JWSS - Journal of Water and Soil Science

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In order to evaluate the effect of row and plant spacings on the yield and yield components of three cultivars of forge sorghum, a field experiment was conducted in Isfahan University of Technology, Lavark, during spring, 2001. Experimental design was a split-factorial with three replications. Main plots consisted of three row spacings (45, 60, 75 cm) and subplots were combinations of three cultivars of forage sorghum(cultivars KFS1, IS722, IS3313) and three plant spacings (4, 6 and 8 cm). The results showed that the number of young and adult tillers, the number of leaf per square meter and shoot and leaf dry weight were influenced by row and plant spacings and significantly decreased with increasing row and plant spacings. Forage yield also decreased with increasing row and plant spacing. The highest dry forage yield was produced by 45 cm row spacing and 4 cm plant spacing. The KFS1 cultivar produced more forage yield than IS722 cultivar. The number of young and adult tiller per square meter and the number of leaf per square meter were significantly (p< 0.01) influenced by the interaction between row spacing and cultivar, row spacing and plant spacing and plant spacing and cultivar in two cuts. Shoot and leaf dry weight (kg/m²) was also significant (p< 0.01) influenced by the interaction between row spacing and cultivar, and between plant spacing and cultivar in the second cut. The density of 45 cm row spacing and 4 cm plant spacing produced the maximum forage yield.

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Many experiments have been carried out to alleviate the negative effect of drought stress and to obtain suitable growth under water deficient condition. Application of plant growth regulators (especially growth retardants) is one of the proposed methods. In a greenhouse experiment using a completely randomized block design with 4 replications at Kerman University Agricultural Department, the effect of 4 drought levels 25, 45, 65, 85 percent of field capacity and 3 different concentrations of chlormequat chloride 0, 1500, and 3000 mg/liter on some factors of winter barley cultivar Valfajr was investigated. Results indicated that increasing the cycocel concentration from 0 to 3000 milligram per liter leads to significant decrease in plant height. Relative water content affected by growth retardants was increased. Numbers of tillers and root and shoot dry weight, were also decreased because of applying cycocel in dry condition. The result also indicated that the root/shoot dry weight ratio, grain number per ear and ear number in dry condition without stress would increase using cycocel treatment.

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The effects of Chickpea (Cicer arietinum L.) varieties, and sowing dates on weed interference were investigated in a 2-year (2002-3, and 2003-4 growing season) field experiment in Agricultural Research Station of Kohdasht in Lorestan Province. The experimental design was a randomized complete block in factorial arrangement with 3 replications. The experiment had 3 factors: weed interference at 2 levels (weed free, and weed infested throughout the total growing season), planting date at 3 levels (autumn, winter, and spring) and Chickpea varieties at 3 levels (ILC482, Hasham, and Greet). Weed density in autumn sowing plots was more than 3 and 7 times greater in autumn chickpea than in winter and spring sowing plots, respectively. Weed biomass in autumn sowing was 2.5 times as much as winter or spring sowing. Wild safflower and volunteer barley were the most frequent among the weed species. Volunteer barley was mainly present in autumn and winter planting dates. Wild safflower was among the weed species that in addition to competition, caused much difficulty to chickpea harvesting. Based on the hyperbolic curve fitted to the data, Chickpea maximum biomass reduction due to weed competition was estimated to be 91.8 %.

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In order to determine the reciprocal relationship between the important characteristics of soil and the growth of Haloxylon ammodendron (C.A. Mey) plant in segsi plain of Isfahan., ordination method was used. The study was performed through the stratified random sampling and the regions were separated according to the plant age and physical physiognomy, then 10 samples of Haloxylon ammodendron (C.A. Mey) of the same age were selected in each region. Meanwhile, factors such as height, canopy cover area, canopy cover perimeter, canopy cover diameter, and basal area were considered. Also, 30 profiles from viewpoint of growth situations in 10 different regions were dug. Soil characteristics such as : pH, Ec, total soluble Ca²⁺ and Mg²⁺, Cl^-, CO3^--, HCO3^-, SP%, CaCO3%, CaSO4%, organic matter%, total nitrogen percentage, phosphorous, Na⁺, K⁺, SAR, and hardpan depth were measured. Data was analyzed using ordination method. According to the results, samples of the same age showed significant differences in plant features. Other results showed that physical characteristics such as depth of hardpan from soil surface, SP%, and chemical characteristics such as salinity, alkalinity and total nitrogen had the highest effect on qualities of this kind of plant. In other words, the results mentioned above showed the important role of Haloxylon ammodendron (C.A. Mey) in sharp increase of salinity and alkanity in it's stratum.

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Selection of efficient indices is very important for detecting and measuring random, uniform and clumped distribution patterns of plants in different plant communities. To compare and evaluate indices of dispersion patterns of plants, three stands were selected in Nodushan, Yazd. A (50m*100m) area was selected within each stand for sampling. Sampling was randomly systematicly conducted. Measurements and counts were made at 50 points and (1 and 2m²) quadrats which were randomly selected along four 100m transects within each sampling area. Indices of dispersion using quadrate studied in this survey include: Standardized index of Morisita, Morisita's index, Green's index, Dispersion (variance/mean ratio) index , Lloyd's index of patchiness and distance indices of dispersion including Pielou, Hopkines, T square, Eberhardt , Hines, Johnson and Zimer and Holgate indices. Results showed that T square and Holgate indices were more powerful than the other indices for detecting intensity of small-scale and tightly clumped pattern of shrubs because the two indices could distinguish between single individuals and the individuals on the edges of dense and small clumps. Johnson and Zimer index and Standardized index of Morisita (in shrublands with plant cover greater than 5%) were more efficient than the other indices for determining spatial pattern of these small clumps and single individuals. Among studied indices of dispersion, Green's index had the highest precision and with the exception of this index, distance indices were more precise than the quadrate indices.

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  In order to study the effects of different levels of irrigation, nitrogen and plant population on yield, yield components and reserved dry matter remobilization of seed corn (SC. 704 hybrid) a research was conducted at the experimental field in Khuzestan Natural Resources and Agricultural Science University 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 drainage 50%, 75% and 100% of available water based on 70%, 60% and 50% of field capacity, respectively). In each experiment three nitrogen levels consisting of 140(N ₁ ), 180 (N ₂ ) and 220(N ₃ ) Kg N ha^-1 were applied in main plots and subplots which consisted of three plant populations (D ₁ =6, D ₂= 7.5 and D ₃= 9 plant m^-2). There were three replications for each experiment. The results of the combined analysis of variance indicated that the effect of water deficiency stress, nitrogen and plant population on grain and biological yield was significant. With increasing severity of drought stress, the grain and biological yield decreased. The maximum grain yield was estimated to be 1017.04 gm ^-2 which was related to optimum irrigation treatment. Grain yield reduction was mainly due to reduction of grain per ear and 1000 seed weight. The increase of nitrogen consumption caused an increase in grain yield. The positive effect of nitrogen application on grain yield considerably decreased as a result of the increased water deficiency in soil. The response of grain yield to plant population was positive. The contrary to interaction effects of irrigation and nitrogen, and irrigation, nitrogen and plant population, the interaction effects of irrigation and plant population and also nitrogen and plant population on grain yield were significant. The results indicated that the difference between different levels of irrigation in the case of dry matter remobilization rate was significant. The least and the highest remobilization rate of reserved dry matter was related to optimum irrigation and drought moderate stress treatment, respectively. The efficiency and contribution of remobilization in grain yield increased in response to increasing severity of drought stress, but these traits significantly reduced as a result of nitrogen consumption. Remobilization rate and contribution of reserved materials to grain yield in the highest density (D₃) were significantly more than other densities. According to the results of this study, under drought stress conditions, the decrease of inputs consumption, in addition to the decrease of costs, will be followed by the increasing efficiency use of the resources.

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  Planting patterns through growth indices affect yield formation. To evaluate these effects on safflower, Koseh local variety of Isfahan, a field experiment was conducted in summer, 2004 at the Agricultural Research Station, Isfahan University of Technology. The experiment was performed using a randomized complete block design with a split plot layout and four replications. Main plots consisted of three row distances (20 and 30 cm flat and 45 cm on bed), and sub-plots included two planting densities (40 and 50 plant m^-2). The experiment was planted on June 25. The results showed that p lant canopy closed sooner, leaf area duration (LAD) increased and plant dry matter weight, leaf area index (LAI) and crop growth rate (CGR) were higher up to the middle of seed development as row distance decreased. In addition, the highest relative growth rate (RGR) and net assimilation rate (NAR) were obtained in 20 cm row distance. The highest (3039 kg ha^-1) and lowest (1930 kg ha^-1) seed yields were obtained with 20 and 40 cm row distances, respectively. Plant density did not affect the rate of canopy closure, CGR, RGR, NAR and seed yield. But, maximum plant dry weight, higher LAI and lower LAD values were obtained with 50 plants m^-2. The results obtained in this experiment indicate that 20 cm row distance with 50 plants m^-2 might be appropriate for summer planting of safflower, a local variety of Isfahan, under similar conditions.

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  Parsi Zira, Bunium persicum (Boiss.) B. Fedtsch., which is called Mountainous or Black Zira, is one of the most important medicinal plants with high economic importance. Generally, there is a little information about in vitro culture of Bunium persicum. Fragmented embryo was used as an explant in Bunium persicum regeneration. In this method, a great callus induction and regeneration only on the same medium without any subculture occurred because of being young and having better interaction with medium, leading to reduction of tissue culture time, infection and chemical consumption. In this research, B5 media containing different concentrations of plant growth regulators, NAA and 2,4-D only or together with Kin, were used. The experiment was conducted using completely randomized design with 30 treatments and 10 replications per treatment. The highest callus number was obtained from the treatment containing 0.1 mg/l 2,4-D and 2 mg/l Kin or 1 mg/l NAA and 2 mg/l Kin. Regeneration occurred in some treatments without Kinetin, showing that Kinetin is not essential for Bunium persicum regeneration. The treatment containing 0.1 mg/l NAA and 4 mg/l Kin was the best one for regeneration. The best treatment for somatic embryogenesis was 2 mg/l 2,4-D.

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  During the past years, safflower genotypes have been selected from local variety of Isfahan, named Kouseh. The response of these genotypes to planting date might be different. To determine this, performances of several genotypes selected from Kouseh plus Arak 2811 ) as check ( were studied at the Agricultural Research Station, Isfahan University of Technology in 2002-2004. The experiment was conducted using a split-plot arrangement within a randomized complete block design with three replications. Planting dates were considered as the main plots and subplots consisted of 22 genotypes of safflower. Number of days from planting to emergence was highest (18.0 days) in early spring planting and lowest (10.3 days) in late spring planting. Days from planting to head visible, flowering and physiological maturity were decreased with delay in planting from autumn to late spring. Days from planting to emergence, head visible and physiological maturity were not influenced by genotype. Genotypes C116 and DP29 had the highest (145.0) and genotype ISF28 the lowest (140.2) days from planting to flowering. Plant height, number of first and second degree branches, number of heads per first and second degree branches, number of seeds per head, 1000-seed weight and seed weight per plant reduced significantly with delay in planting from autumn to late spring. Genotypes C128 and DP7 had the highest (120.0 and 120.5 cm, respectively) and genotype DP9 the lowest (104.2 cm) plant height. Genotypes DP6 and DP9 had the highest (12.8) and the lowest (6.7) first degree branches per plant, respectively. Arak-2811 had the highest (16.9) and genotypes DP9 and DP5 the lowest (7.2 and 7.1, respectively) second degree branches per plant. Number of heads per first degree branches was not significantly affected by genotype. Arak-2811 and genotype C114 had the highest (12.8 and 12.2, respectively) and genotype DP9 the lowest (5.1) number of heads per second degree branches. Genotype DP7 had the highest (45.9) and genotype C111 had the lowest (28.0) number of seeds per head. Genotypes DP3 and C128 had the highest (34.2 g) and lowest (22.0 g) 1000-seed weight, respectively. Genotype DP25 had the highest (20.5 g) and genotypes DP29 and DP9 the lowest (9.9 and 10.0 g) seed weight per plant. Harvest index was not affected by planting date and genotype. The result of this study showed that safflower may yield more in fall planting under conditions similar to this experiment. Genotype DP25 might be recommended for this planting date, genotypes ISF66 and DP25 for early spring planting and genotypes DP7 and ISF14 for summer planting.

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  In order to evaluate insecticidal potential of some botanical extracts, a factorial experiment of complete randomized design with three replications on Callosobruchus maculatus was adopted for a pilot experiment in the laboratory. Plant extracts were prepared from 22 plants with three solvents (Methanol, Acetone and N-Hexane) with 30% concentration. Experiments were carried out at 25˚C and 70 ± 5% RH under 16: 8 (D: L) conditions. Each unit of experiment was a petri dish covered with a filter paper and 1.5 ml of each treatment solution was poured in it and 25 insects were released. Mortality was recorded after 36 hours. In this experiment, each plant extract with more than 50% mortality on C. maculaus was selected for further laboratory screening. In this stage of experiment methanolic leaf extract of Teucrium polium (with 55.04 percent mortality), hexane extract of Sonchus oleraceus (with 54.64 percent mortality), acetonic leaf extract of Calotropis procera (with 53.6 percent mortality), methanolic extract of Fumaria parviflora (with 52.7 percent mortality), methanolic extract of Capsicum annuum (with 50.04 percent mortality), and acetonic extract of Thymus vulgaris (with 50 percent mortality) were selected. After carring out the pilot experiment, the effective extracts with five concentrations of 15, 22.4, 33.5, 50.2 and 75% and one control were evaluated on the C. maculaus. This experiment also was designed in the laboratory as a factorial experiment of complete randomized design with three replications and mortality was recorded after 36 hours. In the highest concentration (75%), extract of Fumaria parviflora and extract of Thymus vulgaris (with 88.3% mortality) and extract of Sonchus oleraceus (with 78.3%) had higher and lower percentage of mortality resectively. The LC₅₀ values of effective extracts were calculated for C. maculaus after 36 hours of treatment with plant extracts. The results showed that C. maculatus with LC₅₀ = 126.27 µl/ml has highest sensitivity against extract of Fumaria parviflora and has lower sensitivity against extract of Sonchus oleraceus with LC₅₀ = 370.09 µl/ml in comparison to other extracts. Amongst the tested concentrations of plant extracts, 5 plant extracts with the concentrations that had the higher mortality on C. maculaus, were selected for experiment on Laphigma exigua in greenhouse. This experiment was carried out with complete randomized design with four replications. The acetonic leaf extract of Calotropis procera (with 57.5 %) caused the highest mortality and acetonic extract of Thymus vulgaris (with 27.5 %) caused the lowest mortality on L. exigua in comparison to other extracts.

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In order to determine the response of yield and seed yield components of red bean )Phaseolus vulgaris L. ( genotypes to delay in planting, this study was conducted in Factorial  experiment based on a RCB design with 3 replications in the Jahad-Keshavarzi Research farm of Miyaneh in 2006. Factors included cultivars in three levels(Naz, Gole and Sayad) and planting date in three levels (5 and 20 April, and 5 May). Results of variance analysis showed that the cultivars and planting dates had significant effects on all the characteristics. The interaction between cultivars and planting dates had significant effect on stem height, number of pod per plant, 100 seed weight, biological yield, grain yield and number of seed in pod. The Results of mean comparison indicated that SAYAD cultivar in the first planting date with 4033.3 kgha^-1 and Gole cultivar in the third planting date with 1500.2 kgha^-1 had the highest and lowest grain Yield, respectively. Total yield with all traits, except for the stem height, 100 seed weight and cultivar protein percentage showed a  positive and significant correlation.

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Polyphenol oxidase (PPO) activities were measured spectrophotometrically in tomato(Roma VF: resistant to Fusarium oxysporum f.sp. lycopersici and susceptible to Meloidogyne javanica) roots inoculated with nematode and fungi in four biological life stages of nematode. PPO specific activity showed a significant decrease in treatments (nematode + fungi) as compared with control plants. Results showed that nematode is able to change or suppress induction of this enzyme in spite of fungal induction. Nematode in all biological stages suppressed the induction of PPO activity in tomato roots but in young adult formation stage the suppression was higher than other life stages including giant cell formation, egg-laying and penetration. Native polyacrylamide gel revealed the presence of five isozymes of PPO with R_m values of 0.26, 0.31, 0.44, 0.50 and 0.63. Isoforms with Rm values of 0.26, 0.44, 0.50 and 0.53 showed significant changes in nematode + fungus inoculated tomato plants compared to plants inoculated with fungus alone. Based on the results obtained in this study, nematode infection resulted in suppression of tomato defenses against the fungi (as secondary pathogen) and intensified the fungal disease. Five PPO isoforms with R_m values of 0.26, 0.31, 0.44, 0.50 and 0.63 were shown in native polyacrylamide gel among which the isoform with R_m value of 0.31 had a thicker band in tomato plants inoculated with nematode or fungus alone. Two isoforms with R_m values of 0.44 and 0.53 in nematode-inoculated plants were similar to the corresponding bands in the healthy control. Isoforms with R_m values of 0.26, 0.44, 0.50 and 0.53 in nematode-fungus-inoculated tomato plants showed significant changes compared to plants inoculated with the fungus alone. Nematode infection of root tissue caused suppression of PPO specific activity and induced changes in PPO isoforms with R_m values of 0.26, 0.44, 0.50 and 0.63 more significantly than isoform 0.31.

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In order to study the effect of planting dates and genistein on nitrogen content and nodulation of three annual Medicago species (Medicago polymorpha cv. Santiago M. rigidula cv. Ragidula, and M. radiata cv. Radiata), an experimental study was conducted during 2004-2005 on the Research Farm of Faculty of Agriculture, Tarbiat Modares University, Tehran (35°43′N and 51°8′E). The factors were arranged as split-split plot in a randomized complete block design with four replications. Planting dates (February 20, March 1 and 11) were randomized to main plots and three annual medics were located in sub-plots, and genistein (0 and 20 μM) was randomized to sub-sub-plot units. Plant nitrogen contnt, nodulation and other traits were significantly different in species and M. polymorpha was better than other species in view of dry nodule weight, nodule number, nodule number in each cluster, nodule cluster number and nodule diameter. Medicago rigidula had more resistance to cold than other varieties, and its forage yield and nitrogen percentage were better than M. polymorpha. Therefore, M. rigidula may be better suited for cold zones. Twenty μmol genistein had remarkable effect on nodulation and nitrogen percentage of annual medics in comparison with control. The result showed that genistein modified negative effect of low temperature environment on nodulation and nitrogen percentage of annual medics. Nodulation and nitrogen percentage increased in all varieties at the first planting date. This finding emphasizes that genistein has a considerable effect on cold resistance establishment in varieties for improving nodulation and increasing plant nitrogen percentage in farm condition.

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To study the effects of plant densities and planting orientation on the seed and forage yield of sorghum, an experiment was conducted at Hossein- Abad – Shahcal village –90 kilometers south of Bam-in 2002. The experiment was a factorial with randomized complete block deisgn and three replications. The treatments were: orientation with three levels (South-North, East – West, Northeast – Southwest) and plant densities with four levels (50000, 70000, 90000, 110000 plants per hectare). Results of analysis of variance showed that planting orientation had significant effects on seed yield, weight of 1000 seeds, number of tillers, dry matter yield, length and diameter of shoot. Mean comparisons, showed that the maximum and minimum amount of the above mentioned traits except for shoot length was obtained under the North-South and East-West orientations, respectively. Significant differences were also found among densities in terms of all the mentioned traits. Results showed that increasing density decreased seed yield, weight of 1000 seeds, number of tillers and shoot diameter. The highest and lowest values (except of seed yield) were recorded for 50000 and 110000 plants/per hectare, respectively. Dry matter yield and the shoot length increased with increasing density. Based on the results of this experiment, the best plant densities to obtain the highest forage and seed yield are 70000 and 110000 plant per hectare, respectively and the best planting orientation is North-South.

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To study the effects of planting date and density on yield and its components in chickpea (Cicer arietinum L.) genotypes under dryland conditions of Khorram-Abad, an experiment was conducted during 2005-2006 growing season at the Agricultural Research Station of Lorestan Weather Department. Three sowing dates (March 6, March 21, and April 5) and two chickpea genotypes (Greet and Flip 93-93) with four plant densities (18, 24, 30 and 36 plants m^-2 ) were evaluated using a randomized complete block design with split-factorial design in three replications. Dates of planting were considered as the main plots, genotypes and plant densities were randomly distributed in sub-plots with factorial arrangement. The result showed that delay in planting from March 6 to April 5 significantly reduced number of pods per plant, number of grains per pod, 100-grain weight, grain yield and dry matter. Increasing plant density led to a significant decrease in number of pods per plant, number of grains per pod and 100-grain weight. However, grain yield and dry matter increased firstly with increasing plant density and then decreased. Planting date and density had no significant effect on harvest index, while genotype of Greet produced a larger number of pods per plant, grain yield as well as final dry matter. Also Flip93-93 produced a bigger number of grains per pod, greater grain weight and harvest index. The maximum grain yield was obtained with genotype of Greet at the first planting date in 30 plants m^-2 density. It could be concluded that due to thermal and drought stress occurring in late spring,, early planting of Greet genotype at 24-30 plants/m² may lead to a suitable increase in grain yield.

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During recent years, several genotypes have been selected from Isfahan land race Kouseh. The performance of safflower selected genotypes was studied in the field conditions, at Agriculture Research Station, Isfahan University of Technology during 2003. The experiment was carried out using a split plot arrangement according to a randomized complete block design with three replications. Planting dates (March 11, April 20, May 22 and June 23) were considered as the main plots and subplots consisted of 20 genotypes of safflower including 19 selections from Kouseh and Arak-2811 genotype. Days from planting to emergence and emergence to stem elongation were reduced as planting was delayed until the fourth planting date. Days from stem elongation to head visible was reduced with delay from the first to the third planting date, and then increased. Days from head visible to 50% flowering was reduced with delay from the first date to the third planting date, but increased in the fourth planting date. Days from 50 percent flowering to physiological maturity was increased with delay in planting. Days from planting to emergence, emergence to stem elongation, stem elongation to head visible and 50 percent flowering to physiological maturity were not influenced by genotypes. Genotype DP7 had the highest and genotype C111 and genotype DP25 had the lowest days from head visible to 50% flowering. The interaction between planting date and genotype in regard to days from stem elongation to head visible was also significant. Seed weight per plant was reduced with delay in planting date. Genotype ISF66 had the highest and genotype Arak-2811 had lowest seed weight per plant. The number of days from emergence to head visible in ISF66, DP5, C128 and Arak-2811 was affected by maximum temperature (Tmax), in genotype DP7 by Tmax², in genotypes DP17, DP1 and C41100 by Tmin² and in genotypes DP9, DP25, ISF28, ISF22, and C111 was affected by day length. It seems that development period from emergence to head visible was affected by temperature in the most genotypes. On March 11 planting date, genotypes had the maximum response to temperature and day length and the minimum response was observed in the fourth planting date. The genotype ISF66 had the highest seed yield on March 11 planting date. The result of this study showed that safflower should be planted in late March under condition similar to this experiment for maximum yield production.

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In order to investigate the effect of sugar plant effluent on shoot solute percentage, yield components and grain yield of two wheat cultivars, a two year field experiment was conducted on a farm near Eghlid sugar plant during 2004-2005. Treatments consisted of two wheat cultivars (Alamot and Zarin) and two irrigated treatment: irrigation with effluent and irrigation with spring water (control). The statistical design was a completely randomized factorial with three replications. The results showed that under effluent treatment, nitrogen, phosphorus and calcium percentage increased in shoot, and Fe, Mn, Zn, Cu and B concentration decreased. However, effluent treatment had not any significant effect on K, Mg and S concentration. The results showed that N percentages in Alamot and Zarin cultivar under control treatment were 2.41 and 2.54% and under effluent treatment were 3.28 and 3.41%, respectively. P percentages under control treatment were 0.42 and 0.47% and under effluent treatment were 0.46 and 0.51%, respectively. Ca percentages under control treatment were 0.29 and 0.32% and under effluent treatment were 0.46 and 0.51%, respectively. In both years, the lowest number of tiller, number of spike, number of kernel per spike, thousand kernel weight, grain yield and harvest index were obtained from effluent treatment in the two wheat cultivars whereas this reduction was higher in Alamot than Zarin cultivar. In Alvand and Zarin cultivars, the lowest number of tiller per plant with 2.33 and 2.50, number of spike per plant with 1.83 and 1.92, number of kernel per spike with 31.67 and 32.50, grain yield with 5233 and 5532 kg ha^-1 and harvest index with 32.03 and 33.53% and water productivity with 0.72 and 0.75 kg m^-3 were respectively obtained from effluent treatment compared to control. Thus, the results showed that using sugar plant effluent could decrease grain wheat quality and wheat grain yield.

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In order to examine the effects of plant density on the morohological traits, yield and essential oil of peppermint, an experiment was conduced in Agricultural College of Tabriz University during 2005 and 2006. The treatments included four plant density levels ( 8,12 ,16,20 plants.m-2) with three replications. The treatments were based on a split plot design in time and result analysis of compound variance was done during two years. The two years’ results of the compound variance showed that the plant density affected the fresh yield, dry yield, the bush essential oil percentage and the essential oil yield, but it had no effect on the bush height and the leaf’s essential oil percentage. In the second year, the maximum fresh yield, dry yield, bush height, the bush essential oil percentage, and the essential oil yield were obtained. In the second year, the maximum essential oil yield in the density of 20 plant/m² was 21.15 li.ha-1.

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In order to evaluate effect of planting date and plant density on grain yield, yield components and some quality and morphological traits of chickpea (Cicer arietinum L.), an experiment was conducted at the research center of agricultural and natural resources of west Azerbaijan in Urmia rain-fed research farm during 2005-2006 growing season in a split plot arrangement, based on a completely randomized block design with four replications. The cultivar of chickpea (Qazvin local mass) was planted in three sowing dates (mid November, mid March and mid April) in main plots, and four plant densities (intra row space: 7.5, 10, 15 and 20 cm) representing (45, 34, 23 and 17 plant/m2) in sub plots. Yield, number of pod per plant, seed protein content, plant height, number of secondary branches and 100 seed weight were evaluated. Results indicated that date of sowing had a significant effect on the yield, number of pod per plant and seed protein content but was not significant for plant height, secondary branches and 100 seed weight. Highest number of pod per plant was obtained in mid November sowing (37.69) and high protein content (22.63) in mid March. Different plant density effects were also not significant on yield, plant height, secondary branches and 100 seed weight but the effect of density on the number of pod per plant and seed protein content was significant. Highest number of pod per plant was obtained in the third density (31.5), and highest protein content in the first density (22.31). The results of study indicated that between mid March planting in the density (45 plant/m2) had highest yield (1042.08kg/ha) and protein content compared with the other planting dates.

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Somatic embryogenesis is affected by several factors. In this research project, we studied the effect of explant size, wounding and desiccation treatments on somatic embryogenesis and their conversion into plantlet among three genotypes of soybean. The explants were sampled from immature embryos of soybean in three different sizes (3, 5 & 7 mm) with wounding treatment on half of each, and then were cultured on the somatic embryogenesis medium. In order to determine desiccation effect on conversion amount of embryos into plantlets, the produced embryos were affected by three levels of desiccation treatments (2, 4 & 6 days). The increase ratio of callus mean weight, percentage of embryogenic calli, embryo number per explant and percentage of embryo conversion to plantlet were used for treatment evaluation. Variance analysis of the data showed significant differences (P<0.01) between treatments regarding the variables. The results indicated that BP was a superior genotype with embryogenic capability (24.19 %) and the best explant size for somatic embryogenesis was immature embryo with 3 mm length. The six day desiccation treatment caused highest percentage of embryo conversion into plantlet (74.7 %). Wounding increased callus production on explants and number of embryos per explant (20.28), but it did not show any significant effect on percentage of embryogenic calli. Germinated somatic embryos were transferred to pots containing peat-moss. Somatic embryogenesis is an efficient method for the plant regeneration and genetic transformation. However, this method still offers low percentages of plant regeneration, and is perhaps related to the maturation process and high morphological abnormalities of the matured embryos. This study aimed to find some solutions for soybean somatic embryogenesis problems.