edris shabani; Shohreh Zivdar; Afrasiyab Rahnama Ghahfarokhi; Abbas Danaeifar; Mehran Davoudi Arshad
Abstract
Introduction
Most of Iran's soils are calcareous soils. In these types of soils, the amount of phosphorus absorption decreases with the increase of soil pH. Phosphorus absorption ...
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Introduction
Most of Iran's soils are calcareous soils. In these types of soils, the amount of phosphorus absorption decreases with the increase of soil pH. Phosphorus absorption from the root surface happens quickly, and as a result, the area of 0.2-1 mm around the root becomes empty of phosphorus. An effective strategy to deal with phosphorus deficiency stress is the secretion of organic acid anions by plant roots. Current evidence shows that the application of silicon greatly increases the secretion of organic acids by the roots. According to the findings of the researchers, there is a positive correlation between the availability of silicon and the mobility of phosphorus in the plant. In addition, the external use of silicon also helps to increase the activation of phosphorus from mineral surfaces. Considering the lack of phosphorus resources in the world, the low mobility of phosphorus in the soil, the increase in its price and its excessive use, conducting studies related to phosphorus fertilizers in order to increase the absorption of phosphorus and fruit quality of greenhouse crops seems to be completely necessary.
Materials and methods
The experiment was conducted in the form of a split plot design and in the form of a basic randomized complete block design with 3 replications. The treatments of this experiment included different levels of phosphorus fertilizer (0, 7.5, 15 and 30 kg/ha, in the main plots) and three levels of silicon aminochelate spraying (0, 2 and 4 ml/L, in the secondary plots). The measurement of chlorophyll a, b and total chlorophyll was done using a spectrophotometer in mature leaves developed according to the method suggested by Arnon (1967). Phosphorus was also measured by colorimetric method. During the experiment, strawberry fruits from different treatments were harvested and counted. The weight of a single fruit was measured by a digital scale with an accuracy of 0.01 g. The total weight of the fruit in each plant was calculated and recorded from the sum of the weight of the harvested fruits during the growth period. The dry matter percentage of the fruit was calculated by dividing the dry weight of the sample by the fresh weight of the sample multiplied by 100 (Tabatabaei, 2013). During the experiment, fruits from different treatments were harvested and their length and diameter were measured by calipers and reported in centimeters. The firmness of the fruit tissue was measured by a firmness meter, and the pH and EC of the fruit extract were measured by a pH meter and an EC meter, respectively. Also, the percentage of TSS was measured by a refractometer.
Result and Discussion
The results of this experiment showed that the application of 15 kg/ha of phosphorus with a concentration of 2 ml/L of silicon aminochelate (P3Si2) had the highest amount of chlorophyll a, chlorophyll b and total chlorophyll. The highest phosphorus concentration of the whole plant (0.98%) was obtained at the level of 15 kg/ha of phosphorus and the concentration of 2 ml/L of silicon aminochelate. Based on the results of average comparisons, the highest amount of total fruit weight (599.93 g) was observed in the treatment of 15 kg/ha of phosphorus and the level of 4 ml/L of silicon aminochelate (P3Si3), which had no significant difference with the P3Si2 treatment. P3Si2 and P3Si3 treatments compared to the control treatment (P1Si1) caused an increase of 67.62 and 68.33 percent of the total weight of strawberry fruits, respectively. The highest percentage of fruit dry matter (7.38%) was observed in the P3Si2 treatment, which had no significant difference with the P3Si3 treatment (6.97%). In many studies, an increase in chlorophyll and yield was observed after the application of foliar spraying with silicon. The use of silicon strongly increases the secretion of malate and citrate by the roots, and in this way, it helps to mobilize and absorb more phosphorus in conditions of its deficiency (Hu et al., 2021).
Conclusion
According to the results, it is recommended to use a concentration of 2 ml/L in silicon aminochelate and a level of 15 kg/ha of monopotassium phosphate to achieve maximum growth, yield and quality of strawberry fruits.
