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
3 استادیار بخش شیمی و حاصلخیزی خاک و تغذیه گیاه، موسسه تحقیقات خاک و آب کرج ایران
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
The purpose of this study was to evaluate Mg fertilization management for citrus trees. This evaluation can lead to a better understanding of the need for Mg, the amount and appropriate time of fertilization, the process of absorption and transfer of Mg to leaves and fruits. Citrus trees are sensitive to the availability and deficiency of Mg, and Mg deficiency affects the growth, morphology, development and reduction of shoot and root biomass of these trees. The removal of Mg by fresh fruit is about 120 to 290 g/ton. There is a relationship between the chemical forms and the distribution of Mg with its upkake and transfer potential in citrus trees, and in the conditions of optimal Mg availability, the majority of Mg in the leaves and roots of citrus trees is in the soluble, organlle and cell wall fraction, respectively. Mg also has an effect on the amount of sugar and organic acids in fruits, and its deficiency causes a decrease in the weight of individual fruits. The results of various researches have shown that the availability of Mg has an effect on Mg uptake, its accumulation and distribution in different organs.
Research results have shown that the fertilization method, chemical form and time of application of Mg fertilizers are very important in the fruit trees and have the greatest impact on the efficiency, quality and stability of production. It is recommended to avoid early application of magnesium sulfate and magnesium nitrate fertilizers in the form of cutan or strips for fruit trees. The application of Mg fertilizers for citrus fruit trees is determined based on yield, soil analysis results, leaf analysis results and its interpretation. If the results of soil analysis show that the amount of Mg in the soil is less than optimum, magnesium (MgO) fertilizer should be used up to 20% of nitrogen. However, if Mg in the soil is in the optimum range, high or excess, but Mg concentration in the leaves is less than sufficient, the soil application of Mg should be stopped or minimized and magnesium fertilizers (magnesium nitrate) should be applied by foliar spraying, especially in the second stage II of fruit growth. If yield is about 20 tons per hectare, about 20 to 30 kg/ha of magnesium (MgO) per year is recommended according to the growth phenology, and in orchards with higher yields, in addition to For each ton of increase in yield, about 1kg of magnesium (MgO) should be added to it. According to research results in different regions of the world and iran, the most appropriate time to Mg fertilization in citrus trees is in the second stage of fruit growth, so it is recommended magnesium application (solution spraying or irrigation) from the end of the first stage (I) and apply the maximum amount of fertilization in the second stage of fruit growth (II) and avoid early fertilization before the beginning of the growing season, bud swelling, flowering and the beginning of the first stage of fruit growth.
کلیدواژه‌ها [English]
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