نشریه علوم به زراعی گیاهی
سال هفتم شماره 1 (بهار و تابستان 1396)

In order to investigate the effect of plant density on yield and grain components of three canola cultivars in north of Khuzestan, an experiment was conducted in Agricultural Research Station of Agricultural Faculty of Islamic Azad University of Dezful Branch in Sanandz in 2012. This experiment was conducted as factorial in a randomized complete block design with three replications. Plant densities were considered at three levels (60, 80 and 100 plants per square meter) and canola cultivars (hayola 308, hayola 401 and S003). The results of analysis of variance showed that plant density and cultivar had a significant effect on grain yield, harvest index and oilseed rape oil yield, while 1000 seed weight, oil percentage and seed number per pod were not affected by density and cultivar treatments. Hayola 401 and Hayola 308 cultivars had the highest seed yield, and their grain yield increased with increasing plant density. The highest grain yield and canola oil yields were  at a density of 100 plants / m 2, with an average of 4470 and 2023.82 kg / ha, respectively. The highest grain yield was obtained at 100 and 80 plant / m2.

Salt stress is one of the major a biotic stresses especially in arid and semi-arid regions. This investigation was conducted to evaluate the effects of the salt stress on APX and SOD activities in safflower genotypes based in a factorial experiment as a randomized complete block design (CRD) with three replications. The experimental factors were six genotypes of safflower (Arak, Isfahan, Khorasan, C111, AC-stirling and Saffire) and five levels salt stress (0(control), 50, 100, 150 and 200Mm NaCl). There was a significant difference between genotypes in activity of SOD and APX enzymes under salt stress, with notable superiority of Isfahan genotype over other genotypes. Maximum activity of SOD was 99.16 uni/g Fw for Isfahan genotype under 150 Mm NaCl. In general, it seems that Isfahan genotype had more tolerance to salinity and AC-stirling was sensitive to salt stress. The results showed that Isfahan genotype had the greatest APX activity with 91unit/gFW while AC-stirling has the lowest content with 58unit/g FW at control treatment. The activity of both enzymes increased with salt stress, that this increase was dependent on genotype. APX and SOD activity decreased at the 200 Mm NaCl concentrations. The reason for declining in enzyme activity may be returned to enzyme protein damage by high salt stress or adaptation of plants to salt stress. Analysis of seedling traits showed that similar to antioxidants context, the genotypes of Isfahan and Ac-sterling had the most and the least values for all of the studied traits. The result showed that Isfahan genotype could be proposed for salt breeding programs in safflower.

This experiment was carried out for two years (2009-2010) with using 17 soybean genotypes at Agriculture and Natural Resources Research Centre of Ardabil (Moghan) as a completely randomized block design with three replications. Eco-physiological and agronomic parameters such as extinction coefficient, light use efficiency, yield and yield components was investigated in soybean at second cropping. Based on analysis of combined variance, the effect of year was significant on number of pods and seeds per plant. All traits were differences significant among genotypes in both years. The maximum (0.62 ± .084) and minimum (0.44 ± 0.034) values for light extinction coefficients were obtained from Hsus-H116 and Apollo genotypes respectively. The highest radiation use efficiency (1.14 ± 0.134) was obtained from Darby, and the lowest (0.91 ± 0.152) from L.17 genotype. Apollo and Zane genotypes had the highest number of pods and seeds per plant in both years. The highest seed weight was obtained from Omaha and NE-3399 genotypes in first and second years, respectively. The highest seed yield was obtained from Apollo (with 3513 Kg. ha-1) in first year and from Zane genotype (with 3774 Kg. ha-1) at second year of experiment, whereas Rend and L.83-570 genotypes had the lowest seed yield in both years.

In order to determine the intercropping of corn and beans control weed growth and yield, this study is a randomized complete block design with factorial experiment 3 Repeat in crop year1391was in the region Gotvand. In this experiment, two-factor, density and mixing ratio were considered for review. Experiment with replacement methods of intercropping of 1:1 (50% + 50% corn, beans), 1:2 (67% + 33% maize, beans), 2:1 (33% + 67% corn and beans) and incremental (100% + 20% maize, beans), (100% + 10% corn, beans), (beans, 100%) (100% maize) and the desired density and optimal hybrid maize than 640 NS (75 and 90 thousand plants per hectare) and local varieties of cowpea (150 and 200 thousand plants per hectare) was considered. Effect of intercropping and plant density on weed number was not significant but was reduced weed dry matter. The highest weed dry matter, 742 g per square meter of cultivated beans, the smallest with 253 grams of pure 100% corn + 20% bean belongs to treatment indicative intercropping system is superior to the system in control of the weed's monoculture. Evaluate the relative density of weed species showed that red root pigweed (Amaranthusretroflexus) with 44% density, the dominant weed species and weed Purple nutsedge  (Cyperusrotundus) Pigweed (Echinochloa crus galli), Alkekengi (physalisalkekengi) , common purslane (portulaceoleracea), white root pigweed (Amaranthusalbus) and cleome(Cleome viscose) in the category were the Also, the results showed that the highest grain yield of maize at a rate of 14,230 kg/ ha monoculture corn and bean density and optimal yield level of 3014 kg, the treatment of corn, 33% - 67% the beans densities the came desirable.

In order to evaluate the effect of triple superphosphate and calcium sulfate fertilizer on yield and yield components of Barley (Hordeum vulgare L.)crop plant in 13 sarasari cultivar, an experiment was carried out at Ahwaz with Factorial arrangement based on a Completely Randomize Block Design with four replications in Research Field of Khouzestan Science and Research Branch which was located in cute abdollah of ahvaz. In this experiment triple superphosphate in three levels (0,30 and 60 kg/ha) and calcium sulfate in four levels (0,50,100 and 150 kg/ha) were strip applied at sowing time. The results showed that the rates of triple superphosphate and calcium sulfate had significant effect on yield and yield components at 1% level. In the base of means comparison, 60 kg/ha triple superphosphate was the most proper treatment on Seed yield, Biological yield, Harvest index, Number of seed per spike, Number of spike per square meter and 30 kg/ha was the most proper treatment on stubble and 1000 Seed weight. Apply of calcium sulfate in comparison with no application condition caused increasing yield of barley but did not observed significant difference among the levels of application in this fertilizer.

In this experiment effect of wheat residuals management, Tillage and Nitrogen fertilizer on agronomic treat of soybean. This experimentwas done in three reptition in form of strip plot and in shap of statistical project of completely random blocks. Experimenting factors includes: Residuals as main factor, Tillage and Nitrogen fertilizer as secondary factors. Results from variance analysis on measured properties of soybean showed that residuals treatment had displayed meaningful difference in harvest index property. Harvest index was highest in the treatment of remains. Nitrogen fertilizer treatment had displayed meaningful difference in seed oil, seed yield and harvest index properties. Starter fertilizer treatment had the highest seed oil content, seed yield and harvest index. Also residuals management interaction and Tillage had displayed meaningful difference in seed yield property. The highest yield obtained in the treatment Residually with tillage, Residually without tillage, no-tillage remains. Also residuals management interaction and Nitrogen fertilizer had displayed meaningful difference in shell number in stem property. Most pods were obtained from the residue treated with starter fertilizer. Also Tillage interaction and Nitrogen fertilizer had displayed meaningful difference in seed oil, shell number in stem and seed yield properties. The highest percentage of oil obtained in the no-tillage treatments with starter fertilizer, tillage and starter fertilizer + NF, tillage and starter fertilizer and Most pods were obtained in treatments with tillage and starter fertilizer and The highest yield was obtained in treatments with tillage and starter fertilizer + NF, starter fertilizer with tillage, no-tillage and starter fertilizer.

This study was conducted to investigate the effect of water extracts of barley plant residues (10, 20 and 30% concentration) on seedling growth and leakage of Ryegrass and wild oat, was carried out as a factorial experiment in a completely randomized design with four replications. The results showed that increasing the concentration of Barley extract was seedling length and seedling dry weight in wild oat and ryegrass reduced. Increasing the concentration of barley extracts increased the degradation of cell membrane and malondialdehyde concentration in weed seedlings. Also, spray application of barley extract stimulated the activity of antioxidant enzymes catalase and peroxidase in seedlings. At the highest concentration of barley extracts, the highest cell membrane degradation (52%) and the lowest seedling dry weight (0.28 g) were observed in ryegrass seedlings.