Seed Treatment With Infra-Red Light
Warren E. Berg, Kent, Washington
For those of you who like to try new ideas, I would like to pass on some information on the treatment of rhododendron seed with infra-red light. Mr. H. A. Merrick of Auburn, Washington, has spent considerable time developing the procedure, experimenting with many different kinds of seeds and has had some rather amazing results. However, when he applied for a patent he found someone else had come up with almost the same exact procedure and had received a patent back in 1939. Very little work has been done with rhododendron seed. I did some experimenting last year and noted some favorable results but nothing conclusive.
The object of the treatment is to improve germination by increasing the percentage of seeds which germinate, to decrease the time required for germination after planting, and to increase the strength and health of the resulting plants. Theoretically this is achieved by irradiating these seeds with infra-red light in the color band between 7,500 and 15,000 Angstrom units with an energy peak in the neighborhood of 10,000 units. The lamp is of the incandescent type having a concentrating reflector. This lamp should produce 2.5 watts of infra-red energy per square inch at a distance of 11 inches from the filament. Tests indicate that with practically all garden and grain seeds, an exposure of from 10 to 20 seconds results in maximum improved germination.
The proper exposure time may be determined by the size and color of the seed. Large seeds were treated half time on each side.
If you would like a copy of the patent, it may be obtained from the U.S. Dept. of Commerce Patent Office under No. 2,300,727-for 50 cents.