Heat stress or nute burn maybe?

[StickyOG]

2 Blueberry CKS growing atm.

They have been great and shown no signs of problems until 2 days ago, one of the plants leaf tips started to curl.
The part of the leaf between the veins on this set of leaves also looks slightly lighter colored over the rest of the plant/plants a day before this happened.
now you can see the areas that are lightning up more so the tips curling and dying off getting crispy.

They are 32ish days from seed growing in 4" grodan blocks being air pruned on all sides atm as i need to keep them small for 2 more weeks before i can veg them properly.

I have been feeding them about every 2-3 days with around 800 ppms along with foliar spraying sometimes water other times with a silica cal mag solution

2 days before the curl i noticed the lighter color between the veins and gave them all a nice big feed, I think i over did it but you live and learn anyway this feed was around 1500 ppms

All the plants seemed fine with it by the next day but the 2 blueberry seemed like they had used all the water in there cubes so i gave those 2 only a bit of water (100 ppms tap)

The next day is when the leaf tips were curled and now today the lighter areas between the veins are prominent

environment conditions:
temps around 70-80 F
RH around 40-50%

One thing to note on day of leaf tip curl was the RH was a bit lower than normally at around 32-35% and warm air blowing on leaves

Sorry for the rambling!

Here are a few pics

Day before the curl and one day after the big feed.

cant seem to get this pic oriented correctly no matter what

first day of curl

today or second day of curl

 

[millertm]

Root bound issues. There trying to out grow their 4"cubes. I'd up size them to larger containers. It seems you ran out of time. It happens, I've fought same issue.

Cheers

Sent from my SPH-L720T using 420

 

[Weaselcracker]

I don't go over 1200 ppm with my plants in ten gallon pots at the peak of flowering. Often much less. I'd be surprised if they weren't showing some nute burn. At this stage I feed around 400 ish.

 

[StickyOG]

Cheers
Appreciate the info. Thought id shoot a photo of the root zone for completeness
Hardly have the cube half full of roots i rekon. this is all that is visable and none on any of the four sides of the cube.
What i was hoping for was to keep these guys air pruned in hopes that in 2 weeks when i can move and transplant these babies they will blow up.
Not much info about air pruning but i thought id give it a try since i dont want them bigger yet.
I figured id start seeing roots from all sides before they started complaining about the root space haha!

pic of the bottom of the block

 

[StickyOG]

I don't go over 1200 ppm with my plants in ten gallon pots at the peak of flowering. Often much less. I'd be surprised if they weren't showing some nute burn. At this stage I feed around 400 ish.

Thanks for the info. I am def learning or trying to learn how and when and how much to feed. i am watching the plants everyday in hopes i can learn signs or problems that arise.

I will def be backing off the nutes

I did soak them for about 15 mins in just water today to try and clear some of the nutes and what not but yeah we shall see.

Nothing seems to be spreading just yet except the curled up parts are dying off rather quick

 

[Kriaze]

1500ppm's? <looking for a faint emoticon>. You would usually work up to those sort of ranges maximum when large plants are flowering, even then you would be pulling back on the nutes. I would suggest that you flush them with plenty of water and then lightly (emphasis on lightly) work up the ppm's as you go along otherwise your plants will lockout nutrients and you will have no end of problems. Good luck and all the best with your grow

 

[StickyOG]

1500ppm's? <looking for a faint emoticon>. You would usually work up to those sort of ranges maximum when large plants are flowering, even then you would be pulling back on the nutes. I would suggest that you flush them with plenty of water and then lightly (emphasis on lightly) work up the ppm's as you go along otherwise your plants will lockout nutrients and you will have no end of problems. Good luck and all the best with your grow

As a new grower i am very anxious for things to happen or i read something somewhere and something else somewhere else and i am just trying things our really.
I think its awesome to have a place that i can post my situation and people can chime in with opinions and stuff and you guys are awesome for trying to help out
I really love the cannabis community its not like any other out there!

I am leaning towards the nute burn myself and i struggled over giving them that much feed as well thinking it was too much but i did it anyway and said to myself "least ill get to see what nute burn looks like most likely" in person

Oh well they will only get water for the next 2 days at least and then i will start slowly adding in nutes again

 

[OldMedUser]

Stop spraying the plants. That's where the problem is coming from.
No need for it if they got lots of roots because stuff like this happens.

 

[Weaselcracker]

The plant I won the plant of the month contest with last month was grown in a solo cup's worth of coco- much less medium than you have now. I set it up in an autowatering system along with a reservoir so it was fed/watered three times a day. The maximum nutrient level I reached was 750 ppm but this was just one feeding- most of the time I hovered around 600-650 ppm. The plant got reasonably big, but more importantly, it was very healthy from start to finish. Those feeding levels seem kind of on the low side- but... the plant didn't think so, apparently. Much easier and faster to fix an underfeeding problem than an overfeeding one.

 

[Racer1921]

Flush with water yes. But i wouldnt recommend everyday. Still only water every 3 mate. Or you will end up with other problems eg root rot.

THE GREEN RACER.

 

[StickyOG]

Flush with water yes. But i wouldnt recommend everyday. Still only water every 3 mate. Or you will end up with other problems eg root rot.

THE GREEN RACER.

Def wont be over watering, ive done pretty good i think about not doing so as it is very easy i rekon with rockwool

As for flushing them - I soaked them in plain water ph'd to 5.7 and 100 ppms (tap water) for about 10 mins and then let them drain off.

Should i flush these in a different manor? also when i water them (hand water) i do so from the top normally and try to get a decent run off. It only takes around 150 ml of water to start getting run off of these cubes and i put about 250 ml of water or feed when i do either of those

I am constantly worried about over watering these cubes as they seem to hold so much water and i am not sure if i should be squeezing some of the excess out.
I have read a light squeeze is ok as long as im not over doing it to mess up the air pockets in them but i still am cautious because im new to rockwool.

 

[Racer1921]

Sounds like your doing it correct. Yes soaked in phd water should of done well

THE GREEN RACER.

 

[Kriaze]

I'm not too sure personally whether soaking would be as good as flushing, how much water were they soaked in? You want to get rid of any excess nutrients and toxins that may have built up so in effect you want to refresh the growing medium and make it a clean blank slate to start again, I'm not sure soaking could achieve that as well as flushing away those excesses would.

 

[StickyOG]

i stuck them in a tub of about 10 liters of water just up to the top of the cubes.so it was a decent amount of water to cube ratio but i do see what you mean as far as rinsing all the old out and trying to get all the nutes out.
I kinda did think this wouldnt get it all out rather just dilute it a fair amount thats why i choose to not completely flush to leave some nutes in because the other three i have with same treatment are fine not sure if this is a bad idea or not lol maybe you guys can tell me if it is and why, im all for learning.
Seems to be all good at the moment, they are reaching for the light again and all perky and no more signs of stress at this moment.