Increasing Fruit Yield and Bioactive Compounds of Strawberry Plants by Foliar Spraying with Some Environmentally Friendly Substances

Abstract

Background: The research study was conducted in the plastic houses belonging to the College of Agricultural Engineering Sciences/University of Baghdad / Al-Jadriya, for the autumn season of 2023-2024. The experiment was laid out in factorial experiment under a randomized complete block design (RCBD) with three replications and six plants per treatment. Methods: The experiment was of two factors: the first factor represented foliage spraying by liquid potassium silicate fertilizer with three concentrations (0, 4 and 8) mL L-1 and the second factor was Roselle extract (RE) at three concentrations (0, 5, 10) g L-1. Result: The results indicated a significant increase in most of the studied traits when treated with potassium silicate fertilizer and Roselle extract individually. Furthermore, the interaction treatment (Si2R2) showed a significant effect in increasing leaf area (46.23 cm2), leaf chlorophyll content (283.1 mg.100 g-1 fresh weight), leaf content of Si, N, P and K (12.64, 2.61, 0.485 and 1.725%, respectively), fruit content of vitamin C, anthocyanin and TSS percentage (12.000, 106.95 and 9.00%, respectively), number of fruits (47.00 fruits.plant-1) and fruit weight (23.35 g). The interaction treatment (Si2R1) excelled in leaf content of total phenols (0.915 mg g-1 dry weight).