Buyer beware, Elaine. Does this stuff work - who knows? Like most OTC things we buy, there is little if any true research proving its effectiveness. SuperThrive is kind of like "natural" supplements. Much more is spent on advertising than in research. Perhaps a university, such as Michigan State, LSU, or Mississippi State, has done some research on this product (they have large, active agricultural research centers), or perhaps your extension service folks knows something about it. One thing's for sure. SuperThrive is very expensive. Ken
