Foliar application of Si-aminochelate: a strategy for increasing P uptake and antioxidant properties of strawberry.

BACKGROUND: Strawberry is one of the most important small fruits. The quantity and quality of this fruit can be affected by nutrition. Silicon (Si) plays a vital role in mineral nutrition of plant and increases photosynthesis and plant growth, prevents water loss, mineral toxicity, and improves element use efficiency. One of the significant problems in calcareous soils is phosphorus (P) deficiency. The latest findings showed that soil application of Si can increase P use efficiency by increasing P availability in the soil and altering P metabolism in the plant, thereby improving performance in low soil P conditions. Therefore, this study aimed to investigate whether foliar spraying of Si-aminochelate (0, 2, and 4 mL/L) can improve P absorption, growth, and the nutritional and quality characteristics of strawberry fruit at different levels of P fertilizer (0, 7.5, 15, and 30 kg/ha). Monopotassium phosphate fertilizer (KH2PO4) was used to provide P fertilizer. Also, growth, yield, antioxidant properties, and inorganic P and Si of leaves were examined during the experimental period. RESULTS: The results showed that the highest yield content (599.93 g) was obtained by foliar application of 4 mL/L of Si-aminochelate combined with 15 kg/h P, which showed an increase of 68.33% compared to the control treatment. Also, no significant difference was observed between the treatment of 4 mL/L Si-aminochelate + 30 kg/ha P and the treatment of 2 mL/L Si-aminochelate + 15 kg/ha P in plant yield, which is one of the interesting results of this study. However, 4 mL/L Si-aminochelate with 15 kg/ha P were the most effective treatments in increasing flavonoid (0.45 mg/g FW), total antioxidant capacity (94.38%), vitamin C (129.03 mg/100 g FW). The highest leaf and root P content was observed in the combined treatment of 2 mL/L Si-aminochelate with 15 kg/ha P. CONCLUSIONS: The results of this experiment showed that the use of P fertilizer and spraying of Si-aminochelate caused a significant increase in yield, leaf P and Si, antioxidant compounds such as total phenols, total flavonoids and vitamin C in strawberry fruit. Previous findings indicate that Si directly improves internal P use efficiency by stimulating root secretion of organic acid anions, such as malate and citrate, and the subsequent change in soil pH, which in turn increase root growth, transpiration, and P uptake and utilization, and indirectly by reducing iron and manganese absorption-processes that ultimately influence plant growth, yield, and antioxidant properties. According to the results of this experiment, using a level of 15 kg/ha of P fertilizer along with a foliar spray of 4 mL/L of Si-aminochelate is recommended to improve growth, yield, and antioxidant properties of strawberry fruits in greenhouse.