Nitrate and nitrite contents in spring cabbage as related to nitrogen fertilizer type, method of fertilizer application and to nitrate and nitrite reductase activity.
S. Rozek et al., Nitrate and nitrite contents in spring cabbage as related to nitrogen fertilizer type, method of fertilizer application and to nitrate and nitrite reductase activity., ACTA HORT, (506), 1999, pp. 153-157
The effect of different forms of nitrogen fertilizer (NO3, NH4, urea), and
different methods of application (broadcast and placement fertilization), o
n the content of nitrate, nitrite. and free amino acids, and on the activit
ies of nitrate and nitrite reductase was investigated in spring cabbage at
harvest and during short-term storage at low (5 degrees C) and high (20 deg
rees C) temperature. In freshly harvested heads the highest activity of bot
h enzymes and the highest content of nitrate were found in cabbage treated
with potassium nitrate, compared with ammonium sulphate and urea. By compar
ison, the highest levels of nitrite and free amino acids were determined in
plants fertilized with ammonium sulphate. A considerable decrease in nitra
te reductase activity and content of nitrite was observed during cabbage st
orage. No significant changes in nitrate in stored cabbage heads fertilized
with potassium nitrate were found, whereas with the other N forms there wa
s a systematic increase in its content.