300 meter is specially adapted for one group. The range of 300-600 and 600-900 meter from sea level is common between two groups. Overall, in both layers one group have over tolerance range than altitudes changes. In addition, there was not any significant relation between vegetation and slope and aspect, but second ecological group (on tree-shrub layer) have special correlation with south and west and 30-70% class of slope.

Vegetation elements with similar ecological needs, constitute ecological groups in a natural ecosystem, In fact, through distinguishing different ecological groups, the differences among environmental variables in various sites can be realized, The aim of this research, done in Tehran University's educational- research  forest located in Kheiroudkenar forest - Noshahr, was to explore ecological groups and their relationship with physiographical conditions. In order to determine plot (releve) area, minimal area method was employed. To study vegetation cover, 98 plots with 400 m2 area were collected according to Braun-Blanquet combinational method. After data collection, plant community was separated and classified using Two Way Indicator Species Analysis (TWINSPAN) and Deterended Correspondence Analysis (DCA) and differential species were indicated in each group. The results showed that the first ecological group, namely Ruscus hyrcanu was occurred in different kinds of physiographical conditioss, and second group including Asperula odorata, Viola odorata, Hypericum androsaemum, Dryoptris jilix-mass, in respect to ecological similarity with first group, was related to elevation property. The third group with Oplismenus undulat (folia, Cyclamen caucasicum, and the fourth group, including Mespilus germanica, Rumex sanguineus, Solanum kisereitzcki were mainly related to elevation property and were occurred in higher elevation than others. Also, in addition to physiographical conditions, soil characteristics should be considered as a main factor to separation of ecological groups.

Performance, maintenance and management of forests and pastures involves a complete and through recognition of them. Studies of sociology plants show that they have a strong correlation with physical factors of environmental conditions. Accordingly, the present study aims at classification based on forest association brown - blanquet method was used. 174 samples related to plant covers were analysed by using Pc-ordwin software and then associations were determined based on presence of indicators and preferable species in sociological tables. The results of the study showed that: Amygdalo Daphnetum mucronata, pistacio Acertum cinerascens, Quercetum brantii based on physiographical conditions of sites, in different associations, it can be concluded that; Quercetum brantii association in all slopes, aspects and class heights are observed rarely except for heights over 2000 the most frequent distribution is observed in 0-40% slopes, southern aspects and 1400-1800 heights. pistacio Acertum cinerascens exists mainly in 40- 60% slopes, 1800-2200 heights and southern and western aspects. Amygdalo Daphnetum mucronata has a great proportion with height from the sea in such a way that heights over 2200 is predominantly covered with species the highest frequency is observed in heights between 2200 and 2400 and in western aspects. 

Walnut fruit worms are known as the main pests of walnut fruit throughout the world. In West Azarbaijan province which is one of the suitable walnut growing regions in Iran, it has a considerable damage. In this study the species of walnut fruit worms were determined based on the specimens collected from all over the province during 2000-200 1.Their relative abundance were studied by using various methods including cloth sleeves, trap bands, mass rearing of the specimens taken from infested fruits of Kahriz Horticulture Station. The population density of prevalent species was compared in apple and walnut orchardsbased on sex pheromone trap catches. The results revealed that two moth species including codling moth, Cydia pomonella (L.) and quince moth, Euzophera bigella (Zeller) are involved in causing damage to walnut fruit and c.pomonella was found to be the predonminant species with 63 percent of the population.Damage of walnut fruit worm was observed in Oroumieh, Salmas, Khoy, Oshnavieh, Piranshahr, Sardasht, Mahabad and Miandoab. The two years study in Kahriz Horticulture Station also showed that, the relative abundance of both pest species varied in accordance with the method of assessment used Studies showed that the mean ratios of percentage of abundance of c.pomonella (L.) and E.bigella (Zeller) obtained from cloth sleeves, trap bands and laboratory rearing was found to be 80:20; 73:27, and 40:60 percent respectively. Keeping single walnut fruits, randomly taken from experimental orchard, in cages in the laboratory showed that 38 percent of the fruits were infested with one and only 3 percent with two larvae of C. pomonella (L.); while 34 percent of the fruits were infested with only one, 14 percent with two, and 11 percent with three to five larvae of E. bigella. As well 16 percent of the specimens were infested with both C. pomonella (L.) and E. bigella (Zeller). One Trichogramma egg parasitiod wasp was collected from Orumieh and identified as Trichogramma embryophagum (Hartig). Its parasitoidism rate was found about 50 percent on eggs of Cydiapomonella (L.) in Barbaran Valley of Orumieh in mid July.

Ink hibiscus mealybug, Maconellicoccus hirsutus (Green), is a polyphagous pest that is distributed throughout many regions of the world. The pest population has increased on mulberry (Morus alba 1.) trees in parks and greenbelts of Jahrom city of Fars province. Chemical control is harmful for visitors of parks. Then it is recommended to use natural enemies instead of chemicals. Identification of natural enemies is the first step in biological control programs. During 2002-2005 surveys in Jahrom region, activity of a complex of the following parasitoids and hyperparasitoids on M hirsutus on mulberry was observed:Parasitoids:Hym., Aphelinidae: 1-Coccophagus pseudococci CompereHym., Platygasteridae: 2- Allotropa mecrida WalkerHym., Encyrtidae: 3- Anagyrus agraensis Saraswat4- A. dactylopii (Howard)5- A. kamali Moursi6- A. mirzai (Agarwal & Alam)7- A. pseudo cocci (Girault)Hyperparasitoids:Hym., Aphelinidae: 8- Marietta picta (Andre)Hym., Pteromalidae: 9- Pachyneuron muscarllm (L.)Hym., Signiphoridae: 10- Chartocerus kurdjumovi (Nikol'skaya,)Allotropa mecrida and Anagyrus kamali are new records for Iranian fauna. Activity of A. agraensis, A. dactylopii so valuable. Except C. pseudococci other species are new records on this pest in Iran.

In order to study the effect of consumption of clinoptilolite natural zeolite on tolerance of water stress and increasing yield of corn (Zea mays L.) single grass 704, a pot factorial experiment was conducted with 12 treatments and three replicates in 36 pots. Four level of zeolit (0, 2, 4, 8 gr/kg soil) and moisture depletion in three levels of depletion (45, 65, 85 % of water available) applied during the plant growth. During to experiment soil moisture was measured by weighting method. After harvesting, fresh and dry weight parameters were measured. The results indicated that zeolite consumption has a significant effect on dry and fresh weight. In addition, there was a significant effect of water stress (levels soil water losses) on fresh and dry weight. There was an interaction between zeolit and moisture depletion on plant of parameters. Based on the results of this research and regarding the important of the amount of fresh and dry weight to assess yield of corn, It is concluded that the level of zeolit (2gr/kg soil) with the lowest level of water stress (45 % water depletion) is recommended to produce the greatest dry and fresh material (561.4 and 138.04 gr).

In order to evaluate heritability and gene action for some of important agronomical traits in barley, two cultivars, Afzal and Cwb were crossed. Parents with FI, F2 and F3 generations were planted in a randomized complete block design with three replications. Plant height, head length, number of tillers, grains per plant, hundred grain weight, number of heads, number of spike lets, awn length, biological yield and grain yield were measured. Analysis of variance indicated that mean squares of generation were statistically significant for all the traits. Generation mean analyses were also performed for all the traits. The results showed that, in addition to additive gene effect, dominance and epistasis effects were involved for most the traits studied however the dominance gene effects were most important for inheritance of all the traits. Average broad sense heritability’s of all the traits were found to vary between 0.58-0.85. The approximate number of genes for all of the traits was estimated to be between two and six.

In order to study yield and traits affecting the yield in white bean lines, an experiment was conducted in National Bean Research Station of Khomein for two years (200I and 2002). In this research, 13 lines and cultivar Daneshkadeh (as control) were arranged in a randomized complete block design with four replications. Evaluated traits were: days to emergence (VI), days to primary leaves (V2), days to first (V3) and 3th trifoliate leaves (V4), days to floral initiation (R5), flowering (R6), pudding (R7), and pod filling duration (R8), days to maturity, pods/plant, grains/pod, grains/plant, 100 grains weight, plant height and grain yield. Combined analysis of variance showed that lines were significantly different in all evaluated traits. The highest growth period (days to maturity, up to 98 days) and the highest grain yield (2798kg/ha) were obtained from line no. 6 (KS-41115) and line no. 9 (KS-41118), respectively. Correlation coefficient analysis revealed that yield components (pods/plant, grains/plant, 100 grains weight) had positive and significant correlation with grain yield. There was highly significant and positive correlation between grain yield and R5, R6, R7, R8, days to maturity and plant height. V4 had the highest negative correlation with grain yield, therefore the value for the trait should be decreased in improvement programs. Overall,4 lines were selected based on their yield and marketing.

In Mazandaran province, harvested Paddy is stored in warehouse for several months before drying and milling. In order to study the effect of storage duration of paddy before drying on broken rice percentage and milling yield an experiment was done at deputy of Rice Research Institute in Mazandaran province (Amol).A factorial experiment in a randomized complete block design of 4 replications with 5 treatments of storage duration (0, 15, 30, 60 and 90 days after transporting to warehouse) and two levels of variety (Shafaghand Tarom) was used. In purpose of drying of paddy an electrical drier was used. The temperature of drier regulate at 45 for all experiments. The samples dehusked and whitened by husker and whitener respectively at moisture of 12 percent (w.b). Results showed that the effect of storage duration before drying and variety was Significant on broken rice percentage (p<0.05). By increasing storage duration the broken rice percentage was increased significantly (P<0.05). Until 15 and 30 days after transporting from field, there was no increase in broken rice percentage in Tarom and Shafagh varieties respectively. The maximum broken rice percentage was related to drying of paddy 90 days after transporting to warehouse.

The influence of nitrogen rates on shoot/root ratio, sodium and potassium uptake of Wheat (Triticum aestivum L. Var Chamran) under saline conditions was studied. The expriment was conducted in factroil design with three replications. The treatments comprised five levels of salinity: 1.5, 5, 10, 15 and 20 ds/m and three nitrogen levels: 50, 100 and 150 kg N/ha. Salinity treatments were applied in a clay-loam soil by irrigating with waters salinized with NaCl and CaCl2 (5:1 by wt). The results of this study showed, by increasing salinity treatments dry matter of shoot and root decreased and this decrease in root at 20 ds/m treatment was very large. therefore, the shoot/root ratio increased. Application of nitrogen resulted in significant increases in shoot and root dry matter contents. In shoot and root by increasing salinity levels, sodium showed an increase in concentration. In root increasing in sodium concentration until 10ds/m treatment. After this level, sodium concentration decreased. Application of nitrogen resulted decrease sodium in shoot and increase sodium in root. By increasingsalinity levels potassium concentration in root and shoot decreased. Application of nitrogen resulted increase in potassium concentration in root and shoot. 

In order to evaluate the effects of water stress in germination and vegetative growth stages, some pure lines of wheat under water treatments were studied in two separate experiments. In germination stage 40 lines of -1.6, -1.2, -0.8 and 0 MP were evaluated in the form of CRB base design in three replications. The treatments were applied during 7 days under 25 C. The following traits were measured: final percentage of germination, length of stemlet and rootlet, dry weight of rootlet and stemlet of seedlings. Then in order to study the accumulation of growth regulator in leaves on 8 lines of wheat obtained from the first experiment in comparison to two commercial lines (Azar2 and Zarrin); water stress was applied under 4 levels of 100%, 75%,50% and 25% of agronomic soil capacity. The results showed that water stress had led to decrease of germination percentage, length of rootlet and stemlet and the dry weight of rootlet and stemlet. The lines were divided into 3 groups: tolerant (15 and 28), semi-tolerant (19 and 17) and sensitive (16 and most of the lines). The lines tolerant to water stress had more length and dry weight of rootlet and stemle than the sensitive lines. Under the conditions of water stress in vase a decrease was observed in water potential and RWC. Decrease in the amount of RWC was parallel with the decrease in the amount of water potential so that the least decrease of RWC and water potential occurred in the treatment 25% of agronomic capacity in Azar2 and the line no 15and the mostdecrease belonged to the line 36 and Zarrin.Accumulation of praline and soluble carbohydrates had negative and significant correlation with plant water potential and RWC. The most accumulation of praline belonged to the line 16 while the most accumulation of soluble carbohydrates belonged to Azar2 and the least one belonged to the line no 36. So, there is a relation between the accumulation of osmotic regulator metabolites and water potential in tolerant lines.

In order to investigate effect of Abscisic acid (ABA) application on yield and yield components of common bean genotypes in water deficit conditions a field experiment was conducted in 2005 in seed and plant improvement institute of Karaj, Iran. The experimental design was split factorial on basis of randomized block design with 4 replications. Main plots were consisted of 2 irrigation levels as common irrigation and alternate furrow irrigation. Sub plots were also allocated to 3 cultivars (Akhtar, Oerakhshan and 081083) and 4 times of ABA applications (Vegetative, Flowering, Poding and Non applications) in factorial form. Results showed that in alternate furrow irrigation treatment, in all cultivars, grain yield, number of pod and seed weight decreased(severely in Akhtar and Oerakhshan cultivars) but number of seed per pod not to be under the influence of this treatment. In common irrigation, ABA application decreased especially in flowering phase, grain yield in vegetative phase, number of pod and in poding phase, seed weight. Number of seed per pod not varied. In alternate furrow irrigation treatment, ABA application increased especially in flowering phase, grain yield and number of pod and in poding phase, seed weight. Akhtar and Oerakhshan cultivars which were more sensitive to water deficit, showed more marked reaction to ABA application. In this research maximumyield (416.2 g/m2) was achieved in common irrigation, Akhtar cultivar and non ABA application treatment. Minimum yield (283.8 g/m2) was obtained in alternate furrow irrigation, Akhtar cultivar and non ABA application treatment. In alternate furrow irrigation treatment, maximum yield (353.05 g/m2) was achived in Derakhshan cultivar and ABA application in flowering phase.

In order to study the effects of drought stress, different levels and split application of nitrogen on yield, yield components and water use efficiency (economical and biological) of a hybrid corn (Se. 704) a research was conducted in summer, 2004. This research was made based on three split-plot field experiments, RCBD. Each of the irrigation treatments implemented separately in each experiment have been as follows Optimum irrigation, moderate stress and severe stress (irrigation after getting out 50, 75 and 100% of available water, respectively). In each experiment three nitrogen levels consist of 140, 180 and 220 kg Nha-1 were applied in main plots and subplots which consisted of split application of nitrogen (S,= %50 at planting + 50% at V6 stage, S2=25% at planting stage and + 75% at V6 stage, S3= %25 at planting + 50% at V6 stage + 25% at V12 stage). There were three replication for each experiment. Results showed that grain and biological yield, were reduced significantly in response to increasing to drought severity. The effect of nitrogen on grain and biological yield and yield components except number of row per ear was significant. When available water decreased, positive effect of nitrogen application on grain and biological yield decreased significantly. In comparison to S1 treatment, S3 increased grain yield and number of grain per ear, significantly. Maximum water use efficiency (economical and biological) 1.8 and 3.4 gm-3 was obtained from optimum irrigation, respectively. When drought stress increased, water use efficiency decreased significantly. The highest water use efficiency was obtained from 220 Kg Nha-1 under optimum irrigation condition. Water use efficiency increased with split application of S3 (%25 at planting + 50% at V6 stage + 25% at V12 stage) significantly.

This research is carried out in order to determine the PC variation of chemimechanical papers produced in the wood and paper factories of Mazandaran when sample treating with metal ions of medium elements and methods of them reading. Two types of chemimechanical paper samples were prepared: bleached and unbleached papers. Samples included two types of treatment. First, the samples were smeared with EOTA in different densities. This process ended in neutralization of existent ions in CMP paper samples. In the second stage treatment, after dehydrating each of the above- mentioned samples that were combined with EOTA, The CMP samples were smeared with solvents including metal ions of medium elements and then put them under the radiance of UV Black Light lamps. One of the objectives of this research was to determine what kind of effect could have different metals on the Aging and Yellowing process. In the final stage, the light specification of samples such as Brightness was measured. The highest spoiling effect on the yellowing process was determined to be Fe2+ ion and the lowest effect was issued by Ae3+ ion. For decreasing the effect of each metal ion, increasing the density of EDTA, decreasing the pH of pulps and methods such as methylation methods were suggested.

This research was done with the aim of determination optimum wood drying schedule for 32 mm thickness Maple (Acer insigne) lumbers. The trees cut from Lireh-sar region of Nousahhr (north of Iran) and dried from green to 8% MC using three different codes as T8-D4 (recommended by FPL), T9-D4 and T8-D5. Specific gravity of the samples was 0.45 and 0.48 with green and dry volume respectively. In addition, volumetric shrinkage was 10.47percent. Number of defects such as wrap, bow, twist and surface cracks in each charge was measured and statistical control charts were drawn. Results shows that defects level were almost in acceptable ranges in all three schedules after drying, but its average was less and were more evenly distributed when using T8-D4 schedule. In other words, one could conclude that this program has decreased drying time, while increasing dried wood quality in comparison the others. Finally, it is recommended doing conditioning treatment for about 36 to 48 hours, if needed.

To study of MDF sawdust wastes as high - density polyethylene reinforced, composites product were used, The reinforced percent in four levels] 0, 20, 30 and 40 percent and the dimension of reinforced particles reinforced in four levels with mesh size 40, 60, 80 and] 00 whit high- density polyethylene were mixed Maleic anhydride grafted polyethylene was also used as a coupling agent. Composites were produced using Resin injection molding method, and finally their mechanical strengths were measured. The results showed that MORb, MOEb, MORt with reinforced percent increased up to 40 percent and reinforced damnation mesh size up to 100 were increased. Also notched impact resistant in 10 reinforced percent and the size of mesh 40 has the most amount.

Pectin is a very precious material, which has a great role in food and industeries because of its ability to produce gel. One of the materials for production of pectin is sunflower head residue that is a potential natural source of low methoxyl pectin. However a advance cultivars of Golestan province consist of, Golshid, Recorde, Gabor, Azargol and Progress have been selected. The pectin was extracted by using 0.75% sodium hexameta phosphate at pH=5 and temperature 85°C for 20 minutes and then, extraction yield, galactomic acid and the degree of estrification were evaluated. The results showed that, Golshid and Recorde verieties had highest yields than the others and their galactoronic acid content (as purity) were 80.4 and 81.8% extracted pectin was low methoxyl type and Estrification degree of pectin varied from 33.2 to 35.1% that there was not significant different between varieties. Gabor variety had second extraction yield whereas Azargol and Progress had (2.3 and 1.8%) the lowest pectin yield.

By drying date and making powder of it, not only the shelf-life of all varieties of two and three grade of date is increased, but also the possibility of its use in industrial foods formulation as a replacement for total or partial sugar, is obtained. In this study, five varieties of date, including: kabkab, khassi, saamaran, zahedi and shahaniwere used for powder production. After chemical analysis, dates were dried at 70°C to below 5% moisture by vaccum oven, then once a mixture of raw cane sugar and dried date, and another time, a mixture of white sugar plus dried date in four levels of 10, 15, 20, 30 percent sugar was converted to powder by mill. After selecting the best sugar percent (which was 20%), silicon dioxid in three levels of .5, 1 and 1.5 percent was added to these mixtures which consisted of 20% sugar at ratio 1.5%to improve flow ability as anticaking. It was found that drying date under these conditions doesn't creat an important and meaningful change in content of total sugar and invert sugars andpH of powders constants at least for 6 months. Powder flow ability of 1.5% silicon dioxid was remained constant for 6 months. These powders were used for preparing date milk with concentration 125 gr/lit and theirs taste and flavor was evaluated by panelists. Factorial experiments in completely randomized design were used to analyse statistical data. It was found that there are different at 1% level between ten powders. It was also found that for shahani, kabkab and khassi varieties, the use of raw cane sugar compared with white sugar, increases acceptability, but in the case of Zahedi variety the same thing didn't happen and in the case of Saameran variety cause a small decline in acceptability. Dates also were dried at 85°C. 10% (w/w) aquaous solutions of powders were evaluated by panilists. All panilists reported bitterness taste.