Science Buddies: "Ask an Expert"

Hi all,
My daughter is undertaking an experiment with basil watering the leaves of one plant only and the roots of another plant only. She will be using 50mls twice a day on both. She will measure plant height, observe plant colour and I am hoping to count the number of leaves and measure their length and width on each plant. Does she have to measure the surface area of the leaves on each plant? Also are 2 plants from each group a reasonable amount? She is going to observe the growth of each plant group.

Hi there,

Cool idea! Remember that the more data you can collect, the stronger the conclusions that are drawn will be. That being said, 2 plants is good to start off with, but more never hurts! I'd personally say at least 3.

It looks like plant height and color are excellent along with leaf count and length/width. Surface area may be a big difficult to measure given a leaf's shape, but it doesn't hurt to have another mode of comparison for results and analysis. I do think, however, this would depend greatly on her hypothesis (that would help determine what exactly she has to compare and how).

Hope this helped!

Thank you very much, much appreciated!

We just wondered as we are using basil, each plant has around 8-10 leaves from a young shoot. Should she be measuring the length and width of each leaf on the plant or maybe just one leaf per plant? Thanks so much!

I'd suggest measuring as many as makes sense, i.e. measuring the "representative" leaves of the overall plant. This would mean taking the leaves of mean/median size and measuring them. Then you can average their values to find data representative of your objective. Just remember to be consistent for all the plants!