Certain Strains stretching in flower transition

I'm having issues for the second time in a row with certnain breeders cuts stretching especially at the top budsites. Growth seems normal untill late week 2/through week 4 where they will stretch and have these tiny popcorn budsites on the top colas. It only seems to be cerain strains. However I have grown the same cuts before in somecases with a healthy stretch an nice sized bud set.

Im wondering if it could be too much light to early, but the leaves all come in healthy with no burning? I keep track of my ppfd as I incresease it and will post below. Running HLG scorpoin diablo 650s. On the second table below (once it reaches flower) you can see the first number is days after transplant, second number is day in flower. Also included a picture of one of the stretched tops.

Lights 24/0.
Day after TP PPFD/DLI /Temp /Humidity IPM _
0 80-95 78/62-68
1 110-130 80/62-68 Monterey (Issues with thrips)
2 180 81//62-68
3 220 81/62-68 Zymes
4 220 81/62-68 Zymes—>Monterey 133% Strength
5 220 81/62-68
6 220 81/55-60 Monterey 133% strength
7 220 81/55-60
8 220 81/55-60 Monterey 133% Strength
9 220 81/55-60

Lights 12/12
Day after TP PPFD/DLI /Temp/%Hu IPM _
10-1 340-360 82/60 Monterey 133% Strength
11-2 360 82/65
12-3 475-500 82/64
13-4 475-500 83/65
14-5 475-500 83/65
15-6 660 83/65 Monterey 133% Strength
16-7 660 83/65
17-8 760 83/65
18-9 880 83/65 Monterey 133% Strength
19-10 900 83/54
20-11 950-1050 84/60
21-12 950-1050 84/63
22-13 950-1050 84/63
23-14 950-1050 85/62 Heavy Defol+unders (SBC,Cap,Sherb 22,Wedding)
24-15 950-1100 85/62 Net dropped:
25-16 950-1100 87/62
26-17 950-1100 87/62
27-18 950-1100 87/62
28-19 950-1100 87/62
29-20 950-1100 86/58

Edited table with temp/ humidity / IPM removed just because it messed up the spacing posting it and was hard to read. Also running CO2 if wondering about the higher temps.
Lights 24/0.
Day after TP PPFD _
0 80-95
1 110-130
2 180
3 220
4 220
5 220
6 220
7 220
8 220
9 220

Lights 12/12
Day after TP PPFD
10-1 340-360
11-2 360
12-3 475-500
13-4 475-500
14-5 475-500
15-6 660
16-7 660
17-8 760
18-9 880
19-10 900
20-11 950-1050
21-12 950-1050
22-13 950-1050
23-14 950-1050
24-15 950-1100
25-16 950-1100
26-17 950-1100
27-18 950-1100
28-19 950-1100
29-20 950-1100

Wow........you sure are making it complicated.

MickFoster said:

Wow........you sure are making it complicated.

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hahaha whats so complicated??

Is it throwing single finger leaves or 3 finger leaves at the top like it’s reveg? Any chance you’ve got a bad light leak? Some strains are more sensitive to light leaks than others.

After enough experience you notice sativa tend to scretch. As in all plant world you get seeds that just dont do well or look great. Those imo may be from a touch of lime or hot soil making A runt on some. I am leaning towards more topping done less stretch trend. i may change but today....

nxsov180db said:

Is it throwing single finger leaves or 3 finger leaves at the top like it’s reveg? Any chance you’ve got a bad light leak? Some strains are more sensitive to light leaks than others.

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The top three leaves in this pic are single finger leaves. There is no light leak, that was my initial thought but came up negative in my search.

Relaxed said:

After enough experience you notice sativa tend to scretch. As in all plant world you get seeds that just dont do well or look great. Those imo may be from a touch of lime or hot soil making A runt on some. I am leaning towards more topping done less stretch trend. i may change but today....

Click to expand...

These are breeder cuts, and I have run them where they didnt stretch like this. Something im doing they arent liking for sure. Def specific to genetics but not that these are bad genetics, they are tried and true. Its def on my environment.

To me the single finger leafs suggest it aint going into full flower, and that's why it's stretching past week 3. No way that a timer is malfunctioning?

nxsov180db said:

To me the single finger leafs suggest it aint going into full flower, and that's why it's stretching past week 3. No way that a timer is malfunctioning?

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I am almost positive the timer is not doing anythign funky. I have the entire circuit of lights on a pool timer wired directly to my breaker panel so it turns off the power even to the outlets. I regularly go in the room just before lights on and just after but I suppose there is some slim chance it kicks on mid night cycle but is very unlikely. I could get one of those pulse monitors to be positive but I dont think it is my issue.

I notice it happens around or shortly after my heavy defoliation at day 21ish when my light PPFD is around 1100 so maybe I need to dim them down a bit so they arent stressed or something. Whatever it is I have to figure it out, really stressing me with these stringy top buds.

Ive seen some plants do that when temps are high. Its possible that its a combination of high ppf and temps.
You could also try flowering them on 11/13. Stretch can be reduced this way also.

jaked3800 said:

I am almost positive the timer is not doing anythign funky. I have the entire circuit of lights on a pool timer wired directly to my breaker panel so it turns off the power even to the outlets. I regularly go in the room just before lights on and just after but I suppose there is some slim chance it kicks on mid night cycle but is very unlikely. I could get one of those pulse monitors to be positive but I dont think it is my issue.

I notice it happens around or shortly after my heavy defoliation at day 21ish when my light PPFD is around 1100 so maybe I need to dim them down a bit so they arent stressed or something. Whatever it is I have to figure it out, really stressing me with these stringy top buds.

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But it doesn't do it every time under 1100ppfd? I have seen strains do funky stuff under lights that are too bright.. I used to try to push everything to 1200ppfd and over the last couple years I've got it to where I won't go over 900 now..

Farmer's Hat said:

Ive seen some plants do that when temps are high. Its possible that its a combination of high ppf and temps.
You could also try flowering them on 11/13. Stretch can be reduced this way also.

Click to expand...

I have noticed this with sativa grows as well, when I pushed them last grow they shot up, the Golden Tiger stretching 6 times it’s height. I had ppfd over 1100 and the temps were mid 80s, I figured the combination caused them to stretch more than normal. This grow I am keeping the ppfd down at 800-900 and temps high 70s-low 80s, and so far much less stretch, these are clones of the ones that stretched, so I think temp and ppfd could be a legit cause.

Did you add red lights recently? that can really make em stretch!