Document Type : Analytical and Applicable Papers
Authors
1 M.Sc. Graduate of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
2 Assistant Professor, Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
3 Associate Professor, Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Abstract
Background and Objective:
One of the important aspects of nutrition physiology in fruit trees is the study of seasonal changes in leaf elements, because the seasonal pattern of absorption and distribution of nutrient elements is very important in estimating the fertilizer requirement of fruit orchards. The movement of nutrients in fruit crops has been reported a lot, and the plants' need for a specific element is influenced by a specific growth stage in the plant. Research has shown that nutrient accumulation occurs as a continuous process throughout the growing season. In plants, the change process of elements is different in the seasons. By examining the dynamics of elements during different seasons and having the necessary information about these changes, it is possible to examine the relationship between the demand for nutrients during the periods of vegetative and reproductive growth.In Iran, many research has been done on the nutritional requirements of different commercial fruit cultivars, and many studies have reported the dynamics of nutrients in fruit trees during the growing season, but in the case of dates, despite the relative diversity Regarding the cultivars of this plant and Iran's presence in the international competitive markets, there was no report on measuring the dynamics of nutrient elements during the seasons. In the upcoming research, the seasonal evaluation of the concentration of some macronutrients and micronutrients in the leaves of three date varieties has been done.This study was carried out in order to evaluate the seasonal changes in nutrients in the leaves of three date varieties.
Materials and Methods:
This experiment was conducted in the date palm research garden in the northern part of Shahid Chamran University of Ahvaz, in a randomized complete block design with four replications, during 2022 on the leaves of ten years old date palm cultivars (Berhi, Estamaran, and Zahedi). In this experiment, the trend of seasonal changes in macro nutrients (nitrogen, phosphorus, potassium and calcium) and micro nutrients (iron, copper, boron, zinc and manganese) concentration, were investigated throughout the four seasons.After collecting the data, the data was statistically analyzed using SAS 9.1 statistical software, and Duncan's test was used to compare the average data at the level of one and five percent.
Results:
The results showed that the seasons have a significant effect on the concentration of the elements except nitrogen and manganese. Also, the interaction of season and cultivar had a significant effect on the concentration of all nutrients. In terms of macronutrients, Berhi had a better condition, especially during the growing season (spring and summer). The highest difference in terms of element concentration was observed between the winter and growth seasons for date cultivars. The minimum concentration of nitrogen (0.94%) was for Zahedi in spring and winter and the maximum concentration was 2.01% for Barhi (winter). Phosphorus concentration was recorded from the lowest (0.13%) in winter and spring to the highest (0.36%) in summer for Barhi. The range of potassium changes ranged from 1.01% (Estamaran, autumn) to 1.18% (Zahedi, winter). The seasonal changes in calcium concentration was recorded between 0.76 and 0.92%. Also, the range of changes in iron concentration during the year was from 65 to 130 mg/kg and during the growing season to mid-summer from 87 to 117 mg/kg. Bades on the results, leaf iron concentration was estimated to be less than optimal in all seasons. Also the concentration of nitrogen, potassium and copper in leaves decreased during the growth season, especially in summer, and can be due to the consumption of these elements for reproductive growth.
Conclusion:
The concentration of minerals in plants depends on the interaction of several factors including soil, plant species, climate, growth stages, plant production and management and the interaction of elements during absorption. The successful growth of plants and trees requires suitable soil and the presence of sufficient amounts of usable elements and the relationship between them, among which nitrogen, phosphorus and potassium elements are among the main essential elements required by the plant.
The results showed that there is a significant seasonal variation in macronutrients and micronutrients in three date varieties. Also, different seasonal changes patterns were observed among cultivars regarding elements. In such a way, potassium and calcium are more stable than nitrogen and phosphorus during different seasons of the year. Macronutrients (phosphorus and calcium) and micronutrients (zinc, boron and manganese) were at the optimal level. But, the amount of nitrogen, potassium, iron and copper was evaluated as less than the optimal level, which suggests the use of fertilizers containing the mentioned elements at the end of winter..
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