Seyyedeh Mahdiyeh Kharrazi; Ahmad Sharifi; Saba Nejatizadeh; Azadeh Khadem; Maryam Moradian
Abstract
Introduction: Considering the occurrence of successive droughts in our country and the necessity of optimal water consumption, the use of modern technologies such as closed systems to increase the efficiency of fertilizer and water use will have an effective role in reducing production costs and increasing ...
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Introduction: Considering the occurrence of successive droughts in our country and the necessity of optimal water consumption, the use of modern technologies such as closed systems to increase the efficiency of fertilizer and water use will have an effective role in reducing production costs and increasing yield. The Nutrient Film Technique (NFT) system is one of the hydroponic culture systems in which the nutrient solution is circulated continuously. In this system, a thin layer of nutrient solution will be available to the plant roots, which has a significant effect on reducing fertilizer and water consumption.
Materials and Methods: The present study was conducted to select an optimal system for cultivation of Gerbera plantlets. Plantlets were cultivated in different systems after the acclimation stage: Integrated bedding system as a closed system containing different culture media (Perlite, vermiculite, vermiculite: perlite, cocopeat: perlite and rock wool) and NFT hydroponic system as a closed system. For fertilization, the following fertilizer combination (mM) was used: K2SO4 (0.22), KNO3 (3.62), KH2PO4 (0.71), NH4H2PO4 (0.35), NH4NO3 (0.53), Ca (NO3)2,4H2O (1.48), MgSO4, 7H2O (0.4), MnCl2, 4H2O (0.0049), H3BO3 (0.020), ZnSO4 (0.0061), CuSO4, 5H2O (0.00048), NaMoO4, 2H2O (0.00058), FeSO4, 7H2O (0.0348), Na2EDTA (0.0384). The experiment was conducted in a completely randomized design with six treatments in six replicates. During six months, the growth parameters of the plants including number of leaves, petiole length, fresh and dry shoot weight, leaf chlorosis percentage, leaf necrosis percentage, flower number, flower diameter, flowering stem height, number of days to flowering, end diameter of the stalk and the middle diameter of the stalk were evaluated. Data preparation was done in Excel and data analysis was performed using the Jump 8 software. Mean comparison between treatments was performed with LSD test at 5% probability level and charts were drawn using the Excel program.
Results and Discussion: The results showed that there was a significant difference between treatments for the number of leaves (p <0.01). Seedlings cultivated in the vermiculite culture medium produced the highest number of leaves; however, there was no significant difference between seedlings cultured in vermiculite and vermiculite: perlite media. The lowest number of produced leaves was observed in plantlets grown in the NFT system. Also, the seedlings grown in the rock wool medium had no significant difference with the NFT system. In this regard, the drought stress on plants and the consequent poor growth of plantlets reduced the number of produced leaves. The percentage of necrotic leaves in the NFT system was more than twice the vermiculite culture medium. There was no significant difference between cocopeat: perlite, perlite, rock wool, and NFT systems. Also, the lowest amount of necrotic leaves was found in the vermiculite culture medium, which did not have a significant difference with vermiculite: perlite culture medium. Low levels of leaf necrosis in these treatments indicate the optimal absorption of nutrients and the proper growth of plantlets in these culture media. The results showed that plantlets cultivated in the vermiculite and vermiculite: perlite flowered more quickly than other culture media and also produced more flowers. Plantlets grown in the rock wool medium did not show the desirable performance, which is due to drought stress. Besides, the use of cocopeat in the culture medium did not have a beneficial effect on plants. Measuring the initial electrical conductivity in the cocopeat culture medium also indicates a high EC concentration in this culture medium, which could affect the growth parameters of the plant and lead to poor vegetative growth of plantlets. Since Gerbera plant has bulky roots, the roots of this plant cannot be developed well in the NFT system, so the use of the NFT system is not suitable for Gerbera cultivation. The best performance of plant samples was obtained from vermiculite culture media, but since there were no significant differences between vermiculite and vermiculite: perlite, so to reduce production costs, the use of vermiculite: perlite culture medium in the closed system is recommended for the cultivation of Gerbera plant.
Conclusion: Since Gerbera plant has bulky roots, the roots of this plant cannot be developed well in the NFT system, so the use of the NFT system is not suitable for Gerbera cultivation. The best performance of plant samples was obtained from vermiculite culture media, but since there were no significant differences between vermiculite and vermiculite: perlite, so to reduce production costs, the use of vermiculite: perlite culture medium in the closed system is recommended for the cultivation of Gerbera plant.
Ahmad Sharif; Seyyedeh Mahdiyeh Kharrazi; Saba Nejatizadeh; Azadeh Khadem; Maryam Moradian
Abstract
Introduction: In traditional agriculture, a high concentration of nutrients is generally available to the plant, and a large amount of it will be leached out and is not available to the plant. But, if properly managed, the nutritional needs of the plant can be identified; it can increase the efficiency ...
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Introduction: In traditional agriculture, a high concentration of nutrients is generally available to the plant, and a large amount of it will be leached out and is not available to the plant. But, if properly managed, the nutritional needs of the plant can be identified; it can increase the efficiency of fertilizer use and also prevent the environmental pollution caused by excessive use of chemical fertilizers in the country. Therefore, the aim of this study was to increase the fertilizer utilization efficiency by choosing optimal fertilizer treatment and its optimum level for acclimation and optimum growth of gerbera tissue culture plantlets.
Material and methods: In the first experiment, different fertilizer treatments with different proportions of NPK were evaluated in a completely randomized design with 10 replications. In the second experiment, the different concentrations of the secondary group treatment (0.5x, 1x and 1.5x) were evaluated to determine the optimum level of fertilizer treatment. This experiment also was conducted in a completely randomized design with 15 replications. At the end of each experiment different parameters such as leaf number, petiole length, shoot dry and fresh weight, main root number, root length, secondary root number, root volume, root dry and fresh weight, chlorophyll a, b and total content were measured. Data preparation was done in Excel and data analysis was performed using the Jump 8 software. Mean comparison between treatments was performed with LSD test at 5% probability level and charts were drawn using Excel program.
Results and discussion: The results showed that the maximum root length, root volume, root dry and fresh weight and secondary root number was obtained from plantlets that was treated by the fertilizer treatment of the second group: K2SO4 (0.22 mM), KNO3 (3.62 mM), KH2PO4 (0.71 mM), NH4H2PO4 (0.35 mM), NH4NO3 (0.53 mM), Ca(NO3)2,4H2O (1.48 mM), MgSO4, 7H2O (0.4 mM), MnCl2, 4H2O (0.0049 mM), H3BO3 (0.020 mM), ZnSO4 (0.0061 mM), CuSO4, 5H2O (0.00048 mM), NaMoO4, 2H2O (0.00058 mM), FeSO4, 7H2O (0.0348 mM), Na2EDTA (0.0384 mM). So among the different fertilizer treatment, application of the fertilizer treatment of the second group was recommended. Calculation of nitrate and ammonium content used in six fertilizer treatments showed that the amount of ammonium used in fertilizer had a significant effect on root number and root dry weight. The maximum root number and root dry weight were observed in the second fertilizer group and then in the first fertilizer group. Urea was not used as a source of nitrogen in the fertilizer formula of these two treatments, while in other fertilizer treatments; urea fertilizer was used in addition to other sources of nitrogen supply. Since urea is converted into ammonium before its absorption by the plant, its application in the fertilizer formula has an effect on the amount of ammonium used in the fertilizer composition. It increases the ratio of ammonium to nitrate in fertilizer composition, which in turn influences root function. The ratio of potassium to phosphorus in the research of Khalaj et al. (4.40) is approximately as the same as the ratio of potassium to phosphorus used in the second group fertilizer treatment (4.50). The results of this ratio were also corresponded to Zheng et al. (4.6), Paradikovic et al (4.4), Hahn et al (4), Savvas and Gizas (4.8).The results of second experiment showed that plantlets grown under 1.5x concentration of second group fertilizer had better growth indices than two other treatments and had higher means in terms of root and shoot dry weight and petiole length. After counting the number of produced leaves at the end of the experiment, signs of leaf necrosis was observed under some treatments. Plantlets treated with 1 and 0.5 x concentrations of the second group treatment showed the highest incidence of leaf necrosis. Application of 1.5 x concentration of the second group treatment resulted in a 40% decrease in leaf necrosis symptoms compared to the other treatments. Also, the highest percentage of healthy leaves was obtained from 1.5 x concentration of the second group treatment, which showed a significant difference with the other treatments.
Conclusion: Generally, for the purpose of acclimation and optimal growth of gerbera tissue culture plantlets, fertilizer treatment of the second group {15(N), 10(P2O5), 30(K2O), 11.10(CaO), 2.10(MgO)} at a concentration of 1.5x is recommended.
Saba Nejatie Zadeh; Saeid Malekzadeh Shafaroudi; Ali Reza Astaraei; Nasrin Moshtaghi
Abstract
Introduction: An emerging field of nanotechnology in recent years is the use of nanoparticles and nanomaterials in agricultural systems which is due to their excellent mechanical, electrical, optical, surface properties, crop protection and nano-fertilizers. Titanium dioxide (TiO2) is a class of nanoparticles ...
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Introduction: An emerging field of nanotechnology in recent years is the use of nanoparticles and nanomaterials in agricultural systems which is due to their excellent mechanical, electrical, optical, surface properties, crop protection and nano-fertilizers. Titanium dioxide (TiO2) is a class of nanoparticles which widely used in the food industry, cosmetics, papers, pharmaceuticals, plastics and industrial raw materials. The widespread industrial application of TiO2 is due to its white pigment, ultraviolet blocking property, and chemical features commonly used to alleviate pollutants concentration in water, soil and air. Owing to its increasing use in the industry, a large part of TiO2 residues are released into the environment, and currently, TiO2 nanoparticles are being considered an emerging environmental contaminant. However, there have been a number of studies reporting beneficial effects of TiO2 on growth and physiological traits of crops. It has been postulated that the TiO2-induced improvement of crop growth is not merely related to the promotion of photosynthesis; other biochemical processes especially nitrogen metabolism are also involved in this event. Ethylene diamine tetraacetic acid (EDTA) is a widely used as a chelating agent, i.e., the chemical is able to sequester metal ions such as Ca2+ and Fe3+. EDTA is used as nitrogen source for doping of TiO2 nanoparticles which improves TiO2 photocatalytic features. The present study was conducted to investigate the effects of TiO2 nanoparticles and EDTA on growth indices and biochemical parameters in spinach (Spinacia oleracea). For detailed evaluation of treatment effects, different concentrations of TiO2 nanoparticles were sprayed on spinach leaves and the samples were collected in a time course.
Materials and Methods: A factorial experiment was carried out in the form of completely randomized design (CRD) with three replications. Soil samples were taken before cultivation of spinach (S. oleracea) seeds (Var VIROFLAY) and analyzed for nutrients’ concentration. Treatments include different levels of TiO2 (T1=0, T2=0.05mg/l and T3=0.1mg/l) and two concentrations of EDTA (E1=0 and E2=130mg/l) sprayed on spinach plants in research greenhouse of agriculture faculty, Ferdowsi University of Mashhad. Aqueous solutions of nanoparticles were treated by ultrasound for 10 min to enhance homogeneity. The solutions were sprayed on the plant at six- leaves stage. The plant samples were taken before reproductive phase for measurement of biochemical parameters. Nitrogen content of plant samples was measured by PDV 500 Macro- Kjeldahl device; Potassium content was determined by 310c flame photometer; phosphorus concentration in plant samples was measured by spectrophotometer model 2100. Chlorophyll and carotenoid contents were measured by the method proposed by Lichtenthaler (1978). For analysis of growth parameters, plant samples were taken a week after TiO2 treatments and leaf area, shoot fresh/dry weight, stem length, internode length, root area, root fresh/dry weight and total root diameter were measured.
Results and Discussion: Application of 0.05mg/l of TiO2 nanoparticles without EDTA resulted in 13.5% and 9.48% increase in nitrogen and protein; respectively, however by increasing nanoparticles to 0.1mg/l, nitrogen and protein content in the treated plants were respectively reduced to 21% and 19.57% of those of control group (p
