فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 61 (بهار 1401)

This experiment was performed to investigate the effect of beta estradiol hormone application on increasing salinity stress tolerance of different potato genotypes in a factorial split plot experiment based on a randomized complete block design with three replications in Mohaghegh Ardabili University in 2020. Salinity stresses with three levels (0, 50 and 100 mM sodium chloride) and beta-estradiol also with three levels (0, 10-12 and 6-10 M) were assigned to main plots, and 10 potato genotypes to subplots. The results revealed that plant height, number and weight of minituber per plant, average tuber weight and content of antioxidant enzymes in the studied genotypes showed a positive response to beta-estradiol. Thus, with increasing the amount of beta-estradiol application from 10-12 to 10-6 M, the number and weight of minitubers increased in most of the studied genotypes, but the amount of this increase was varied between genotypes. G5 and G6 genotypes with an average of 7.85 and 7.83 minitubers had the highest number of tubers per plant at 10-6 M beta-estradiol, respectively. The lowest value of this trait belonged to G10 genotype with an average of 3.66 minitubers, without significant differences with those of G8 and G9 genotypes. With increasing salinity level, the enzymes of superoxide dismutase, catalase and polyphenol oxidase and also soluble sugars were increased. In all of three salinity levels, beta-estradiol application significantly increased the levels of these enzymes. The highest levels of these enzymes were observed at salinity level of 100 mM with the use of 10-12 or 6-10 M beta estradiol. In this study, the use of beta-estradiol, depending on the genotype, was able to moderate the effect of salinity on the quantitative and qualitative characteristics of potatoe tubers. Overall, in this study, G5 and G6 genotypes had relatively high minituber number and weight per plant under salinity stress conditions, Thus, selection of these genotypes is recommended for future breeding programs. Also, these two genotypes had the highest number and weight of minitubers per plant at 10-12 and 10-6 M beta estradiol, which indicates that these genotypes have a high genetic potential for consumption of this hormone as compared to other genotypes.

This experiment was carried out in split plots based on randomized complete block design with three replications during 2015-2016 and 2016-2017 cropping years in Khuzestan province. The main factor, consisted as water shortage stress with four levels of irrigation after depletion of 45, 60, 75 and 90% of plant usable water was optimal irrigation, mild stress, severe stress and very severe stress, respectively. The levels of 100% chemical fertilizer, 75% and 50% combination of chemical fertilizer with 100% nitroxin and plant density at three levels of 57, 71 and 95 thousand plants per hectare were as sub-factors. The results showed that the interaction of water shortage stress, combination of nitrogen biochemical and chemical fertilizer and plant density had a significant effect on grain yield, 1000-grain weight, number of seeds per head, harvest index and biological yield. The highest seed yield was obtained from the optimal irrigation treatment by combining 75% of chemical and biological fertilizers and a density of 95,000 plants per hectare, which showed a 75% increase compared to the very severe moisture stress treatment with 75% of chemical and biological fertilizers and a density of 57,000 plants per hectare. The interaction of moisture stress and density and fertilizers on oil percentage and leaf area index was significant. In general, the use of nitrogen from both chemical and biological sources at a density of 95,000 plants per hectare may reduce the effects of moisture stress on the sunflower plant in the experimental condition.

In order to evaluate the role of super absorbent polymer (SAP) for mitigating the water deficit stress at sandy and clay-loam soils, the effect of five values of SAP (0, 0.1, 0.2, 0.4 and 0.8 g.kg-1 soil), three water treatment (the relative soil water content of 80, 60, and 40%) and two soil textures (sandy and clay-loam) on biomass production, photosynthetic pigments, leaf gas exchange parameters, leaf relative water content (RWC), electrolyte leakage (REC), proline content, catalase, super oxide dismutase, and ascorbate peroxidase activity. The experiment was carried out with a factorial arrangement based on complete randomized design in triplicates at the Agricultural and Natural Resources Research and Education Center, Kerman, Iran. The results revealed that water deficit stress caused a significant decrease in net photosynthesis rate, leaf stomatal conductance, chlorophyll a+b content, RWC, plant height, and dry matter production of maize. CAT, SOD, APX activity, REC, and proline were elevated with increasing water deficit stress levels. Application of SAP under water deficit stress increased the net photosynthesis (32.3%), stomatal conductance (38%), chlorophyll a+b (23.9%), RWC (11.9%), and dry matter production (24%), while it decreased REC (10.8%), proline content (66.9%), CAT (42.7%), SOD (33.2%), and APX activity (34.3%) as compared to control. It can be concluded that application of SAP (0.8 g.kg-1 soil) improved plant growth of maize under water deficit stress through increasing the water holding capacity in soil.

This study was carried out in a split plot experiment based on randomized complete block design with three replications at Sarableh Agriculture Research Station in Ilam. Irrigation and non-irrigation (rainfed cultivation) were assigned to the main plots and 20 wheat genotypes to the sub plots. The amount of total SOD, CAT, and APX activities, RWC, prolin and yield were measured. Irrigated condition showed a significant difference effect on grain yield, yield, 1000 grain weight, grain number per spike, relative leaf water content, prolin content and anti-oxidant enzymes activities. Relative water content of leaves decreased by 33% and 21% compared to optimal irrigation conditions in the first and second years of experiment, respectively. Prolin content increased by 81% in rainfed conditions. Catalase, Superoxide Dismutase and Ascorbate peroxidase activities were also increased under rainfed condition. Significant variation was observed among genotypes for traits under study and the rate of variation of traits under dryland conditions was not similar for different genotypes. Cultivation under rainfed conditions decreased grain number per spike (24%) and grain weight per spike (16%). Cultivation under rainfed conditions reduced grain yield by 29 and 41% in the first and second year, respectively. But, the percentage of yield losses in both two years of experiment were not similar for different genotypes. The results showed that the rainfed condition affected the crop yield, and all of traits under experiment. Thus, the means of traits of genotypes under irrigated and rainfed conditions were significantly different. The activity of antioxidant enzymes (catalase and superoxide dismutase and ascorbate peroxidase), relative water content of leaf and proline percentages in rainfed conditions were significantly increased as compared to irrigated condition.

In recent years, growing awareness of environmental problems, particularly global warming, has raised concerns about the impact of greenhouse gas emissions on the global atmosphere. More life cycle assessments are used to assess and compare the environmental impacts of energy production and the economic aspects of producing a product worldwide. The aim of this study was to evaluate and analyze the environmental effects of canola production in terms of life cycle assessment (LCA) using SimaPro software with the aim of focusing on environmental impacts. In order to perform the experiments, one ton of rapeseed was used as the operational unit. Required data were collected from 30 farms in Alborz province. The results indicated that the potential of human toxicity, terrestrial ecotoxicity, freshwater aquatic ecotoxicity, and arine aquatic ecotoxicity per ton of rapeseed production were 881.63, 7.08, 288.67, and 618515.14 kg 1,4-dichlorobenzene equal (1,4-DB eq.), respectively, and photochemical oxidation potential was 0.43 kg C2H4 eq. The amount of nitrogen, phosphate and potassium used to produce each ton of rapeseed was about 84, 63 and 63 kg, respectively, and the amount of diesel fuel and electrical energy were estimated at 133.5 liters and 586 kW, respectively. Also, the CO2, CO, N2O and NOX emissions were about 361, 4.1, 11.5 and 4.8 kg per ton of rapeseed, respectively. It was also found that chemical fertilizers had the largest contribution among the evaluated inputs in the canola life cycle. As a whole, this study showed that the management of nutrients and pesticides can be considered as a strong point for optimizing the environmental impact of rapeseed production.

Industrialization of todays societies, resulted in increased use of machinery and excessive use of fertilizers and chemical pesticides in agriculture. Life cycle assessment is one of the environmental assessment methods that is used to assess processes, products and services. Life cycle assessment method in this study is used to evaluate the environmental effects of bean production with sprinkler and flood irrigation methods in the crop year of 2016-2017 using the effects of global warming, acidification, land euotrophication, depletion of fossil, phosphate and water resources exploited in Yasuj city. The results showed that the final index of the three groups of environmental impact factors (global warming, acidification and land euotrophication) in rainfed more than flood farming and the indices of the three groups of resource depletion effects (fossil, phosphate and water depletions in both croppimg system. The environmental indices for sprinkler, flooding and flood irrigations were 0.634, 0.513, 1.14 and 2.26 respectively. Elimination of unnecessary operations in the planting process and reduction of fuel consumption, irrigation in the last hours and the beginning of the day when evaporation is low, the use of biological methods to remove pests and attention to general recommendations for chemical fertilizers can be effective in reducing environmental effects.

To investigate the effect of using nano-chelate zinc and iron ratios on yield and yield components of maize and cowpea seeds, a factorial experiment was conducted by using randomized completely block design with three replications in the south of Kerman, Iran, during 2018-2020. Experimental treatments consisted of five levels of mixed culture of corn and beans (100% beans, 75% beans + 25% corn, 50% beans + 50% corn, 25% beans + 75% corn, and 100% corn) and four levels of iron and zinc nanoclates combination (iron nanoclate, zinc nano-chelate, iron nano-chelate + nano-chelate zinc and control). Number of seeds per ear row, 1000-seed weight, seed yield and harvest index were measured. The results showed that the effect of planting ratios on number of seeds per ear, 1000-seed weight and harvest index were statistically significant at 1% and on grain yield at 5% level of probability while it was not significant on number of seeds per ear row and number of rows per ear. The highest number of seeds per ear (707.8), seed yield (12787 kg.ha-1) and 1000-seed weight of corn (253 g) were obtained from 25% bean + 75% corn crop ratio. The highest harvest index (52%) was obtained from pure culture. Simultaneous application of nano-chelate iron and zinc increased the quantitative and qualitative properties of corn. Intercopping of 25% cowpea + 75% corn with nano-chelate application produced the highest proein percent (22.3 %). The highest value of land equality ratio (total) (2.12) was obtained by using a mixed cultivation treatment of 75% bean + 25% corn and the lowest (1.57) by 25% of beans were +75% of corn and zinc combinations. Finally, the highest grain yield of 12,993 kg.ha-1 was obtained from a intercropping of 75% corn + 25% bean and application of iron and zinc.

To investigate the effect of foliar application of iron and zinc from sulfate and EDTA-chelated sources on quantitaty and qualitaty of corn seed yields were compared. Thus, field experiment was carried at Dezful, using maize single cross 701 cultivar, in a randomized complete block design for one years. The experiment consisted of seven treatments: control, foliar spraying with chelate or sulfate of iron with a concentration of three mg.L-1, foliar application of sulfate or chelate of zinc with a concentration of mg.L-1, foliar application of combined sulfate or chelate of zinc and iron with a concentration of 1.5 mg.L-1 for each element. Results at the experiment showed that the effect of different foliar treatments on all factors, except cob weight and grain manganese concentration, were significant. The highest grain yield was 9520 kg.ha-1 and biological yield (37.73 ton.ha-1), in the combined foliar application of iron and zinc, was 13% increase, as compared to the control. There was no significant difference in grain yield between the two sources of iron chelate and iron sulfate. The highest concentration of iron grain was observed by using foliar application with ferrous sulfate at a concentration of 3 mg.L-1 and the highest concentration of zinc foliar application observed with zinc sulfate at a concentration of 3 mg.L-1. The highest percentage of protein content was observed by using foliar application of iron and zinc. The results of this study showed that foliar application of corn with iron and zinc increased seed yield and improves its quality. There were no significant difference between the two sources of sulfate and chelate applications, while in some cases the use of sulfate source showed better results.