JOURNAL OF RESEARCH IN CROP SCIENCES
Year:2011 | Volume:3 | Issue:11|Papers Count:10

The date of planting and defoliation of sunflower have some effects on the amount of the damage that is caused by birds. To determine these effects an experiment was done in 2008. in Tazeshahr area, of Salmas. Expriment carried out as factorial experiment arrenged in RCBD with four replications. The first factor of the experiment was the date of planting that was done five times in a year, on 24th April, 9th and 24th May and 8th, 24th June. The second factor was leaf cutting that was done in three forms. In the first one, there was not any leaf cutting. The second form was based on cutting of three terminal leaves after the end of pollen dispersion period and in the third one there was not leaf cutting and it included covering of leaf. The final results showed, the first factor had effects on attributes of diameter of flower, amount of seeds, the yield of seeds, harvest index, biological yield, oil percentage, oil yield and productivity index. Also the leaf cutting had effects on the attributes of seeds yield, harvest index, oil yield and percentage of birds' damage. The date of third planting had the average of 532.3 gram seeds in one square meter. It was the highest yield of seeds. The date of fifth planting had the average of 304.9 gram seeds in one square meters. It was the lowest operation of seeds. The cutting of three terminal leaves could lessen sixty percent of birds' damage; however cutting of the leaves had no effect on the yield of seeds.

To evaluate the effect of different irrigation systems on the growth, yield and yield components of sunflower, an experiment was conducted at Khoy Agricultural Research Center in 2003. Treatments, irrigation levels as main plots (irrigation at 70-70-70, 90-90-90, 110-110-110, 90-70-90, 110-70-110 and 110-90-110 mm evaporation from the standard pan) and cultivar as subplots in 3 levels (Record, Hisun 33 and Armavirusky) in Split Plot in the basis of Randomized Complete Block Deigns were arranged in four replications. Leaf and stem dry weights at HV, FA and PM were significantly reduced as irrigation intervals increased. Difference between irrigation treatments for head dry weight was not significant at FA Increased in irrigation intervals significantly reduced seed yield. The high increase in irrigation water use, water use efficiency decreased. Consequently where the least water use efficiency (0.55) was obtained by 70-70-70 treatment, cultivars only differed for leaf dry weight at HV stage. Armavirusky produced the least leaf dry weight at this stage. Thus, where irrigation water is scarce, 90-90-90 irrigation treatment might be appropriate for sunflower production under condition similar to this experiment.

To investigate the study of interaction of water stress in the end stages of wheat growth and impact of zinc sulfate foliar application on total dry matter, grain yield and its components in three wheat cultivars, a research in the form of split factorial design in the form of complete random block design with three replications was done 2008-2009 in Agriculture Research Center and Natural Resources of Isfahan. In this experiment, treatments of water stress in three levels of complete irrigation to the end of growth season, cutting off the irrigation in the flowering stage and cutting off the irrigation in the phase of grain filling in main plots and treatments of foliar application of the zinc sulphate solution in three level (0, 2.5 mg.l-1 and 5 mg.l-1) in tillering and wheat cultivars including the Mahdavi, Shiraz and Pishtaz in sub-plots were located. The results showed that the difference between water stress treatments on grain yield, total dry matter and 1000 grain weight at the 1% probability level and harvest index at the 5% probability level were significant. Significant increase in grain weight due to use of zinc sulfate in no stress condition was observed. Also increase the amount of zinc sulfate consumed up to 2.5 mg.l-1, compared with 5 mg.l-1 concentration increased average grain yield and harvest index. Pishtaz cultivar compared with the Mahdavi cultivar as a tolerant cultivar because of having as a good genetic potential in water stress condition had higher grain yield.

To determine the Response of yield and yield component of sunflower, cv. Eiroflor to plant density and weeds control methods, an experiment was carried out in Gareziaaddin city, during 2009. This experiment was conducted in factorial design as a base of randomized complete block design with three replications and two factors, included plant density in three levels ( 8, 9.5 and 11 plant per square meter) and weeds control methods with four levels (noncontrol weeds, terifeloralin pre emergence herbicide, nabo-s post emergence herbicide and hand weeding). The results showed that density of 11 plants per square meter with trifloralin pre emergence herbicide method had yield maximum about 741 gr/m2. Minimum yield harvested from density of 9.5 plant with non weeds control method that had yield reduction about 42%. Also harvest index maximum from density of 9.5 plant with trifloralin herbicide about 41%. But grain number per anthodium maximum was to density of 8 plant and trifeloralin herbicide with 1303. With attention to experiment results, the density of 11 plants and trifloralin herbicide for yield increase of sunflower is recommended.

To study the effects of nitrogen levels and its application time on fresh, dry matter and agronomic traits of Speed-feed cultivar of forage sorghum an experiment was carried out in factorial design as randomized blocks with three replications in Khoy agricultural and natural resources research station in 2009. Four levels of N (60, 120, 180 and 240 kg/ha) were applied together with four application times of nitrogen (T1: all applications prior to sowing, T2:1/2 prior to sowing + 1/2 start of 2th cut, T3: 1/4 in every prior to sowing, 30-40 cm of plant height in 1th cut, start of 2th cut and 30-40 cm of plant height in 2th cut, T4: 1/6 in every prior sowing, 30-40 cm of plant height and swelling of flag leaf of 1th cut and start, 30-40 cm of plant height and swelling of flag leaf of 2th cut The highest total dry matter, total fresh fodder and protein yield was obtained from application of 240 kg/ha N (92.06, 20.16 and 2.22 t/ha respectively) but there weren't significant differences with application of 180 kg/ha. That the highest total fresh fodder and Dry matter, 89.28 and 19.62 t/ha respectively were obtained from T4 application times with no difference with T2, T3.the highest dry matter correlation showed by stem dry weight and fresh fodder by r=0.686 and r=0.872 respectively. Because of the absence of significant differences between amounts of 180 and 240 kg/ha, application of 180 kg/ha N with T4 splits is recommended and it is concluded that there was loss of nutrients via leaching and sublimation of N in one stage application.

To evaluate the effect of drought stress at different growth periods of chickpea genotypes on biological nitrogen fixation, an experiment was carried out in Saatloo agricultural research station in cropping seasons of 2008-2009. The experiment was in Split Plot based on Randomized Complete Blocks Design with four replications. Irrigation treatments including water holding at flowering, pod formation and grain setting stages with control were the main plots. Genotypes of Pirooz, ILC482, Kaka and Gazvin were considered as sub plots. Drought stress had significant effect on nitrogen percentage of plants‚ number of root nods‚ root dry weight‚ nods dry weight‚ grain yeild‚ total dry matter‚ number of pods per plant and 100- kernel weight. All of genotypes had significant differences (P≤0.01). The most susceptible growth stage in nitrogen fixation was the occurance of drought stress in flowering stage. Ghazvin and Pirooz genotypes in drought stress had respectively the lowest and highest decrease in nitrogen fixation in their optimum growth condition. Pirooz and Kaka consequently were the most susceptible and tolerant genotypes to drought stress. Correlations of traits that related to nitrogen fixation in drought stress and control in flowering and grain setting stages showed the most positive significance (P≤0.01). Correlation was in number of root nodes with nod dry weight and in drought stress treatment in pod formation stage, the most positive and significant correlation (P≤0.01) was in the number of root nods with root dry weight.

A two-year field investigation was conducted to evaluate the effect of N and K fertilizers on yield and some other qualitative parameters in potato tubers cultivar Agria. This study was carried out in 3 replications, consisting 5 levels of nitrogen and 3 levels of potassium fertilizers during the years 2004-2006. The results showed significant differences between N and K fertilizer levels and their interaction effects on the studied parameters in potato tubers. Increasing in applying of nitrogen from 0 to 120 kg/ha caused raising of yield and moisture, vitamin C, acidity and reduced sugar content of tubers, but decreasing in seed tubers percentage. Accumulated nitrate did not change in this span. Using more nitrogen fertilizer caused reverse results. By Increasing in potassium fertilizer consumption, yield, moisture content, acidity and size of tubers are increased but accumulated nitrate and reduced sugar are decreased.

This experiment was carried out with the aim of attaining a suitable variety and culture method and optimum culture condition in a randomized complete block design in 3 replications with method of culture factor (traditional, Mechanical and direct seeding), variety factor (Barakat, Alikazemi, Hashemi) and condition of culture factor (concurrent rice-fish and mono culture of rice) in Astara in, 2010. The results showed a significant difference between the studied varieties for all traits except grain number per panicle. Between the method and culture conditions there was a significant difference for all traits. Interaction effect between variety and culture method did not have any significant difference for traits except panicle weight, tiller number per bush and straw weight. Interaction effect between method and culture condition had a significant difference only for straw weight. On the basis of the results of the experiment, the Hashemi variety for more paddy yield with mechanical culture of rice seedling method in concurrent rice - fish culture was suitable variety, method and culture condition.

To study the effects of Plant Growth Promoting Rhizobacteria (PGPR) on yield and yield components of bread wheat under irrigated and normal stress conditions, an experiment was conducted at Ilam Agricultural Research Station, in 2009-2010. The experiment was arranged as split-plot in RCBD (Randomized Complete Block Design) in four replications. Cultivars of Chamran and Verinak were allocated to main plots and four levels of biofertilizer including both Azotobacter biofertilizer, Pseudomonas, that's, without biofertilizers and two levels of irrigation (normal irrigation and its termination) were arranged in sub plots as factorial experiment. The results showed that the variety of all the traits were significant except the biological yield. Verinak cultivar produced higher seed yield (4565.4 kg/ha) than Chamran cultivar (4112.5kg/ha). The irrigation had significant effect only on seed yield, weight of 1000 seeds, and harvest index. The biofertilizer levels had significant effect on all of the traits and both of biofertilizers produced higher seed yield (4758.3kg/ha) than others. Among double and triple interactions, only the interaction between variety and biofertilizer was important on the number of spike per m2 and other interactions were not significant. Finally, in this study, results showed that the highest seed yield was obtained using both of the biofertilizers in Verinak cultivar and lowest yield was produced in no biofertilizers in Chamran cultivar.

Study and evaluation of landraces and using suitable genes of these resources is one of the important and basic methods in crop breeding programs. In order to evaluate the genetic diversity in three durum wheat landraces (Zardak, Gerdish and Cheheldaneh), their purification and selection of the best lines with good agronomic traits this study was carried out during three cropping seasons (2004-2007) in Maragheh Dryland Agricultural Research Station. Two hundred individual spikes were selected among each landrace in first year. In second year each spike was planted in separate line and six agronomic traits (cold tolerance, date of heading, date of maturity, plant height, spike color, awn color and tiller number) were noted. Because of winter cold damage in 2nd year, 64 lines from Gerdish and Cheheldaneh and 49 lines from Zardak were planted in square lattice design (8×8 and 7×7) with two replications. Results of study on agronomic traits and grain yield(15 traits) in 3rd year showed that the most diversity in three landraces were belong to cold tolerance, angel of spike with plant, curve of peduncle, flag leaf duration, grain yield and growth vigor at flag leaf emergence and date of heading and date of maturity were the least diversity. Regarding the results and existing suitable diversity in cold tolerance, direct use of the tolerant lines or use of them in crossing programs is recommended.