[Plant-education] greenhouse lighting

[Carl Pike]

Dear Plant-Ed list:

We are exploring some new greenhouse lights.  The traditional view 
that I'm aware of is that metal halide lamps are preferable over high 
pressure sodium.  I've heard that there is some new kind of high 
pressure sodium lamp with much better spectral qualities.  Does 
anyone know about these?  What is the best-practice recommendation 
now for greenhouse lighting?

Thanks.  Please pass this along to anyone else you know who might 
have some information.

Carl Pike