Effects of Daily Light Integral and LED Spectrum on Growth and Nutritional Quality of Hydroponic Spinach
To achieve clean and high-quality spinach production, the effects of daily light integral (DLI) and light spectrum on growth, nutritional quality, and energy yield of hydroponic spinach (<i>Spinacia oleracea</i> L.) were investigated in a closed plant factory under light-emitting diode (...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-07-01
|
| Series: | Agronomy |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4395/10/8/1082 |
| _version_ | 1797561251237199872 |
|---|---|
| author | Wei Gao Dongxian He Fang Ji Sen Zhang Jianfeng Zheng |
| author_facet | Wei Gao Dongxian He Fang Ji Sen Zhang Jianfeng Zheng |
| author_sort | Wei Gao |
| collection | DOAJ |
| description | To achieve clean and high-quality spinach production, the effects of daily light integral (DLI) and light spectrum on growth, nutritional quality, and energy yield of hydroponic spinach (<i>Spinacia oleracea</i> L.) were investigated in a closed plant factory under light-emitting diode (LED) lighting. The hydroponic spinach plants were grown under 16 combinations of four levels of DLI (11.5, 14.4, 17.3, and 20.2 mol m<sup>−2</sup> day<sup>−1</sup>) with four light spectra: LED lamps with ratio of red light to blue light (R:B ratio) of 0.9, 1.2, and 2.2 and fluorescent lamps with R:B ratio of 1.8 as control. The results show that total fresh and dry weights, energy yield, and light energy use efficiency (LUE) of harvested spinach were higher under D17.3-L1.2 treatment compared to other treatments. The higher net photosynthetic rates were shown at DLI of 17.3 mol m<sup>−2</sup> day<sup>−1</sup> regardless of light quality. Higher vitamin C contents of spinach in all LED treatments were obtained compared with the control. L1.2 treatments with higher fraction of blue light led to more vitamin C content, lower nitrate content, and higher LUE independent of DLI. L2.2 treatment with more fraction of red light was beneficial to reduce oxalate accumulation. Power consumption based on increased total fresh weight under LED lamps with R:B ratio of 1.2 in different DLIs was over 38% lower than that under the fluorescent lamps and 1.73 kWh per 100 g FW at DLI of 17.3 mol m<sup>−2</sup> day<sup>−1</sup>. In conclusion, lighting environment in DLI of 17.3 mol m<sup>−2</sup> day<sup>−1</sup> using LED lamps with R:B ratio of 1.2 is suggested for the design of a LED plant factory for hydroponic spinach production. |
| first_indexed | 2024-03-10T18:11:24Z |
| format | Article |
| id | doaj.art-bc09534b392d466f9c3239621e03ac8a |
| institution | Directory Open Access Journal |
| issn | 2073-4395 |
| language | English |
| last_indexed | 2024-03-10T18:11:24Z |
| publishDate | 2020-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Agronomy |
| spelling | doaj.art-bc09534b392d466f9c3239621e03ac8a2023-11-20T08:06:53ZengMDPI AGAgronomy2073-43952020-07-01108108210.3390/agronomy10081082Effects of Daily Light Integral and LED Spectrum on Growth and Nutritional Quality of Hydroponic SpinachWei Gao0Dongxian He1Fang Ji2Sen Zhang3Jianfeng Zheng4Key Laboratory of Agricultural Engineering in Structure and Environment of Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, ChinaKey Laboratory of Agricultural Engineering in Structure and Environment of Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, ChinaKey Laboratory of Agricultural Engineering in Structure and Environment of Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, ChinaKey Laboratory of Agricultural Engineering in Structure and Environment of Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, ChinaKey Laboratory of Agricultural Engineering in Structure and Environment of Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, ChinaTo achieve clean and high-quality spinach production, the effects of daily light integral (DLI) and light spectrum on growth, nutritional quality, and energy yield of hydroponic spinach (<i>Spinacia oleracea</i> L.) were investigated in a closed plant factory under light-emitting diode (LED) lighting. The hydroponic spinach plants were grown under 16 combinations of four levels of DLI (11.5, 14.4, 17.3, and 20.2 mol m<sup>−2</sup> day<sup>−1</sup>) with four light spectra: LED lamps with ratio of red light to blue light (R:B ratio) of 0.9, 1.2, and 2.2 and fluorescent lamps with R:B ratio of 1.8 as control. The results show that total fresh and dry weights, energy yield, and light energy use efficiency (LUE) of harvested spinach were higher under D17.3-L1.2 treatment compared to other treatments. The higher net photosynthetic rates were shown at DLI of 17.3 mol m<sup>−2</sup> day<sup>−1</sup> regardless of light quality. Higher vitamin C contents of spinach in all LED treatments were obtained compared with the control. L1.2 treatments with higher fraction of blue light led to more vitamin C content, lower nitrate content, and higher LUE independent of DLI. L2.2 treatment with more fraction of red light was beneficial to reduce oxalate accumulation. Power consumption based on increased total fresh weight under LED lamps with R:B ratio of 1.2 in different DLIs was over 38% lower than that under the fluorescent lamps and 1.73 kWh per 100 g FW at DLI of 17.3 mol m<sup>−2</sup> day<sup>−1</sup>. In conclusion, lighting environment in DLI of 17.3 mol m<sup>−2</sup> day<sup>−1</sup> using LED lamps with R:B ratio of 1.2 is suggested for the design of a LED plant factory for hydroponic spinach production.https://www.mdpi.com/2073-4395/10/8/1082hydroponic spinachratio of red light to blue lightvitamin C contentnitrate contentenergy yield |
| spellingShingle | Wei Gao Dongxian He Fang Ji Sen Zhang Jianfeng Zheng Effects of Daily Light Integral and LED Spectrum on Growth and Nutritional Quality of Hydroponic Spinach Agronomy hydroponic spinach ratio of red light to blue light vitamin C content nitrate content energy yield |
| title | Effects of Daily Light Integral and LED Spectrum on Growth and Nutritional Quality of Hydroponic Spinach |
| title_full | Effects of Daily Light Integral and LED Spectrum on Growth and Nutritional Quality of Hydroponic Spinach |
| title_fullStr | Effects of Daily Light Integral and LED Spectrum on Growth and Nutritional Quality of Hydroponic Spinach |
| title_full_unstemmed | Effects of Daily Light Integral and LED Spectrum on Growth and Nutritional Quality of Hydroponic Spinach |
| title_short | Effects of Daily Light Integral and LED Spectrum on Growth and Nutritional Quality of Hydroponic Spinach |
| title_sort | effects of daily light integral and led spectrum on growth and nutritional quality of hydroponic spinach |
| topic | hydroponic spinach ratio of red light to blue light vitamin C content nitrate content energy yield |
| url | https://www.mdpi.com/2073-4395/10/8/1082 |
| work_keys_str_mv | AT weigao effectsofdailylightintegralandledspectrumongrowthandnutritionalqualityofhydroponicspinach AT dongxianhe effectsofdailylightintegralandledspectrumongrowthandnutritionalqualityofhydroponicspinach AT fangji effectsofdailylightintegralandledspectrumongrowthandnutritionalqualityofhydroponicspinach AT senzhang effectsofdailylightintegralandledspectrumongrowthandnutritionalqualityofhydroponicspinach AT jianfengzheng effectsofdailylightintegralandledspectrumongrowthandnutritionalqualityofhydroponicspinach |