“Climate control under artificial light” By André Kool, consultant Green Q 10 February 2010
HPS-lights+LED (Komeett, IC) TEKST
HPS-lights+LED (Komeett, IC)
LED-lights = growth pipe? TEKST
Curly leaves near LED sugar accumulation? TEKST
Botrytis
Leaf tips in tomatoes weak plant cell walls
Weak plant cell walls high humidity less Ca in cell wall weak root pressure, (sudden) evaporation cell wall burst
Weak plant cell walls
Botrytis hits damaged leafs……
…..and finally stem botrytis
Humidity rims in cucumber
Problems related to artificial light Artificial light crops evaporates Ca uptake by leaves Ca = required for strong cell walls Too high humidity crop evoporates loo less too less Ca in leaves too less Ca in plant cell wall “Shocks” in humidity and /or root pressure cell wall burst leaf rims > X hours Y % air humidity = botrytis
Prevention / solution For uptake of Ca in leaves create evaporation during hours of lighting HD >3 ( ) Avoid extreme high greenhouse air humidities: pre-night not <1.5, but certainly not < 1.0 after-night , preferably >2.0 morning afternoon peak (tomatoes )
Prevention / solution Create sufficient air movement en evaporation by: (Growth) pipe > 20°C warmer than surrounding air. Careful ventilation during cold weather (frost) and lights on no cold air falling down on heads blocks evaporation problems……… Try to ventilate with small % at lee-side even at (heavy) frost at artificial light and high greenhouse humidity Feel if windows are not frozen to construction In Finland small ventilation % at -16°C (no wind). Small % (1-2%) is enough too get rid of humidity more =risk of cold heads
Questions?
Thanks for your attention!