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Short-term alteration of nitrogen supply prior to harvest affects quality in hydroponic-cultivated spinach ( Spinacia oleracea).

Authors :
Lin, Xian Yong
Liu, Xiao Xia
Zhang, Ying Peng
Zhou, Yuan Qing
Hu, Yan
Chen, Qiu Hui
Zhang, Yong Song
Jin, Chong Wei
Source :
Journal of the Science of Food & Agriculture. Mar2014, Vol. 94 Issue 5, p1020-1025. 6p.
Publication Year :
2014

Abstract

BACKGROUND Quality-associated problems, such as excessive in planta accumulation of oxalate, often arise in soillessly cultivated spinach ( Spinacia oleracea). Maintaining a higher level of ammonium (NH4+) compared to nitrate (NO3−) during the growth period can effectively decrease the oxalate content in hydroponically cultivated vegetables. However, long-term exposure to high concentrations of NH4+ induces toxicity in plants, and thus decreases the biomass production. Short-term application of NH4+ before harvesting in soilless cultivation may provide an alternative strategy to decrease oxalate accumulation in spinach, and minimise the yield reduction caused by NH4+ toxicity. RESULT The plants were pre-cultured in 8 mmol L−1 NO3− nutrient solution. Next, 6 days before harvest, the plants were transferred to a nutrient solution containing 4 mmol L−1 NO3− and 4 mmol L−1 NH4+. This new mix clearly reduced oxalate accumulation, increased levels of several antioxidant compounds, and enhanced antioxidant capacity in the edible parts of spinach plants, but it did not affect biomass production. However, when the 8 mmol L−1 NO3− was shifted to either nitrogen-free, 4 mmol L−1 NH4+ or 8 mmol L−1 NH4+ treatments, although some of the quality indexes were improved, yields were significantly reduced. CONCLUSIONS Short-term alteration of nitrogen supply prior to harvest significantly affects quality and biomass of spinach plants, and we strongly recommend to simultaneously use NO3− and NH4+ in hydroponic cultivation, which improves vegetable quality without decreasing biomass production. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00225142
Volume :
94
Issue :
5
Database :
Academic Search Index
Journal :
Journal of the Science of Food & Agriculture
Publication Type :
Academic Journal
Accession number :
94857367
Full Text :
https://doi.org/10.1002/jsfa.6368