Effects of environment lighting on the growth,photosynthesis,and quality of hydroponic lettuce in a plant factory  

作　　者：Xin Zhang Dongxian He Genhua Niu Zhengnan Yan Jinxiu Song 

机构地区：[1]Key Lab of Agricultural Engineering in Structure and Environment of Ministry of Agriculture,China Agricultural University,Beijing 100083,China [2]Texas A&M AgriLife Research at El Paso,Texas A&M University System,1380 A&M Circle,El Paso,TX,79927,USA [3]Beijing Research Center for Information Technology in Agriculture,Beijing 100097,China

出　　处：《International Journal of Agricultural and Biological Engineering》2018年第2期33-40,共8页国际农业与生物工程学报（英文）

基　　金：supported by the National High Technology Research and Development Program(“863”Program)of China(2013AA103005).

摘　　要：Leafy vegetable production under controlled environment using artificial lighting has many advantages over conventional greenhouses and open-field production.However,high initial investment and operation costs are restricting the wide application of this technology.In order to design an optimal artificial lighting environment for lettuce production,effects of different combinations of light intensity,photoperiod,and light quality on growth,quality,photosynthesis,and energy use efficiency of lettuce(Lactuca sativa L.cv Ziwei)were investigated under a closed plant factory.Lettuce transplants were grown under photosynthetic photon flux density(PPFD)at 150μmol/m^(2)·s,200μmol/m^(2)·s,250μmol/m^(2)·s,and 300μmol/m^(2)·s provided by fluorescent lamps(FL)with a red to blue ratio(R:B ratio)of 1.8 and light-emitting diode(LED)lamps with R:B ratio of 1.2 and 2.2,in combination with photoperiod of 12 and 16 h/d.In order to examine the“long term”photosynthetic characteristics,net photosynthetic rates of hydroponic lettuce leaves were continuously measured for 2 d(15^(th) and 16^(th) day after transplanting)before harvest.There was no difference in leaf fresh weight(FW)between PPFD of 250μmol/m^(2)·s and 300μmol/m^(2)·s with photoperiod of 16 h/d,regardless of light quality,and same results showed in contents of nitrate,soluble sugar,and vitamin C,respectively.The results of continuous measurements of net photosynthetic rate of lettuce leaves before harvest indicated that plants grown at PPFD of 250μmol/m^(2)·s had consistently higher compared to those grown at PPFD of 300μmol/m^(2)·s.Combining the results from growth,photosynthesis,quality,and energy consumption,it can be concluded that PPFD at 250μmol/m^(2)·s with photoperiod of 16 h/d under LED with R:B ratio of 2.2 is a suitable light environment for maximum growth and high quality of commercial lettuce(cv.Ziwei)production under indoor controlled environment.

关 键 词：plant factory daily light integral artificial light photosynthetic photon flux density net photosynthetic rate energy use efficiency 

分 类 号：F42[经济管理—产业经济]