nutrient burn or nitrogen toxicity?

labratlee

Well-Known Member
hey there peeps.

I'm 5 weeks into my first grow. I'm growing 4 autos. I have done some real extensive reading... All day everyday lol. I have a general grasp on most things... Just lacking the hands on experience. There is a few things in struggling to diagnose. One of which is nitrogen toxicity or nitrogen deficiency, obviously making the wrong diagnoses. Drastically increases the damage of the other. My bottom leaves on one plant are turning yellow then brown and falling off. Once they start turning yellow th colour spreads across the leaf and then tips turn brown and that spreads. It is only at the bottom of the plant, iv not noticed any burn on new growth or top leaves.
I diagnosed my plant with N toxicity.... So flushed it with PH'd water, the yellowing seemed to continue or even speed up... So I guessed I got it wrong and gave a mild dose of nutes and its kinda slowed it right down. Iv removed the yellow/brown leaves and am keeping a close eye. The now new bottom leaves are getting a slight brown tip and slight yellow on the leaf. Is this nute burn or just natural due to the leaves not receiving much light ( I'm using cfl's) id like to sort this out once and for all as I don't want an effect on my yeild. I'll attach pics of plant and the leaves in question lol.
the reason I originally thought they were N toxic was because the leves were clawed. The new growth was drooping like it was over watered but it wasn't, also on an upper leaf there was a couple of quite destinctive bright yellow stripes between the veins. I read that was a symptom.
so... Lol... Have I got it all wrong or is there something going on? Love to hear all your experienced idea's. Thankyou for taking the time to read my thread.
peace.
 

labratlee

Well-Known Member
Pics? Have u tired using some cal-mag and some silica?


-Jugz
yo, cheers for fast message. I have just started using a small amount of silica in hope it would help... I did read that its a bit late for me to use silica as it gets into the bud and leave a nasty taste and bad burn. I don't have cal mag.. Here in the UK, our tap water contains quite high calcium. I have been wanting to add som magnesium but just not got rount to it yet as I didn't think I had a mag deficiency, I will get some epsum salt tomorrow. Do u think it could be a mag deficiency yeah? Cheers for input mate. Appreciate it alot.
 

jugz420

Well-Known Member
yo, cheers for fast message. I have just started using a small amount of silica in hope it would help... I did read that its a bit late for me to use silica as it gets into the bud and leave a nasty taste and bad burn. I don't have cal mag.. Here in the UK, our tap water contains quite high calcium. I have been wanting to add som magnesium but just not got rount to it yet as I didn't think I had a mag deficiency, I will get some epsum salt tomorrow. Do u think it could be a mag deficiency yeah? Cheers for input mate. Appreciate it alot.

Silica i always give that to my plants untill 2 weeks before chapping it down..

-Jugz
 

DirtyMcCurdy

Well-Known Member
N toxicity will make the leaves a real dark green and can cause them to "claw". N deficiency will show up with yellowing of bottom growth.
Silica i always give that to my plants untill 2 weeks before chapping it down..

-Jugz
Just curious. Why do you keep pushing the silica? What do you think it does?
 

labratlee

Well-Known Member
ok sweet, I will get some tomorrow. Dunno if we have calmag in uk, I can get some Epsom salts ( magnesium sulphate) I dunno if I can just add to water and poor onto soil... I'll check it out..if not ill order calmag. I'll carry on with the silica too. How often u feed with silica? I am using biobizz all mix soil. Biobizz grow and biobizz bloom. Iv cut right back on the grow mow they are in bloom. I also give molasses... I thing the biobizz nutes have molasses in them too. Not to happy with biobizz nutes but they were cheep and all I could get at the time. Think ill try different nutes next grow. Any recommendations?
 

labratlee

Well-Known Member
N toxicity will make the leaves a real dark green and can cause them to "claw". N deficiency will show up with yellowing of bottom growth.

Just curious. Why do you keep pushing the silica? What do you think it does?
o seem to have lost the clawing effect after the flush. Now its just goin yellow bottom up.. What about the brown tips on the bottom leaves? Is that burn or deficiency? Cheers nan
 

DirtyMcCurdy

Well-Known Member
o seem to have lost the clawing effect after the flush. Now its just goin yellow bottom up.. What about the brown tips on the bottom leaves? Is that burn or deficiency? Cheers nan
If its just a few small ones, like the bottom leaf in your photo, I would just pull them off. The rest of the plant looks good in the full sized picture.
 

labratlee

Well-Known Member
If its just a few small ones, like the bottom leaf in your photo, I would just pull them off. The rest of the plant looks good in the full sized picture.
yeah I pulled the worst off. I'm a bit reluctant to remove leaves tho as its an auto flower... People say any defoliation will slow their growth temporary... I dunno if they mean damaged bottom leaves tho... . Id like to remove a couple of lower branches to so tat they don't steel energy from my top buds. Apparently its a big no no on autos though... Fuck knows... 6 of one half a dozen of the other I think. If u wanna see more pics of my girls have a look through my threads. I'll give u a link to one now. Its some bud shots from earlier today.
 
Top