How is leaf temperature taken in scientific studies? Which method can a layman use as a substitute that would approximate this reading? Alternatively, how can a published leaf temperature be translated for use in real life?
I believe that an infrared gun is used. I know some agronomists use this device as one of their tools for plant management. I have no idea what we could use otherwise, as a budget conscious layman...putting a thermometer in the vicinity of a leaf doesn't account for the heat absorption/reflection/conduction nor the evaporative cooling that is peculiar to the plant's tissue. Root temps can be measured pretty accurately with a soil thermometer, easily purchased, and useful in my experience. And damage to roots from overheating, or extreme freezing in containers is hidden, so that makes the thermometer all the more helpful for monitoring and predicting the damage. Heat and cold damage to leaves is at least quite often obvious once it's occurred.
I suspect the cost of an infrared gun will be prohibitive and there probably isn't a substitute for the reasons you cited. Agreed. Soil thermometers are very affordable and indispensable for nursing plants back to health. A recommended buy.
My IR thermometer cost about $150, but I use it for plumbing. It sure is handy for a lot of other things. Ralph
Do you know they can't? They work on the same principle and my IR thermometer gives a pretty good reading into an open mouth (open it just before reading). Ralph
After reading a page describing how an ear thermometer works I was given the impression it was somehow calibrated according to human body temperature. Perhaps someone reading this thread who happens to own both devices can do an experiment by taking the temperature of various objects and report back. Who knows, maybe an ear thermometer would work or at least be close enough. I'm sure there are other gardeners who would also be interested in an affordable tool to measure leaf temperature.
