LED Research WUR Horticulture: Results & Bottlenecks. Tom Dueck, Wageningen UR Glastuinbouw 6 februari 2014

Transcription

1 LED Research WUR Horticulture: Results & Bottlenecks Tom Dueck, Wageningen UR Glastuinbouw 6 februari 2014

2 9960 ha horticulture in the Netherlands 3100 ha with artificial lighting

3 Why LEDs in horticulture? Insufficient development in HPS HPS more light? More light hours: 1% more light -> 1% more production Higher light intensities: 1% more light -> 1.7% more production Result: more light ~ more (surplus)heat Are LEDs the answer?...no radiative heat, higher efficiency, longer life, can be dimmed, specific wave lengths...

4 First tomatoes under LEDs

5 Toplighting in rose, tomato, pepper: which problems encountered? Intensity too low had to be supplemented Efficiency too low - (sometimes) lower than HPS Expectations for production increases not realized Insufficient radiative heat

6 28 26 Insufficient radiative heat (necessary for truss and leaf initiation) [ o C] LED-top 30 air temp. plant temp. [ o C] HPS time Leaf T < Air T at night time Leaf T ~ Air T night and day

7 But why (LED)lighting? Produce year-round crops GROW LIGHT: increase production STEERING LIGHT: increase quality steer/influence crop (form, morphology, flowering)

8 Zonlight (spectrum) Stralin g Golflengte Opmerking UV-C << 280 nm Komt niet aan op de aarde UV-B nm > 300 nm komt aan op aarde UV-A nm Gevaarlijke straling in de zon VIS IR-A IR-B nm ( ) nm nm Licht! Zichtbaar voor menselijk oog paars, blauw, groen, geel, oranje, rood Nabij infrarood ( N I R ) IR-C Ver infrarood ( V I R )

9 Which wave lengths doe a plant see? PAR blue red Far red Wave length (nm) Average plant sensitivity(mccree, 1972)

10 Grow light progression, development in tomato cultivation 2007 toplight, air-cooled, water-cooled interlight, in hybrid systems hybrid systems with LED interlight and/or LED toplight

11 Consensus: hybrid system HPS + interlight (LED) Advantages: Interlight ~ 10% more efficient than HPS Light distribution over larger leaf area Less (HPS) light in top of crop -> less excess heat, with sufficient radiative heat for truss and leaf More hours (LED) lighting possible in warm weather (spring) Intermittent lighting possible (on/off)

12 Optimal use of light and hybrid lighting

13 Application of hybrid lighting Tune assimilation light to crop requirement Calculate light requirement according to crop (fruit) load in time Light requirement = sun light + lamp light Sunlight is known (last 5 next 3 days) Lamp light number of extra hours necessary is then known as well HPS lighting out at 200 W radiation LED lighting out at 400 W radiation (longer use in spring is possible)

14 Joule/(cm².dag) Mol/(m².dag) Light strategy /10 30/10 13/11 27/11 11/12 25/12 8/1 22/1 5/2 19/2 4/3 18/3 1/4 15/4 29/4 Globale straling in J/cm².dag Gewenste lichtsom mol/(m².dag) 0 Lichtsom mol/(m².dag) (voortschrijdend gemiddelde van 7 dagen) Belichting PARsom + SON-T geinstalleerd+ LED geinstalleerd per dag

15 Next Generation Lighting with Diffuse Light Crop duration 1 whole year HPS 83.6 kg / 100% Hybr LED 87.2 kg / +4.3% Hybr Dir 84.9 kg / +1.6% Hybr Diff 89.1 kg / +6.6%

16 Cumulatieve productie (kg m -2 ) Light efficiency Diff hybr Dir hybr Dir LED Dir SONT Cumulatieve PARsom (kmol m -2 ) Efficiency: Diff hybr > Dir hybr > Dir HPS > Dir LED PAR sum (mol m -2 ) Prod. (kg m -2 ) Efficiency (kg kmol -1 ) HPS Dir hybr Dir LED Diff hybr

17 Situation: Interlighting LEDs for production Good energy savings realised (ca. 30%) Production more or less equal to practice Light distribution sub-optimal Management strategy promising for crops like tomato, but application requires practice Current research: combination of hybrid lighting and diffuse glass (increased utilization of light sun light and assimilation light)

18 Situation re: use of LEDs in general Cost price still too high Production (growth) increase still too low Light interception higher than HPS (ca. 7% vs 3%) Electrical connection often 230V vs 400V Replacement of individual LEDs vs whole module

19 LED efficiencies (ca ) Approximate Interlighting (µmol/w) TopLEDs (µmol/w) ca ca Red 1.6 > > 2.4 Blue 1.4 -> > 2.0 System r/b 1.6 -> > 2.3 System r/b/ + w/g 2.0 HPS

20 Energy thrifty Chrysanthemum Aim: Save 30% electrical energy Use of efficient LEDs Lighting ~ plant requirements Switching on/off with LEDs Lighting ~ crop stage

21 Spectral influences on Chrysanthemum Stimulates elongation (in shade of a crop) 80red:20blue HPS Plasma Van Ieperen et al. 2010

22 Setup in greenhouses SON-T Hybride LED

23 Lichtintensiteit (µmol/m2/nm) Lichtintensiteit (µmol/m2/nm) Lichtintensiteit (µmol/m2/nm) Spectrum SONT hybride Golflengte (nm) LED Golflengte (nm) Golflengte (nm)

24 HPS hybrid LED

25 Results long day (LD) period Lighting ~ plant requirements (LD): 7 days: less light used for 3 to 6 h per day 12% less light used Proportion lamp light ~ total light: HPS 79% Hybrid 76% LED 76% Transition to short day (SD): Same development/growth after 15 days in all 3 crops

26 Lengte (cm) Results: plant length end of LD 29 Gemiddelde lengte 14 rassen (n=168) * SONT hybride LED LED: 0.9 cm higher than hybrid and 0.7 cm higher than HPS

27 Light quality & LEDs Mostly red (95%) and blue (5%), combinations with far red are being explored Is green light necessary in supplementary lighting? Effects other colors?? especially on vegetables But, many possibilities in ornamentals Quality, not intensity (1-20 µmol m -2 s -1 ) Distribution in space and time important

28 Light quality influences Effect UV plants harden, production of secundary metabolites (eg herbs)

29 Light quality influences Effect UV plants harden, production of secundary metabolites (eg herbs) Effect far red/red ratio Flowering Morphology Stem elongation (longer internodes) Leaf area, orientation

30 Light quality influences Effect UV plants harden, production of secundary metabolites (eg herbs) Effect far red/red ratio Flowering Morphology Stem elongation (longer internodes) Leaf area, orientation Production of secundary metabolites Influence on plant resilience? Inhibition of plant disease?

31 Assimilation lighting without sun light HPS, flat, Horizontal leaf, good lightinterception LED: curved leaf, shiny, moderate light-interception

32 Measuring photosynthetic efficiency Snel & Driever 2010

33 Spectral efficiency in rose 10-30% higher efficiency with red light in Prestige Cv Akito Cv Prestige Driever & Snel 2012

34 Use of steer light: quality and tomato LED light on trusses increases vitamin C Supplementary LED light Increases vitamin C content in tomato Driever & Verkerke 2010

35 Red light at night = less mildew spores Suthaparan 2009

36 Local leaf reaction systemic resistence Biotrophic organisms: mildew, bacteria, virusses. Salicylic acid -> (SAR) Also effects of light or P-fertilizers, amino acids. Hofland et al

37 Future research focus on: Crop specific responses Optimal growth of other crops under LEDs Dynamic lighting During day During crop Feedback from plant Intensity Spectrum

38 Innovation Demonstration Centre LED

39 Future for LEDs (2020)? Lighting systems will include: Lower cost price Replacable individual LEDs Location of light (LEDs) in the crop Optimized light distribution Larger array of colours Also UV, far red, etc Varying wave lengths and intensity throughout the day

40 Wageningen UR Glastuinbouw With thanks to my colleagues: Arie de Gelder Jan Janse Wouter Verkerke Jan Snel Filip van Noort Jantineke Hofland