Infra-red and Ulta-violet lights

I don't know how infra-red effects the plants, but studies have shown that a higher UV concentration has a definate effect on the resin production of the buds. Researchers think that the tricomes may actually be produced to protect the seeds from harmful UV rays. Most plants that recieve higher UV light concentrations do produce higher tricome ratios, but I have not heard of anyone using a UV light on their plants for flowering, but the results would definately be interesting. :)