Effect of Humic Acid, Arginine and Different Levels of Vermicompost on Quantitative and Qualitative Characteristics of Strawberry (Fragaria × ananassa L. cv. Gaviota)

Strawberry is one of the temperate fruits, which is among the most important commercial horticultural crops. This product has found its place in the diet of millions of people due to its aroma, taste and vitamin-rich contents. Therefore, present study was conducted in the greenhouse to investigate the effect of humic acid and arginine at different levels of vermicompost on quantitative and qualitative characteristics of Gaviota strawberry. This research was carried out in a factorial experimental with complete randomized blocks design with 16 treatments, three replications and 48 plots. The first factor was substrates in 4 levels (garden soil, "garden soil + 5% vermicompost", garden soil + 10% vermicompost "and" garden soil + 20% vermicompost ") and the second factor included organic acids in 4 levels [control (water), humic acid (100 mg/l), arginine (100 mg/l) and humic acid + arginine (100 + 100 mg/l)]. The measured traits included number of leaves, fruit yield, number of fruits, fruit weight, fresh and dry weights of shoot, chlorophyll a, b and total, carotenoids, anthocyanin content, vitamin C, total soluble solids (TSS), titratable acid (TA) and TSS/TA. According to the results, "garden soil + 20% vermicompost" had a positive effect on all tested traits and increased physiological and vegetative parameters in strawberry. The highest fruit weight, chlorophyll a, b and total, carotenoids, anthocyanin content, and vitamin C were obtained in the treatment of "humic acid + arginine". Interaction effect of "planting medium × organic acid" showed that the highest number of leaves, highest yield and number of fruits were related to "garden soil + 20% vermicompost × humic acid + arginine" treatment.