JWSS - Journal of Water and Soil Science

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Planting pattern through changing vegetative growth and utilization of environmental resourses affects yield components and seed yield. These effects were studied in the spring of 2000 at the Agricultural Research Station, Isfahan University of Technology, using a randomized complete block design with a split plot layout and three replications. Main plots consisted of three row distances (30 cm flat, and 45 and 60 cm on bed), and sub-plots included three planting densities (30, 40, and 50 plants m^-2). The experiment was planted on March 13 using local safflower variety of Isfahan, named Koseh. Increase in row distance and plant density enhanced most developmental stages of safflower. Leaf area index was not significantly affected by row distance but increased as planting density increased. Up to the 50% flowering stage, 30 cm row distance produced highest plant dry weight, but had the least dry weight at the end of the growing season, probably due to the strong shedding of leaves. Up to the end of flowering stage, 50 plants m^-2 treatment produced the highest plant dry weight, but ranked lower as compared to 30 plants m^-2 treatment at the physiological maturity, probably due to the shedding of leaves. Row distance had no significant effect on number of branches per plant and per square meter, number of heads per branch, number of seeds per head, 1000-seed weight and harvest index. But number of heads per plant and per square meter as well as seed yield per plant and per square meter significantly decreased as planting distance increased. Plant density had no significant effect on number of branches per plant, number of heads per square meter, number of seeds per head, 1000-seed weight and seed yield. Increase in planting density increased number of branches per square meter, but reduced number of heads per branch and per plant, seed yield per plant and harvest index. The highest seed yield (4769 kg ha^-1) was obtained with 30 cm row distance and 40 plants m^-2 treatment. On average, 397 kg ha^-1 petal was harvested, which has a large economic value. However, petal clipping, over all treatments, reduced seed yield by about 7.4%. Considering the advantages of uniform distribution of plants and adaptation of safflower to flat planting, 30 cm row distance with 40 plants m^-2 might be appropriate for planting safflower under conditions similar to this experiment.

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Although safflower is known to be a cool-season crop, it is usually planted as a summer crop in Isfahan. Thus, an experiment was conducted in 2000 at the Agricultural Research Station, Isfahan University of Technology, to study the effects of date of planting on growth, yield components, and seed yield of safflower. Five planting dates (March 12, April 12, May 10, June 8, and July 12) and four safflower genotypes (Arak 2811, local variety Koseh, Nebraska 10, and Veramin 295) were evaluated using a randomized complete block design with split-plot layout in three replications. Date of planting was considered as the main plot and cultivars were randomized in sub-plots. Delay in planting from March 12 to may 10 reduced plant dry weight per unit area, number of heads per plant, number of seeds per head, seed yield per unit area, harvest index and petal yield. The above traits increased as planting was further delayed from May 10 to June 8. Highest seed oil and lowest seed protein contents were also obtained for this planting date. Plants of July 12 planting date did not reach physiological maturity. Among the genotypes evaluated and over planting dates, the highest and lowest number of heads per plant, 1000-seed weight, and seed yield were produced byArak 2811 and Veramin 295 (mean of the first and second planting dates), respectively. Highest seed yield (4512 kg ha

^-1) was produced by local variety Koseh in June 8 planting date. It might be concluded that this variety has adapted to the summer planting conditions of Isfahan by natural selection.

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To evaluate seed germination and seedling growth of safflower in moisture stress, germination of 15 genotypes at four water potential levels (ψ: 0, -0.4, -0.8 and –1.2 Mpa) was tested by Polyethylene glycol (PEG6000). Maximum germination (Gmax), germination rate index (GRI), time length to reach 50% germination (T₅₀), rootlet length (RL) and shootlet length (SL) were investigated. Effects of water potential levels and genotypes were significant for all the characteristics studied. Minimum water potential for germination was estimated between –1.17 and –1.59 Mpa in Goshkhani and LRV-51-51 genotypes, respectively. Different responses to moisture stress were found for rootlet length. In lower potential levels, seedlings had longer, weaker and thiner rootlets in comparison to the zero water potential (control). An increase in stress to –1.2 Mpa led to a severe reduction in rootlet elongation. All stress levels decreased GRI and SL, while potentials lower than –0.4 Mpa decreased Gmax. With a decrease in water potential from 0 to –0.8 Mpa, the T₅₀�stage was delayed three-fold compared to the control. Exotic genotypes had longer T₅₀ stage than Iranian genotypes. The highest GRI was related to three Iranian genotypes LRV-51-51, Varamin 295, and Isfahan local, and the lowest was related to CW-74 exotic genotype. Some of genotypes were evaluated for seed yield, oil yield and seed oil percentage under rainfed condition in 2004-05. The highest oil yield average belonged to two exotic genotypes PI- 537598 and Lesaf (326.4 and 313.9 Kg/ha, respectively) and the least was related to Zarqhan 279 Iranian genotype (133.2 Kg/ha). Negative and significant correlation was observed between seed oil percentage and GRI in the 0, -0.8 Mpa potential levels. According to the results, the existing genetic variation for germination parameters can be used for genetic improvement of seed early vigor in safflower.

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Canola (Brassica napus) is one of the important oil seed crops cultivated in many parts of Iran. One of the main problems of seed production of canola is pollination and fertilization of flowers. Insects are the major pollinators. In order to study the fauna of insect pollinators of 3 cultivars of canola including Talaye, Okapi and S.L.M. and the difference between the attractiveness of these cultivars to insects during the flowering period, insects were collected by sweeping net and identified. Their abundance was determined at different periods of time during a day. Results showed that insect pollinators belonged to five orders and 18 families. The most abundant pollinators were Hymenopterous insects specialy honey bees (Apis mellifera) which were about 50%. Irrespective of Apis mellifera, the most abundant insects captured belonged to Diptera. Three Dipterous insects, Bibio hortulanus, Metasyrphus corollae and Platypalpus sp. were collected and identified. During the flowering period (March to mid April) in Isfahan, honey bees were more abundant in the warmer hours of the day, mostly noon and afternoon, but were less active in the early hours of the day, morning, because of cold weather and low nectar production. Honey bees were more active than other pollinators on Talaye at 9 a.m. and on Okapi at mid-day, noon, and during afternoon. Results also showed that insect pollinators could increase seed yield by 53%.

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Sunflower (Helianthus annuus L.) can have an important role in vegetable oil production. Also, appropriate soil fertility is necessary to obtaine higher seed yield and quality of the crop. This experiment was conducted to investigate the effect of fertilizer treatments of macro and micronutrients on seed yield and other agronomic traits in sunflower. The effects of thirteen fertilizer treatemts (as main factor) were investigated on agronomoic traits of two hybrid cultivars, "HiSun33" and "Euroflor" (as sub factor) in a randomized complete block design with three replications. The results showed that there was significant interaction between fertilizer treatments and cultivars for most of the traits and the effects of fertilizer treatments were dependent on the cultivar. Almost all of the fertilizer treatments of N, P, K, Fe, Zn and Mn either significantly or non-significantly decreased the means of head diameter, 1000-seed weight, seed yield/plant, seed yield and oil yield in Euroflor cultivar however, in HiSun33 cultivar, each of N, P, and K fertilizers had no significant effect on seed yield. Application of Zn and Mn fertilizer in soil or spraying them on plants had no significant effect on seed yield and yield components in HiSun33 cultivar however, application of Fe feritilizer (Sequestrene) significantly increased the seed yield of this cultivar and had no significant effect on its seed oil. In HiSun33, seed yield and oil content for treatments of control, NPK and NPK+Fe were 4946, 5155 and 7090 kg/ha and 40.72, 43.10 and 43.07 %, respectively. The effects of fertilizer treatments on oil concentration of seed were not significant, thus the variation of oil yield was due to the seed yield. The correlation coefficients and regression analysis showed that seed weight and head diameter were most important seed yield components,. In general, it seems that in a soil conditions like that of this experiment, Fe fertilizer can increase seed and oil yield in HiSun33 cultivar.

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To determine the effects of different intensities of leaf removal at different reproduction stages of sunflower on seed yield and oil percentage, and the most sensitive stages to defoliation, an experiment was carried out by split-spilt plot design in randomized complete block with 3 replications at research farm, College of Agric. Urmia University, in 2004. The main factor, sub factor and sub-sub factor in our experiment were: 1. two cultivars, Uroflor and Alstar, 2. defoliation at four reproduction stages, star shape of inflorescence (R₂), pollination stage (R₅), seed setting initiation (R₆) and final period of seed setting (R₇), and 3. four defoliation intensities ( 0% as an undefoliated control, 25%, 50% and 75% ). Seeding was accomplished on May 23. Average triple factor interactions verified that different defoliations at R₂ stage have significantly reduced seed yield and oil percentage of both Uroflor and Alstar cultivars. Out of this reduction, 75 percent defoliation at R₂ was the most, while at R₅ and R₆ stages 50 and 75 defoliation caused significant reduction on seed yield in comparison with control. At R₇ stage different defoliations had no significant effect on seed yield of Uroflor cultivar, while, on Alstar cultivar, 75 percent defoliation at R₇ stage caused significant difference in relation to control. Also average triple interaction among factors showed that none of defoliation percentages had significant effect on oil percentage. In view of the fact that, seed development and filling occurred after defoliation at R₂ and R₅ , the most variation resulted from defoliation of valued traits like number of filled seed per head and weight of 1000 seeds, observed at R₂ and R₅ stages and consequently reduced seed and oil yields. On the bases of this experiment it could be concluded that sunflower cultivation with losses of 50 and 75 percent will be economically unprofitable and it will be more desirable to replace it with any other suitable crop in the region.

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Fescues (Festuca spp) are widely distributed in the temperate regions and are used for turf, forage and soil conservation. Though seed traits are important measures of the effects of endophytic fungi on their host, little information is available in this respect for Festuca. In this study, endophyte-infected (E⁺) and endophyte-free (E^-) clones of the six fescue genotypes were used to investigate the effects of endophyte on seed production. The relationships between seed traits plus direct and indirect effects of components on seed yield were also studied. Endophyte infection resulted in 38.1% to 249% more seed yields in some genotypes, though some were not affected by this symbiotic relationship. Correlations between traits and also results of stepwise regression were influenced by the presence of the symbiotic fungi. Path analysis showed that endophytic fungi changed direct and indirect effects of components on seed yield. In endophyte containing clones, panicle fertility had the most direct effects and number of panicle per plant and seed per panicle the most indirect effects on seed yield. In E- clones, panicle fertility had the highest indirect effects and other components had direct effects on seed yield. The results suggested that breeding strategies for increasing seed yield in fescue should consider the presence or absence of endophyte in germplasm.

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Thirty soybean cultivars from different maturity groups were evaluated in a randomized complete block design with four replications in Research Station of College of Agriculture at Tehran University in Karaj in 2004. The purpose was to determine genetic relationship of some important agronomic traits related to seed yield. Analysis of variance showed that there were significant differences among varieties for the traits under study, indicating the existence of genetic variation among varieties. Number of pods/plant, number of seeds/plant and 100-seed weight, all of which are considered yield components, had the highest genotypic correlation with seed yield. Using stepwise regression analysis, 85.6 % of seed yield variation was attributed to four traits, including harvest index, biological yield, protein precent and number of seeds /plant. Harvest index was more important for predicting seed yield compared to other traits based on standardized ßs. Results of path analysis showed that the harvest index and protein precentage had the highest and lowest direct and positive effect (p=0.536), (p=0.008), respectively. Therefore, harvest index may be considered as a selection criteria to improve seed yield in breeding programs. Results of factor analysis showed five independent factors accounted for 80.2 % of total variations in data. The first principle determined 28.2 % of total variation and was designated as phenologic factor.

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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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  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 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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Rapeseed (Brassica napus L.) is one of the oilseed crops in the temperate regions and is adapted to different climate conditions. This crop can have an important role in production of vegetable oil, and providing appropriate soil fertility can increase its seed and oil yield. In order to investigate the effect of N, P, K, Fe, Zn and Mn on seed yield and other agronomic traits of rapeseed, an experiment was carried out at the Research Farm of Isfahan University of Technology in 2006. The experiment was arranged as split plot in a randomized complete block design with three replications in which eleven fertilizer treatments and two cultivars of rapeseed (Ocapi and Zarfam) were considered as the main and sub factors, respectively. The results showed that there was no significant effect of fertilizers on days to maturity, but application of NPK+Fe significantly increased the plant height in both cultivars. The fertilizer treatment had no significant effect on the number of pods per plant and seeds per pod. The interaction effects indicated that application of N, P, K, NP and NK significantly increased 1000-seed weight in Ocapi cultivar however NPK+Fe significantly decreased 1000-seed weight and non significantly increased seeds per pod in Zarfam cultivar. Application of N, NPK and NPK+Fe increased the seed yield by 13, 7 and 43%, respectively. Averaged over two cultivars, N significantly increased seed oil content, but significant interaction between fertilizers treatments and cultivars indicated that application of K and NP significantly reduced the seed oil content in Zarfam cultivar. Fertilizer treatments of N, NPK and NPK+Fe had higher effects on seed oil content and oil yield and means of these traits for fertilizer treatments of control, N, NPK and NPK+Fe were 39.7, 41.7, 39.4 and 39.8%, and 681.1, 816.4, 730.2 and 983.3 kg/ha, respectively which indicate that N and Fe increased the seed and oil yield in both cultivars. However, the application of Zn and Mn had no significant effect on seed yield and seed oil content. In this study, the variation of seed yield and oil yield was mainly due to the variation of number of pods per plant and seed yield, respectively. In conclusion, it seems that in soil and climatic conditions like this experiment, application of N and Fe can be economically important and increase the seed and oil yield in rapeseed.

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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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This study was conducted to investigate the effects of thirteen fertilizer treatments (as main factor) on agronomic traits of two local cultivars (as sub factors) of sesame (Sesamum indicum L.), "Mobarakeh" and "Ardestan" in Isfahan by using a randomized complete block design with three replications. The results showed that applying fertilizer treatments of N, P, K, Fe, Zn and Mn had no significant effects on yield components, seed yield and oil yield. However, comparing the control treatment, simultaneous application of all fertilizers significantly reduced days to maturity. Significant interaction between cultivars and fertilizer treatments was observed for seed oil content, as application of N, P, NPK and NPK+Fe+Zn in Mobarakeh and application of N+K in Ardestan reduced seed oil content. However, the other fertilizer treatments had no significant effects on this trait. The Mobarakeh cultivar compared to Ardestan had significantly higher plant height, higher seeds per capsule, lower 1000-seed weight, higher seed yield per plant and per hectare and higher oil yield. Seed yield for Mobarakeh and Ardestan cultivars were 1646 and 1169 kg/ha and their seed oil contents were 52.88% and 53.81%, respectively. The correlation coefficients and regression analysis showed that the variation of seed yield was mostly due to the number of capsules per plant and seeds per capsules, thus these two traits were the most important yield components. Oil yield had a very high correlation coefficient with seed yield (r=0.99^**), whereas its correlation with seed oil content was very low (r = -0.10^ns). Therefore, it seems that seed yield was the main cause of higher oil yield.

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Safflower (Carthamus tinctoius L.) is an Iranian native crop that is adapted to different environmental conditions of this country. Sixteen safflower varieties/lines were spring-planted in 6 research stations including Sararood (Kermanshah), Maragheh, Ghamlo (Kordestan), Khodabandeh (Zanjan), Shirvan (North Khorasan)and Khohdasht (Lorestan) with and without drought stress conditions each in a RCBD with 3 replications. Some drought resistante indices including Mean of Productivity (MP), Geometric Mean of Productivity (GMP), Tolerance (TOL), Stress Tolerance Index (STI), Stress Susceptibility Index (SSI) for seed yield and genotypes Cell Membrane Stability (CMS) were calculated. Results showed that STI was the most appropriate index to identify drough resistant genotypes. Estimation of STI from mean of all stations revealed that Gila, CW-4440 and PI-537598 with high STI showed high seed yield in both stress and non-stress conditions. Caculation of STI standard deviation for these genotypes showed that Gila had less STI stability over the locations than other two genotypes so, CW-4440 and PI-537598 are more stable in drought stress resistance. Analysis of variance for cell membrane stability (CMS) of genotypes showed the significant differences in 1% level of probability between genotypes. S-541 had the highest and Kino-76 had the lowest CMS. There were significant and strong correlations between STI, MP and GMP with CMS namely, genotypes with more stable membrane having more drought resistance in field condition. So, cell membrance stability can be a useful and fast method to screen germplasm and identify drought resistant genotypes. Cluster analysis based on STI,MP,GMP, CMS and seed yield in both stress and non-stress conditions divided genotypes into 3 groupes. Results of clustering also identified S-541, Gila, CW-4440 and PI-537598 as 4 superior genotypes and confirmed the results of other methods.

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In order to evaluate the interaction effects of nitrogen and organic matter on growth and yield of dryland wheat, an experiment was conducted at the research station of the College of Agriculture, Shiraz University at Bajgah in 2005 and 2006. The experimental design was split plot in which three levels of nitrogen (0, 40, and 80 kg N ha ^-1) were main factors and additive organic matters including liquorice root residue at 15 and 30 Mg ha ^-1, municipal waste compost at 10 and 20 Mg ha ^-1, and wheat residues at 750 and 1500 kg ha ^-1 (all rates equivalent to 50 and 100%) were sub factors. A check treatment (no additive materials) was also included in the experiment. Results indicated that with increasing nitrogen level from zero to 40 and 40 to 80 kg ha^-1, wheat yield increased significantly. Among yield components, number of seeds per spike increased significantly with zero to 40 and 40 to 80 kg nitrogen ha^-1, but number of spikes m^-2 increased significantly only when nitrogen level was increased from zero to 80 kg ha^-1. Compared to check (no additive materials), maximum wheat grain yield (32%) was obtained from 100% compost application. Results of nitrogen and organic matters interaction effects indicated that 100% compost application and increasing nitrogen level from 40 to 80 kg ha ^-1 had no significant effect on dryland wheat yield. This showed the positive impact of compost application on the reduction of nitrogen fertilizer. Thus, it appears that 50% of the required nitrogen fertilizer could be replaced by compost. Applying organic matter increased soil water in both years, however, among organic matters, compost had a more pronounced effect on increasing soil water.

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In order to investigate the relationship among seed yield and its components in safflower, path and factor analysis were conducted using the agronomic and morphological traits of 32 genotypes. Genotypes were evaluated on the Research Farm of Isfahan University of Technology, using a randomized complete block design with three replications. The correlation coefficients showed that number of seeds per capitula and number of capitula per plant had the highest positive correlation with both seed yield and seed yield per plant. The results of regression analysis showed that number of capitula per plant explained 43.6%, and along with seeds per capitula and plant height 60% of the phenotypic variations for seed yield. The regression analysis for seed yield per plant also revealed that seeds per capitula, capitula per plant and seed weight in order had more contributions to the variation of seed yield per plant and explained 81.2% of its variation. Path analysis showed that capitula per plant had the most direct positive effect on both seed yield and seed yield per plant however, this effect was decreased by the indirect and negative effect of seed weight. Results of factor analysis recognized 3 main factors which explained 81.81 % of total variation of the data. These factors were named the seed yield and its components, phenological traits and branching. In general, it can be concluded that seeds per capitula, capitula per plant and seed weight in order contributed more to the seed yield of safflower genotypes. In conclusion, these yield components can be used as selection criteria in breeding programs.

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Development of oil seed crops is the most important aim in our country to achieve self sufficiency. This study was conducted to assess the suitability of oil brassicas species in rain-fed warm areas of Iran. This research was performed for three years in Agricultural Research stations of Gonbad (Golestan). Twenty varieties and hybrids (B. napus, B. rapa, B. juncea ) were compared in RCBD with three replications under rain fed conditions. Each plot had 4 rows 5-meter long. Combined analysis results indicated that there were significant differences at 1% probability level among years and varieties for No. of days to maturity, No. of pod per plant, oil%, oil and seed yield. The highest seed yield was obtained in the 2nd year (2103.48 kg.ha), followed by the 1th and 3rd year (1771.50 and 1575.13 kg.ha, respectively). Namely, year environment factor had a significant effect on the rape seed product. j-98-102.51-5 (B. juncea), Alexandra and comet (Spring B. napus) showed the highest seed yield (2484, 2326 and 2290 Kg.ha, respectively). Regression analysis via step by step method explained that No. of pod per plant and oil percentage had significant positive effects (508.53 and 96.48 respectively) and No. of days to maturity significant negative effect (-78.63) on the seed yield. Factor analysis extracted four factors. Factor loading of the first three eigen values showed that the first three factors explained 98.794%, sum of variance. Rates of first, second and third factors were 45.575%, 36.816% and 16.403%, respectively. The first factor, second factor and third factor were named productivity factor (seed yield and oil yield), sink factor (No. of pod per plant), fixed capital factor (No. of day to maturity and plant height) respectively. Generally, j-98-102.51-5, Alexandra and comet varieties are advisable for Fall planting under rain fed conditions in Gonbad area because they had the highest seed yield and earliness. Also, we can introduce less No. of days to maturity (earliness) and more No. of pod per plant as select index under rain fed conditions in Gonbad.

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A study was conducted in 2007 to investigate the effect of nitrogen fertilizer rates (0, 30, 60 Kg ha-1) on some agronomic characteristics, seed yield and oil percentage in three Sesame(Sesamum indicum L.) cultivars (Dashtestan, Darab 14, and Zarghan) in Kaki region (Bushehr Province). The type of design was completely randomized block with factorial arrangement and three replications. Nitrogen(N) fertilizer had a very significant effect on agronomic characteristics, such as number of capsules in the main stem, number of capsules per plant, branches /plant, biological yield, seed yield ,and oil percentage, but had no effect on 1000 seed weight. There was no significant difference between the application of 30 and 60 Kg of N fertilizer ha-1 with respect to harvest index. Seed yield increased as N rate increased, but each cultivar had a different response to different rates of nitrogen. Dashtestan and Zarghan had superiority over Darab 14 with respect to overall agronomic properties such as response to fertilizer and early maturity, but from the qualitative point of view, Darab 14 produced higher percentage of oil.

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The optimum levels of soil moisture and nitrogen are important to obtain higher yields. To investigate the effects of water stress, nitrogen levels and application times on yield and yield components of sunflower (Helianthus annuus L.), the cultivar Euroflor at different growth stages, a two year study (2006-007) was conducted at Research Fields of College of Agriculture, Shiraz University (Badjgah) using a split factorial design with four replications. Treatments were water stress at three levels, (non-stress and stress at flowering and seed formation) as main plot and three N levels (0, 70, 140 kg ha-1) and N application times (split application at planting and stem elongation, planting and heading, and stem elongation and heading) as subplot. Number of seed per head, 1000-seed weight, seed yield, Oil yield and HI were measured. Results showed that the effects of water stress and N rates on yield and yield components were significant, but the effects of N application times and interaction between water stress, nitrogen rates and application times were insignificant. Overall, the crop showed more sensitivity to drought stress at flowering time, and 70 kg N ha-1 is recommended for the region.