نوع مقاله : مروری
نویسندگان
1 عضو هیات علمی مرکز تحقیقات مازندران
2 استادیار بخش علوم زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی مازندران، سازمان تحقیقات، آموزش و ترویج کشاورزی
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
This study was amid to evaluate calcium fertilization management for citrus trees. This evaluation could lead to a better understanding of the calcium requirement, the amount of fertilization, the appropriate time of fertilization, the process of calcium absorption and transfer to leaves and fruits in these trees, which is very effective in optimizing calcium fertilizer recommendations. After potassium and nitrogen, calcium has the highest concentration in citrus fruits, but it is the first element in terms of quantity in the biomass of citrus trees (more than potassium and nitrogen). The amount of calcium harvested by fresh citrus fruit is about 550 to 600 gr per ton. After post setting, the developing fruits have an immediate and stable need for calcium, which is supplied by the xylem vessels, which is strongly dependent on transpiration from the surface of these tissues and organs. Therefore, inappropriate climatic and management conditions such as drought stress, flooding stress, heat stress, lack of sunny hours, high relative humidity, high application of nitrogen and potassium fertilizers in the first stage of fruit growth (I), intensifies the possibility of calcium deficiency in these developing tissues. The results of various researches have shown that the most appropriate time for application and increasing calcium in citrus fruits is the first and early second stages of fruit growth, and after that the efficiency of transferring calcium to fruits decreases drastically. On the other hand, calcium has the greatest effect on the firmness of the fruit tissue, reducing the softening and reducing the weight of the fruits process during the storage period, reducing the physiological disorders and reducing the fruit rotting percentage during the storage period. Therefore, the purpose of calcium fertilization is to increase the fruit calcium content, increase fruit quality and marketability, stability of production, reduce fruit physiological disorders, increase the storage life and maintain the quality of fruits during storage period. Based on research results in different regions of the world and Iran, the most appropriate time to increase calcium in fruits and application calcium in citrus trees is the first stage of fruit growth (from post setting to June drop) and early to mid-second stage of fruit growth (II). So, it is recommended that gardeners do calcium fertilization (foliar application or fertigation) in the first stage (I) and early to mid-second stage (II), and avoid from Ca application at Late of the second stage of fruit growth, pre harvest application and fruits immersion in calcium solutions after harvest.
کلیدواژهها [English]
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