THE EFFECT OF NITROGEN SOURCES ON YIELD AND QUALITY OF SALAD ROCKET GROWN IN DIFFERENT MONTHS OF THE YEAR


TUNCAY Ö. , EŞİYOK D. , YAĞMUR B. , OKUR B.

JOURNAL OF PLANT NUTRITION, cilt.34, ss.477-491, 2011 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 34 Konu: 4
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1080/01904167.2011.538111
  • Dergi Adı: JOURNAL OF PLANT NUTRITION
  • Sayfa Sayıları: ss.477-491

Özet

The effects of months of the year and nitrogen (N) sources on salad rocket (Eruca sativa Mill.) yield, quality, and nitrate accumulation was investigated during the years 2002 and 2003. In both years, seeds were sown on the first day of April, May, June, July, August and September. Three different nitrogen sources were used: farmyard (cattle) manure (100 tonnes center dot ha-1), calcium nitrate [Ca(NO3)2]-15.5% N (150 kg N center dot ha-1) and ammonium sulfate [(NH4)2SO4)]-21% N (150 kg N center dot ha-1). Yield, leaf color, dry matter, vitamin C and total glucosinolate content and nitrate accumulation was assessed. Growing months affected all the assessed parameters significantly both years, with the exception of hue angle in 2003, whereas nitrogen source only influenced yield and nitrate accumulation in 2003. In both years the highest yield was obtained in April, but vitamin C and total glucosinolate contents were higher during summer months, and leaves were slightly darker colored. Chemical fertilizers increased the yield compared to farmyard manure; however, they also increased nitrate accumulation slightly, without any significant difference between them. Nitrate accumulation never exceeded 300 mg kg-1 fresh weight (FW), which is well below the acceptable daily intake of 3.7 mg nitrate per kg-1 bodyweight set by European Commission's Scientific Committee on Food.