Transcript Dia 1 - ghservice

“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
Humidity rims in cucumber
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 (3.0-6.0)
Avoid extreme high greenhouse air humidities:
pre-night not <1.5, but certainly not < 1.0
after-night 1.5-2.5, preferably >2.0
morning 2.5-3.0
afternoon peak 3.0-5.0 (tomatoes 4.0-6.0)
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!
www.greenq.nl