Geotropism: an article on how a peanut field lost its way

August 05, 2012

When Down Becomes Up: How 379 acres of peanuts got confused

Here's a quick piece of bell work for your students.  It's a quick read with a funny story and will work well with a geotropism lesson. If you think geotropism confuses your students imagine how this field of peanuts felt. 


What is geotropism (gravitropism)? 

Natural ability of seeds to detect the gravitational pull of the earth and send stems up and above the surface and send roots down in the soil to uptake moisture and nutrients.

If geotropism is working correctly which part of the germinating seed grows up and which part grows down?  
Stems grow up and roots grow down.

How did the peanut seeds get confused in this situation?  
The warm soil in combination with a very cool period above ground caused the seeds to believe that the warm soil ( usually next to the soil surface ) was the direction of growth for the stems and the cool soil was the direction of growth for the roots.

So is it possible to plant seeds upside down?  
No, that is the whole purpose of geotropism.  Normally the seeds will send the roots and stems in the correct direction at germination.   

What is the cotyledon?  
Stem or shoot part of the plant that contains the first two leaves of the germinated plant.