جستجوی مقالات مرتبط با کلیدواژه « maize » در نشریات گروه « اکولوژی »

This paper was conducted to study the quantitative traits related to grain yield and to investigate the relationship between different traits and to select the most important quantitative traits affecting grain yield in maize hybrids.

The experiment was conducted in a randomized complete block design (RCBD) with three replications in the two cropping years of 2017-2018 in Shiraz region. sampling and taking notes were performed from the two middle rows.

Based on the combined analysis of variance at the probability level of 0.01, all hybrids had a significant difference. Also, the effect of hybrid year was significant in all traits except ear diameter. Based on the comparison of the mean performed by Duncan method, two genotypes KSC704 and KSC707 were identified as hybrids with superior rank. Based on the correlation analysis, grain yield had a positive and significant correlation with grain width and 1000-grain weight. Also, the results of the correlation diagram showed a positive and significant correlation between grain yield and grain length, 1000-seed weight, plant height, ear length and number of rows per ear. The drawn polygon diagram also showed that KSC705 genotype is more desirable than other genotypes. Based on the ranking chart of genotypes based on the ideal genotype, SC647 hybrid was identified as a hybrid with better desirability.

Conclusion :

Based on the studied traits, KSC704 and KSC705 genotypes were identified as better ranked hybrids and SC301 and SC302 genotypes were identified as unfavorable genotypes.

This experiment was performed to evaluate the effect of organic amendment and growth-promoting bacteria on phytoremediation of maize under cadmium (Cd) stress.

This experiment was performed in the form of factorial in a completely randomized design with 4 replications. Experimental factors were: 1- biochar as a soil organic amendment at two levels (non-application and application (20 g.kg-1 soil), 2- Pseudomonas putida at two levels (non-inoculation and inoculation of bacteria) and 3- heavy metal levels (0, 25, 50, 75 and 100 mg Cd. Kg-1 soil). 

Cadmium in all concentrations had reduced the dry weight of roots and shoots, while biochar application and bacterial inoculation increased these traits; when the maximum shoot dry weight (9.43 g per plant) was observed by biochar application and inoculation of Pseudomonas putida and no cadmium contamination, which increased 45.30% compared to the control. The highest amount of available cadmium in soil, roots and shoots were 23.29, 33.90 and 36.25 mg/kg, respectively, which all three were obtained in the concentration of 100 mg Cd/kg soil. The lowest amount of bioconcentration factor (0.75) and bioaccumulation factor (1.03) were related to the synergistic treatment of biochar and Pseudomonas putida at the concentration of 25 mg Cd/kg soil, which decreased up to 17.90 and 10.62% compared to the control, respectively.

In order to study the effect of Plant Growth Promoting Bacteria and Mycorrhizae Fungi application as seed coinoculation on three late maturity maize single cross hybrids seed germinability and seedling vigour a laboratory research conducted. 

Experiment conducted as 18 treatments (3 single crosses × 6 seed inoculations) two factorial based on complet randomized blocks design by four rplications. Studied Plant Growth Promoting Bacteria were Azotobacter chroococcum, Azospirillum lipoferum, Azospirillum brasilence and Pseudomonas fluorescens and studied arbascular mycorrhizae fungi were Funneliformis mosseae and Simiglomus hoi. Also studied late maturity maize single cross hybrids were SC700, SC704 and a new promising late maturity maize single cross hybrid B73×K18. Effect of coinoculation of seeds by studied Plant Growth Promoting Bacteria and Mycorrhizae Fungi on germination ability and seedling vigour of studied late maturity maize single cross hybrids evaluated by germinability, mean germination time, coefficient of velocity of germination, mean daily germination, daily germination speed, seedling length, primary shoot length, primary root length, seedling dry weight, primary shoot dry weight, primary root dry weight and  seedling vigour Index measurement.  

The results revealed that except of mean daily germination and coefficient of velocity of germination, other studied traits affected by intractions of hybrids and coinoculation. Likewise,  revealed that application of an inoculant of  three bacteria combination and Glomus mossae have highest growth promoting effect on germinability and traits related to seedling vigour of all hybrieds and Azotobacter chroococcum and Azotobacter chroococcum+ Pseudomonas fluorescens and Glomus mossae seed co inoculation by those bacteria  have most growth promoting effect respectively. Also, revealed that studied characters of SC704 more than other hybrids affected by growth promoting effect of studied bacteria and mycorhizae and respectively B73×K18 and SC700 affected by studied Plant Growth Promoting Rhizobacteria and mycorhizae fungi stimulating effect and studied characters have high correlation among them. 

Based on this research results application of studied Plant Growth Promoting Rhizobacteria and mycorhizae fungi as seed coinoculation had considerable effect on studied late maturity maize single cross hybrids seed germination enhancement and seedling improvement. Therefore, application of them as commercial biofertilizer maybe possible through seed coating for maize cultivation development.

Since improving the efficiency of environmental resources utilization in intercropping is one of the essential strategies for achieving sustainable agriculture, Therefore, in order to assess some ecophysiological properties of maize S.C 704 in additive intercropping with mungbean, an experiment was conducted.  

The experiment was based on randomized complete block design with six treatments and four replications in Dezful region during the summer of 2018. Experimental treatments consisted of different additive intercroppingof maize-mungbean intercropping (adding 10%, 20%, 30%, 40% and 50% of optimum density of mungbean to optimum maize density) and a pure stand of maize (control).  

The results showed that the effect of different maize -mungbean additive intercropping treatments on leaf area index, leaf area duration, light absorption, crop growth rate, dry matter accumulation and light use efficiency was significant. But the relative growth rate was not significantly affected by the treatments. In this study, with increasing in mungbean density, the evaluated traits in all intercropping treatments were higher than that of pure maize. However, the additive intercropping treatment of maize+40% mungbean utilized higher leaf area index (5.28), leaf area duration (217 LAI-day), absorption of photosynthetically active radiation (18.12 MJ/m2), Crop growth rate (30.14 g/m2/day) and relative growth rate (0.0838 g/g/day) compared to the other treatments, resulting in the highest dry matter accumulation (1996.50 g/m2) and consequently the highest radiation use efficiency (2.91 g/mJ).  

In general, maize+40% mungbean treatment can be introduced as the best maize-mungbean additive intercropping system, regarding environmental resources consumption and dry matter production.

The development of energy supply from biomass to reduce greenhouse gas emissions has led to focus on producing important crops from energy perspective which culminated in water consumption increase. Therefore, in this study for analyzing the water and bioenergy nexus, an index called water footprint was used. In this regard, information about maize in the plains of Khuzestan province, was collected. Based on the calculations, it was found that the water footprint of maize crop in the province has an average of 3355.6 m3/ton and the biomass water footprint is equal to 214.9 m3/ton. Moreover, in the study of water footprint of maize biomass, it was found that the highest and the lowest water footprints devoted to Behbahan plain (27.1 m3/GJ) and Abbas Abad plain (10 m3/GJ), respectively. Accordingly, Khuzestan province with an average of 13 m3/GJ, has better condition in terms of water consumption in compare to countries such as Zimbabwe, Brazil and the United States with a water footprint of 200, 39 and 18 m3/GJ, respectively. Mapping the biomass energy production potential with the water footprint approach also showed that water footprint in southeastern plains of the province (especially Behbahan, Omidieh, and Hendijan) are in the interval between 12 up to 27.1 m3/GJ and have low priority for biomass production. In contrast, the northern and eastern plains (especially Abbas Abad, Andimeshk, Sidon and Qaleh Tal) with bioenergy water footprints of 10 to 10.9 m3/GJ have high priority to the use of maize biomass for energy production.

In order to investigate the response of grain yield, plant height and phenological traits of maize hybrids (Zea mays L.) to planting date, a factorial experiment was carried out based on complete randomized block design with four replications during two growing seasons (2013-2014) at Moghan Research Station. Treatments consisted of two planting dates (May 1 and June 25) and five maize hybrids (namely SC704 and SC720 from a late maturing group, TWC600 and SC647 from mid maturing group and SC301 from early maturing group). The results of statistical analysis showed a significant difference between years, planting dates and hybrids. The highest grain yield and plant height were related to SC704 and SC720. The results showed that the planting date on May 1 increased plant production compared to June 25. The highest average of days to physiological maturity related to planting date was May 1. SC704 and SC301 had the highest and lowest average of days to flowering and days to pollination in two different planting dates during two growing seasons (2013-2014) in Moghan region, respectively. Multiple regression analysis by stepwise method showed that in regards to days to pollination and days to physiological maturity with grain yield of maize hybrids there was a significant positive association (P<0.01) in two different planting dates (May 1 and June 25) during two growing seasons (2013-2014) in Moghan region. In conclusion, The phenological traits with grain yield can be used to select the best maize hybrids for different planting dates.