Great question. I'm looking forward to the responses. My guess is, speaking as a person with some education in botany and ecology but new to tomatoes, is that all plants probably have their mycorhyzza in the wild, as well as a favorite type of soil that they are adapted to. Since both heirlooms and hybrids are variations from the wild, they may also have variations in these requirements, but they are still going to be pretty close. As I understand it, tomatoes are native to Central and South America, but I don't know anything about the soil requirements in the wild. Most people say they are pretty easy to grow, thus I would guess they are adapted for a wide variety of soils. As a science, the study of mycorhyzza is as new as plate techtonics. Enough is known to say that mycorhyzza and earthquakes happen, but there is much to learn about the details. Linda Kuczwanski In a message dated 4/18/99 8:42:45 AM Central Daylight Time, orchid@ispchannel.com writes: << Well, my question here is.....is VAMF for people who have low moisture, low phosphorous soil and the fungi compensates for it, and the rest of us with well watered, good fertilized soil don't need it? Or is going the low phosphorous, VAMF Fungi better in the long run? Peter, South Florida, Zone 10 >>