جستجوی مقالات مرتبط با کلیدواژه « غده » در نشریات گروه « آب و خاک »

Proper irrigation and optimal nutrition of plants have a significant effect on the yield and quality of the plant. To investigate the effect of irrigation period, sulfur and boron levels on turnip yield and quality, an experiment was conducted as the split split-plot (twice split plots) with randomized complete block design with three replications in the field. Irrigation as a main treatment in three levels (3, 5 and, 7 days), sulfur (0, 400, 800 and, 1200 kgha-1 from powdered sulfur source) and boron (0, 1.7, 3.4, and 5.1 kgha-1 from Boron acid source) were considered as a sub-treatments at four levels. The results showed that the highest and lowest dry weight of turnip tuber obtained from S800B3.4I3 and S0B0I7 treatments, respectively, had 82.3% differences. The highest and lowest concentrations of turnip tuber sulfur were obtained by 0.8% and 0.19% in S800B3.4I3 and S0B0I5 treatments, respectively. In this study, the synergistic effect between boron-potassium and the antagonistic effect was observed between sulfur-phosphorus and boron-nitrogen, sulfur, calcium, and magnesium. The highest boron concentration of turnip tuber was obtained 39.4 mgkg-1 in S0B3.4I3 treatment and the lowest boron concentration was 18.19 mgkg-1 in S1200B0I7 treatment. Overall, it can be stated that the highest turnip tuber yield and the best balance of macronutrients and boron were observed in S800B3.4I3 treatment.

Due to climate change, one of the limiting factors of crop production is environmental stress which, by disrupting the natural metabolism of the plant, limit plant growth and finally reduce crop production. Drought stress causes the greatest reduction in crop productivity compared to other environmental stresses. Therefore, the use of methods to reduce water consumption in agriculture is more important due to the lack of freshwater resources. Increasing water use efficiency and maintaining plant yield by reducing water consumption has a particular importance for crop production and should be paid special attention. Drought stress reduces photosynthesis, stomatal conductance, biomass, growth and consequently plant yield. The effects of drought stress on the yield of plants such as potatoes (Solanum tuberosum L.), wheat (Triticum aestivum L.), rice (Oryza sativa L.) etc., which play an important role in the nutrition and food of the world, has a great importance. Achieving the desired soil moisture range is one of the most important approaches to increase water use efficiency and not significantly reduce yield. For this goal, a factorial experiment was conducted in a completely randomized design with five replications in the research greenhouse of Ferdowsi University of Mashhad.

Factors studied in this experiment included three levels of irrigation 1- full irrigation (100% of field capacity), 2- medium drought stress (70% of field capacity), 3- partial root-zone drying (70% of field capacity), time of induction of water stress (two weeks after planting and 50% at flowering time) and two levels of phosphate (CaH4[Po4]2 H2O) fertilizer (based on soil analysis (25 mg.kg-1) and adding 25% more than recommended (31 mg.kg-1)) at the beginning of the period phosphate was mixed with soil inside the pot in greenhouse condition. Fontane potato cultivar was used in this study. In irrigation treatments, one part of the pots was stressed two weeks after planting and the second part of the pots were fully irrigated until the beginning of flowering and irrigation treatments were applied at 50% flowering stage. From the prepared samples, membrane stability index, osmotic potential, and relative water content were measured in the laboratory and at the end of experiment, plant height, tuber weight, biomass and plant water use efficiency were measured. Minitab 18 software was used to analyze the data.

The results showed that with increasing phosphate fertilizer from 25 mg.kg-1 to 31 mg.kg-1, plant biomass increased significantly and in all treatments biomass increased between 2 to 28% . Partial root-zone drying treatment showed a 17.4% increase in biomass. In the medium drought stress treatment, the total growth period and phosphorus level of 31 mg.kg-1, the lowest water use efficiency was observed, and there was no significant difference in the medium drought stress treatment of the total growth period and the phosphorus level of 25 mg.kg-1. Partial root-zone drying treatment of roots from flowering time and 31 mg.kg-1 P, with full irrigation treatment 25 mg.kg-1 P have the same water use efficiency, but the performance of this treatment  compared to full irrigation treatment was reduced by 28%. Water use efficiency in partial root-zone drying (intermittent irrigation) has increased compared to traditional irrigation, which indicates a more optimum use of water in the medium drought stress method. Full irrigation treatment had the highest tuber weight per plant and partial root-zone drying during the growing season treatment had the lowest tuber weight per plant (65%) compared to full irrigation. The partial root-zone drying treatment after flowering, ranked second after full irrigation treatment, for tuber weight per plant and more tuber weight per plant compared to other drought treatments. Using 31 mg.kg-1 phosphate, tuber weight per plant in full irrigation treatment reached 332 g.plant-1 which increased by 13% and was significantly different from all treatments. With increasing phosphate level from 25 mg.kg-1 to 31 mg.kg-1, in the partial root-zone drying treatment from flowering time, tuber weight per plant increased by 28% to 207 g.plant-1. Tuber weight per plant in other drought treatments decreased with increasing phosphate level from 25 mg.kg-1 to 31 mg.kg-1, although this decrease was not statistically significant.

Compared to deficit irrigated methods, partial root-zone drying from the beginning of growth and full irrigation has the ability to use available nitrogen at the end of the growing season and has more greenery than other drought treatments. This effect probably explains the filling of the gland tubers at the end of the growing season and thus the keeping of yieldyield production. The best methods for saving water consumption and maintaining the yield, the partial root-zone drying methods is better than the medium drought stress method.

Many scientists have discovered the useful effects of magnetic field in agriculture and are have become interested because cheap and eco-friendly technique. The purpose of this study was to investigate the effect of magnetized water and priming with magnetized water under drought stress on some morphological traits of radish plant. The experiment was carried out with factorial experiment in completely randomized design with three type water treatment, four priming treatment and three irrigation deficit treatment in four replications in greenhouse ferdousi university of mashhad. After harvesting, root cleaning was performed, and the most important morphological indices including fresh and dry weight of three plant parts, tuber length and diameter, leaf area, tuber density, root length and tuber volume and root volume were measured. Results showed that with increasing drought stress all measured traits decreased but the use of magnetic water has improved all the traits, So that the simple effect of magnetized water for one hour increased leaf area, shoot and tuber dry weight, shoot, root and tuber fresh weight, root length, diameter and tuber length and tuber and root mass by is respectively 15, 24, 56, 20, 48, 80, 11, 11, 31, 85 and 50 Percent but in priming treatment, leaf area, fresh and dry weight of shoot, tuber fresh and dry weight and tuber density had no significant effect. In general, the results showed that magnetized water protects radish plant as a protective agent against drought stress and cause increasing plant yield and decreasing water consumption.

One of the most important legume forages of Iran is alfalfa، which annually covers more than 600 thousand hectares of arable land. This plant is capable of fixing significant amounts of molecular nitrogen، if Sinorhizobium meliloti bacteria exist in the soil and suitable climatic and soil conditions prevail. In order to isolate and study the effect of different strains of S. meliloti on alfalfa yield، 20 soil samples were taken from different fields in Karaj and were planted to alfalfa in the green house. Later، 32 strains related to S. meliloti were isolated and 20 of which were confirmed، using the contamination test. To study the effect of these 20 different strains on alfalfa yield and to compare with applied nitrogen fertilizer in the presence of S. meliloti bacteria، an experiment was done using factorial treatments with completely randomized design in three replications (total of 72 treatments). Treatments were (inoculation، no-inoculation، and nitrogen fertilizer). Results of soil analysis showed that the amount of P، B، Fe، and Zn in most of alfalfa fields was less than critical level. Deficiency of these elements was one of the limiting factors of yield and nitrogen fixation in the field. The greenhouse experiment results showed that the effects of inoculation and nitrogen fertilizer on yield were significant (P<0. 05). Also، the effect of nine isolates on height of plant and fresh and dry weight of roots were significant compared to the control، while 10 isolates had significant effects on the nodules weight. Application of nitrogen fertilizer decreased nodulation significantly (P<0. 05) compared to the control and the inoculated treatments. The S11 treatment، which had the highest mean of shoot dry matter (1. 38g)، was in the same statistical group with S9 (with the average of 1. 36 grams) and both treatments showed a significant increase compared to the control. The S17 had the lowest average dry weight (0. 77 g).