Journal of Agricultural Sciences and Natural Resources
Year:2003 | Volume:10 | Issue:2|Papers Count:24

Both agronomic practices and genetic controls affect wheat grain qualities. In order to study the effects of row spacing and plant densities on protein content and other qualitative traits of bread wheat cultivar (M-75-10), an experiment was conducted in the Field of Seed and Plant Improvement Institute in Karaj region in cropping season of the year 1999-2000. Three row spacing (12.5, 15.6 and 18.7cm) and seven plant densities (310,320,330,340, 350, 360 and 370 plantlm2) were randomized to the vertical and horizontal plots respectively. Result showed that row spacing had not significant effect on increasing protein content and other qualitative traits. Also there is low correlation between qualitative traits and row spacing. Protein content, SDS, zeleni number and wet gluten firstly increased with increasing density and then decreased, whereas by increasing density, water absorption percent and gluten index decreased and seed hardness increased. Significant positive correlation occurred between dry gluten with zeleni number and protein percent. The optimum plant density for increasing the most qualitative traits was 340 plants/m2.  

In order to evaluate the effects of nitrogen fertilizer on yield, yield components and dry matter remobilization of different rice genotypes, a field experiment was carried out in the Rice Research Institute (Rasht/lran) during 1999-2000.A split-plot layout in the basic of randomized complete blocks design with four replications, was used. Three nitrogen levels, including of 0,150 and 300 kg/ha as the main plots and three rice genotypes including of 424, 506 and 507 as the sub plots were used. The results showed that grain yield and dry matter remobilization had significant differences among rice genotypes and different levels of nitrogen. Grain yield and dry matter remobilization in 424 genotype was more than others, and the highest dry matter remobilization was obtained under 300 kg/ha level of urea. Moreover the interation between nitrogen treatments and genotype had significant effects on grain yield and dry matter remobilization. Different rice genotypes and also different plant parts showed different responses related to remobilization of dry matter. 424 and 506 genotypes showed the highest dry matter remobilization under 300 kg/ha and 507 under 0 kg/ha level, of urea. In general, contribution of grain dry matter from stem was more than other parts(like flag leaf and other leaves). There were positive and significant correlations between grain yield and 1000-grainweight and fertile tillers number. Correlation voefficient between grain yield and dry matter remobilization was not significant.  

BUllium persicum is an umbelifer growing wild on mountains of IRAN. The species found only in some natural habitate and isn't cultivated because their seeds are dormant. Some physical and chemical agents affect germination of seeds and overcome seed dormancy in plants. The purpose of this research was to found suitable treatments for breaking dormancy in Bunium persicum seeds. Different concentrations of KNO3, Polyethylen Glycol, Thiourea, NaEDTA, Gibberellic Acid (GA3), Kinetin(Kl), enzyladenin (BA), NaEDTA +BA, BA+GA3 and PEG+BA were used to release seed dormancy. In these experiments two light (Darkness and 8h light: l6h darkness) and temperature (15 and 20°c) conditions were used. There was no significant difference in germination in two light treatments but germination was occurred better in 15°C. In this condition (15°C and darkness) BA(10-5M)+ GA3(10 mgl-1 BA(10-5M)+PEG(%3), BA(10-5M), BA(10-5M) + NaEDTA (10-3 M), KI(10-5M) substantially decrease dormancy of Bunium persicum seeds. BA(10-5M)+GA3(10mgl-1) treatment showed greatest germination percentage(%96.87) and in BA (10-5M) + PEG(3%), BA(10-5M), BA(10-5M)+NaEDTA (10-3M) and KI(10-5M) treatments subsequently 89.06,76.56,64.06 and %57.8 of seeds were germinated. GA3(10, 100mgl-1), KI(10-4M) and BA (10-4 M) treatment slightly promoted Bunium persicum seed germination but applied concentration of KN03, NaEDTA, Polyethylen Glycol and Thiorea were unable to break dormancy of the seeds.  

Saffron, Crocus sativus L. is a plant from the Iridaceae. Eight species of saffron have been known in Iran, Crocus sativus L. is the most important. It is the most expensive agricultural product and the world's dearest spice. It is widely used in medicine and food dyeing industries because of its color pigments, essences and other valuable substances available in its stigmas. The color of saffron is due to a carotene pigment called Crocein, which is highly important. Also its flavor is due to a colorless glycoside Picro-crocein, and its aroma to its Saffronal essences. The most important countries producing saffron are Iran, Spain, India, France, Greece, Germany and Turkey. The greatest part of the saffron produced in Iran is planted in Khorassan province. The harvesting process, which is the most difficult process of plantation, is done in a traditional manner. As saffron is harvested with hand in an environment close to soil it may be contaminated with microorganisms in the early stages of harvesting and processing. Based on the tests carried out, we designed a method that would reduce the risk of contamination. Thus we used ultra violet beams and mutual heat to reduce microbial contamination. It is to be noted that color power, which is an important property of saffron, was examined so that quality of saffron may be evaluated during the tests. The results show that each of the factors included in the examination has a direct relation with the reduction of microbial contamination but the greatest effect is attained when using heat and UV beams together.  

In order to study the effects of the fall and winter sowing of chickpea (Cicer aritinum L.) on morphological characteristics, yield and yield components under irrigated conditions, an oxpeniment was carried out on 1995-96 and 1996-97at Agricultural Research Station of Nishabur. Planting date levels in the first year were 6 Nov., 6 Dec., 16 Mar. and 5 Apr. In the second year, 22 Oct. also was added. Six Kabuli chickpea cultivars in each planting date level were sown in a factorial experiment based on randomized complete block design. In the first year, total number of branches and their length per plant, Decreased in the fall sowings (6 Nov. & 6 Dec.) in comparison with the following plantings (16 Mar. & 5 Apr.), because of chilling and cold losses. Thence pods number per plant and seed yield in the fall sowings decreased as compared with the next planting also. In this year, the highest of seed yield was obtained at 5 Apr. In the second year, planting date levels had not significant differences in total number of branches, their length per plant and pods number per plant. In this year, probable severe precipitation (such as hail) at early spring decreased secondary and te11iary branches in 16 Mar. and 5 Apr. severely. Moreover the occurring of late spring precipitation with irrigation provided conditions for lengthwise expansion in vegetative organs and their competitions with reproductive growth members, specially in late sowings. Thus late in planting date, was increased field of lodging. Total of these caused that seed yield in each 16 Mar. and 5 Apr. levels decreased compared with each fall sowings, significantly. Generally, with considering results and climatic characteristics of this area, it seems essential to obtain cultivars with tolerance temperature like -15°c along the sowing to emergence period and early vegetative growth period for success in fall sowmg.  

The experimental design was conducted at the Citrus Research Institute, Kotra, Tonekabon located in the north of Iran. We have used split-plot design on the basis of randomized completely in three replications. In this investigation the effects of fruit harvest time of Marsh grapefruit (Citrus paradisii Macf.) on weight, diameter, peel thickness, dry matter, total extract and naringin content in the total extract were evaluated. Extraction of total extract took place by hexan and measurement of naringin used by high performance liquid choromatography (HPLC). On the basis of the results, fruit harvest time had significant effect on the mentioned parameters. Fruit diameter variation was proportional to the fruit weight and was pretty rapid. Fruit peel thickness at the first step of growth increased (8/3mm) then with fruit development and growth it decreased (3/8mm). Percentage of dry matter at the first step of harvest increased (35/94%) then decreased (30/64%). The total extract significantly affected by fruit harvest time. The highest total extract (3 g/100g DW) obtained from the fruits were harvested 65 days after full bloom. Results also show that the highest naringin content (61.59% of total extract) found in the fruit was obtained 45 days after full bloom.  

Seed storage proteins, leaf soluble proteins and an activity of esterase were studied in 12 tea varieties. Protein bands and enzyme bands were investigated by SDS – PAGE and PAGE systems, respectively. A total of 47 bands were used to estimate the genetic distance among the varieties. These varieties were clustered together between around 0.1 to 0.5 level of distance and their mean genetical distance was estimated to be 0.316. Clustering of varieties were carried out based on 47 markers by simple matching and UPGMA method. Cluster analysis differentiated the 12 varieties in to 3 classes: 1) DN, 62.5, B275, 11, 24, 2) 10, 14, 19, 20, 31 and 3) 28, 100. The presence of Srilanka cultivars in one class and selected cultivars in a different class is a reflection of their dissimilarity and the existence of genetic distance between them. Of course, in each class a considerable amount of genetic variation can be observed.    

Effects of nitrogen, potassium and micronutrient fertilizers application on yield and quality of tea were studied during 1997-1998-growingseason at Fasha-leme Foman Research center. Using a factorial split-plot with three factors in three replications carried out the experiment. Nitrogen and potassium fertilizers were both distributed in two levels in a factorial form in mainplots and micronutrients, because of having many replications and better study in subplots were distributed in four levels. This experiment included ten plucking. The total yield was obtained from the sum of ten harvests and was evaluated the tea quality. The percentage of tannin and water extract was measured twice and caffeine percentage once. Micronutrients application, specially treatment of magnesium sulphate+Zinc sulphate indicated significant effect (P=0.01) on the increase of yield. Urea application had significant effect (P=0.05) on tannin and water extract percentage. Interaction of nitrogen, potassium and micronutrient effects were significant on caffeine percentage (p=0.01). In this case urea with potassium chloride without micronutrients had the best effect.  

order to select drought resistant olive cultivars for expansion of olive orchard cultivation in arid and semi-arid region of Iran, an experiment was conducted to evaluate the morphological, biochemical and physiological responses of some rooted cutting Iranian native olive cultivars (Zard, Mary-Tarom and Roghani) under drought stress. One-year-old olive plants of mentioned cultivars were used in a factorial experiment based on randomized complete block design. Irrigation treatments were at field capacity (control), medium stress (at -0.5 MPa) and severe stress (at -1.5 MPa ). According to obtained result there were a reduction in root, shoot and leaf dry weight of all cultivars with increasing the level of stress. Decreasing of root, shoot and leaf dry weight was higher in Roghani, Zard and Mary-Tarom in comparison of control plants. Mary-Tarom had better production and distribution of dry matter under water stress than the other cultivars in compare with its control. Plant heights of Mary-Tarom and Zard cultivars under water stress showed no significant differences than control but not Roghani. In general, leaf proline content increased with increasing of water stress in all cultivars. Predawn leaf water potential in plants was exposed to medium (-0.5 MPa) and severe (-1.5  MPa) water stress decreased with increasing duration of water stress. This increasing was significant in compare with control plants. Decreasing of predawn leaf water potential of plants under severe water stress was significant among cultivars. The amount of relative water content was decreased with increasing of soil drying during the measurement period. Reduction in leaf relative water content in Roghani, Zard and Mary-Tarom was higher, respectively. We can conclude that Mary-Tarom, Zard and Roghani had better growth and adaptation to drought stress conditions, respectively.  

Studies on rose sawfly (Arge rosae; Hym. Argidae) in 1999 revealed that there was another sawfly belonging to Tenthredinidae family whose larvae also feed upon rose leaves. Several specimens of adult sawfly were collected from rose by ordinary insect net and identified as Allantus viennensis (Schr.) (Hym.; Tenthredinidae)and named as minor leaf eating sawfly. Male and female are generally dark in color with yellowish bands on legs and abdomen. Eggs are elliptical, white in color and are laid individually beneath the bark of the young shoots and also soft spins. Newly hatched larvae are yellowish white but become gradually green. The young larvae feed gregariously on the parenchyma of youngest leaves and as larvae grow, they eventually eat the entire leaf except main rib. Feeding also occurs on flower petals causing the color of larvae change into pinkish. Final instar larvae bore into rose shoots or enter stem crevices for pupation. There are three generations in a year and over wintering occurs as prepupa in rose shoots or broken branches. For determination of spatial distribution pattern of this pest Taylor's power law model was used. The results indicated that the distribution of different larval stages populations of this wasp was clumped (b=2.395±0.14).  

The population growth parameters of Trichogramma embryophagum Hartig on the eggs of Ephestia kuehniella Zell and Sitotroga cerealella Oliv at T 25  1º C, RH 50 ±5% and photoperiod 16:8 (L: D) hours were compared. In both experiments, 150 densities of related host eggs plus honey solution were located into test tubes for 24 hours beside a fertile female wasp. After 24 hours the above-mentioned eggs were replaced with another egg. This process continued to be repeated every 24-hour until the wasp died. This study had 40 replications. The reproduction rates including gross and net reproduction rate in wasps reared on S. cerealella (Te-S) were 41.76 and 37.63, and in wasps reared on E. kuehniella (Te-E) were 55.24 and 48.88, respectively. The intrinsic rate of increase (rm), finite rate of increase (λ), mean generation time (T) and doubling time (DT) were 0.2184, 1.2441, 16.487 and 3.174, in Te-S wasps and were 0.2376, 1.2683, 16.367 and 2.917, in Te-E, wasps respectively. Thus, it can be inferred that reproduction rates and growth rate are larger in Te-E wasps than Te-S wasps, but growth time was less than that of Te-S wasps. The results revealed that in Te-S and Te-E wasps 95 and 96 % population respectively were immature, and the rest, that is 5 and 4% respectively, were mature insects and their cooperating role being gradually decrease from early oviposition period on. In other words, mature insects played less important role in stable population. Therefore it can be claimed that adult insects in the Te-S wasps played more important role in stable population than Te-E wasps.  

Functional responses of adult females of Nabis capsiformis and second instar larvae of Chrysoperla carnea to different densities of second instar nymphs of Creontiades pallidus were determined. In addition to type of functional response, the rate of searching efficiency, handling time, and related parameters were estimated. Second instar nymphs of C. pallidus in densities of 2, 4, 8, 10, 20 and 30 were presented to females of N. capsiformis and larvae of C. carnea for 24 hours in 10 replications, and then the numbers of eaten preys were counted. Analysis of functional response was conducted in two stages using Juliano method. Logistic regression indicated that the functional responses of both predators to different densities of C. pallidus nymphs were type n. Holling disc equation was used for estimating functional response parameters. The values of searching efficiency (a), handling time (Th), the rate of fitting of data to model (r2) maximum estimated rate of eaten preys (T/Th) and maximum observed rate of eaten preys (Namax)for N. capsiformis were 0.039, 1.82,0.89, 13.19 and 13, respectively and for C. carnea were 0.041, 1.11, 0.97, 21.69 and 15, respectively. The results indicated that the second instar larvae of C. carnea were more successful in attacking to their prey in comparison with adult females of N. capsiformis.    

In order to describe competitive relationships between winter wheat and wild mustard by competition indices, an additive series experiment was conducted in 2001- 2002 at agricultural research station of Mashhad University. The experiment had 3 factors: 3 levels of wheat seed rate (175, 215 and 225 kg/ha), 2 levels of nitrogen rate at optimum and upper optimum rate of wheat (150 and 225 kg N/ha), and 4 levels of wild mustard density (0,8, 16 and 32 plants/m2). Regression analysis was used to describe competitive relationships. The reciprocal of per plant model was used to determine intra and interspecific competitive coefficient. Plant relative competitive abilities (RCA) revealed that wild mustard was more competitors than wheat (based on wheat biomass RCA of 0.37 for wheat and wild mustard biomass RCA of2.75 for wild mustard). Degree of inch differentiation for wheat and wild mustard decreased from 1.67 to 0.54 as nitrogen rate increased. Wheat relative competitive intensity (RCI) showed reduction in interspecific competition due to increasing in wheat seed rate.  

  The Study was conducted in sugar beet fields of Minadoab plain, Northwest of Iran, during 2000-2001 resulting in identification of 27 species, 15 genera and 7 families. Families Laelapidae and Ascidae had the highest population densities. The new records for the mite fauna of Miandoab region and Iran are indicated by one and two astricks respectively. Ameroseiidae Ameroseius plumosus*. Ascidae: Arctoseius cetratus*., Gamasellodes Bicolor*, Lasioseius yousefi, Proctolaelaps pygmaeus*, P. ventrianalis** , Protogamasellus massula**, P. mica**, Digamasellidae: Dendrolaelaps brevipilis**, D. zwoelferi*,  Dendrolaelaspis** lobatus**. Laelapidae: Androlaelaps casalis** , A. shealsi **, Hypoaspis aculeifer** , H asperatus** , H kargi , H minor** , H karawzewi *, H near myrmecophila** . H. rectangularis*, Laelaspis near humerata**. Pachylaelapidae: Pachylaelaps siculus**. Phytoseiidae: Neoseiulus bicaudus*, N brevispinus**, N zwoelferi, Proprioseiopsis messor*. Rhodacaridae: Rhodacarellus silesiacus **.  

There is no choice to use saline water for agriculture. Because, population is increasing and fresh water resources are limited. Of course, saline water utilization needs some management practices in the field. One of the management practices is the conjunction use of fresh and saline water. This study was conducted to investigate the effect of three conjunction methods on corn yield and salt distribution in the root zone. Therefore a complete randomized design consists of four treatments; each with three replicates (except the control treatment with one replicate) was performed in 10 lysimeters. Corn (604 varieties) was planted in all lysimeters and irrigated (five times) with fresh water (0.7 dS/m) until stemming step. From stemming step till crop harvesting, lysimeters were irrigated (seven times) with fresh and saline water, using different strategies (treatments). In the first (half-alternate) treatment lysimeters at each irrigation event, half of the irrigation water was applied with saline water (7.3 dS/m) and the other half with fresh water (0.7 dS/m). In the second (one-alternate) treatment lysimeters, irrigation was practiced with saline and fresh water alternatively (one irrigation with saline water and the next one with fresh water). In the third (blending) treatment lysimeters, irrigation was practiced with blended water (4 dS/m). In the fourth treatment (control) lysimeter, irrigation was practiced only with fresh water. The results of this study showed that in case of using saline and fresh water for irrigation, the half-alternate treatment has better efficiency (in terms of grain yield and total dry matter weight) than the two other treatments (one-alternate and blended treatment). Water use efficiencies were estimated to be 0.82, 0.65, 0.56 and 0.58 kg/m3 for control, half-alternate, one alternate and blended treatment, respectively. Also, the results of this study showed lower ECe in the half-alternate lysimeters at 25 and 50 cm depth, compared to one-alternate and blended lysimeters.  

An experiment was carried out to determine the nutritive value (chemical composition, voluntary feed intake and digestibility) of two Artemisia species of Art. Sieberi and Art. Aucheri. These species grow in arid and semi-arid rangeland, of Iran. The experimental plants were fed to two groups of 4 castrated adult rams, which were kept in individual metabolic cages. The results obtained were as follows: the means of daily feed intake (kg/DM), ratio of feed intake to body weight (percent) and feed intake per kg metabolic body weight (W0.75) respectively were for Art. Sieberi 0.583, 1.445 and 34.353 and for Art. Aucheri were 0.552, 1.335 and 33.855, respectively. The difference between the forage species were statistically Significant in ratio feed intak to body weight (P<0.01). Means of organic matter digestibility (OM), crude protein (CP) and crude fiber (CF) of Art. Siberi were 55.68, 61.17 and 58.28, respectively and for Art. Auchery were 53.06, 50.88 and 64.44 percent, and difference between species were statistically significant (P<0.05) in OM, CP and the CF (P<0.01).The means of total digestible nutrients (%TDN) and digestible energy (DE/Mcal/Kg DM) of Art. Siebery were 55.177 and 2.616 and for Art. Aucheri were 51.77 and 2.493, respectively. The results of the experiment showed that nutritive value and chemical composition of the Art.sieberi were higher than the Art.aucheri.    

In spite of frequest flood events in the eastern part of Hormozgan province, appropriate flood records are not available. There are many rivers that are ungauged at all or have very scares data. To estimate flood peaks at ungauged sites, two different hydrological model structures namely, the statistical and the conceptual models are applied and evaluated. The statistical models included in the study are Index Flood (based on Gumbel and Log Normal distributions) and Generalized Extreme value (GEV) regional distribution. The HEC-I is selected among the existing conceptual models. The selected models are applied to the study area and the obtained results are compared with the flood frequency analysis of the existing stations. Furthermore, recommendations are made for the advantages and disadvantages of the methods. Among the first series of the model, the GEV performed better than the other methods. However, when compared with the second series (HEC-l), both of the hydrological model structures showed that each one has their own advantages and disadvantages. Therefore, it was not possible to select any of them as a preferable model for the entire region. To be in a safe side, it is more convenient to apply both of the models, simultaneously. Also, in order to increase the accuracy of flood quantiles, the results of flood frequency analysis of nearly gauged catchments to be used for indicating proper model.  

The role of natural zeolite efficiency for absorption of ammonia in rainbow trout has been studied. The fish weight was 9.5-21 grams that exposed to four different concentrations of 10-25mg/1 (10, 15, 20, 25 mg/l) total ammonia nitrogen. A group of 13 fish considered as control. Lethal and sublethal concentrations of during 24 hours determined. Under stable temprature and pH condition (T= 16+1°c PH=7.7-7.8t) he lethal concentration of total ammonia nitrogen was 25 mg/l. In lethal concentration of ammonia different amounts of zeolite (2, 5, 10, 13, 15g/l) were used. Application of 15g/l could prevent mortalities. Samples were taken from liver, gill and kidneys of fish (exposed lethal ammonia as groups with only zeolite) and histopathological sections were prepared. The histopathologic lesions were studied. The major lesions in the gills were hemorrhag, hyperplasia, edema and epithalial cells necrosis. In the kidney lesions were degenerated tubules of kidney, expansion of Bowman's capsule, hemorrhage and hyperamia. In liver the lesions were hepatocytes necrosis, hemorrhage and hyperamia.  

Exotic conifers species area desirable point of view and particular characteristics have been planted in wide areas of Iran to test adaptability vigur many years ago. There is a small stone pine (Pinus pinea) stand with 14 years old seeding in 4 * 4 m spacing in Chamestan research station. Stone pine stand's d.b.h., total height, pruning height factors were measured and analyzed with climatology and ecology information in 1997. The results are as follows: Average diameter at breast height is 16.75cm and total height 5.7 m and average volume per hectare is 35.66 cubic meters. Average growth in diameter (D.B.H) is 12mm and height growth is 42 cm and growth in column is 2.5 cubic meter. Pruning height is 84 cm and survival percentage of seedlings is %70. Regard to average growth, survival percentage and adaptation of stone pine species we command the afforestation of this species in sandy soil near coastal in north of Iran.