NASA

Here is an email I got back when trying to buy NASA's LED snaplites. For my own amusement, I figured it didn't hurt to try. I'm sure his center director is very interested in the project for obvious reasons.

Offered by Steve.

From: "Yorio-1, Neil", INTERNET:[email protected]
To: "'Steve Ferguson'", steveferguson
Date: 1/19/99 12:54 PM
RE: RE: LED lighting details

From: Steve [SMTP:[email protected]]
Sent: Wednesday, January 13, 1999 1:16 PM
To: neil yorio
Subject: LED lighting details

>Dear Neil,

>I've been looking at the web pages concerning plant growth with LED
>lighting and have a couple of questions. Many of the hydroponics books I
>have been reading report lighting needs in either lumens or foot candles
>(lettuce needing 2000 lum, fruiting and flowering plants needing 4-6000
>lumens etc.), how does this relate or translate to umol measurements?

A footcandle is one lumen per square foot. A Lux is one lumen per square meter. So depending on your lamp type, you can convert lux to umol. For example, a cool white fluorescent lamp has 74 lux per umol, sunlight has 54 lux per umol (these examples are for PAR; 400-700 nm). The reference for this is Thimijan and Heins (1983) HortScience 18(6):818-822.

>Quantum Devices QBeam, Snap-Lite, and Ceres 2010 products seem to be
>excellent products, but are tremendously expensive, even considering the
>high cost of LEDs, do you know any other sources for LED grow lights?

We have only used LEDs purchased from Quantum Devices. Snaplite are made by Quantum Devices and CERES uses SnapLites. I don't know about Q Beam.

>Have you done any studies on the maximum spacing of LEDs where you still
>get a good growth rate?

No, we used lamp arrays that were custom built by some engineers at Ames. Spacing was never an issue in our studies as long as the distribution and intensity were OK.

>I have been trying to work with Delta light in developing a reasonably
>affordable LED grow light system that is more affordable. Do you have
>any other studies or info available on LED lighting and results not
>on the web pages that I can get hold of?

I don't know of any other information available than the studies we did (or what you can find in the bibliography contained in our published papers), but if you contact Quantum Devices, they should be able to provide you a list of research done with LEDs. They hold the patent on using red LEDs for plant growth. Also, good luck making an affordable LED array.

>Is there anyplace I can get some of the superdwarf wheat seed to
>experiment with mentioned on the web page? Does it have a good yield
>compared to regular wheat? Is it hybrid-ized to the point of future
>yields not having the same characteristics of the parent crop?

Contact Dr. Bruce Bugbee at Utah State University. He is our source for the seed. They have a web site and you should be able to get to him that way.

>I appreciate any help you could give. I
>would be happy to freely share any results I come up with if you are
>interested.

>Thanks, Steve

I don't think we can sell them. They were pretty expensive and we purchased them with money provided by our center director. He has an interest in what we are doing. This project will likely be for a long while, and the individual Snap Lites we are using have different wavelengths of red (i.e. an entire array of 660, 670, 680, 690, 700, and 720 nm) with blue LEDs mixed in. The older discrete type arrays are already being used by some other researchers within our group (and some collaborators) to do other investigations. So, at least at this moment, they are all gobbled up.

Neil

>From: Steve
>Sent: Wednesday, January 20, 1999 3:44 PM
>To: Yorio-1, Neil
>Subject: RE: LED lighting details

>Dear Neil,

>I have another question. What do you do with the Quantum Device's
>Snaplites when the LED project is over? Do you ever sell them? I would
>be interested if they are for sale.

>Thanks, Steve