نشریه فیزیولوژی گیاهان زراعی
پیاپی 12 (زمستان 1390)

Optimum canola planting date in the hot dry climate of southern Iran due to crop rotation, weather condition and soil is very limited, So determine the relationship between yield and yield components with planting date is essential. This research was conducted based on split plot experiment on Compeletly randomized block design by four planting date in main plots and four canola variety in sub plots in three replication. Analysis of variance showed that grain yield, yield components and total dry matter were significantly affected by planting date. Planting date of November 15 was superior characteristics. All under studies Varieties, also in terms of yield and yield components and other traits had significant. Totaly, Hybrid Hyola 401 because of more of leaf area index (3.51), total dry matter (1248.91 g.m-2) and the highest grain yield (2610 Kg.ha-1) in mid-November sowing date in the first priority and if not possible, open pollinated variety of R.G.S 003 on November 6 is recommended.

In oder to study the effect of sulfur and thiobacillus with organic matter on quantitative and qualitative of Canola, an glasshouse experiment in factorial form, in complete random block design with 4 replications was conducted in cropping year 2007- 2008, at the Agricultural and Natural Resources University of Ramin. In this experiment Thiobacillus in two levels NT (With Thiobacillus inoculation) and T(With Thiobacillus oculation), three levels of Sulfur (0, 500, 1000 kg/ha), organic matter in two levels, O1 (without organic matter) and O2 (20 t/ha organic matter) were considered. The results showed oculation with Thiobacillus causes significant increasing grain yield and increasing Fe and Zn in seed. With increasing sulfur level to 500 kg/ha, grain yield, total dry matter and oil, 4/39, 15/28, 1/69 persentage increased, arrangemently. A significant increase was observed in Fe and Cu in stubble pots with organic matter in comparision with pots without organic matter. The results showed applying 500kg/ha sulfur inoculation Thiobacillus with organic matter and or sulfur inoculation Thiobacillus cause pH soil decrease and absorption micronutrient, grain yield and oil percentage increase.

To evaluate and analysis growth parameters and the effective quantities on them, an experiment was conducted in the Agricultural Research Station, Ahvaz Islamic Azad University, during 2006-2007 and 2007-2008 cropping seasons.Under studied treatments were 3 wheat cultivars (Chamran, Dez and Vee/Nac), waterlogging period (0,7 and 14 days) and waterlogging stress in different Growth stages containing stress at the beginning of tillering stage (ZG21),stress at the beginning of stem elongation stage (ZG31)and stress at the commencement of booting stage (ZG45).Among the using cultivars,the growth stage period of Vee/Nac was about 2 weeks shorter than other cultivars. Experimental design was a factorial randomized complete block design (RCBD) with three replications. Results showed that increasing waterlogging stage,significantly decreases LAI (Leaf area index) and tiller number in m2, especially when stress applying at ZG21 and ZG31. The maximum LAI and tiller number was observed in Chamran cultivar and the minimum in Vee/Nac cultivar. NAR (net assimilation rate) decreased significantly when waterlogging stress was applied at ZG21 and ZG31 stages, but the duration of waterlogging affect was not significant. The maximum NAR was observed in Vee/Nac cultivar. TDM (total dry matter weight) and CGR (crop growth rate) decreased significantly after increasing the duration of waterlogging and applying stress in ZG21 and ZG31 stages. The maximum CGR at primary growth stages and the minimum TDM in the end of growth stage in Vee/Nac cultivar was obcerved.

In order to study the effect of water stress on morphological traites, yield, and oil quantity in 3 Canola cultivars, an experiment was conducted out in cropping year 2009-2010 at Eghlid region. The study was done in a split plot experiment based on Randomized Complete Block Design with three replications. Main factor including three water stress levels 1)water stress at flowering stage, 2) water stress at pod formation and 3) control) and subfactor was including three canola cultivars )Talaye, Okapi and Licor). The traites like period of flowering, period of pod formation, period of planting to maturity,Plant height, number of pods per plant, number of seeds per plant, the first pod height, 1000 seed weight, Seed yield, harvest index, oil percent, Oil yield, Protein percent and Protein yield was measured. The results showed that applying water stress significantly decreased all the traites. Cultivar had significant effect on all of under studied traites(except harvest index) too. Generally, Okapi cultivar,without drought stress conditions, showed the highest Seed yield (6880Kg/ha) and noticing no significant difference with irrigation stress treatment in pod formation stage(6700kg/ha), this cultivar was assessed as drought tolerant cultivar and Licord cultivar as drought sensitive cultivar in drought stress becouse of owening low amounts of the most traites.

In order to investigate the effect of soil cobalt concentrations on chlorophyll a,b and total chlorophill density in pinto bean,a pot experiment was conducted in Shahrekord University's greenhouse,separatly for two pinta beans cultivars Khomein and Talash in cropping year 2010-2011. The experiment included five treatments (0,20,70,150,and 220 mg of cobalt chloride per kg of dry soil) and four replicates arranged in a completely randomized design. After physiological maturity of plants,chlorophylls a and b were measured and total chlorophyll in middle leaves of each pod was calculated as sum of chlorophylls a and b. Results showed a tendency to increase (up to soil CoCl2 concentrations of 20 mg/kg) and then a decrease in both chlorophylla.b and totall densities (at soil CoCl2 concentrations more than 70 mg/kg). Totally,Soil CoCl2 concentrations of 150 and 220 mg/kg significantly decreased the chlorophyll densities compared to control (P<0.05). Despite the negative and significant effect of high soil cobalt,more than 100mg/kg CoCl2, it seems that low soil cobalt(lower than 20mg) for Khomein cultivar and lower than 70mg Co for Talash,may have positive effect on chlorophyll densities in pinto bean leaves. The tolerance threshold for chlorophylls a,b and total chlorophyll were estimated to be approximately 60,30 and 40 mg of CoCl2 per kg of dry soil,respectively,for Khomein pinto bean.For Talash cultivar,the tolerance threshold for chlorophylls b and total was obtained 90 and 55 mgCoCl2 on kg soil. The synthesis of chlorophyll b in pinto beans leaf,in Khomein and Talash cultivars, is more sensitive to high soil cobalt conditions than chlorophylla.

Wheat, by the scientific name of Triticum aestivum L. is one of the most valuable and strategically important products and food in the world, especially third world countries. Therefore, any effort to improve the quality and quantity of thisvery important product is inevitable. Therefore, the phenological characteristics of some Omidbakhsh wheat lines in Isfahan climate conditions was taken. In this study, 17 selected advanced lines from experiments comparing the yeild in KabutarAbad region of Isfahan, in a randomized complete block design with three replications compared to spring control cultivar in two successive cropping years 2008-2010 was examined. Quantitative traits investigated include grain yield, Rosetta germination, Rosetta tillering, stem feeding Rosetta, Rosetta heading, the seeds of milk Rosetta, Rosetta. The results of Omidbakhsh wheat linesas compared with spring wheat cultivar as control showed the tested characteristics as regard to understudied quantitive traites in the first and second years and the combined analysis of two years with each other and with the different control cultivar and a significant effect on the level of 1% risk are seprable. Noticing that among the studied phenological adjectives, the most important factor is the number of days to maturity, so, so the maximum number of days to maturity among the lines in the combined analysis test consists of two lines of 4, with 212/6 days, meanwhile the minimum number of lines were related to 17 and 12, respectively, with 206/5 and 205/8 days. Also, based on the results of comparing the average grain yield in the combined analysis of two years, the highest grain yeild was related to line number 13 with 8/80 tons per hectare and the lowest lines numbers 16 and 1 respectively 7/75 and 7/70 tons per hectare .

In order to evaluate the influence of nitrogen application and duration of weed interference on corn (Zea mays L. ) an experiment as compeletly randomized split plot with three replications was conducted in Ahvaz agricultural research center station the summer 89.The main factor was different amount of N in 3 levels at 60N, 120N and 180N kg per hectare nitrogen from urea and sub-factor, the interaction of weeds includes 3 levels, weeding persistent weeds until the end of the growth of corn (W1), weeding 1 grass in 6 leaf stage of weeds (W2) and compelete weeds interfere with the corn until the end of growth period (W3) . The results showed weeds interfere on yeild and yeild componants of corn had significant effect and with increasing weeds interfere duration ,grain yeild decreased. Increasing competition between weeds made 1000 grain weigth,grain yeild, biological yeild and harvest index ,significant. But nitrogen increasing from 120 kg to 180 kg/ ha, had no significant effect on corn yield and in some cases (interference all season) due to pressure from weed competition, nitrogen and corn grain yield was reduced. The low level of biological nitrogen and high nitrogen levels,corn grain yield was affected more by weed competition.Based on the results of experiment, can be concluded that reducing the duration of weed competition, increasing nitrogen can increase the grain yield.In return, with increasing duration of weed competition,adding nutrients , affect the weed growth more than cropping plant and has increased weed competition tendency.