Fereshteh Kamiab; Hamid Mohammadi
Abstract
Introduction: Narcissus is one of the most important ornamental plants in the world. The deficiency of microelements is a major problem limiting the production of ornamental plants under high-pH soils in most regions of Iran. Cu and Mn are essential microelements for the growth and development of plants ...
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Introduction: Narcissus is one of the most important ornamental plants in the world. The deficiency of microelements is a major problem limiting the production of ornamental plants under high-pH soils in most regions of Iran. Cu and Mn are essential microelements for the growth and development of plants as they are involved in many physiological reactions. Fe is involved in the synthesis of chlorophyll and many enzymes, respiration, and nucleic acid metabolism. Cu is a cofactor for numerous enzymes and is also involved in ethylene biosynthesis and activity, respiration, photosynthesis, regulatory proteins, cell membrane metabolism, and hormone signals. The deficiency of microelements, especially Fe, influences productive and reproductive growth of ornamental plants. Thus, this experiment aimed to evaluate the uptake rate of Cu and Mn nano-chelates and their effects on some morphological and physiological Characteristics of ‘jonquil’ narcissus.
Materials and Methods: This study was carried out in the research garden of Agriculture Faculty of Rafsanjan University in 2015 in factorial experiment based on randomized complete block design with two factors of Fe at four levels of 0, 1, 2 and 3 (g/l) and Cu at three levels of 0, 1 and 2 (g/l) in three replications. The weight of the cultivated bulbs were about 8-10 g. They were planted in eight rows spaced 20 cm with on-row spacing of five cm at the depth of 15 cm in each plot in August. According to soil analysis, 40 tons of manure and 100 tons of urea per ha were applied. The nano fertilizer was purchased from Nano-research Biozar Company. Foliar application was done three times: 1- when the plants had three leaves, 2- before flowering and 3- after flowering at 45-day intervals. Different parameters were recorded including plant height, number of leaves, width and length of leaves , number of main bulb, main bulb weight and diameter, , bulblet diameter and weight, flowering stem height and diameter, number of florets, florets diameter, fresh and dry weight of florets, flower vase life, Cu and Fe concentration, protein, chlorophyll and total soluble solids. Foliar spraying was done three times at the intervals of 45 days.
Results and Discussion: The results showed that the concentration of Cu and Fe in the leaves were enhanced with increase in the rate of each nano-chelate, implying high uptake rate of these nano-chelate by leaves in this plant. The application of Fe (2g/l) and Cu (0.5 g/l) resulted in the highest vegetative growth such as plant height, number of leaves, leaf width and length, number of main bulb, main bulb weight and diameter , and bulblet diameter and weight. High pH in experimental soil caused low absorption of micro elements in this condition. This deficiency was compensated with foliar application of nano-chelates and as a result, the Fe and Cu involved processes were improved in them. On the other hand, enhanced Fe and Cu concentrations in leaves could cause more photosynthesis and higher level of assimilation in plants. Likewise, these elements influence some enzymatic activity such as peroxidase, catalase and cytochrome oxidase; consequently, more vegetative growth was observed. Reproductive growth such as flowering stem height and diameter, number of florets, floret diameter and fresh and dry weight and flower vase life were improved in this experiment. The control of abiotic stress is one of the most important roles of Cu and also it is cofactor of superoxide dismutase that has been known as a free radical scavenger in plants that could increase quantitative and qualitative traits of flower. This treatment resulted in the highest amount of protein, chlorophyll and total soluble solids in the leaves of narcissus. Fe is one of the essential elements for chlorophyll synthesis. It also has an important role in activating nitrate reducates enzyme that uses ammonium to synthesize proteins. Cu is involved in the synthesis of proteins and enzymes that have major roles in such processes as respiration, photosynthesis, phenol metabolism, lignifications and ouxin regulation in plants. Thus, the results of this experiment showed that these nano-chelates were absorbed considerably by leaves of narcissus and they are suitable for foliar application. It should be noted that higher concentration of this fertilizer in this experiment has toxic effects. It is suggested that 2g/l Fe plus 0.5 g/l Cu were used to improve vegetative and reproductive growth of ‘jonquil’ narcissus, especially in high-pH soils.
Hamid Mohammadi; Gholamhossein Davarynejad; Masud Khezri
Abstract
Introduction: Pistachio is one of the most important horticultural crops in Iran, USA, Turkey and some Mediterranean countries. Some physiological problems such as abscission of inflorescence buds, blankness, non-splitting, early splitting, cracking and nut deformation reduce the pistachio yield and ...
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Introduction: Pistachio is one of the most important horticultural crops in Iran, USA, Turkey and some Mediterranean countries. Some physiological problems such as abscission of inflorescence buds, blankness, non-splitting, early splitting, cracking and nut deformation reduce the pistachio yield and quality. A proper nutrition management of pistachio orchard might decrease the physiological problems and increasing the yield. Calcium is an essential plant macro-nutrient that has several distinct functions within plants. These functions can be divided into main areas including effects on membranes, enzymes, cell walls, and interactions of calcium with phytohormones. Free polyamines (putrescine, spermine, spermidine), are the widely distributed of N containing organic molecules binding to the intracellular anions (DNA, RNA, chromatin and proteins). They are also known to possess several regulatory functions. In plants, they have been associated with regulating many physiological processes, such as organogenesis, embryogenesis, floral initiation and development, leaf senescence, fruit development and ripening, and abiotic and biotic plant stress responses. Although the spray application of calcium compound and free polyamine has been investigated separately, application of calcium compounds combined with free polyamines has not been investigated yet. Therefore, the aim of this study was to evaluate the effect of combined treatments of calcium and free polyamines on decreasing the physiological problems and improving the yield of ‘Ahmad-Aghaii’ pistachio trees.
Materials and Methods: This experiment was carried out in a commercial 20-year old ‘Ahmad-Aghaii’ pistachio orchard in Rafsanjan, Iran. It was arranged as factorial based on randomized completely block design with three replications. The treatments were control, calcium compounds (calcium nitrate and calcium chloride at concentration of 0.5%) combined with free polyamines (putrescine, spermidine and spermine at concentration of 0.5 mM). Spraying were applied at different growth stages including two weeks after full bloom (stage 1), six weeks after full bloom (just before endocarp hardening) (stage 2) and the combination sprays of stage 1 and stage 2. Different traits including the percentages of abscission of inflorescence buds, cracking, blankness, early splitting, nut deformation, non-splitting and splitting as well as yield, leaf area and vegetative growth were measured. The individual shoot was the experimental unit and analyses of variance were performed using the General Linear Models procedure of SAS. Means were separated by Duncan’s multiple range test (P < 0.05).
Results and Discussion: Results showed that the main physiological problems of pistachio crop were decreased by application of calcium compounds combined with free polyamines. Spray application of the mentioned treatments was more effective at combined stages of 1 and 2 rather than the stages separately. It was resulted that calcium nitrate combined with spermine and spermidine treatments at combined stages of 1 and 2 reduced the abscission of inflorescence buds, blankness, nut deformation and non-splitting. Also, it was found that calcium nitrate combined with spermidine at combined stages of 1 and 2 reduced the percentage of early splitting while splitting and yield were increased. Spray application of free polyamines combined with calcium compounds did not affect the length and diameter of current-year shoots but significantly increased the leaf area. It seems that calcium plays a key role in conjunction with free polyamines especially spermidine and spermine in decreasing the abscission of inflorescence buds via improving the stability of cell wall and preventing abscission layer formation. It also seems that polyamines reduce the abscission of inflorescence buds by antagonism with ethylene, possibly by competing for S-adenosylmethionine (SAM), a common precursor of both plant bioregulators. Increasing the shoot yield and decreasing the percentage of blankness might be due to improving leaf photosynthesis as well as regulating kernel growth and development. It was found that free polyamines and calcium might promote a regulatory system against environmental stresses especially heat, drought and salinity which are the main concerns of pistachio growers.
Conclusion: According to the results, the application of calcium compounds combined with free polyamines could reduce the physiological problems and increased the yield of ‘Ahmad-Aghaii’ pistachio. Among calcium treatments, calcium nitrate was significantly more effective than calcium chloride. In the case of free polyamines, both spermidine and spermine were more effective than putrescine. It was concluded that application of calcium nitrate combined with spermidine or spermine at both stages (stage 1 + 2) was the most effective treatments in reducing physiological problems and increasing the yield of pistachio trees.
