Running hps 13/11 to increase yield

Roger A. Shrubber

Well-Known Member
they clearly say the plant will yield less both because its getting less light to convert into fuel, and it has less time to use what light it is getting. that seems to directly contradict the point
 

CannaBruh

Well-Known Member
Can you quantify "yield less" because experiences has shown that it is not discernible?

Saturation is a physical phenomenon in many things, it is the point where your direct relationship of more light = more growth falls apart.

12/12 is awesome, it works fantastic, but lots of us have been cooking on 10/14.

Try it or don't.

For me 10/14 keeps my throughput on time, it forces stubborn sexers (subjectively) to throw preflowers faster, and it hasn't yielded any adverse effects. If I'm missing a gram or two here or there that's fine. Takt time is more important than a speculation of yield loss that cannot be quantified or justified.
 

Fevs

Well-Known Member
Good thread here people! Just switching to photoperiods myself as I'm using too much electric on 24-0, so very interesting stuff indeed!

For me having listened to all you guys/girls I'd like to try 24-0 for veg, 12/12 for 6 weeks, then 10-14 until they are done. Would 8on/16off not increase the chances of the plant growing seeds? Maybe the plant would think winter is really here way too early? Maybe not?

Still, very good thread with great info.

Thanks
 

dandyrandy

Well-Known Member
Interesting thread. I run 10.5 hrs on time ( give or take) and 80w sq ft. Since I cut The on time the last 3 cycles my plants have finished a week or so quicker? I thought I was just learning more.
 

CannaBruh

Well-Known Member
Interesting thread. I run 10.5 hrs on time ( give or take) and 80w sq ft. Since I cut The on time the last 3 cycles my plants have finished a week or so quicker? I thought I was just learning more.
Have you witnessed noticeably decreased yields as compared to a 12/12 bloom cycle?
 

BobCajun

Well-Known Member
Good thread here people! Just switching to photoperiods myself as I'm using too much electric on 24-0, so very interesting stuff indeed!

For me having listened to all you guys/girls I'd like to try 24-0 for veg, 12/12 for 6 weeks, then 10-14 until they are done. Would 8on/16off not increase the chances of the plant growing seeds? Maybe the plant would think winter is really here way too early? Maybe not?

Still, very good thread with great info.

Thanks
Yeah actually using low hours is said to cause herms. That's why it may be best to use 12/12 until the last week. They wouldn't be able to crank out ripe pollen sacks in just a week I don't think. That's why my plan is 13/11 for 6 w then 12/12 for 2 and a lesser amount on the last week, somewhere around 8-10. Just a matter of seeing how low you need to go to get them to ripen in that last week. In Kabul the days only get down to 9.9 hours so 10/14 would probably suffice.

Somebody mentioned that they may be getting higher yields from fewer hours. It's a possibility because I've read an article on other short day plants and they found that long hours of light actually inhibited flowering somewhat, using the same hours of darkness. Some plants flower more on 8 hours than 12 apparently. However, they didn't experiment to see if they needed that few hours for the whole flowering period or maybe just the end of it. The article is called "Floral Inhibition in Relation to Photoperiodism in Biloxi Soybean, G. S. Sirohi & K. C. Hamner".

I have also read an article on Cannabis specifically which showed that 11 hours gave a lower yield of weight and potency than 12. The article is called "OPTIMISATION OF CANNABIS SATIVA L AS A PHYTOPHARMACEUTICAL, A thesis submitted by David Potter JP". You can find the pdf if you google it. That's also the article that said that all strains flowered with 13/11 as soon as with 12/12, just that the 13 hour ones didn't ripen as fast though almost all produced higher yields. So I don't think using low hours for the whole flowering would be wise but for the last little while it may be fine and may even cause more trichs to form.

Another thing I'm doing btw is giving them 24-48 hours straight light on their last day. That makes up for the lower hours on the last week and packs on some final weight and potency. I did that last time and it turned out fine. I only turned the lights down to 9/15 for the last 3 days though and could barely see any extra ripening. I think it needs to be a whole week. I also stopped giving them 36 hours dark before chop. That just burns off all the starch and makes less weight. I'm curing it now anyway so the starch gets converted to sugar, which gives a sweet taste. The darkness before chop does increase quality some but at the price of weight reduction. My last batch turned out fine with 24 hrs light followed by immediate chopping and curing, meaning quick curing with heat like flue curing tobacco. 3-4 days later it's cured and dried. Wasn't harsh like the uncured was even with the 36 hrs dark at the end.
 
Last edited:

dandyrandy

Well-Known Member
Have you witnessed noticeably decreased yields as compared to a 12/12 bloom cycle?
Not really but I see no less from what I can see. Just growing for myself and a friend I really don't weigh anymore. I just know I get 8 half gal jars of bud give or take each cycle from 4 or 5 plants in 15 sq ft. Some bud is airy like Tangerine peel. Some like zeta sage is solid. But I like the quicker turn around.
 

Olive Drab Green

Well-Known Member
So do you guys know how the flowering process works?

During the dark hours, the flowering hormone builds up. If it builds to a particular level, the flowering process begins. Usually at least 3 consecutive days of bloom time signatures. So yeah. Flowering hormone builds in the dark hours.
 

BobCajun

Well-Known Member
Here's a quote from the article on Biloxi soybeans I mentioned earlier. Whether or not it applies to Cannabis is unknown. Seems fairly similar, critical day length of a little under 14 hours.

"Seven consecutive cycles with variable high intensity photoperiods between 2 and 14 hours were inductive. Flowering increased with increasing photoperiods from 2 to 5 hours; it was maximum with photoperiods from 5 to 10 hours while it decreased with photoperiods from 10 to 14 hours. No flowering occurred with photoperiods of more than 14 hours."
 

Olive Drab Green

Well-Known Member
Here's a quote from the article on Biloxi soybeans I mentioned earlier. Whether or not it applies to Cannabis is unknown.

"Seven consecutive cycles with variable high intensity photoperiods between 2 and 14 hours were inductive. Flowering increased with increasing photoperiods from 2 to 5 hours; it was maximum with photoperiods from 5 to 10 hours while it decreased with photoperiods from 10 to 14 hours. No flowering occurred with photoperiods of more than 14 hours."
So this pretty much solidifies what I was saying earlier.
 

BobCajun

Well-Known Member
So this pretty much solidifies what I was saying earlier.
Yes, but does "increased flowering" equal increased weight yield? They say in the article that there were more flowering nodes but they didn't give plant weights. So it's not entirely clear yet what the outcome would be. They only ran the experiment with the beans for 7 days too. It's suggestive that 5-10 hours may be better than 12/12 but we can't be sure yet. Maybe it's only needed for the first few weeks and maybe again for the last week, with longer days in the middle.
 

CannaBruh

Well-Known Member
Yes, but does "increased flowering" equal increased weight yield? They say in the article that there were more flowering nodes but they didn't give plant weights. So it's not entirely clear yet what the outcome would be. They only ran the experiment with the beans for 7 days too. It's suggestive that 5-10 hours may be better than 12/12 but we can't be sure yet. Maybe it's only needed for the first few weeks and maybe again for the last week, with longer days in the middle.
Keep experimenting, we'll be watching for sure. This is what I love so much about this plant, so much uncharted findings, and everyone seems to find their own way so a lot becomes subjective.
 

Fevs

Well-Known Member
@BobCajun Thanks for your in depth reply. This really interests me. My electric is 1/3 of the day price when I use leccy between 00:00 and 07:00. So 7 hours at bargain rate... just having to pay for another 5 hours or so will be very cheap compared to the usual 24-0 auto's.
 
Top