Announcements

Job offersmore »



Tweeting Growers

Top 5 - yesterday

Top 5 - last week

Top 5 - last month

Exchange ratesmore »




HortScience study finds similar seedling growth under HPS and LED

Light-emitting diodes (LEDs) have the potential to replace high-pressure sodium (HPS) lamps as the main delivery method of supplemental lighting (SL) in greenhouses. However, few studies have compared growth under the different lamp types.

Authors of a new study grew seedlings of geranium (Pelargonium ×hortorum), pepper (Capsicum annuum), petunia (Petunia ×hybrida), snapdragon (Antirrhinum majus), and tomato (Solanum lycopersicum) at 20 °C under six lighting treatments: five that delivered a photosynthetic photon flux density (PPFD) of 90 μmol·m−2·s−1 from HPS lamps (HPS90) or LEDs [four treatments composed of blue (B, 400–500 nm), red (R, 600–700 nm), or white LEDs] and one that delivered 10 μmol·m−2·s−1 from HPS lamps (HPS10), which served as a control with matching photoperiod.

Lamps operated for 16 h·d−1 for 14 to 40 days, depending on cultivar and season. The LED treatments defined by their percentages of B, green (G, 500–600 nm), and R light were B10R90, B20R80, B10G5R85, and B15G5R80, whereas the HPS treatments emitted B6G61R33. Seedlings of each cultivar grown under the 90 μmol·m−2·s−1 SL treatments had similar dry shoot weights and all except pepper had a similar plant height, leaf area, and leaf number.

After transplant to a common environment, geranium ‘Ringo Deep Scarlet’ and petunia ‘Single Dreams White’ grown under HPS90 flowered 3 days earlier than those grown under HPS10, but flowering time was not different from that in LED treatments. There were no consistent differences in morphology or subsequent flowering among seedlings grown under HPS90 and LED SL treatments.

The inclusion of white light in the LED treatments played an insignificant role in growth and development when applied as SL with the background ambient light. The LED fixtures in this study consumed substantially less electricity than the HPS lamps while providing the same PPFD, and seedlings produced were of similar quality, making LEDs a suitable technology option for greenhouse SL delivery.

Access the full study at HortScience

Publication date: 5/19/2017

 


 

Other news in this sector:

4/26/2018 US (NC): Recent storms may impact North Carolina strawberry crops
4/25/2018 US (CA): Lettuce production completes transition to Salinas
4/25/2018 Asparagus season - growing the white gold in the Netherlands
4/23/2018 "It's worth the labor cost to prune and train"
4/20/2018 Composting the full crop at the end of the season
4/20/2018 India: Nilgis growers trained on advanced horticultural technologies
4/19/2018 South Africa: Unlimited possibilities to produce in greenhouses
4/18/2018 Distantly related crops are not better rotation partners for tomato
4/16/2018 Real time soil testing in Zambia
4/16/2018 “Far-red light boosts tomato yield”
4/13/2018 Plants 'hedge their bets' in germination
4/12/2018 UK: Cambridge and four other universities form agritech partnership
4/12/2018 El Niño affected two-thirds of the world’s harvests
4/12/2018 Next Generation Growing 2.0: no inner rot in peppers
4/10/2018 New Mid-Atlantic Commercial Vegetable Production Recommendations available
4/6/2018 "Water essential to feed New Zealand"
4/6/2018 Canada: New World crops online resource now available
4/4/2018 Australian experts to help Indian growers go soilless
4/3/2018 "Jordan growers can grow anything they want"
4/3/2018 Dutch restaurant has rooftop greenhouse with LED-lighting