Seasonal variations in vitamin C and mineral contents and some yield and quality parameters in komatsuna (Brassica rapa var. pervidis)

The aim of this study was to determine the changes in yield, growth and quality of komatsuna in successive growing seasons. Experiments were carried out in a PE covered cold greenhouse in late autumn-early winter and late winter-early spring growing period during 2009-2010 in Corlu, Turkey (41 degrees 11' N, 27 degrees 49 E). Results showed that vitamin C content of plants grown in late winter-early spring and late autumn-early winter growing period were 61.70 and 42.35 mg/100 g, respectively. While N (4.35%), P (0.51%), Cu (8.35 ppm), Fe (886.5 ppm) and Zn (48.15 ppm) values were higher in plants grown in late autumn-early winter in comparison with plants grown in late winter-early spring, K (4.70%), Ca (2.30%), Mg (0.42%), S (0.72%) and Mn (61.85 ppm) values of plants were higher in late winter-early spring growing period. All the quality and yield characteristics investigated in the research were also affected by season. Furthermore yield obtained in late winter-early spring growing season was about 3.79 times higher than those in late autumn-early winter growing season