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How do I measure Dry weight of Plants using a kitchen oven

Postby juanbanana » Fri May 10, 2019 11:00 pm

Hi everyone,

I have a science project on plants and want to measure its dry weight to calculate a root shoot ratio. I plan to do the procedure in a kitchen oven but have a few questions:

- what is the best temperature I should set the oven to (considering the fact that my plants are radishes and I have only grown them for two weeks)

- Exactly how long should I leave them in the oven (a sciencebuddies project guide said 'overnight'- however I will not be doing that since it is a safety hazard.)

- Is there any requirements for where the plant should be placed? (on the project guide https://www.sciencebuddies.org/science- ... ant-growth it said in a ziplock bag- however wouldn't this melt under heat of oven?)

Thanks so much!

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Re: How do I measure Dry weight of Plants using a kitchen oven

Postby DrSullivan » Tue May 14, 2019 1:14 pm

Referring back to the science buddies project guide, the instructions are as follows:

Remove the plants from the soil and wash off any loose soil.
Blot the plants removing any free surface moisture.
Dry the plants in an oven set to low heat (100° F) overnight.
Let the plants cool in a dry environment (a Ziploc bag will keep moisture out) - in a humid environment the plant tissue will take up water. Once the plants have cooled weigh them on a scale.
Plants contain mostly water, so make sure you have a scale that goes down to milligrams since a dry plant will not weight very much.

In other words, put the plants directly in the oven (either on a cookie sheet or directly on the rack) and set to 100° F and let it run overnight.

Once you take them out of the oven, THEN put them in a ziploc bag while they cool. This will allow them to cool without moisture getting back in.

Hope this helps!

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