Plants on middle/top shelves yellowing faster than bottom shelves?

[headees]

Anyone else experience this? Im doing a NF style stadium and the plants on the middle and top shelves are yellowing(from the bottom up) while the plants on the bottom shelves remain green.
My old stadium had this problem as well and I assumed it was from heat, but I have an AC in this one, so Im guessing its just from a sped up metabolism from getting much more light than the bottom plants.
I have the lights raised right now,but will drop them after the stretch, hoping that will help things out, but Im sure the middle shelf will have this problem all the way through. I guess I will just have to add more nitrogen to the middle plants.

 

[whodare]

you got it with the light being less intense down low but heat plays a part too as no matter what you do youll be a few degrees different top to bottom...

just up the overall feed on the middle plants and drop the light after stretch.

 

[laylow]

you dont want to be adding to much nitrogen to flowering plants... i found the foiler feeding helped a lot with this.. are you growing in coco? do you use a clamag supplement? in the end i put it down to some sort of Radiant heat problem that was 2 out of my league to comprehend..

if you have time money and can be botherd get 2 digital thermo meters and hang/position one where your lower plants are level with the buds and canopy and one where the top plants are... getting the top one to 80 at its highest was the only way i stopped this problem with the other advise i have given about calmag and feeding with a spray...

any pik's of your stadium?

 

[headees]

I just did a foliar today(H&G Magic Green, Nitrozyme, Cal Mag, and Calcium). Hopefully it will help. Running soil(FFOF) right now, but will switch to coco in near future. Yea am adding calmag.

So you really think its a temp issue, more than nutrient? I am running CO2, so keeping the AC at like 80+. Going to add another light soon, making it 3k, so if it is a heat issue, it might make things worse.
Its hard to get a real reading with the digital thermometer I have because of radiant heat. I will see if I can just shield them with something and try and get a true reading of top and bottom shelves.

No pics now, maybe later.

 

[mg75]

how are you watering your stadium? by hand?
every time i had yellowing leaves from bottom to top... it was a result of root issues (root rot, root bound, root aphids and/or fungus gnats). not saying you are having any... but that is my experience with plants yellowing from the bottom up.
are all the plants getting the same amount of water? is any row sitting in standing water?

just check the roots to see. nothing to lose by doing so.

 

[headees]

Yea by hand as of right now(see my other thread)

It could be a root issue, there are fungus gnats but nothing out of control. I had this same problem with my last stadium years ago though, and had no pests then.

Try to give the plants equal water, they do for the most part.

I will check the roots though, and see if I cant get rid of those gnats.

Im going to take some pics tomorrow.

 

[Hundred Gram Oz]

Are the leaves bleeched or do they look hungry? A few pics would be great.

 

[headees]

No bleaching, looks like nitrogen deficiency. Ill get some pics tomorrow

 

[headees]

Ok took some pics today, did it in a rush so not the best.
Looks like I overferted a bit trying to correct what I think is a nitrogen deficiency.
They are droopy cause they needed water, the ones on the upper shelves always turn their leaves down to catch light though. Are those brown spots gnat damage?

Bottom Shelf

 

[laylow]

dont look like bleeching to me as its on the bottom leaves not the tops or whole plant if you like... i vote Calmag Def and maybe this was caused by a slight PH fluctuation at some point which is indicated to me from the few rusting spots on the leaves on the second from last and last pik...

IMO theres not to much to worry about your plants look healthy and if you say you have give them a clamag sup as long as you keep your PH in check everything should be cool...

 

[megayields]

yeah I would say Cal-Mag is needed ..are you using Silica or Silica blast as well? It helps to build up the cell wall I "just" started to use it both on my indoor and outdoor and I have to say they look even better a bit with it.

 

[headees]

I hope it is just a cal mag issue. Come to think of it I have been cutting back on it lately. I water with 6.5(give or take) ph always, never check the run off though.

Mega yea started using silica about two weeks ago. Can you burn your plants with that stuff, cause I use it as a PH up, and Im pretty sure Ive exceeded the recommended dose a couple times. And I use it every water.

BTW Laylow I checked out your stadium, HOLY SMOKES!

 

[headees]

BTW repped everyone. Thanks!

 

[mg75]

fungus gnats do not create spots on leaves, but their larvae will eat on your roots and make the plant look like it is having deficiencies. when i first encountered gnats, i did not know and thought it was a lockout or under-feeding. the more i fed, the worst it got. even flushing them did not help. turned out the gnats transmit root rot from plant to plant (they are a vector for diseases). i also encountered root aphids which like to hang with gnats and even look somewhat like them as adults.
your plants do not look too bad. if you lower the temps in your grow room, you will have the upper hand on bugs (and bring out some nice colors in your buds). make sure the gnats don't get out of control. don't expect them to stay the way they are. they will multiply many many times. i suggest IMID and treating ALL of the plants in/out of the house/grow space.

those spots look a bit like PH issues. are you mixing your nutrients properly?
also, when you water, does any of the water splash on the lower leaves?

 

[headees]

Will IMID take care of root aphids as well? (Just in case) Ive been batteling spider mites and thrips this go around, but Ive never noticed any damage from the gnats so I didnt think they were much of a problem as of now. I dont see too many really, but its better safe than sorry so I will pick some of that up. I did skim a bit of the fungus gnat/root aphid thread, havent seen anything that looks like aphids yet.

Ive got co2 so trying to keep temps around 80, but near the end I will probably drop them.

When you say mixing nutes properly, you mean adding each nutrient into water one at a time? If so yes, but some times Im in a rush and dont really stir them after adding each one, need to stop doing that.
They are getting a good bit of nute water dumped on them when I water, its kind of hard not to, but putting in a watering system here in the next couple weeks.

 

[mg75]

IMID will take care of aphids and gnats. HOT SHOT pest strips will take care of the mites and thrips. i use both in the beginning of veg. i also leave the HOT Shot pest strip in the flower room for the first 14 days of 12/12 so i am sure all the new eggs die. spider mites are a big problem for growers and you must take preventative action. after the 14 days, i remove the Hot Shot pest strip and place it right outside the grow room. this way, if i bring anything into the house, it gets zapped before multiplying and causing a problem.
it might be too late to use IMID, so i would use mosquito dunks and azamax/azatrol along with some sticky traps just to control them until harvest. i would not put IMID in my medicine if i am about to harvest in about 45 days. it is systemic and stays in the plant for up to 60 days.

root-issues, fungus gnats, and root aphids have a direct relationship with over-watering... so monitor that as well.

 

[headees]

Ok yea I read up on IMID, seems you dont want to use it in flower. Im probably going to pick some up for the round Im about to flip.

Yea Ive already been at war with sptder mites and thrips. I already used 2 No Pest Strips when I first noticed the mites and they did nothing. Weird cause I used them before years ago and 1 strip took out my spider mite problems in 24 hours and the room was bigger than my veg room now. So I just ended up getting Floromite/Forbid and Spinosad(Monterey) for the thrips. Im probably going to spray the flowering plants one more time with Forbid/Spinosad just to be sure, even though I see no evidence of the bastards. Think its too late, they are on day 12?

 

[laylow]

do you use House and garden drip clean? if not then i strongly suggest you get some as you dont need run off with it as its keeps all the salts broke down and helps for calmag issues and various other problems...

 

[headees]

Yea been using drip clean for the last month or so.

 

[laylow]

dont worry about runoff now then mate just use what you need top feed the plant... for example if you give them a litre and there is no run off then give them another 1/2 until there is and then just back off to the last half.... this way you are saving on juice and dont have runoff this will also help in late flower so you dont have water laying about.... win win