LED Grow Lights Spectral Output
We understand we have a large number of options and configurations of lighting systems, so here we will explain which lights are best suited for which spaces and requirements.
So when choosing the right light you should consider the points below so that you can find a light which has the right power intensity and coverage for your required space.
- The floor space you are trying to light in Square feet
- The height of the grow room or headroom
- Preferred Watts per square foot (30w psf is optimal)
- Growing method
- Is corner to corner coverage important to you ? or is a central light suitable ?
Once these points have been established you can get a better understanding of which lights would be suitable for your grow room.
| Lighting conditions | Plant | Effects | Reference |
|---|---|---|---|
| Red (660 nm) | Lettuce seedlings | Elongated hypocotyls and cotyledons | Hoenecke et al., 1992 |
| Red (660 nm) | Strawberry (Fragaria xananassa L.) | Increased photosynthetic rates in leaves | Yanagi et al., 1996 |
| Red (660 nm) + blue (470 nm) | Rice | Increased photosynthetic rates in leaves | Matsuda et al., 2004 |
| Supplemented blue with 30 μmol•m-2•s-1 PPF or red with 100 μmol•m-2•s-1 PPF | Wheat seedlings | Restored chlorophyll | Tripathy and Brown, 1995 |
| Infrared (880 nm and 935 nm) | Etiolated oat seedlings | Increased and decreased concentration of mesocotyl and coleoptile tissue respectively; straightened seedlings; activated gravitropism | Johnson et al., 1996 |
| Red + white + far-red (700 to 800 nm) for night interruption | Dianthis (dianthus chinensis 'Floral Lace Purple' and 'Super Parfait Strawberry' Petunia (Petunia xhybrida 'Easy Wave Burgundy Star') Dianthus, both cultivars | Delayed flowering Promoted early flowering Promoted longer internodes (height) | Kohyama et al., 2014 |
| Red + white (600 to 700 nm) for night interruption | Ageratum (Ageratum houstonianum 'Hawaii Blue') and calibrachoa (Calibrachoa x hybrida 'Callie White') | Inhibited height | |
| Red:blue (100:0; 450 nm or 627 nm) with 70 μmol•m-2•s-1 PPF | Petunia (Petunia x hybrida 'Suncatcher Midnight Blue') cuttings | Stem length shortened; increased dry mass of leaves, roots, and root:shoot ratio | Lopez and Curry, 2013 |
| Sole course lighting of blue (446 nm) with 160 μmol•m-2•s-1 PPF | Impatiens (Impatiens walleriana 'SuperElfin XP Red'), petunia (Petunia x hybrida 'Wave Pink'), salvia (Salvia splendens 'Vista Red'), and tomato (Solanum lycopersicum 'Early Girl') seedlings | Inhibited height | |
| Sole source lighting of red (634 nm and 664 nm) with 160 μmol•m-2•s-1 PPF | Impatiens, petunia, salvia and tomato seedlings | Increased leaf area and fresh shoot weight | Wollaeger and Runkle, 2014 |
