Bad leaf curl, rust spots. I think vpd/envionment. Head banging on wall!!

[topset1976]

Hello all, I have been growing for many years but have had this issue pop up recently. I am getting bad leaf curl, weak stems, slow veg growth, buds not ripening and lower smell then I ever got. It especially happens in my gogi og and doc og strains but i've grown them for years without issue. Other day i put some box fans on the floor and within a day i had bad leaf curl on the plants where the wind hit them. I'm thinking its vpd or something else environmental. Heres my setup...

Flower room - 12 double ended hoods, 36k btu mini split, drip feed 2x a day with 10% runoff DTW, co2 @ 1200ppm, cutting edge solutions 6 part @ 900 ppm with florolicious plus, filtered water, day temps 80 degrees top canopy/68 floor with 65% humidity, night temps 65 degrees 75% humidity, plants in 3-5 gallon smartpots in coco/perlite, multiple fans up high, no air intake, hot air in attic is pushed out via exhaust fan 24/7, dehumidifier set to 65%, room size 20x30x12, have 7 8x4 trays with 6 plants in each tray.

Veg room - 3 600w MH and 2 cmh, drip fed 2x a day @ 600ppm, lights on 20 off 4, outside air in take and 2 smaller fans blowing air out.

I'm fairly sure it isn't nutes or lockout since i would see it everywhere. I have many plants that are doing just fine but they still don't grow as fast or finish like they should. I'm perpetual and pull a tray every 10 days or so. This is making me crazy and I really need your advice. Ever since i moved to double ended hoods i've been having trouble like this. I keep the lights 3-4 feet away and mostly have temps at canopy level around 78 degrees. I recently read about vpd and it makes a lot of sense. The leaves on the affected plants seem moist when lights come on and the leaf curl sets in super fast, pretty much overnight. I'm phasing out those strains but I still want to fix the issue going forward. I am seeing a lot of stretching in veg, weak stems, leaf curling up, rust spots on mostly fan leaves and new growth but it happens to older mid level fan leaves as well. Let me know what you think. thanks!

 

[emeraldcityog]

Are the stems brittle? Hollow? Could possibly be a fungus in the plant.

 

[topset1976]

Stems aren't hollow. When I take a leaf of our break a stem there is lots of liquid inside stem. It effects 3 strains (mothers milk, goji og, doc og) much worse then other strains. Seems to effect upper leaves worse

 

[topset1976]

Stems are fine no hollow. Seems to effect goji og , doc og, and mothers milk much worse then anything else. I have used the same setup for years with no issue which is why I think it must be environmental since it's happened since de hoods were put in. They must lower rh so I think it might be vpd. Had anyone see this with de hoods and lower rh?

 

[mowood3479]

If Those sites haven't gotten dryed out somehow and wilted then I'd get out a scope and start looking for pests..
do u have any fliers in the room? Fungus gnats perhaps?

 

[mowood3479]

Good luck btw.. wish I had a more definitive guess.. but there is def something going on, so start figuring out what it's not. (At least that's what I'd do).

Idk, about vpd issues being the culprit, seems like that would effect the entire room and not just a handful of plants..
The localized nature of the issue has me thinking pests but I'm not there to check..
Hope u get it sorted asap

 

[HqFarms]

Scope for russets. The rust spots are kind of a give away

 

[GonjaLove]

I would think if it was vpd, all of your plants would be affected. What is your medium? I run coco and it seems like almost every bag I've bought in the last handful of months has been plagued with fungus gnats. Only brand I haven't had problems with lately is Mother Earth.

 

[Mikell]

The first picture looks like wind burn.

Check out DE threads, some users have issues flipping plants grown under SE bulbs in veg.

 

[Wendull C.]

That isn't russets. That is what happens to foliage that goes too long without water. The plant will pick up, but if the leaves are too far gone that happens.

I know it isn't drought, but have you checked your root system to see if it is healthy?

 

[topset1976]

If Those sites haven't gotten dryed out somehow and wilted then I'd get out a scope and start looking for pests..
do u have any fliers in the room? Fungus gnats perhaps?

hi wood, i keep my room pretty clean. I don't think i've ever had fungas nats. I'll have some small nats sometimes but haven't had them for some time. I did have a few spider mites a month ago but they are gone now. The severe leaf curl is only happening on a few plant strains but overall explosive growth is slow on all my plants. Most seem ok but just not right. If it were fungas nats I'd expect the same damage on everything but I have plants right next to a severely leaf curled plant and it looks fine. Also if i take the leaf curled plant out of the direct light for a couple days it seems to come back quick. Also the lower leafs away from the light aren't affected much. only the top leafs. This is why i think its humidity. The air close to the light is less humid. Also when i turn on a fan it makes it even more less humid. When i blow a fan on them they will leaf curl up within 48 hours. My mini split takes a ton of water out of the air. My humidity is down to 48%. Could this be it? I am almost ready to buy a big humidifier but want to hear your thoughts. thanks

 

[topset1976]

Scope for russets. The rust spots are kind of a give away

i agree it looks like it could be but wouldn't plants right next to them also have the same issues? Those plants in the pic are all in the same tray and the same scrog. If i get a bug the scrog is a highway for the basterds so I'd expect them to be on all of them but it only happens to a extemsive degree on a few strains but i know its effecting other plants by the way they grow slowly and aren't finishing right

 

[topset1976]

I would think if it was vpd, all of your plants would be affected. What is your medium? I run coco and it seems like almost every bag I've bought in the last handful of months has been plagued with fungus gnats. Only brand I haven't had problems with lately is Mother Earth.

i am 70/30 coco/perlite. i use canna coco blocks. Been using them for years without issue. i even thought it could be that so i tried 4 other kinds and still got same issue. sometimes it only happens in flower and if i take the plant out of the direct hood light it comes back fine so can't be bugs i don't think

 

[topset1976]

That isn't russets. That is what happens to foliage that goes too long without water. The plant will pick up, but if the leaves are too far gone that happens.

I know it isn't drought, but have you checked your root system to see if it is healthy?

hi wendull i feed via drip twice a day so they definatly aren't dry. Roots are super happy. They pop through the smart pots all the time and they are nothing but white. When i harvest and pick up the pots i'll see about an inch of pure white roots that have grown through the bottom of the pot. Since when i move the plants out of direct light they return i think it must be something else.

 

[topset1976]

The first picture looks like wind burn.

Check out DE threads, some users have issues flipping plants grown under SE bulbs in veg.

yes i agree this could be the problem. I am experimenting right now on one flower tray with a de hood and a 600w cmh instead of just 2 de hoods to see how they react. I must say, that tray is looking very good but also I don't have any strain that reacts to the extreme but still they look amazing so perhaps it is having 2 de hoods creating extra heat from the cross light. i'll check out de area. if anyone has any other info please let me know since this also happens in veg just usually not as bad. thanks

 

[James Howlett]

You say you're feeding 900ppm in flower? Are you using the 700 or 500 scale?

 

[Mikell]

Can you lower the wattage or raise the DE?

From your descriptions it sounds like the worst symptoms are from foliage closest to the lights. Too much light will raise foliage temperature, and while measurements of the room will be within ideal variable, the plant is suffering. A laser thermometer is not required but may show these differences.

Try moving fans or fan direction to avoid blowing directly on some plants, but as importantly to defeat the heat stratification you have.

 

[topset1976]

Can you lower the wattage or raise the DE?

From your descriptions it sounds like the worst symptoms are from foliage closest to the lights. Too much light will raise foliage temperature, and while measurements of the room will be within ideal variable, the plant is suffering. A laser thermometer is not required but may show these differences.

Try moving fans or fan direction to avoid blowing directly on some plants, but as importantly to defeat the heat stratification you have.

I think we have a winner! I have been using my laser thermometer to get temps on my canopy for a long time and they always showed 80-82 max but i went up in the attic and pointed down towards the middle of the canopy and i found some rows had temps of 87-92. This wasn't good! I switched everything to 600w and raised up my lights as high as they would go. This probably explains why some plants are effected more then others as some care more about higher temps then others since this was happening to same strains in veg. Is two DEs per 8x4 tray to much light? I also saw something very strange on the same strains that have issues in flower.

I found drops of water on the leaves. At first I thought it was a leak in my roof but I checked and wasn't that. I've heard of leaves perspiring when leaves are touching. Is that an issue? My RH when i was above the plants were 36% and temps 90 degrees. When I raised everything it went to 78 degrees and 50%. I'll monitor and let you know but please do let me know about leaf leaking and if 2 des per is a bit much. I used to run 3 SE 1k bulbs over each tray and i swear i had better yields and no issues. I almost want to go back but I don't want to get defeated by these hoods thanks again

 

[str8flame]

...and if 2 des per is a bit much. I used to run 3 SE 1k bulbs over each tray and i swear i had better yields and no issues. I almost want to go back but I don't want to get defeated by these hoods thanks again

Any chance these plants that are suffering are where the lights intersect...how do the rows along the walls look?

Here's some info from Gavita that a friend shared with me. I recently built a 12x9 room w/ 6 DEs (3x6 footprints) using this layout & have very even lighting. I think a 4x6 print is another option, but 4x4 is too much. A friend of mine had 3 rows of 4 DEs across 16', he took 1 off each string, spread them out, & got great results. [FONT=Arial, Helvetica, sans-serif]

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