Original poster: "Steve Cook by way of Terry Fritz <twftesla-at-qwest-dot-net>" <steve-at-g8cyerichmond.freeserve.co.uk> Some years ago a group of school students did a study on the effects of magnetic fields on plant growth, at low levels they noted improvement but the reverse once the levels got high, now all coils generate magnetic fields maybe this could be a part explanantion too.