light filters

[Kathleen Archer]

 Regarding the question about light filters:
I just discovered that Sigma sells disposable plastic seedling trays with
lids which can be purchased in tinted form (Phytatray II, tinted).  They
come in blue, red and yellow tints, and Sigma provides information on what
wavelengths are transmitted and excluded.  The cost is about $25.00 for 25
trays with lids.  If you are growing seedlings non-sterilly, it might be
possible to re-use them.

These might be just the ticket for student experiments where expensive light
filters or setups are hard to come by.  This way a single cool-white
fluorescent source can be used to provide light simultaneously to plants
getting just the desired wavelengths.
(Sigma technical service phone # 1-800-325-5832 for questions about the
trays, to place an order ph# 1-800-325-3010)
Kathleen Archer
Dept. Biology
Trinity College
Hartford, CT 06106

e-mail: kathleen.archer at mail.trincoll.edu
Ph:     (203) 297-2226