Is this a deficiency in K, P, Ca, Mg, or a fungus?

[lalstalls]

This is how my last grow started, and it got bad (see below). The dry edges and spots on the leaves gave way to crumbling by early bloom. Poring over deficiency descriptions and pictures isn't helping me discern what these symptoms point to: K, P, Ca, or Mg deficiency? Or fungus?



What do I have wrong?:

• As in K deficiency, the tips of the leaves curl and their edges die, and growth slows. (On this hypothesis, I gave a light, pH-adjusted wood ash + emulsifier foliar spray to one of the plants yesterday. No visible improvement yet.)
• As in P deficiency, brownish leaf edges work their way inwards, causing the leaves to curl up; growth slows.
• As in Ca deficiency, the leaf tips and edges (including on new growth) turn yellow/brown, and there are spots.
• This looks like the the end-game in the bloom room. But I've read Mg deficiency works its way up the plant (and that's not the MO here).
• I don't think it can be light burn: these are vegging 18-hour days under a few T5s.
• It might be a fungus, e.g., septoria.
• The RH is fairly low - around 30% - 40%. Could that be causing this?

Should I hit these with a diluted foliar application of BioBizz Grow? Bloom?

Here's how the last grow was ending:



Ouch!

Thanks for any help.

 

[MrBungle]

It looks like more than one thing going on there... I'd start with media pH

 

[Collembola]

do you spray them often ?

pic 1 looks like it has some residue / damage from foliar application ?

but some of the rest look different.

if you did not spray pic 1, then i think it is some environmental / pathogen problem, but i dunno (pic 2 looks like simply too much N, locking out K (guessing))

your last finish looks very dodgy, but again if it is environmental / pathogen, then it would not make sense that it grew that big in the first place (unless you changed soil / changed some variable throughout).

somethings don't seem to add up,

 

[TanzanianMagic]

This is how my last grow started, and it got bad (see below). The dry edges and spots on the leaves gave way to crumbling by early bloom. Poring over deficiency descriptions and pictures isn't helping me discern what these symptoms point to: K, P, Ca, or Mg deficiency? Or fungus?

pH issues, salt buildup, basically wrong NPK and probably too much nutrient solution as well.

I think a big mistake was made when people started thinking of plant nutrition as adding nutrients to the plant, like putting gas in a car.

I like to think of plant nutrition as supporting the basic functions of the plant - mainly putting on a large root system. Keep the NPK near 3-8-12, and the EC/PPM low, and not a lot can go wrong.

However, giving a developing plant like that too much nitrogen, magnesium, etc. is going to burn them.

Also, don't neglect the water - filter it, and remineralize it by adding a pinch of magnesium lime or maerl and let it stand overnight. That should take care of any hard water issues and cal/mag deficiencies that result from filtered water.

 

[lalstalls]

Thanks, TanzanianMagic, Collembola, and MrBungle.

Collembola, although the spots preceded the spraying, you're right: there's a residue there. I don't stray often; but I think I might need to work at removing residues. I've tried just spraying with water, which was insufficient; so I tried wiping with a wet rag, and that takes numerous passes (doesn't work well). I'm open to suggestions.

Thanks for the pH tip, MrBungle.

pH issues, salt buildup, basically wrong NPK and probably too much nutrient solution as well.

If it's nute burn, it's not that I'm adding too much liquid ferts. Maybe it's that I'm using FFOF soil though. I'm really not adding nutes, except a little molasses every couple weeks, and just recently, a chamomile tea, and a couple days ago, an aloe vera foliar spray (emulsified with a few drops of Dr. Bronner's).

I think a big mistake was made when people started thinking of plant nutrition as adding nutrients to the plant, like putting gas in a car.

I like to think of plant nutrition as supporting the basic functions of the plant - mainly putting on a large root system. Keep the NPK near 3-8-12, and the EC/PPM low, and not a lot can go wrong.

Right on. I'm giving it up, and trying the ROLS approach in a no-till bed. Happy soil makes happy plants. Feed the microbes, support the myco life.

Also, don't neglect the water - filter it, and remineralize it by adding a pinch of magnesium lime or maerl and let it stand overnight. That should take care of any hard water issues and cal/mag deficiencies that result from filtered water.

Very good point. I used to just water with straight tap. Now I use output from a Brita filter. Should I be adding? I've got dolomite lime, but hear it can be strong. Maybe azomite?

Anyway, it occurred to me that windburn might be a factor. The plants receiving super-direct fan currents are indeed the most troubled. So I turned one fan off (leaving only a small one running) just to see... Although nobody looks any worse, I'm still waiting for definitive signs of improvement.

Will post news.

Many thanks!

 

[TanzanianMagic]

Sorry for the double reply.

 

[doams]

from the third picture would say underfed notice burned tips pointing up thats underfed sign.
also are you using fresh nute bottles or few years old?
organic last around 1y.
synthetic maybe 2y.

got same problem a while ago using old nutes lead to deficiencies harvested quarter of normal amount and buds were underdeveloped smoke is not very potent.
lesson learned.

 

[resinryder]

".If it's nute burn, it's not that I'm adding too much liquid ferts. Maybe it's that I'm using FFOF soil though. I'm really not adding nutes, except a little molasses every couple weeks, and just recently, a chamomile tea, and a couple days ago, an aloe vera foliar spray (emulsified with a few drops of Dr. Bronner's). "

Looks like you just answered your own question. Feed em