In Clarke’s Marijuana Botany, Gibberellic Acid (GA) is said to promote male flowers, while Indoleacetic Acid (IAA), among other hormones, is said to promote female flowers. This is prior to flowering. No Mercy (nomercy.nl) sells GA spray as a bloom stimulator. Hybrid-Tech (hempqc.com) sells a product that allows selfing for breeding. I assume this is GA. Why the apparent discrepancy? Is this because of use during pre-flowering and flowering?
No Mercy also sells CO2 tablets to be put in soil or solution to deliver to roots. I have heard of watering with carbonated water or mineral water. I know of the benefits of CO2 and improved yield. But I always thought O2 was more important for roots and CO2 for above ground. Aren’t O2 and CO2 antagonistic? How much CO2 should be delivered to the roots without causing problems with O2?
Gibberellic acid promotes male flowers in female plants prior to flowering. I don’t think it has this effect during flowering. However, female flowers sprayed with GA will be lanky and loose rather than tight because GA promotes stem stretching. It should not be used during the normal female bud cycle. I wouldn’t use a product that promotes GA as a flower promoter for marijuana.
It’s recommended that water circulate in fish tank and hydroponic systems. This is to constantly change the surface between the air and water. The water exchanges dissolved CO2 for oxygen in the air, which then dissolves into the water. Fish are able to use this oxygen and are constantly exchanging it for CO2 in much the same way that land animals do. Roots also use oxygen to maintain their metabolic processes, burning sugar for energy. No photosynthesis takes place at the root level, so no CO2 is needed there.
If CO2 were added to the water it would displace the oxygen from the solution with the water. This creates a bad environment for the roots, which are unable to absorb oxygen, which is needed for their survival. At the same time, anaerobic bacteria, which thrive in the absence of oxygen, begin to attack the roots, causing them to rot and releasing a telltale ammonia odor.
Using a product that increases the CO2 level in the root zone is a bad idea and can harm your plants.
Readers with grow questions (or answers) should send them to Ed at: Ask Ed, PMB 147, 530 Divisadero St., San Francisco, California 94117, USA. You can also email Ed at [email protected], and send queries via his websites at www.ask-ed.net. All featured questions will be rewarded with a copy of Ed’s new book, Best of Ask Ed: Your Marijuana Questions Answered. Sorry, Ed cannot send personal replies to your questions.