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In many areas of country, rapeseed yield and yield components are exposed to water stress. In order to investigate water stress effect on quantity and quality characteristics of rapeseed cultivars, a research was conducted in split-plot design on randomized complete block design with four replications at the research field of Pardis Abouraihan-Tehran in 2007/8 cropping year. In this experiment, two spring rapeseed (Brassica napus L.) cultivars including RGS003 and OPTION500 as main plot and irrigation treatment in three interval as sub plot (once in 6 , 8 and 10 days) were studied. Net irrigation depth, intervals between irrigations and the amount of water at every turn which was given to the ground were calculated by using related equations. The results indicated that the highest seed yield, biological yield, oil yield, plant height, silique number and silique length in plant was obtained in RGS003 cultivar with 6 irrigations periods. The highest 1000-seeds weight, harvest index, oil percentage and stem dry weight (STM) was observed in OPTION500 cultivar with 6 irrigation periods. Also, the highest plant hollowness percent was related to OPTION500 cultivar with 10 irrigation periods.

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In order to investigate the effect of seed aging and plant density on yield and yield components of wheat (CV. Chamran), an experiment was conducted in 2010-2011 cropping year in Agricultural Research Center of Safi-Abad (Dezful).The experiment was factorial with randomized complete block design with three replications. The treatments consisting of seed aging in five levels (control, 48 , 72 , 96 and 110 hr) and plant density (300 , 350 , 400 and 450 plant m2).The results showed that seed aging decreased field indices as grain number per spike, spike density, harvest index, biological and grain yield. The mean comparison of aging simple effect showed that the highest (4179 kg ha-1) and the lowest (3166 kg ha-1) grain yield belonged to control treatment and treatment with 110 hr seed aging, respectively. The effect of plant density on the traits such as spike density, 1000-grain weight, biological yield and harvest index was significant, too. In addition, the correlation between grain yield and biological yield, harvest index, spike density and 1000-grain weight was positive. In this study, observed that temperature and seed aging duration are the most important factors that influence the occurrence and progression of seed aging. Hence, the development of seed aging with increasing temperature and its implementation duration is predictable.

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This research was conducted in order to investigate the effective factors on germination, growth and seedling establishment of maize seedling hybrid SC704 cultivar under salinity and drought tension conditions and determine the best priming treatment in tension conditions at Safi-Abad Agriculture Research Center of Dezful in summer 2010. This research was performed as a factorial experiment basis on completely randomized design with three replications in two parts lab and pot. The first factor including three levels of priming (control, potassium nitrite and distilled water), the second factor including two levels of osmotic solutions (NACL and PEG) and the third factor including five levels of osmotic potentials (0,-0/3, -0/6,-0/9 and -1/2 MPa). In this research some related indices to seed germination such as germination percentage, length, fresh and dry weight of root and shoot and mean required time for germination were measured. Results indicated germination delay in both solutions of NACL and PEG. Priming treatment and tension conditions affected germination percentage and other germination indices as well, and had significant difference. In lab conditions, seeds were germinated at all concentrations of NACL solution, but no germination was observed at -1/2 MGa caused by PEG treatment. Seed priming increased germination and seedlings growth under salinity and drought tensions. According to the observed results, in lab conditions, halopriming treatment and in greenhouse hydropriming treatment, were the best and the most effective treatments.

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This research was conducted in order to investigate the effect of planting date and plant density on phonological characteristics, yield and yield components of hybrid corn Karun 701 in Agriculture Research Center of Safiabad Dezful (seed certification branch) in the north of Khouzestan province in summer 2011. The research was conducted in randomized complete blocks design with split plot arrangement, with four replications. Main treatment planting date as main treatment including: 1 July, 10 July, 20 August and plant density in five levels (3, 4, 5, 6 and 7 plants per square) were considered as subplots. The results showed that the effect of planting date on investigated traits such as days number to flowering, days to physiological maturity, the percentage of green field, the number of grain per ear, one- thousand grain weight, grain yield, biological yield and harvest index was significant. The effect of plant density on traits number of days to physiological maturity, number of grain per row, the number of grain per ear, grain yield and harvest index was significant. The interaction of planting date and plant density on any of the traits was not significant. The highest grain yield belonged to planting date on 1 July and among the densities, planting density of 6 plants per square also produced the highest grain yield. Among the evaluated traits number of grain per row and one- thousand grain weight with 0.679 and 0.656, respectively, had the most significant and positive correlation and the trait number of row per ear with - 0.098 had the highest negative correlation with grain yield.