Open AccessEffects of HPS and LED lighting on cucumber leaf photosynthesis, light quality penetration and temperature in the canopy, plant morphology and yield
Author(s) -
Liisa Särkkä,
Kari Jokinen,
CarlOtto Ottosen,
Timo Kaukoranta
Publication year - 2017
Publication title -
agricultural and food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.347
H-Index - 35
eISSN - 1795-1895
pISSN - 1459-6067
DOI - 10.23986/afsci.60293
Subject(s) - photosynthesis , canopy , horticulture , yield (engineering) , elongation , biology , botany , agronomy , materials science , metallurgy , ultimate tensile strength
In Nordic countries during the winter months supplemental lighting is essential for year-round cucumber production. In this research the effects of full HPS (top and interlights) illumination is compared to hybrid (HPS top, LED interlights) and full LED (top and interlights). The results showed that fruit yield was highest in the HPS-LED treatment whereas the electrical use efficiency (kg yield J-1) increased when HPS was replaced with LED. In LED-LED the light use efficiency (g fruit FW mol-1 PAR) was highest but resulted in a fewer number of fruits in mid-winter particularly and the lowest yield potential. The lower temperature and lower light level due to LED-LED lighting lead to reduced photosynthesis capacity, flower initiation rate and water use efficiency whereas increased stem elongation and leaf expansion compared to other treatments. Differences in light quality of LED and HPS are also discussed in terms of cucumber yield formation.