At 11:14 AM 2/22/96 -0800, Tim Metz wrote:
>The only chemical I substituted from the Hoagland's solution recipe
>listed in Vodopodich and Moore is Molybdenum trioxide instead of
>H2Mo4*4H2O . Could that have caused the problem? Any suggestions??
I cannot imagine that this is the problem.
Did you adjust the pH of all the solutions?
I always make sure everything is starting
at the same pH.
In these exercises, I have always found that
the student's handling of the plants is to
blame. The roots are very delicate, particularly
grown in perlite, and students do not realize
that the functional part of the root is near
its morphological apex. I have given up the
idea of transplanting seedlings into the solutions.
I now do this whole project in plastic cups of
perlite and have the students sow sunflower seeds
in the perlite. The planted seeds are watered
with the solutions to the point that the perlite
just begins to float. Then, the cups are watered
with distilled water for the remainder of the project
by adding it until the perlite just begins to float.
I have had outstanding results with this project
ever since switching to sunflowers and planting the
seeds directly in the perlite-saturated with the
solutions. BTW, sunflower seeds used for bird
feeders works just fine as long as they are fresh
\ Ross Koning \
\ Biology Department \
\ Eastern CT State University \
\ Willimantic, CT 06226 USA \
\ Koning at ecsu.ctstateu.edu \
\ http://koning.ecsu.ctstateu.edu/default.html \
\ Phone: 860-465-5327 \
) Fax: 860-465-5213 )