YIELD AND QUALITY OF LEAFY PARSLEY AS AFFECTED BY THE NITROGEN FERTILIZATION

Abstrakt

Leafy parsley is a spice rich in vitamins and minerals widely used in West European countries in fresh, dried and frozen form to enhance the flavor of many foods.
In Poland till now the leaves of tuber-rooted parsley are commonly produced for this purpose. Little information is available with respect to the effects of N fertilization on yield and crop quality of different type of leafy parsley cultivars. In a field experiment conducted in 2005–2007 nitrogen fertilizer in the same amount of 160 kg N· ha^-1 was supplied as a single preplant or split dose (80 + 80 kg N·ha^-1, and 80 + 40 + 40 kg N·ha^-1). In the other treatment the split dose was reduced to 120 kg N·ha^-1, (40 + 40 + 40 kg N·ha^-1). There was determined the yield, dry matter, vitamin C, total N and nitrates content in leaves of two cultivars (Paramount and Titan) in three subsequent harvests. Irrespective of N fertilization, Paramount-a curled leaf cultivar producent higher yield of leaves with favourable percentage of blades and was a richer source of vitamin C, with higher tendency than Titan for nitrates accumulation. Single preplant nitrogen application was preferable
for leaf growth and yield only in the first term of harvest which contained lower amounts of vitamin C, and showed higher tendency for total N and nitrates accumulation compared with split doses. The most favourable method of leafy parsley nutrition was the application of 80 kg N·ha^-1 before seedlings transplanting, and the same amount in two top dressing doses used directly after subsequent harvests. Gradual decrease of dry matter, vitamin C, and nitrates while the increment of total N contents was observed at the subsequent arvests of leaves during the growing period.