So I'm growing a auto blue cheese seed in soil using bio bizz nutrients mars hydro Ts 1000 light and dehumidifier lights and humidity are good but the plant is very tall and in week 9 overall and should be finished by week 11 but I don't think it will be there are some yelling leaves and the buds haven't really formed I'm not sure what the issue is and weather this plant will actually produce budds and y advice would be great.....thanks people
Slow grow auto flower ? Deficiency? What's the problem?
- Thread starter 2rilla
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Ah ok cool thanks it's my first grow so every stage is new to me and I get a bit nervous thanks for the reply I'll post moor picks in a week or soIt's in a stage now where those flowers will bulk up some, so don't dispair. They go thru those phases where everything happens quick, then a slow down then another spurt. Never trust the done in 8 to 10 weeks statements, many go longer and some shorter.
Oh really that long ok I'll keep a eye on them
budman111
Well-Known Member
yep, whats the temperatures?
Heat Between 25 Lowest and 29 highest and humidity 49 lowest 60 highest
budman111
Well-Known Member
Humidity is OK, temps could be a bit lower though, Prof. Bugbee says veg is best at (85F) 29c but flowering temps is best at (75F) 23c
Ok cool I'll get another fan blowing
Mitch Westmoreland, a student under Bugbee, did a great video in which he shared some of the research he did for his PhD. From the video:
I've seen a few references to growers saying that he has said that temps should be lower in flower and have gone through his vids (he released a video on this topic in 2020) and I cannot find that. He does state, in the 2023 and 2020 videos, that the temperatures of the buds/colas should be <=78°, cultivar dependent.
I caught a Mr Growit short in which Bugbee was asked about shutting off the lights for two days prior to harvest. Bugbee's reply was that while there's no evidence not to do that, it's contrary to what we know about how terpenes are created. The issue is that plants create terpenes using the sucrose from photosynthesis. The rate of photosynthesis increases as light levels increase (up to the light saturation point) as well as increasing as temperature when increases (up to the high 80's, per Chandra). On that basis, it's arguable that temps should remain in the mid-80's through chop.
How do you get an ambient in the mid-80's while keeping temps of the colas <=78°?
That's where VPD comes in.
A VPD of 1.5 in flower vs 1.2, for example, is ~25% more transpiration and the increased transpiration has the benefit of allowing the plant to cool off.
How well does that work out in a grow tent?
For my most recent run, ambient temps stayed in the low 80's while my colas were in the mid-70's. I followed the practice of 1 air change per minute (when buttoned up) and had fans blowing up into the canopy from the top of the res.
It worked out OK, per below, keeping in mind that I foolishly tried to grow two plants and that I also managed to break off three of the stems on Donna over the course of the grow (SMH).
| Erica | | | | |
| All small buds | 87 | 87 | 3.1 oz | |
| 81gm at 50% | | | | |
| | | | |
| Donna | | | | |
| Small buds | 106 | 106 | 3.7 oz | |
| 99gm at 50% | | | | |
| Gross | Net | | |
| Shelf 1 | 406 | 74 | | |
| Shelf 2 | 429 | 97 | | |
| Shelf 3 | 400 | 68 | | |
| Shelf 4 | 388 | 56 | | |
| | 295 | 295 | 10.4 oz |
| | | 488 | 17.2 oz |
| | | | |
| Final weights at 62% RH | | |
Attachments
budman111
Well-Known Member
He even says in one interview that it can be beneficial to have warmer nights to keep the plant more compact
Until yesterday, I've been relying on my memory for a lot of this stuff but I installed a little "file search" app on my laptop yesterday.
When I watch a video, I usually make notes about it. Apparently "temperature" is commonly used—who knew!
You were absolutely right about Bugbee saying to drop temps.
The text of my notes (attached):
=======
We the Growers Episode 21 - June 2023
pH is low you get toxicities but he's running higher for cannabis. He says that he's running 6.5
Running 6.5 in all media. You can err on the high side for pH because cannabis does not suffer from iron deficiency that comes with high pH.
Started doing research in 12/18.
Nutrient Management
Review paper driven by research for NASA. Driven by the fact that NASA can't have any runoff.
Nutes go from the water into the plant and you have to determine what percent of a given chemical you want to have in the leaves.
Mass Balance-it's either in the res or in the plant.
Don't keep adding specific chemicals.
Are you feeding the same nutes all the time?
Precision stress-keep nutes either high or low.
NPK are mobile are taken up very quickly. Older leaves yellow first because they're translocated.
Mg is taken up quickly but not translocated.
Ca accumulates in old leaves
WUE- is a critical ratio because that effect how much nutrient you give your plants.
With low RH, WUE is about 3 gm per liter. Indoors, with CO2 and with LED's, WUE may go to 6 so nutrient concentration should double.
Heat from the HPS makes them use more water. LED's use less water
"That's a fundamental principle and we've shown that."
If you double PPFD, the plants will grow faster but water uptake will go up so nutrient uptake increases along with water uptake.
With CO2, the stomates Don't have to open so they don't need as much water. WUE may go from 3 to 6. You'll need to increase nutrient levels.
"Put as much light as you can on, depending on the electric bill and the economics of the input of electricity and the value of the crop."
400 to 1200 (which is 99% of the value to saturation) will get about a 30% increase in yield.
That's without changing anything else.
Stressing the Root Zone in Early Flower
High EC stress for the first four weeks of flower. Precision stress - if EC is high, they got a compact plant but yield dropped by 20%. They run EC 2. They went to 6 then 8 and then back down.
All palnts move P into seeds. Cannabis needs 15 PPM in flower. It puts the P in the seeds but it doesn't need more P. They run P at 30, 60, and 90 PPM and it has no effect on yield. But one Israeli researcher did get a benefit on low THC cultivars.
The downside to using high P is that it gets into bodies of water and that causes algae blooms which kills fish and damages the ecosystem.
===>>
Start warm and cool it off. Mid 80's (with CO2) to develop quicker and in early flower. But cool it off "at the end". You didn't rush it. Can get a little more dense. Mid 70's.
Gradually bring it down starting in week 2, 3, or maybe week 4.
<<==
==>>
Day and Nigh Temps
Should night be cooler than the day? Can't run negative diff because it reduces yield.
Zero diff works beautifully.
Haven't seen a benefit of a large diff in cannabis.
<<==
What about temps and CO2?
"The temperature optimum shifts up 3-5°C when you have high CO2"
Can elevate temperature 3-5°C with CO2 to get better results.
Starting with he segment at 55:24
Mid 80's is with elevated CO2. If no CO2, 78-80? "Yeh, in that ballpark."
"85 could be a little hot."
RH 60% in the canopy.
Below 40% is making the plant work pretty hard.
If photosynthesis falls, there could be less synthesis of cannabanoids.
======
A few issues…
Re CO2 WUE = water use efficiency. With the stomata closing, WUE goes up meaning that water uptake as decreased so EC should be increased.
Bugbee says to drop temps but I don't think Westmoreland does. As I read my notes, it sounds like Bugbee isn't adamant about it but the best thing is to "review the tape". That might be the best approach but it could well be that Westmoreland just didn't mention it.
Re. diff - I think Bugbee was asked about that and he shook his head or sat back or something (going from memory). Again, the best way to find out is to "go to the tape".
I don't have another grow coming up until September so I don't need the answers but is some good soul were to "go to the tape" and update the thread with what they'd found….
coreywebster
Well-Known Member
Another fan blowing won't lower temps.
You need more extraction.
Assuming your measuring the temp properly
Thanks for this Alot of info hear
Thank you I'll read this through and check out the tape alsoUntil yesterday, I've been relying on my memory for a lot of this stuff but I installed a little "file search" app on my laptop yesterday.
When I watch a video, I usually make notes about it. Apparently "temperature" is commonly used—who knew!
View attachment 5464208
You were absolutely right about Bugbee saying to drop temps.
The text of my notes (attached):
=======
We the Growers Episode 21 - June 2023
pH is low you get toxicities but he's running higher for cannabis. He says that he's running 6.5
Running 6.5 in all media. You can err on the high side for pH because cannabis does not suffer from iron deficiency that comes with high pH.
Started doing research in 12/18.
Nutrient Management
Review paper driven by research for NASA. Driven by the fact that NASA can't have any runoff.
Nutes go from the water into the plant and you have to determine what percent of a given chemical you want to have in the leaves.
Mass Balance-it's either in the res or in the plant.
Don't keep adding specific chemicals.
Are you feeding the same nutes all the time?
Precision stress-keep nutes either high or low.
NPK are mobile are taken up very quickly. Older leaves yellow first because they're translocated.
Mg is taken up quickly but not translocated.
Ca accumulates in old leaves
WUE- is a critical ratio because that effect how much nutrient you give your plants.
With low RH, WUE is about 3 gm per liter. Indoors, with CO2 and with LED's, WUE may go to 6 so nutrient concentration should double.
Heat from the HPS makes them use more water. LED's use less water
"That's a fundamental principle and we've shown that."
If you double PPFD, the plants will grow faster but water uptake will go up so nutrient uptake increases along with water uptake.
With CO2, the stomates Don't have to open so they don't need as much water. WUE may go from 3 to 6. You'll need to increase nutrient levels.
"Put as much light as you can on, depending on the electric bill and the economics of the input of electricity and the value of the crop."
400 to 1200 (which is 99% of the value to saturation) will get about a 30% increase in yield.
That's without changing anything else.
Stressing the Root Zone in Early Flower
High EC stress for the first four weeks of flower. Precision stress - if EC is high, they got a compact plant but yield dropped by 20%. They run EC 2. They went to 6 then 8 and then back down.
All palnts move P into seeds. Cannabis needs 15 PPM in flower. It puts the P in the seeds but it doesn't need more P. They run P at 30, 60, and 90 PPM and it has no effect on yield. But one Israeli researcher did get a benefit on low THC cultivars.
The downside to using high P is that it gets into bodies of water and that causes algae blooms which kills fish and damages the ecosystem.
===>>
Start warm and cool it off. Mid 80's (with CO2) to develop quicker and in early flower. But cool it off "at the end". You didn't rush it. Can get a little more dense. Mid 70's.
Gradually bring it down starting in week 2, 3, or maybe week 4.
<<==
==>>
Day and Nigh Temps
Should night be cooler than the day? Can't run negative diff because it reduces yield.
Zero diff works beautifully.
Haven't seen a benefit of a large diff in cannabis.
<<==
What about temps and CO2?
"The temperature optimum shifts up 3-5°C when you have high CO2"
Can elevate temperature 3-5°C with CO2 to get better results.
Starting with he segment at 55:24
Mid 80's is with elevated CO2. If no CO2, 78-80? "Yeh, in that ballpark."
"85 could be a little hot."
RH 60% in the canopy.
Below 40% is making the plant work pretty hard.
If photosynthesis falls, there could be less synthesis of cannabanoids.
======
A few issues…
Re CO2 WUE = water use efficiency. With the stomata closing, WUE goes up meaning that water uptake as decreased so EC should be increased.
Bugbee says to drop temps but I don't think Westmoreland does. As I read my notes, it sounds like Bugbee isn't adamant about it but the best thing is to "review the tape". That might be the best approach but it could well be that Westmoreland just didn't mention it.
Re. diff - I think Bugbee was asked about that and he shook his head or sat back or something (going from memory). Again, the best way to find out is to "go to the tape".
I don't have another grow coming up until September so I don't need the answers but is some good soul were to "go to the tape" and update the thread with what they'd found….
I think I am I have two humidity and temp meaters one by the plants and one higher near the top of the canopy there is a 3-4 % differential between the two is there a different or better method?
Fish scale
Well-Known Member
To me the yellow leaves look like you have got a nitrogen deficiency that is in it's late stages. And the small buds indicate you have a lack of light.
coreywebster
Well-Known Member
You need to block them from direct light, shading them with a bit of white card stops the light from heating the actual device so it only reads the air temp.
Even though led has low radiant heat. It can still throw off the readings
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