I read an article recently where it said that yield was in direct relationship to the size and health of the roots...all else the way it should be i.e. light, ventilation, temps, etc.. I'll see if I can find it (probably not as I read a lot) but it was suggesting that larger containers were the most effective means of getting the holy grail of yields we all dream of. It also mentioned that many of the top growers were experimenting with longer (deeper) containers as they felt the tap root was the most important part of the root system and not allowing it to bend all over the place to fit in a smaller container was also a key to mega yields and a super healthy plant.

Some of these same people have said that they did tests with Superthrive vs. no Superthrive and saw absolutely no difference in yield or the quality of the root systems or plant. I thought you might find that interesting HD.