جستجوی مقالات مرتبط با کلیدواژه "ammonium nitrate" در نشریات گروه "باغبانی"

To investigate the effects of different nitrogen sources including ammonium nitrate, asparagine, and glutamine in five concentrations of 0, 50, 100,150, and 200 mg l-1 on some physiological and biochemical characteristics of rosemary (Rosmarinus officinalis L.), an experiment was conducted in a completely randomized design with five repliacations. The indices including plant height, shooting rate, number of leaves, necrotic leaf size, chlorophylls a, b, and total chlorophyll content, and the content of carotenoids, phenols, and flavonoids were measured. The results showed that the nitrogen sources significantly (P≤0.01) affected the all measured indices except the necrotic leaf size. The results of means comparison showed that the highest shooting rate and number of leaves were obtained at 100 mg l-1 of glutamine and asparagine and the highest plant height was obtained at 200 mg l-1 of ammonium nitrate. Also, the highest amount of photosynthetic pigments was obtained at 50 mg l-1 of asparagine and the highest amount of phenols and flavonoids was related to 200 mg l-1 of glutamine. In general, the results showed that the various nitrogen sources studied could positively and significantly improve the morphological and physiological characteristics of rosemary under in vitro conditions.

In this research, effects of iron and nitrogen nutrition in three concentration (Iron chelate 0, 5 and 10 ppm and Ammonium nitrate, 0, 40 and 60 ppm) were evaluated on nitrogen, potassium and phosphorous contents in fruits and leaves of apple (cv. Fuji) in harvesting time and on fruit quality during storage. The experiment was carried out using a factorial completely randomized block design (CRBD) with three replications in 2013. Results showed that nitrogen treatment had no significant effect on fruit quality, except Vitamin C content that significantly increased. Iron nutrition mainly decreased the fruit weight loss during the storage. Storage time affected fruit quality and decreased that, which after 95 days, fruit were more injured. During the storage, Vitamin C, fruit firmness, dry weight and total acid were decreased. Nitrogen nutrition increased the nitrogen content in fruits and leaves but decreased potassium level in these organs. Iron treatment had no significant effects on nitrogen and phosphorous contents but significantly decreased potassium content in fruits. These results indicated that, storage of Fuji cultivar for three month had no reducing effects on quality.

Production of medicinal crops in soilless culture systems and controlled environments provides an opportunity for increasing the quantity and quality of primary materials of medicinal plants. A factorial experiment based on completely randomized design was carried out with four culture systems (aeroponics, nutrient film technique, classic hydroponics and soil) and three different nitrogen sources (nitrate, ammonium nitrate and ammonium) and three replications. Results indicated that vegetative traits such as plant height, stem and root diameter, number of lateral branches and leaf area were affected by culture system and source of nitrogen. Plants grown in aeroponics fed by ammonium nitrate had the highest plant height and root and stem diameter. The results also showed that nitrogen source and culture system had significant effect on root dry and fresh weight, shoot dry and fresh weight and root yield per hectare. Maximum and minimum of these parameters were observed in plants fed with ammonium nitrate in aeroponics and ammonium in aeroponics system, respectively. According to the results, ammonium nitrate is recommended as the most proper nitrogen source for production of licorice in aeroponics system.

In order to evaluate the effect of different levels of benzyladenine, nitrogen and salinity on growth characteristics of pistachio seedlings, cv. Badami Zarand, a factorial experiment with three factors: benzyladenine (0, 250 and 500 mg/L), nitrogen (0 and 100 mg N/kg soil as NH4NO3) and salinity (0 and 2000 mg NaCl/kg soil) was carried out as completely randomized design with three replications for 24 weeks under greenhouse conditions. Results showed that although salinity significantly decreased dry weight of shoots and roots of the seedlings, but application of 500 mg/L benzyladenine increased dry weight of shoots and roots by 125 and 86 percent, respectively. However, simultaneous application of nitrogen and benzyladenine increased dry weight of shoots and roots more than 3 and 2 folds, respectively. Results also showed that salt stress significantly decreased leaf area and length of root system. But simultaneous application of nitrogen and the highest concentration of benzyladenine increased leaf area and length of root system more than 3 and 2.5 folds, respectively. The results of triple effects also showed that although height, leaf number and stem diameter significantly decreased under saline conditions, but simultaneous application of nitrogen and benzyladenine resulted in more prominent increase of these growth characteristics than individual application of these treatments. Finally, it is concluded that simultaneous application of nitrogen and benzyladenine resulted in more effective reduction of harmful effects of salinity on growth characteristics of pistachio seedlings than application of these treatments alone.

Regular watering and application of nitrogenous fertilizers in turf-grasses is a conventional operation, especially in warm and dry or semi-dry climates, which arecommon in many parts of Iran. Nitrogen is a mobile nutrient in soil or substrates, especially in the form of nitrate. Nitrate leaching due to the regular watering has been reported in many sources. The managing nitrogen application can help to minimize the loss of this element regarding the ability of soil-plant system. Attempts have been made to control the growth of turf-grass using various types of chemicals, but similar to the concerns associated with the consumption of nitrogenous fertilizers, this is also concerned with environmental pollutions. Therefore, the growth of turf grasses can be controlled without using chemicals and by limiting the use of nitrogen and managing the irrigation.The purposes of this study were to limit the application of nitrogen in order to control vegetative growth of the turf grass and maintain its visual quality, and to manage irrigation in order to preserve this mobile element (nitrogen) near the root system and prevent its leaching.
The effects of reduced water and nitrogen supply on the control of vegetative growth of turf grasses, commonly named as sport turf,were evaluated.Therefore, an experiment was designed in a factorial based on randomized complete block design with three replications. Mixed seeds of sport turf grass were planted with the density of 40 g m-2in boxes, which placed atthe depth of30 cm and leveled with sandy loam soil in mid-spring. Nitrogen was applied as ammonium nitrate via fertigation in five levels of 0, 0.5, 1, 1.5 and 2 mg m-2 month-1, andirrigation treatments performed at four levels of 100%, 80%, 60 % and 40% of field capacity. Watering was done every two days for 5 months during the warm season of the year after the first mowing on June 2013. Some traits such as plant height, fresh and dry weight, density, color and quality, and chlorophyll and proline contents were evaluated during growth period or at the end of the experiment.The data were subjected toananalysis of variance (SAS, 1996),and differences among the treatments were compared using Duncan’s multiple range test at 95% probability level.
The results showed that decreasein nitrogen level up to 0.5 gdid not significantly change density index,,whilethe index showed a significant reduction in treatment containing zero nitrogen application and the lowest irrigation regime (40% of the field capacity).Quality and color of the turf grass had no significant correlation with nitrogen treatment, while the factor was significantly decreased when irrigation regime of 40% of the field capacity was applied. It was determined that although color of the turf grass was greener with lower levels of water,a good color was found with high level of non-organic fertilizer at the time that the amount of nitrogen leaching was also limited. Therefore, regardless of the different nitrogen levels applied, quality and color indiceswerethe lowest when irrigation at 40% of field capacity was applied. Limiting the level of nitrogen up to 0.5 gramand irrigation up to 60% of field capacity was desirable to control and reduce the height of turf grass. Reduction in water level up to 80% of field capacity caused no significant changes in fresh weight, but a significant decreasewas resulted with the reduction of water consumption up to 60% of field capacity. The maximum fresh weight was found with 1.5 grams nitrogen. However, reducing nitrogen level upto 0.5 gramdid not bring about significant changes in this trait. Dry weight also followed the same pattern as fresh weight. Although reduction in the level of applied nitrogen did not reduce the height, it caused a significant reduction in fresh and dry weight of the turf grass. The highest chlorophyll content was found when 2 grams of nitrogen and irrigation regime of 40% of field capacity were used. Regardless of the nitrogen level, the highest chlorophyll content was found in irrigation of 40% of field capacity,while the lowest amount was observed in the treatment containing irrigation at100 and 80% of field capacity. Plants were dark green in 40% of field capacity. Proline content showedincreasealong with the decrease inirrigation as well as nitrogen levels.
Plant height, fresh and dry weight, chlorophyll and proline contents were significantly affected by limiting the use of nitrogen and water, but density and quality indices were not significantly influenced. Regardless of the nitrogen levels applied, quality and color traits were the lowest only in irrigation regime of 40% of field capacity. Therefore, it was concluded that reduction of nitrogen supply to 1 mg m-2 month-1and irrigation regime up to 60% of field capacity could result in thereduction ofvegetative growth of turf grass, while quality traits were not affected negatively.