Cultivation Possibilities for Pak Choi (Brassica rapa var. chinensis) growing in Different Nutrient Solutions in Floating Water Culture

Abstract

For this study, two different pak choi (Brassica rapa var. chinensis) cultivars, a standard cultivar ‘Black Summer’ and a mini cultivar ‘Little Shanghai’, were cultivated in floating water culture utilizing two different nutrient solutions. Plants were evaluated for agromorphological development, yield, leaf quality characteristics, and water consumption. The plants were grown in either Hoagland nutrient solution or Alberici nutrient solution, which has a partially reduced macroelement content. Cultivation was carried out in a greenhouse in horizontal troughs containing aerated nutrient solutions; seedlings obtained from seeds sown in a peat medium were transplanted into foam boards and floated on the nutrient solutions in the troughs. Each trough contained 11 seedlings. Air was supplied to the nutrient solution via a compressor to ensure oxygenation of the plant root zone. The seedlings, grown in the hydroponic system for one month, were harvested at a single time for subsequent measurements and analyses. According to the findings, no significant differences were observed between the two nutrient solutions. It was determined that the Alberici nutrient solution, which has a lower element concentration, but is less popular than the Hoagland solution, could be utilized as an alternative solution in hydroponic pak choi cultivation instead of the higher salts concentration Hoagland solution. In the cultivar-based evaluation, distinct genotypic differences were detected. The ‘Black Summer’ cultivar exhibited a significantly superior performance compared to the ‘Little Shanghai’ cultivar in terms of leaf area, total fresh/dry weight, plant height, and yield per unit area. On the other hand, the ‘Little Shanghai’ cultivar stood out in terms of visual quality, characterized by a higher seed emergence rate, a greater number of fresh leaves, and higher brightness and color chroma values. In conclusion, the use of Alberici nutrient solution is recommended in hydroponic pak choi production to prevent excessive fertilizer utilization, to ensure environmental sustainability, and to reduce production costs. Depending on the production targets, the use of the ‘Black Summer’ cultivar grown in Alberici nutrient solution was found to be most suitable for higher tonnage and larger leaves.