Need help teaching 2nd graders

[chris freeman]

These are some good ideas for childrens' experiments.  The only thing I 
would add is that roots will often "shy" away from light.  Therefore 
when constructing the rhizotron, a removeable cover would be useful to 
keep the roots in the dark except when being demonstrated.  Otherwise 
they will grow away from the side of the glass to avoid the light.

Chris