Photoperiod Gorilla Glue #4 & White Widow

[Death The Cultivator]

Just got a reply from the programmer at Photone and you hit it on the head:
"The sources of research can be found on the bottom of our articles which is this one: https://growlightmeter.com/lighting-requirements-of-cannabis-over-the-full-grow-cycle/#sources
The background generally is light stress: Running the lights at a PPFD of 700 at 18 hours produces a DLI of 45 (the veg target) and then dropping the photoperiod to 12 hours on the same intensity equates to a DLI of around 30 which can then be increased (the PPFD) as the plants get more mature and are better acclimated to high light levels. Staying on the same DLI would require a way higher light intensity that may burn the plants at such an early stage."

The drop in DLI is a function of a ceiling of 700 µmoles and then increasing PPFD to 900 to hit 40 moles. That's right at the non-CO2 supplemented limit.

My response - "Got it — the drop is because of the change in the light schedule. I can see how that works for photoperiod cannabis but what about autoflowers? "

I realize that you're not doing autos, for this grow anyway, but I think it will be interesting to read his reply. BTW, my two GG autos got 46 and 43 moles yesterday, the "sickly" one getting 46 and they responded by growing an inch overnight!

View attachment 1450819

I've got beef with their numbers and calibrated the lux meter conversions they are trying to pass off as PAR meters(par meters read the full spectrum 400-700nm whereas lux meter, in every cell phone, read only the blue and red spectra so they create a conversion factor for certain sensors but not all. Ymmv simply because a screw driver isn't a wrench). So I read several studies between the past five years and their numbers are pretty high

30ish ppfd is 3 DLI which is suitable for seedlings and clones, think T5s on a 24/0

170-230ppfd is 15-20 DLI which is perfect for non c02 levels. With c02 in the grow facility at 800ppms, large mothers could only tolerate close to 350ish ppfd in a 24/0 otherwise the leaves would begin to crinkle and why away from the light. This extended to veg and late veg right before flower transition.

700-900ppfd is bloom levels on a 12/12. With c02, 1000-1200ppfd is perfect. In the facility, 1000ppms of c02 at around 1100ppfd equalled 120g per sqft of canopy.

I haven't grown enough autos to say conclusively but I was under the impression that because they originate from areas where there's less light overall - rather than blasting them with light in a 12/12 they could take the same DLI over a longer day so 600ppfd over 18/6 would still give 40 DLI or 500ppfd over 24/0 would be 40 DLI.

 

[tronN00dles]

Day 13 since flip to 12/12

Tops of the plants are about 4" above the net. Canopy is looking real nice:

I'm starting to see a few nutrient-related issues I often see during this stretch period - mainly a few burnt tips here and there. But it seems to be pretty minimal so I'm not too bothered:

A few "front-on" shots:

I'll be doing some light defoliation soon. I think I'm going to target those "squished" areas of super dense growth. The vertical fan leaves seem to be a good indicator of where those thick areas are...

-tron

 

[tronN00dles]

They grew another inch over night. This stretching phase brings me so much joy

I'll probably do another light trim tomorrow...

tron

 

[Auto Tay]

WW stretches for 3 weeks then slows down in the fourth and stops in the fifth for me. Here’s mine week 7 day 5

 

[tronN00dles]

Early Flower - Day 16 since flip to 12/12

This grow has been a pretty stress free-experience so far, at least compared to previous grows. I'm still a numbers/control nerd, but I've tried to be a bit more chill with my approach this time around, and I think the plants are better off because of it:

They're looking wicked, if I do say so myself :smoking:

I did a bit more tucking and cut off a few scragglers maybe 2 nights ago. I'll give them one last hair cut - focusing up top - around day 21. Then I'll let them do their thing.

Lights currently drawing 240W from the wall.

Also, for the first time this grow, the plants reached that tipping point where they were supplying excess humidity to the tent, rather than requiring supplemental humidity. I suspect in the coming weeks, I'll be relying less on my humidifier and more on my exhaust fan to maintain VPD. All good.

tron

 

[tronN00dles]

Day 21 since flip to 12/12

I gave the plants another haircut just now. I probably could have taken a lot more, but I like being conservative with my pruning and defoliation. Maybe on my next grow I'll have to confidence to get rid of a lot more of the scrappy growth lol.

Before haircut:

After haircut:

I'd normally wait until the next day for the plants to perk up before I'd post the "after" pics, but who cares lol. It was also this time last grow where I discovered that a plant had hermied. I'm happy to report I observed no ballz today

I have my eye set on my first one-pound grow this time around, and so far, I think it's do-able

-tron

 

[Death The Cultivator]

Day 21 since flip to 12/12

I gave the plants another haircut just now. I probably could have taken a lot more, but I like being conservative with my pruning and defoliation. Maybe on my next grow I'll have to confidence to get rid of a lot more of the scrappy growth lol.

Before haircut:

View attachment 1454536

After haircut:

View attachment 1454546 View attachment 1454547

I'd normally wait until the next day for the plants to perk up before I'd post the "after" pics, but who cares lol. It was also this time last grow where I discovered that a plant had hermied. I'm happy to report I observed no ballz today

I have my eye set on my first one-pound grow this time around, and so far, I think it's do-able

-tron

Looks really good! Pound+ club?

 

[Suki]

Side note, I really love your flooring lol

 

[tronN00dles]

Side note, I really love your flooring lol

Hehe, I will tell my wife! She picked it out

 

[tronN00dles]

Morning after: