Horticultural Science and Technology 원예과학기술지 ISSN:1226-8763(Print) 2465-8588(Online)

This study investigated the influence of sulfur concentration on crop growth and bicarbonate injury during hydroponic cultivation of ‘Seolhyang’ strawberry plants. The concentrations of sulfur added to the pine bark and coir dust root medium (5:5, v/v) used as pre-planting fertilizer were 0, 0.23, 0.45, 0.90, and 1.80 g·L^-1. We modified Hoagland nutrient solution to contain that contained 240 mg·L^-1 HCO₃^- using KHCO₃ and the concentrations of all essential nutrients were equal. The plug-grown seedlings with three leaf stage were transplanted as mother plants and fed with the solution at two weeks after transplanting. The measurement of the growth of mother and daughter plants, as well as the analysis of the nutrient contents in above-ground tissue of mother plants was conducted at 140 days after nutrient solution application. Soil solution from the root media was also collected every two weeks and analyzed for pH, electric conductivity (EC) and nutrient concentrations. The growth characteristics of the mother plants was assessed by recording the number of leaves, petiole length, and fresh and dry weights of above-ground tissue; these parameters were the highest in plants treated with 1.80 g·L^-1 sulfur and the lowest in the control treatment (0 g·L^-1 sulfur). The growth of daughter plants was also the greatest in plants treated with 1.80 g·L^-1 sulfur. The HCO₃^- concentrations and pH of the root media solutions increased continuously when sulfur incorporation was 0.23 g·L^-1 or less; however, the HCO₃^- concentrations gradually lowered and pH was maintained around pH 6 when the sulfur concentration was higher than 0.90 g·L^-1. The concentrations of K, NO₃, and PO₄ in the soil solution were lower in sulfur condition of 0.90 g·L^-1 and 1.80 g·L^-1 than other sulfur treatments, while SO₄ concentration increased at these sulfur treatment levels. The tissue content of essential nutrients was lowest in the control treatment and increased with sulfur concentration. In addition, the pH goes up in root environment of control treatment resulted in the incidence of Ca, Mg, and microelement deficiency symptoms. In conclusion, the incorporation of sulfur should be more than 0.90 g·L^-1 to reduce bicarbonate injury during the cultivations of the ‘Seolhyang’ strawberry.