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Dew indoors????


YT2095

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I`v just made the Strangest observation during an experiment I`m conducting that Has nothing to do with what I`v seen.

 

Look at the very Tips of the plants in these pics:

 

gr1.JPG

 

gr2.JPG

 

now I can Assure everyone that these have Never been outside, it doesn`t rain in the lab and the Relative Humidity is that of any other ordinary indoor room ~40-60% and the temp hasn`t been below 18c.

these plants are Wheat in one beaker and Barley in the other.

 

can Anyone explain these liquid droplets on the tips of the blades?

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well I`m calling it "Dew" because that`s what it resembles, the sort you get on the tips of grass 1`st thing on a spring morning.

The PH tests perfectly neutral and it`s quite clear as a liquid and not as all viscous.

 

but I`m Fairly sure "Dew" cannot or doesn`t occur indoors (I think).

 

it seems I could be Wrong???

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I wonder how that works then?

 

I can honestly say there have been NO wild or rapid temperature fluctuations in here since these were planted 4 days ago, and I`v done nothing strange to them yet either.

they are in ordinary potting compost with a 1cm layer of silver sand at the bottom of the beaker.

there`s no excess water, and their light source (other than ambient) is a 20W Halogen bulb, they get 8 hours "sleep" in total dark at night.

 

and I thought I could understand it at 1`st when the shoots were in the Hollow straw stage, but this is on open and flas blades now and sometimes on the back of the blades, so that rules out capillary action.

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well I`v just put in a .5mm SC hypodermic needle in there as well as a 50 micron glass fiber in there, maybe the same thing will happen on the tips of these?

 

also, I did an evaporation test and it leaves no residue, so I tasted it and it seems to be plain water.

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BINGO! found it!

 

or Rather my Friend Glyn found it for me (he`s my neighbor at the gardens and also an ex-Chem teacher).

 

it`s called "guttation"

here: http://en.wikipedia.org/wiki/Guttation

 

most notably it says at the bottom of the article: "Guttation is not to be confused with dew, which condenses from the atmosphere onto the plant surface."

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You can get dew (water condensing on a surface) indoors — it happens a lot if you run the shower; relative humidity and dewpoint temperature are related to each other. And when the surface has a high heat conductivity and heat capacity, you can remove the latent heat quite readily.

 

But that doesn't mean that's what is going on here. It probably isn't.

 

The presence of water at the tips but not the rest of the stalk suggests it's not dew (or not entirely dew). I suspect it's biology and not physics.

 

<pause to Google>

 

AHA!: Guttation

 

http://en.wikipedia.org/wiki/Guttation

http://sparkleberrysprings.com/v-web/b2/?p=526

 

Learned something new! :)

(technically there is some physics going on with the capillary action drawing the water up, etc. but it's still biology overall)

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