I use the stuff that grow the biggest vegetables on earth. Its working really well if only I could use it in my hydrosystem. Check out this quote from a world record grower:
"RTI's pumpkin pro is the mycorrhizae used to produce the worlds largest pumpkin three-years in a row. (2006 1502 pounds Ron Wallace, 2007 Joe Jutras 1689 and 2008 Steve Connolly 1568 pounds.) Every leaf node from beginning to end was trenched, treated and buried using Pumpkin Pro. The big difference we noticed is that later in the season the pumpkins were able to maintain a "top" weight for a longer period of time and also our pumpkins grew into the month of October. Something that has never seemed possible before in our area."
Ron Wallace