Hi I'm doing a science fair project to see what kind of beverage preserves roses the longest. What I can't figure out is how would I scientifically measure the end life span of the roses. My teacher won't let us use results based off how they look. He wants actual measurements. Basically when do I know when the roses are dead enough to make a conclusion and record the results?

Number of petals fallen off?
Percentage droopyness?

For preserving roses I suggest trying Sprite or 7Up.
About measuring the rose.

How about using a fresh rose petal(or leaf or a sepal or a bit of the stem) under the microscope before the experiment and then again after the experiment.
You will see the difference each beverage has on the rose petal when you look at it under a microscope.Note these down and make your presentation based on these.

About the time measurement.
Keep all the roses in each beverage for the same length of time, like a 24 hour period or 48 hour period.Or if you have time, a week.

Also try a solution with asprin and sugar.

As controls to find out whether it is the sugar or other ingradients in the drink that is increasing the roses lifespan try compairing the diet version (no sugar) drink against the normal one.

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Originally Posted by templelane

Also try a solution with asprin and sugar.

As controls to find out whether it is the sugar or other ingradients in the drink that is increasing the roses lifespan try compairing the diet version (no sugar) drink against the normal one.

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Good idea!

Asprin in water solution does keep roses longer,never tried with sugar though.

Glucose and fructose are basically what plant use as energy sources for respiration. They can store it in polymers sugars - starch in the roots and tubers. If they don't have roots they don't have an energy store hence why the die (amoungst other reasons) so by giving them sugar you are bypassing this problem. Energy supply will no longer be a limiting factor for death.

My hypothesis is that it is the sugar in 7-up and Sprite that keeps the roses alive, not any other ingredients. I have never tested this though so I could be wrong!

I'm really showing my science geekiness here. I bet I'll be trying this out by next week!