Co2 and ethylene

S

Scottmurphy12

Member
Many growers cut down co2 to atmospheric levels the last 2 or 3 weeks to help trichome maturation as co2 can/will inhibit ethylene production which will cease trichomes maturing.

What ppm do people reduce co2 levels to and for how long before chop. Atmospheric is around 400ppm no (slightly higher in the city?)
Would 800ppm be the best of both worlds? Yield/maturation/potency?

The last 2 weeks some cultivars pack on a vast proportion of their potential weight. So running co2 till chop you'd expect to see an increase in yield at the cost of maybe delayed maturity?.

Also could you delay maturation of trichomes to induce an exponential yield or would it be negligible, radicalisation occur?

Although anecdotal I've always found trichomes to mature even keeping co2 ppms at 1100 until chop (around 10 weeks) with significant yield. But striving for the best product we can produce for the consumer must be prioritised imo but if it is negligible, and the cost on yield heavy, may be a "fruitless" process!

Anyone who can shed light on any points is greatly appreciated as I've exhausted the information available/digestible to me on the interwebs.

Thanks
 
Renfro

Renfro

Well-Known Member
At the lowest setting I have mine run up to 600 and drop to 400 before running back to 600.

I haven't noticed a problem maturing even if at higher PPM's but I do have a daily vent cycle when the lights go off, this prevents the ethylene gas from building up in the room, one daily vent cycle is all you need. I cut down the CO2, dim the lights and drop the temps over the last three weeks, in increments and by the last week it's all the way down. I do this because it prevents foxtailing and makes for denser nugs that weigh more. When I kept things at full throttle till the end the buds were fluffy and not hard, lots of foxtailing. I actually yield more and a better product by using less energy on the lighting. Maybe the AC has to keep things cooler but it's not fighting as much heat from the lights or my CO2 generator so the AC energy usage is probably a wash.

At peak growth I like to let my CO2 run up to 1200 PPM then down to 800 before it goes back up to 1200. This forces the plant to make better use of the CO2 somehow, something to do with it producing a chemical thats used to metabolize the CO2. Keeping the CO2 at say 1000 - 1200 all the time would not make the plant work as hard, so kinda like taking someone to the moon they are really strong and can jump really high but if they stay on the moon they get weaker. lol Between this and regulating the temp and humidity to create a proper VPD for your strain you will get optimal growth I believe.

Thats my experience and thoughts on the matter however unscientific lol. I am interested in what others have to say.
 
S

Scottmurphy12

Member
Renfro said:
At the lowest setting I have mine run up to 600 and drop to 400 before running back to 600.

I haven't noticed a problem maturing even if at higher PPM's but I do have a daily vent cycle when the lights go off, this prevents the ethylene gas from building up in the room, one daily vent cycle is all you need. I cut down the CO2, dim the lights and drop the temps over the last three weeks, in increments and by the last week it's all the way down. I do this because it prevents foxtailing and makes for denser nugs that weigh more. When I kept things at full throttle till the end the buds were fluffy and not hard, lots of foxtailing. I actually yield more and a better product by using less energy on the lighting. Maybe the AC has to keep things cooler but it's not fighting as much heat from the lights or my CO2 generator so the AC energy usage is probably a wash.

At peak growth I like to let my CO2 run up to 1200 PPM then down to 800 before it goes back up to 1200. This forces the plant to make better use of the CO2 somehow, something to do with it producing a chemical thats used to metabolize the CO2. Keeping the CO2 at say 1000 - 1200 all the time would not make the plant work as hard, so kinda like taking someone to the moon they are really strong and can jump really high but if they stay on the moon they get weaker. lol Between this and regulating the temp and humidity to create a proper VPD for your strain you will get optimal growth I believe.

Thats my experience and thoughts on the matter however unscientific lol. I am interested in what others have to say.
Click to expand...
The swings in co2 is to not Inhibit the rubisco enzyme I believe
A poster on here suggested I believe to have the controller kick on at 600ppm and rise to 1200ppm,he was the one talking about rubisco activase I believe. I've heard many suggest lower rh for increased resin production and less intense lighting to prevent foxtailing but foxtailing is also cultivar dependent as some varieties no matter what you do probably won foxtail and will still be dense and even with some foxtailing would probably increase yield albeit not as aesthetically pleasing however you'd have immature growth on top of the bud structure. However similar to when people propensiated flushing during last two weeks this is when production is at peak and it seems counter intuitive to reduce workload at this time although they will consume a much smaller amount of nutrients so I suppose adhering to vpd if you was coinciding that with light intensity as well as rh would make sense.

Ultimately I want someone to shed light on how co2 reacts with a plant towards the end of the growth cycle and how ethylene is inhibited and at what rate.
I saw a thread on here a few years back where a guy was designing cge (sealed growrooms) and he talked about how he always found venting improved the final product (yield/potency). And ofc ethylene can have detrimental effects which have been listed here but I'm solely concerned with how co2 effects the onset of ethylene production with regards to trichome maturation and inadvertently how yield will be affected and ways to mitigate/optimise this.
 
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