Send to

Choose Destination
PLoS One. 2018 Aug 29;13(8):e0202090. doi: 10.1371/journal.pone.0202090. eCollection 2018.

Electrical conductivity of nutrient solution influenced photosynthesis, quality, and antioxidant enzyme activity of pakchoi (Brassica campestris L. ssp. Chinensis) in a hydroponic system.

Author information

Shanghai Dushi Green Engineering Co., Ltd. Shanghai Key Lab of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai, China.
School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, China.
Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, Tennessee, United States of America.
Department of Biological Sciences, Tennessee State University, Nashville, Tennessee, United States of America.


To find an electrical conductivity (EC) in the nutrient solution used for pakchoi (Brassica campestris L. ssp. Chinensis) cultivation that optimizes the plant's physiology, growth, and quality, we conducted an experiment with eight EC treatments (from EC0 to EC9.6) in a hydroponic production system (i.e. soilless culture) under greenhouse condition in Shanghai, China. Plants biomass production, leaf photosynthesis, vegetable quality variables, tissue nitrate and nitrite contents, and antioxidant enzyme activities were measured. The results showed that very high (EC9.6) or low EC (EC0-0.6) treatments clearly decreased plants fresh weight (FW) and dry weight (DW), leaf size, leaf water content, leaf net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and taste score. Nitrite content, and antioxidant enzyme activities were low in medium EC treatments (EC1.8 and EC2.4), but high in very high or low EC treatments. Leaf relative chlorophyll, ascorbic acid, and nitrate contents increased gradually from low EC to high EC treatments, while crude fiber and soluble sugar contents decreased. Based on growth and quality criteria, the optimal EC treatment would be EC1.8 or EC2.4 for pakchoi in the hydroponic production system. Too high or too low EC would induce nutrient stress, enhance plant antioxidant enzyme activities, and suppress pakchoi growth and quality.

[Indexed for MEDLINE]
Free PMC Article

Conflict of interest statement

Co-author Dafeng Hui is Academic Editor for PLOS ONE. Shanghai Dushi Green Engineering Co., Ltd is a commercial company that belongs to Shanghai Academy of Agricultural Sciences. The company provided support in the form of salaries for authors XD, YJ, LH, FL, QZ, JY. The company and founders did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section. These do not alter our adherence to PLOS ONE policies on sharing data and materials.

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center