Cracks in leaves?

Drew2k

Member
Very new to growing, just got thrown a learning curve - many cracks have appeared on leaves. I'm just growing one plant right now in a 4x4x6'10' under a 1000w MH for veg (overkill, I know, but I had about 14 seeds and only one survived past seedling due to weather conditions outside of the tent (Barney's Farm seeds did not make it - made me cry). This specific plant was from bag seed, fairly sure it's a herm (could be wrong) - but not concerned with that - what I'm also concerned with is the short stature of the plant (it's about a foot and very bushy) that I chalk up to being a highly indica dominant variant. I have the cool tube ballast being pushed through with a 240cfm duct fan & air being pushed out from the top with another 240cfm duct fan. I keep the ambient room temp around 70 degrees while the fans & lights are off (they are on the same timer as the ballast, minus the oscillating temp controlled fan in the tent)

Over the course of the past two weeks there are many cracks forming on leaves - I live in a cold climate during the winter (top of New England), this is grown in a large spare room and I have the light ~3' from the plant. Humidity is low, about 16% during light times and 28% during dark (18-6) which I recently changed over from 24-0 when I noticed the top starting to yellow - also put the light up about a foot and a half because I speculated that it just was too close. Temp's flux from 68 - 86 depending on dark/light (I also have a temp controlled fan that kicks on above 74 & turns off below). I topped it about 3 days ago as the top was looking rather yellow and it was spreading to other leaves - this stopped it in it's tracks.

I use distilled water with the full line of GO's organic nutes, FF Ocean Forest with 35/40% perlite. I notice about 1/2"-1" of growth day to day. Since the topping the leaves are in a bit better condition but still some cracks are forming in/around the center and tips of the leaves, both on fans and branches. I'll post photos in a bit. I was not adding the CalMag nutrient up until a week ago or so, and before that I had been using tap water that was high PH but used PH down on. It's an older house, so I assume the culprit might be crummy water conditions.

I've searched the threads & googled this, but all I see is nutrient problems that turn the leaves brownish, they look very dissimilar to my problems. I've since trimmed off the really badly cracked leaves (some had the crack in the middle of the fans and made them pretty much fall over) and the plant seems to be less angry and cracks have relatively stopped spreading.

Any help would be greatly appreciated! Thank you in advance!
 

Drew2k

Member
Bit of heat stress ( from lights )...along with improper ph levels can effect plant. Plus your humidity could be higher ...plants like around 60% for veg.

Thank you. I assumed as much, I'll keep watching over the next few weeks and update as necessary for my own notes as well as others who might experience similar problems with similar set ups.

I've been looking at getting a humidifier, but I keep seeing horror stories of mold & such - along with the constant need to fill. Is there any humidifier you might suggest that would elate these worries as I progress into growing a decent crop?

Any input would be very appreciated, as I've also done quite a bit of research but I'd like to know from someone educated with first hand experience using a humidifier in a 4x4. Thanks again.
 

Drew2k

Member
critters.....
I hope not! I've been very diligent in checking and spending time meticulously looking over the plant since germination and haven't seen anything that would alert me to being a pest problem.

But. I'm a newb. So I'll heed your warning and continue to check and see if I can spot anything. Thank you for your input.
 
Last edited:

nfhiggs

Well-Known Member
I hope not! I've been very diligent in checking and spending time meticulously looking over the plant since germination and haven't seen anything that would alert me to being a pest problem.

But. I'm a newb. So I'll head your warning and continue to check and see if I can spot anything. Thank you for your input.
Yeah, I've just not seen any deficiency that make holes like that. It looks like somethings is eating them to me. I could be wrong, hope I am.
 

Drew2k

Member
is it mostly older growth?
No, it's a mix between new and old, in some cases the new growth isn't growing in spots, much like the the cracks in the older growth but more predominant. What troubles me though is it's not just the top growth, it's also forming on the bottom fan leaves.

I also have been misting the leaves with water..... which I probably should have added in the beginning.... perhaps it's magnifying on the leaves and burning them? But I still don't understand how it's making cracks and small holes since the humidity is so low so I don't think it would be sitting long enough to do any actual damage. I've stopped doing that for the past few days in hopes that by eliminating things one by one and monitoring steadily I'll be able to figure it out.

I'll be happy to see this plant flourish regardless of the end quality, it's definitely seen some stress factors and lived through quite the ordeal. This is my first grow, so much to learn. I think after I figure this out I'll find a thread about humidifiers and ask questions there, as I most likely am putting this plant through a torture chamber due mostly to improper humidity and light levels.
 

OldMedUser

Well-Known Member
Major heat stress, (radiant heat from the big light), low RH and and spraying your plants is doing it. Try the thrift store for a cheap misting humidifier, cut back a bit on the air going out to keep humidity in and let the temp get up to 75 - 80 which will allow higher RH and better grow temp. Have that light 24" at least above the plant. Even then it's so strong the plant isn't likely to stretch at all. A 400 would be a lot better for one plant unless it gets huge.

You can hang wet towels in the room to up the RH but humidifier would be better. I have to use one for veg here too but flowering now with a nice 25 -35% and a Heat/RH controller on my exhaust fan to keep it that way.

And stop spraying the plant even with the light out.

Good luck.
 
Top