Register ICMag Forum Menu Features Mark Forums Read
You are viewing our:
in:
Forums > Marijuana Growing > Cannabis Infirmary > twisted yellowing leaves, stunted growth (pix inside)

Thread Title Search
Click to Visit Seedsman for Cannabis Seeds
Post Reply
twisted yellowing leaves, stunted growth (pix inside) Thread Tools
Old 06-01-2012, 10:50 PM #21
SeaMaiden
Guest

Posts: n/a
That looks like scorching to me, either from heat caused by light or from 'too much' light itself. You say the leaves are getting in the way? Is it on any shaded leaves? Same height? Do you see any other pattern to it at all?

Examining what few leaves around that area that you're showing suggest that it's not happy with the pH range. I suggest shifting it down.

Right now I can't remember your media, if it's soil I personally prefer to go with a slightly lower pH range, 6.2-6.8 (the exception here for me are my outdoor ladies. They are grown in raised beds utilizing soil food web methods, and so are simply irrigated with unfiltered well water and fed teas and the like using clean, neutral pH water, either RO/DI or rain water).

If it's a soilless media the pH range needs to be lower.
Quote


Old 06-02-2012, 10:19 AM #22
Hans-von-Dampf
Member

Hans-von-Dampf's Avatar

Join Date: May 2012
Posts: 50
Hans-von-Dampf is on a distinguished road
that might be a noob question, but how do I determine the soil's PH (yes, organic soil + perlite is my medium) from measuring water and runoff PH?
I did measure the soils PH with specific agricultiral PH pills & destilled water, but those were like the strips: wait, look, compare to the scale which gave me pretty much nothing, oher than a vague "neutral to slightly acidic" 6-7.

this specific issue appeared on some of the lower leaves, they're shaded (or were until now). they turned very pale (because I stopped feeding the plants to fix the overfeeding problems and to clear the soil), but they're coming back now. it's a ery localized problem, it's on that branch only (oh well, it was on a few of the huge fan leaves from way under the canopee, but those shrivelled and died, I think because they didn't get too much light after it got kinda crowded in my tent and weren't very useful anyway).

other than that they seem to look healthy: sideshots are growing like crazy, I move up the lights pretty much every second day and they eat & drink a lot (we had some very hot / dry days around here now it's cooler and they seem to like that, too).

but thanks so much for your helpful input, SeaMaiden ... MUCH appreciated

one more question, as I'm not 100% sure: I'm slowly switching them to 12/12, which means I shift the on/off cycle from 6-24 to 20-8 o'clock over the course of 2 weeks.
why? because summer's coming and I reckoned that having the lights on at night might keep temps in an acceptable range. from what I measured temps seem to be about 5-10°C over room temp in my tent, and since we get 25-30° on really hot days, I thought I'll keep them asleep during daytime and have the lights on at night.

I'll install the exhaust fan + scrubber on Sunday, which should help to prevent too high temps in the tent as well. anyway: does that make sense? My issue: lights off during daytime is more vulnerable to light leaks than lights off at night, right (because it's dark, of course ... and I think electricity is indeed cheaper at night, for some reason)? I will examine & tape up every inch of the tent to prevent light leaks, but that's all I can do ... either this or lights off at night

so what's better: to avoid excessive heat build up or to minimize the risk of light leaks?
Hans-von-Dampf is offline Quote


Old 06-02-2012, 12:17 PM #23
airplane
Banned

Join Date: Apr 2012
Posts: 129
airplane is on a distinguished road
it.s a "P" problem"deficenicy in , there are some good pictures of plant problems in the forums of icamagizane also go to www.homegrownbud.com
airplane is offline Quote


Old 06-02-2012, 04:58 PM #24
SeaMaiden
Guest

Posts: n/a
Quote:
Originally Posted by Hans-von-Dampf View Post
that might be a noob question, but how do I determine the soil's PH (yes, organic soil + perlite is my medium) from measuring water and runoff PH?
I did measure the soils PH with specific agricultiral PH pills & destilled water, but those were like the strips: wait, look, compare to the scale which gave me pretty much nothing, oher than a vague "neutral to slightly acidic" 6-7.
Just concern yourself with the feed and water pH here. When you can get a decent pH meter then you can more easily perform a slurry test that has some accuracy.
Quote:
Originally Posted by Hans-von-Dampf View Post
this specific issue appeared on some of the lower leaves, they're shaded (or were until now). they turned very pale (because I stopped feeding the plants to fix the overfeeding problems and to clear the soil), but they're coming back now. it's a ery localized problem, it's on that branch only (oh well, it was on a few of the huge fan leaves from way under the canopee, but those shrivelled and died, I think because they didn't get too much light after it got kinda crowded in my tent and weren't very useful anyway).

other than that they seem to look healthy: sideshots are growing like crazy, I move up the lights pretty much every second day and they eat & drink a lot (we had some very hot / dry days around here now it's cooler and they seem to like that, too).

but thanks so much for your helpful input, SeaMaiden ... MUCH appreciated

one more question, as I'm not 100% sure: I'm slowly switching them to 12/12, which means I shift the on/off cycle from 6-24 to 20-8 o'clock over the course of 2 weeks.
why? because summer's coming and I reckoned that having the lights on at night might keep temps in an acceptable range. from what I measured temps seem to be about 5-10°C over room temp in my tent, and since we get 25-30° on really hot days, I thought I'll keep them asleep during daytime and have the lights on at night.
Why are you doing it this way, by making the change slowly? If you're growing inside, there seems to be little benefit to be gained by changing the photoperiod slowly over time. Just change the photoperiod to 12/12, get over that two week post-flip stretch, and be on your way to flowering them out.
Quote:
Originally Posted by Hans-von-Dampf View Post
I'll install the exhaust fan + scrubber on Sunday, which should help to prevent too high temps in the tent as well. anyway: does that make sense? My issue: lights off during daytime is more vulnerable to light leaks than lights off at night, right (because it's dark, of course ... and I think electricity is indeed cheaper at night, for some reason)? I will examine & tape up every inch of the tent to prevent light leaks, but that's all I can do ... either this or lights off at night
Depending on where you live your power provider may reduce rates during off-peak hours. Maybe that's where you got that idea.
Quote:
Originally Posted by Hans-von-Dampf View Post
so what's better: to avoid excessive heat build up or to minimize the risk of light leaks?
Avoid excessive heat. If you're running bagseed, then there's a big risk of hermaphroditism, if not then don't worry too much about it. Excessive heat will kill the grow a lot more certainly than light leaks, IMO.
Quote


Old 06-06-2012, 10:31 PM #25
Hans-von-Dampf
Member

Hans-von-Dampf's Avatar

Join Date: May 2012
Posts: 50
Hans-von-Dampf is on a distinguished road
okay, clones are fine, plants are fine, everythings back to normal I guess

the scrubber is installed and seems to be able to keep the temps incheck as well (I have like 20°C romm temp here, the tent + lights take like 15mins to go from that to 32°C which is ... not so good. but that the exhaust sucks in enough fresh air I can keep it at a steady 26°C

I'm changing to flowering slowly as I still want them t grow around my net a bit, also it seemed like getting them from 6am-12pm to 8pm-8am in one step ... dunno, I had to decide between a very long light or dark period or doing it gradually. they seem to like it.

okay, so I'm going 8 to 8 (12/12) on them next week, changing bulbs & feeding schedule soon. oh boy, I'm exited

one more thing: I bind them down to the net so the tips form a single surface sooner or later. I try to leave holes in that roof for smaller shots to come up and join the parade, but the big fan leaves below started dying off, probably becase there's not much light around to be had ... is that normal for a SCROG? (It's my 1st time SCROGing, so please excuse that noobish question)
Hans-von-Dampf is offline Quote


Old 06-07-2012, 03:57 PM #26
SeaMaiden
Guest

Posts: n/a
I don't think you need to do that (changing to flowering slowly) just to get your net/screen filled. Depending on the strain (we always say that!) the post-flip stretch will be all you need.

Lower leaves die off when they've given up the food they're storing. Focus on the good growth instead of trying to get inferior growth to catch up, if that makes any sense.

Glad to read that everything is in order!
Quote


Old 06-11-2012, 12:15 PM #27
Hans-von-Dampf
Member

Hans-von-Dampf's Avatar

Join Date: May 2012
Posts: 50
Hans-von-Dampf is on a distinguished road
okay, got them on 12/12 now, changed the bulbs, feeding schedule, lowered RH and everything. thanks for the advice, I guess I'm still somewhat "outdoor" oriented when it comes to lights. but you're right: having one big leap might confusing for the plants, but many smaller leaps in between might be even worse. dunno.

oh but one mire question, I couldn't really find n answer to that in sick plants thread:
one of them appears to display signs of a calcium def. is it enough to water with our regular (very 'hard' tap water) for some time or should I get some proper lime? I usually use rain water, which is rather soft.

our tap water is so hard, it leaves white residue on whatever it touches ... I read elsewhere that this might be enough to help plants cover their need for calcium, but it wasn't a growers forum, but something about tomatoes. so ... dos that actually work?

thanks in advance, you're a great help here ... I try and worry not too much, but it's hard not to for a 1st time tent grower. everything is new and exciting ... and a possible problem, too ;D
Hans-von-Dampf is offline Quote


Old 06-11-2012, 04:42 PM #28
SeaMaiden
Guest

Posts: n/a
Oooo... you know, that's difficult for me to say, purely based on my own experience at home. We're on a well and it's high in both carbonate (CaCO3 and MgCO3 are the most commonly found forms) and general hardness, and when I was growing in coir I thought it should be sufficient. Nothing could have been further from the truth! I had to switch to RO and then add back Ca and Mg (mostly Ca).

Ca is an extremely important element, too, so you do want to address laying down this relatively immobile element early on in the plant's life. Blossom end rot has ruined a LOT of tomatoes in my garden!

So, I would say yes, go ahead and add the lime, which I'm assuming is dolomite/ag lime and not gypsum or hydrated lime. You can also foliar Ca, which won't 'fix' the problems, it will keep them from progressing. I should qualify by saying that for Ca- ANY treatment will not fix what's already become a problem like spotting and necrosis, it will ONLY stop the progression. Make sense?
Quote


Old 06-16-2012, 10:31 PM #29
Hans-von-Dampf
Member

Hans-von-Dampf's Avatar

Join Date: May 2012
Posts: 50
Hans-von-Dampf is on a distinguished road
thanks, SeaMaiden. added lime and it seems to be okay so far

so ... the plants appear to stretch and slowly go into flowering. sweet. one of them developed little white hairs on the knots. I take that as a very good sign. the second doesn't do anything much ... undecided so far

but one of them clearly does something and I'm afraid it's a rooster in the hen house, so to speak. is already possible to confirm my suspicion from those pics ... or am I just paranoid and that's actually just new shots?



Attached Images
File Type: jpg SAM_253_small.JPG (81.1 KB, 90 views)
File Type: jpg SAM_2531_small.jpg (77.0 KB, 91 views)
File Type: jpg SAM_2532_small.jpg (67.9 KB, 92 views)
Hans-von-Dampf is offline Quote


Old 06-17-2012, 04:12 PM #30
SeaMaiden
Guest

Posts: n/a
Yeah, I think I see his berries down in there. But if he's a good guy, maybe he's a keeper, worth his pollen, ya know?

Double-checking his package. It's a dude.
Quote


Post Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT +2. The time now is 02:39 AM.


Click to buy cannabis seeds at Ace Seeds


This site is for educational and entertainment purposes only.
You must be of legal age to view ICmag and participate here.
All postings are the responsibility of their authors.
Powered by: vBulletin Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.