Four field experiments were conducted to determine the effects of the use of plane (Titan, Karnaval, Festival, and Natalka) and curled-leaf cultivars (Paramount, Petra), the quality of transplants raised in different cell volumes (95, 69.3, 32.0, 25.6, 10.0 cm³), Jiffy pots – (112.5 cm³) and the number of plants per cell (1, 2, and 3), as well as plant cover in the field with perforated foil fleece, and plastic tunnel on yield and nutritional value of parsley leaves. Harvest of leaves was conducted three times: in early July, at the end of August, and mid October. The samples of leaves were collected for evaluation of the content of vitamin C and nitrates.
All plain leaf cultivars significantly overyielded those of curled-leaf and the highest total leaf biomass was produced by ‘Karnaval’, appreciated also for its high value of vitamin C, but showing a tendency to nitrate accumulation. Jiffy pots and multicell trays with the cell volumes 95.0 and 69.3 cm³ were preferable for the quality of seedlings and total yield of leaves obtained during three subsequent harvests. The enhanced number of seedlings produced in the cell had disadvantageous effects on the yield and nutritional value of parsley, expressed by a decreased amount of vitamin C and higher value of nitrates in the first two harvests. The most suitable for covering plants of leafy parsley proved to be fleece, followed by perforated foil and plastic tunnel. All these covers caused an increment of vitamin C and a decrease in nitrate accumulation in leaves.