The measured ambient air temperature at canopy height was measured with a thermister @ 28.8 deg C.
FLIR is measuring leaf temperature, I was concerned with high temp tips, I think transpiration was being inhibited at those points?
Led Temps - Air vs Leaf Surface
- Thread starter ilovereggae
- Start date
FLIR is measuring leaf temperature, I was concerned with high temp tips, I think transpiration was being inhibited at those points?
getogrow
Well-Known Member
I dont think so but im not a vpd guy. 28.8 is not hot enough to slow anything down and the heat may actually speed growth/transpiration up.
HippieDudeRon
Well-Known Member
Google away..."leaf temperature photosynthesis"
Cannabis...
Cannabis(hemp)...levelled off at 25–35 °C and decreased when TL became higher than 35 °C. Based on a C3 leaf photosynthesis model,
https://onlinelibrary.wiley.com/doi/full/10.1111/gcbb.12451
It is known that optimum temperature for leaf photosynthesis in citrus plants is between 20 and 30ºC under humid conditions (KRIEDEMANN, 1968; RIBEIRO et al., 2004), however, this optimum temperature shifts under CO2–saturated conditions, i.e. non–photorespiratory conditions (BERRY & BJÖRKMAN, 1980), as found in this study (35–40ºC). According to Berry & Björkman (1980), this shift happens because there is CO2 limitation for carboxylase reaction and/or changes in the ratio of photorespiratory CO2 release to total photosynthetic CO2 fixation under natural CO2 concentration. Monson et al. (1982) found an increase around 10–15ºC in the optimum temperature for photosynthesis of a C3 species under low O2 air concentration (2%) and high CO2 concentration (800 µ mol mol–1).
Plenty more in just the image search for chart with temps and photosynthesis.
Cannabis...
Cannabis(hemp)...levelled off at 25–35 °C and decreased when TL became higher than 35 °C. Based on a C3 leaf photosynthesis model,
https://onlinelibrary.wiley.com/doi/full/10.1111/gcbb.12451
It is known that optimum temperature for leaf photosynthesis in citrus plants is between 20 and 30ºC under humid conditions (KRIEDEMANN, 1968; RIBEIRO et al., 2004), however, this optimum temperature shifts under CO2–saturated conditions, i.e. non–photorespiratory conditions (BERRY & BJÖRKMAN, 1980), as found in this study (35–40ºC). According to Berry & Björkman (1980), this shift happens because there is CO2 limitation for carboxylase reaction and/or changes in the ratio of photorespiratory CO2 release to total photosynthetic CO2 fixation under natural CO2 concentration. Monson et al. (1982) found an increase around 10–15ºC in the optimum temperature for photosynthesis of a C3 species under low O2 air concentration (2%) and high CO2 concentration (800 µ mol mol–1).
Plenty more in just the image search for chart with temps and photosynthesis.
I'd guess transpiration creates a cooler boundary layer around the leafs and it's disrupted at the tips by air movement..... but I don't see a pattern of higher tip temp in that image, I see it in the buds. At any rate, I wouldn't be to concerned. And more FLIR pics please.
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Doubled E.C.I'd guess transpiration creates a cooler boundary layer around the leafs and it's disrupted at the tips by air movement..... but I don't see a pattern of higher tip temp in that image, I see it in the buds. At any rate, I wouldn't be to concerned. And more FLIR pics please.
