Humic Acid Lowering THC Study

[Cerebral Goo]

This one?

Frontiers | Impact of N, P, K, and Humic Acid Supplementation on the Chemical Profile of Medical Cannabis (Cannabis sativa L) | Plant Science (frontiersin.org)

This one?

Frontiers | Impact of N, P, K, and Humic Acid Supplementation on the Chemical Profile of Medical Cannabis (Cannabis sativa L) | Plant Science (frontiersin.org)

Yes, that is the one. Don't know why it didn't copy. Was in a hurry and didn't check before I posted. Sorry bout that!!!

 

[BII]

Basically.

Their main point was that it improves uniformity of cannabinoids among colas (top vs. bottom) vs. the typical "top cola is much danker than other colas".

They didn't really mention or discuss the net effect on "total plant THC". But, if you look at Fig 4, it looks like THC in the side / bottom colas did not make up for the reduction in the top cola - so, total plant THC may have been lower, too.

However, a few things I noticed:

• The effect varied between cannabinoids (THC vs. CBD vs. CBC, etc) - so could be very cultivar specific
• No significant change in plant height with humic acid, but smaller stem diameters with HA (Table 1). Stem diameter growth rate has been found to be a decent predictor of final total bud dry weight (this article)
• This was one of Bernstein's first studies before focusing on optimizing nutrient levels, so the baseline nutrient levels for the HA-fed plants were a bit low, which could have had an effect. It would have been better if they had a "+NPK and HA" test group.

Overall no real positives and mostly negatives seen with supplementation, no data on buds' or total plant THC, etc. The experiment and its outcome seem not useful for us at all.

Crazily, incongruous for a study of salts-based nutrient supplementation(?), these plants were grown in soil, not by hydroponics, with the soil and its nutrient content not described at all. So to me, it seems we know nothing about the total nutrient levels here, whether they were actually high or low relative to what we are used to. Also, there is no information about the number of plants, statistical significance of the data, bud yield or even % mortality/survival among the groups, etc. [How did such a study, about supplementation but totally lacking baseline nutrient data, ever get published, get past journal peer review?]