Browning leaves - black spots on one of three plants.

The attached pictures show problems that are occurring on one of three plants. Several of the mid-canopy leaves look like this - browning and yellowing with black spots.

I'm using the Canna line of products and just started flowering. I foliar fed for the first time today - very low strength blend of Rhizotonic, Bio Flores and Bio Boost. Going to pick up PK13/14 and Cannazyme this weekend. I'm hoping this feed and this addition to the line assists in whatever deficiency this plant is suffering.

Until then, can anyone help me diagnose what this issue is? I'd rather attack the problem specifically and fix this directly instead of just guessing with new additions to their feed.

Thank you!

I may be completely wrong but it looks like nutrient burn.

anyone is welcome to correct me

kingwarrick said:

I may be completely wrong but it looks like nutrient burn.

anyone is welcome to correct me

Click to expand...

Thanks for responding. I feed the other two plants the same proportion of nutrients. I wonder why they aren't affected this way?

dude i just found the exact same thing on 1 of mine!!!! whats ur soil mix?? maybe it was in the description and i missed it. ill be stickin round for the solution.

Dr.Dope said:

dude i just found the exact same thing on 1 of mine!!!! whats ur soil mix?? maybe it was in the description and i missed it. ill be stickin round for the solution.

Click to expand...

Just Roots Organics with extra perlite added in for good measure. The perlite had no nutritional value (not Miracle Gro style).

They're about 45 days old and just began flowering yesterday. This plant has not seemed stunted in size, but has always exhibited some sort of symptom - light leaves all the way to the current problem.

nebody have ne ideas?? seems like this is a real problem. and imo i dont think its nute burn because i too feed both mine the same. its odd.?.



also what kind of light are ya using grolog?? im using a 300 watt equiv. 2700k cfl and 3 26w 2700k cfl and 1 26w 6500k cfl.

I'm growing under a 400w HPS.

Other information:

Daytime temps range from 75 - 81, depending on the outdoor weather.
Nighttime temps typically stay at 71.

I water with Primo RO water. PH is around 6.9.

Please help!

Your temps seem fine. Maybe a little hot during the day, but DEFINATELY NOT whats doing that... I think you've got either a nute burn, or a Magnesium Deficiency. Let me explain...


Maybe these pics will help... Here's a plant with nute burn...


That photo is of nutrient burn.

This is a plant with a magnesium deficiency. ( See the picture below.)



Magnesium deficiency looks similar to a nutrient burn, but the leaves start curling UP.

If you think you may have a Magnesium deficiency, foliar feed your plants 1/2 teaspoon of epsom salts to a quart of water. Mash up the salt, put it in a quart of hot water (not boiling!) and let it dissolve...then foliar feed it to your plants (spray on the leaves, top and bottom). Couldn't hurt. I was told to do just that, when a couple of my girls did that, and they bounced back in a few days.

Hope I helped!

Thanks for that post. +1 for you sir. I'll try the salts. Seems more likely because the issue seems isolated to a single plant.