HELP!! I have rusted leefs which look dead all over my tops!

Hi I really could do with abit of advise, I have 4 white widow and I'm in 5 week of flowering. They in 1m x 1m x 2m tent, under a hps 400w. About week and half ago I noticed and few yellow spots appearing and then before I knew it it was a over the plant (mostly on top). As soon as I noticed the spots I started flushing, and adding call mag. I'm still flushing at the moment. Now 3 out of 4 plants are like it. At first it thought it was calcium so which it why I got calmag, but now I'm not sure. Maybe a mix of nut deficiency and heat stress? I haven't got that long left now, and just hopping they see it through. I don't think this is developing anymore, maybe slowed down abit. Should I trim can all the leafs which are rusted and tried up. I'll add some pictures, please can somebody help me out with this, this is my first grow, so need advise.

Thanks alot

Those look to be the following.

Late stage Mg deficiency.

Over use of high P and K boosters.

Possible heat problem.



Leaves won't recover and flowering has probably been stunted excessively.



Grow medium?

Nutrients used?

Temperatures?

How often have you been feeding?
At what strength?




J

What are you feeding them? How much and how often. That looks like a very bad nutrient burn. What are you pHing your water to as well? What substrate are they in?

jondamon said:

Those look to be the following.

Late stage Mg deficiency.

Over use of high P and K boosters.

Possible heat problem.



Leaves won't recover and flowering has probably been stunted excessively.



Grow medium?

Nutrients used?

Temperatures?

How often have you been feeding?
At what strength?




J

Click to expand...

Cheers for the reply j,
I'm using canna pro soil with canna tores and canna flowering
also risertonic and big bud. They are watered every other day and flushed every 3 feed
they have liter each, which have in each liter 3ml canna flowering, with 2ml big bud and then 1 ml risertonic.
they are in 11lt pots with about 9lt actual soil.
heat is bit of a problem, running at 29c, but as a small ac and one 12 inch fan and a 6 inch fan.
I just really hope they see it through, I've been trying to find out what's going on but can't find the answer and now this is really starting to stress me out. Would you like anymore pics?
Cheers ben

Cheers for reply, my ph is alway 6.4 to 6.8, don't know exact number due to using ph testing kid with colour chart
cheers ben

Maybe a mix of nut deficiency and heat stress?

Click to expand...

Ding-ding-ding we have a winner....

You think it might be heat stress, because --> How hot did it get inside your tent, 10-15 days ago? and for how long was it 84+ f ????
Then you flushed, because you thought or were told to, and you knocked all your nutes out of your plant....yellowing leaves, are going to die...soon...
So...Now, you are deficient... and sorry to say, prob there is nothing you can do...
From now till you harvest, buds will prob stay the same...
This time of year, somehow, the heat sneaks up on us, and blam, too hot in our grow areas....
I speak from personal experience....
Do not flush again...
Feed regular and water regular...from now till harvest...
Plants usually do not come back from heat stress....
Sorry man...
Better luck next time...

Its been sitting at around that from the start to be fair, the only thing is if this was heat stress wouldn't they all be like it, I have one of the four which hasn't gone like this. The buds are in good shape, and stink! I'll add pic of other plant which isn't like the others, strangely the one which is ok is the tallest one, which surely would get the most heat stress? Due to it being closer to light?
Cheers

This is wat it all started off looking like then went crisp.

Looks like heat stress from here. I'd harvest them now as you have to trim off ALL the rusty shit from your finished product. If you have the time you can go thru and trim off all the rusty leaves, mist and water them daily. That will get you another week or 2. I'd still chop today and learn. BigSteve.

Murphyb said:

Its been sitting at around that from the start to be fair, the only thing is if this was heat stress wouldn't they all be like it, I have one of the four which hasn't gone like this. The buds are in good shape, and stink! I'll add pic of other plant which isn't like the others, strangely the one which is ok is the tallest one, which surely would get the most heat stress? Due to it being closer to light?
Cheers

Click to expand...

Not really... I use a laser temp gauge and there are hot spots in your grow room....and probably....
The tallest one, had the best root system, so it was more 'hardy' and able to withstand the added heat...

So, what was the hottest your grow space got? and what's your RH ?
Good Luck, I wish I had good news for you....
You can nurse them.... for a while... or do what BigSteve above says..
Again, it's the time of season, it got too hot too fast....

your issue seems to stem from the excessive flushing. dude you should not be flushing after every 3 feeds, especially in soil. if you were growing in coco i could understand, but in soil?

i suggest letting that medium dry out almost completely before your next water/feed. after that, i also suggest feeding properly to prevent the excessive flushing.

Heat stress not, I run my canopy at 105 during the summer here folks (no CO2 either). I'm in the Mojave and I do not air condition. That is not heat stress.

But good luck with this.. Usually it's the simple stuff like nutrient burn in this case. but I'm sure I'm wrong LOL I'd keep on using correctly pH'ed water with Ca/Mg.

Oh and your post #8 is Ca/Mg deficiency.

hth,
Annie

Murphyb said:

Cheers for reply, my ph is alway 6.4 to 6.8, don't know exact number due to using ph testing kid with colour chart
cheers ben

Click to expand...

Huge problem here.... get a pH Pen the color game is not accurate enough for this game.

Cheers Steve, I have time to trim them all up just Didnt know if they would be alright by trimming them at this stage? It's only the top leafs don't think you can see that in the pic, all others are ok? It's as if the top ones have covered the one below. If I was look at them side on and level with them you would think there is anything wrong with them, until you stand up! It's one horrible feeling when they go wrong, only want nice personal bit

The picture #8 is what it all started off like? Then just when crispy, once they have ca/mg deficency for the leafs crisp and die alot quicker? Because that is what it could be? Apart from its mainly the top layer of leafs. Thanks for help Annie.

curious2garden said:

Huge problem here.... get a pH Pen the color game is not accurate enough for this game.

Click to expand...

Which pH monitor do you recommend? Looking for something that is easy to calibrate, etc.

nietzschekeen said:

which ph monitor do you recommend? Looking for something that is easy to calibrate, etc.

Click to expand...

bluelab ph pen.


J

View attachment 2711486View attachment 2711487It's not everywhere just on the tops? Side on they look fine, with no yellow or dead leafs in sight.

Murphyb said:

The picture #8 is what it all started off like? Then just when crispy, once they have ca/mg deficency for the leafs crisp and die alot quicker? Because that is what it could be? Apart from its mainly the top layer of leafs. Thanks for help Annie.

Click to expand...

If you are feeding too much it makes Mg very hard to absorb.

Its also harder for the plant to take in when using excessive amounts of K boosters.



Here is a pic about Mg deficurncy and what to look out for.




J

What do you think the next best move is? Trim the leaves which are dead and go back to feeding them? They haven't had anything for 1 and half weeks. This is my first grow, so am not sure what to trim and not want to trim? Thanks for your help