The effect of micro- and nanoparticles of silicon dioxide (SiO2) on some qualitative characteristics and nutrient elements of strawberry fruit (Fragaria ananassa Duch.)

Background and objectives: Silicon (Si) is one of the beneficial nutrient elements for the most of the plants. Recent studies have shown that Si increases the yield and crop quality and plays an important role in plant resistance against the environmental stresses. Strawberries are the good resource of bioactive compounds being an important and valuable fruit in the world from the economical and commercial point of view. For the agricultural purposes, feeding strawberry plants by different nutrient elements such as silicon can affect nutritional value and fruit quality. With science development and nanoparticle production, their application in different industry such as agriculture introduced The aim of this study was to evaluate the effect of different concentrations of micro- and nano-SiO2 with two methods of usage including foliar spray and root feeding applied through the growth stage of strawberry plants on some qualitative characteristics and nutrient elements of fruit.

Materials and methods: This study was conducted in the research laboratory and greenhouse of
Bu-Ali Sina University in a factorial experiment based on a completely randomized design with 3 replications and 4 plants in each replicate. Foliar spray and root feeding were carried out using 20, 40, 60 and 80 mg L-1 micro- and nano-SiO2 at two separate growth stages. After fruiting, the ripened fruit were harvested, and some nutrient elements as well as qualitative characteristics of fruit including phosphorus, potassium, magnesium, iron, nitrate, total soluble sugar, vitamin C, TSS and juice acidity measured, and finally the data were statistically analyzed.
Results: Application of silicon increased the amounts of potassium, magnesium, iron, total soluble carbohydrate, vitamin C, TSS and TA significantly, but reduced phosphorus amount, and nitrate remained unchanged. Among the treatments, 60 mg L-1 nano-SiO2 in root feeding method showed the better effects on studied traits than the other treatments as well as the control. Overall, the application of nano-SiO2 proved to have better results than micro-SiO2.
Conclusion: Application of silicon had a significant influence on nutrient elements and quality of strawberry fruits. The effect of silicon on nutrient elements and quality of fruits depended on the form, concentration and application method of silicon. Based on the results, utilization of SiO2 particularly in nano-scale during the growth stage increased the majority of nutrient elements and quality of strawberry fruit. Overall, in soilless culture and greenhouse production of strawberries, the application of 60 mg L-1 nano-SiO2 through the root feeding method is recommended.