CROP PHYSIOLOGY
Year:2010 | Volume:2 | Issue:3|Papers Count:9

In order to evaluate of integrated weed management efficiency, a comprehensive study was conducted in Research Field of Shushtar Islamic Azad University in the summer of 2006. The experimental design was randomized complete block (RCBD) with 4 replications. Treatments were 8 different combinations as Atrazin+Lasso, Atrazin+Lasso+one time cultivator+24D, Atrazin+Lasso+two times cultivator, Eradican, Eradican+ one time cultivator+24D, Eradican+two times cultivator, one time cultivator +24D, two times cultivator+24D with two control treatments, consisted of free control weeds and complete control weeds. Atrazine, Lasso and eradican applied as pre-sowing and 24D applied in 2-5 leaf stage. Cultivator treatments were used 15 and 25 days after applying 2.4D, respectively. Corn grain yield and yield-related traits as total dry weight and yield components were significantly affected by the treatments. The highest grain yield was obtained in T3 with 11800 kg per hectar.Our results indicated that integrated methods of weed management are more efficient than chemical and mechanical ones.

In this research to survey the effects of irrigation interval and nitrogen fertilizer on physiological indexes of growth and function of silage corn (hybrid S.c.704), we did an examination as split plots in randomized complete block design with 3 replications in agricultural research station- Biokola (Neca) in 2009 culturing year. Irrigation interval were in four levels of irrigations 75, 100, 125 and 150mm evaporation from class A evaporation pan as main factor and three levels of nitrogen values 0, 96 and 184 kg/ha (in order 0, 200 and 400kg urea/ha) as sub ordinate factor. Results showed that irrigation interval in characteristics like grain yield, biologic yield and stalk yield (5%) and nitrogen values in characters like grain yield, biologic yield and stalk yield, harvest index, hundred grain weight, ear length, number of row in row of ear, number of grains in each row and grain number per row of ear (1%) and ear thick (5%) became significant and also interaction between irrigation interval and nitrogen values and biologic yield and stalk yield had significant effect (1%). Grain yield consumption 184 kg nitrogen in hectar than to not consuming 19.8% had significant in crease. The maximum harvesting index obtained for treatment without consuming nitrogen and increasing nitrogen consumption until 184 kg/ha, harvesting index decreased because of intensity of increasing stalk yield than to grain so that stalk yield than to control in creased about 45.3%. The relatively growth rate under nitrogen values for irrigation interval 75, 125 and 150mm evaporation from class A evaporation pan was almost equal and just under irrigation interval 100mm evaporation from evaporation class A evaporation pan, the relatively growth rate consuming 96 and 184 kg/ha nitrogen increased in all growth stages. In leaf area index and special leaf weight in treatments of irrigation interval consuming 184 kg nitrogen in hectar specially in final stages of growth period was maximum. Net assimilation rate in conditions without consuming nitrogen for all irrigation interval in final of growth period comparison to consumption 96 and 184 kg nitrogen in hectar became negative. The most changes processes of bush height observed from stage 8 leaves to then consuming 184 kg nitrogen in hectar and bush height in tassel appearance with irrigation interval 125mm evaporation from evaporation class A pan obtained.

This research was conducted for preparing pedo - transfer functions and mapping of -Iron (Fe) on seed and wheat farms soils of some regions Khuzestan province. In order to, at maturity growth stage of wheat, 121 samples (soil and wheat) were taken from Ahvaz, Dasht-e-Azadegan, Hendijan, Khoramshar, Mahshar, Shadegan, Ramhormoz and Omedeyeh using a weighing method. All samples (seed and soil) were analyzed for soil properties and Fe of seed. The results revealed that Fe concentrations average on seed and soil were measured 56.5 and 12.56 (mg.kg-1) respectively. Also, more than 50% soils, Fe-DTPA concentration was less than 10 (mg.kg-1). A significant correlation was obtained between the seed-Fe and soil salinity (r=0.74*). There was significant (p<0.05) correlation between DTPA-Fe and Clay content (r=0.73*), cation exchange capacity (CEC) (r=0.82*), P-available (r=0.82*) and EC (p<0.01) (r=0.86**) of the soils. Hence, The soil salinity had main role on soil- Fe bioavailability for plant uptake. The regression pedo-trasfer function showed that seed Fe concentration depended on sol salinity, P-available and CEC (R2=0.96). The semivariograms of seed and soil Fe concentrations revealed spherical model can explain seed and soil Fe spatial variability in study regions.

In order to study the effect of aging acceleration test on seed germination and seedling growth of wheat cultivars an experiment was done based on a randomized complete block design with 3 repetitions in 2 media (aging and normal) using combined analysis of variance during 2008-2009 in laboratory of seed control and certification department in Agricultural Research Center, Safiabad, Dezful.Factors were best selected wheat cultivars (chamran, veerynak, dez, kavir, chenab, zagrous, star, behrang, dena and karkhe). All cultivars incubated in incubator (temperature, 45°C; humidity, 100 %) for 72 hours to quicken aging. Dena, karkhe and behrang belonged to durum species and the other ones were subspecies of bread wheat. Results showed that there were significant effect of cultivar, medium and as well as interaction of them on germination percentage and germination rate at 1% probability, the other traits were significant at 1% and 5% probability.Among cultivars. zagrous revealed the highest germination percentage (92%) and star cultivar showed the highest germination rate with 75%, and these results, are because of vigor and high quality of these cultivars in aging medium.There were not signicant differences between chamran, veerynak and star cultivares in germination percentage when grown in normal medium. Finally results indicated that there were a positive significant correlation between germination percentage and seed yield at 1% probability.

In the present study two types of canola, Elite and Talaieh were subjected to simultaneous stress of drought (three levels) and ascorbic acid (one level). After the period of stress, plants were harvested and different growth parameters as Dry and Fresh Weight of the shoots and roots, Leaf Surface Areas, Relative Growth Rate, Relative Leaf Growth Rate, Leaf Water Content Area, Specific leaf Area, Unit leaf Rate were measured. In both plant varieties, Acid ascorbic reduced the negative effects of drought. The Elite type showed better results than Talaieh. Both plants were harvested in 40th day after exposure to drought and ascorbic acid and then water extracts of different parts of treated plants were prepared. The allelopathic effects of canola plants on germination and growth rates of soybean plant (type TMS) was evaluated. According to the results the water extract obtained from Talaieh revealed better effects on longitudinal growth of roots and aerial parts of soybean seedlings. Canola extract from ¼FC irrigation and ascorbic acid treated plants showed significant rise in activity of ascorbate peroxidase, catalase, and peroxidase enzymes in soybean plants compared to canola extracts under other treatments with ascorbic acid. The same results were seen in Elite type, although the highest level of ascorbate peroxidase activity in soybean seeds was observed with the extracts from plants under FC.

The present study was conducted to investigate the effect of different levels of irrigation and withholding irrigation on yield and yield components of corn; hybrid S.C.704 in 2009 in Ahvaz Shahid Salemi Experimental Field. The experiment was set up as a factorial in a randomized complete block design with three replications. Treatments were arranged with three irrigation levels: I1, I2 and I3 in which each was irrigated equivalent to 100% (control), 80% and 60% available water into targeted soil respectively.Using pan evaporation of class A to calculate the quantity of water in regard to evaporation for each treated plot, and three levels of withholding water: S1, S2 and S3 which following with no implement of water stress (control), withholding water at the stage of 8th leaf growth and withholding water at the silk stage, respectively. The results of data analysis indicated that there was significant effect on kernel and dry matter yield due to irrigation and non-irrigation treatments. As drought stress severity was promoted kernel, dry matter yield, harvest index and biological yield were significantly decreased. Severe drought stress (I3) caused reducing the kernel yield by 59% when compared to plants grown under control (I1) condition. Withholding water during silk stage drastically reduced corn yield in comparison with withholding water at the stage of 8th leaf growth and control treatments.Reduction in number of seed row in cob, number of seeds per row and 1000–grain weight were primary factors for corn yield and yield declining.

In order to investigate the effect of planting date and leaf cutting (defoliation) on yield and yield components of corn (hybrid single cross 700), an experiment was conducted in 2009, as split plot in randomized complete block design with three levels of planting date (June 26, June 11, July 27) as main-plot factors and defoliation in three levels (no defoliation, defoliation in tassel emergence stage, defoliation in anthesis-silking interval) as sub-plot factors. Results showed that there were no significant effect of planting date and defoliation on number of kernel rows per ear, kernel number per ear, kernel weight per ear and grain yield.Planting date revealed no significant effect on number of rows per ear, in contrary, defoliation showed significant effect on that, at 1% probability, also 1000-kernel weight was not affected by planting date and defoliation.There were significant interaction effect of planting date × defoliation on kernel rows per ear.The highest grain yield was obtained in planting date of June 26 with 10.56 ton/ha.The treatment of no defoliation showed the highest grain yield. Interaction effects of treatments indicated that the lowest yield was related to defoliation in tassel emergence stage on July 27.Our results showed that late planting and defoliation can cause yield decline in corn. Finally grain yield depends on the time of defoliation, as well as, the weather conditions of the region.

In order to study of nourishing systems effect (input, fullput and organic) on two bean cultivars an experiment was carried out in the summer of 1388 at Agriculthural Research Station, in Ivan town (Ilam province) as split plot in a randomized complete block design with four repetitions. Nourishing systems (input, fullput and organic) were considered as subplots, with three levels, and bean cultivars (flourished, collage) were as the main factor. Variables such as, number of sheathes per bush, number of seeds per bush, number of branches per bush, bush height, hundred seeds weight, seed yield, biological yield and harvest index were measured. Analysis of variance showed that there were significant interaction between variety and characteristics as seed yield, biological yield, hundred seeds weight, number of sheath per bush, number of seeds per bush, number of seeds per sheath, and bush height as well as significant interaction between nourishing systems and characteristics as harvest index, number of sheathes per bush and number of seeds per bush. Comparison of means revealed that the highest seed yield belonged to the treatment of organic nourishing system with flourished cultivar, and also the highest number of seeds per bush, number of seeds per sheath, number of branches per bush, weight of hundred seeds and bush height obtained from the same treatment. Otherwise, the greatest number of sheathes per bush and harvest index belonged to college cultivar with organic nourishing system treatment. Finally our results emphasize on using of organic nourishing system with flourished bean cultivar.