k deficiancy?

Discussion in 'Sick Plants and Problems' started by booyaa, Aug 11, 2011.

  1. anyone know what this issue could be?
    day 27 of flower, run off ph is 6.7
    using all organic ferts
    400 watt hps
    plant 1= cosmic nights
    plant 2= nirvana special

    originally thought nitrogen def but used mexican guano the last feedings and it didnt fix it.

    plant 1 looks like k def and plant 2 looks like nitro def... pls docs share your diagnosis. thanks :)
    *will post more pix if needed
    plant 1

    plant 2
  2. Need to see where on the plant the first leaf is from.

    The yellowing leaves in the second pic are definitely from nitrogen deficiency. Keep in mind that deficiency damage doesn't heal. When you fix the problem, it just doesn't spread to other leaves, but the damaged leaves stay damaged.
  3. [​IMG]

    plant 1 - better shot of leaf placement, top feeder...
  4. That's probably early Phosphorus deficiency.
  5. #5 booyaa, Aug 13, 2011
    Last edited by a moderator: Mar 15, 2016
    Really you don't think that is potassium? I gave the girls some Hyphos twice in the last month...
  6. I don't think it is potassium. K+ deficiency appears more along the leaf edge and is usually accompanied by an upwards curling of the leaf. It is a deficiency, but it looks across the board (everything from nitrogen to magnesium) and is probably just the plant cannibalizing itself for flower production. This is extremely common in organics and really shouldn't be a concern for most growers. If the issue is gradual then I would expect it to be a natural process. If the issue is sudden and getting worse fast then I'd think it was more of an issue with the root zone. Perhaps a pest like root aphids or fungus gnat larva, or maybe a simple element imbalance. If there are no bugs present then a good rinsing (3 gallons in, 2 gallons out kind of thing) should remove any buildup. After the rinse you can top her off with a good balance of bloom nutrients for those organics to chew through so your plant can get what she needs out of the soil via the root system.
  7. The defining trait of Potassium deficiency is yellowing (& ultimately necrosis) along the leaf margins, as SCMC stated, but it causes downward curling. Phosphorus def. causes upward curling. Here's a good pic of K def:

    Attached Files:

  8. You may need to start upping the doseage.
  9. Not entirely accurate as phosphorus deficiency will cause downward curling as well. The curl of the leaf is often situational.

    The reason leaves will curl upwards is to assist in the rate of transpiration. The leaves sweat to keep themselves cool. If the room is too warm, or too humid, the leaves will curl upwards in an attempt to cool themselves better. The process that pulls water up through the root system and to the leaves for evaporation brings in other elements. Namely Calcium. This interferes with the Potassium cycle.

    So it's not that leaves curling one way or another will necessarily indicate the issue. If the temperatures are on the higher end then due to the purpose of Potassium in the plant the two symptoms are commonly presented together despite being a priori.

    Not that I was citing his lack of curl as evidence against potassium deficiency but it just didn't seem as likely given the other physical appearances of the plant. Though, I have been wrong before...
  10. Appreciate the feedback. Within 24 hours of feeding the plants their normal nutes with an addition of the boost in P and K the feeder leaves had spotted up brown turned yellow and were curling up... A very light tug and the leaves fell off the plant.

    I ended up flushing with 4 gallons of water and followed that up with a straight bloom feeding and a foliar feeding of Meta-K and HyPhos.. Will post back as to the state of the Cosmic Nights. It's probably 3 weeks out so will hopefully keep it going long enough to not lose the entire plant.

    Also am thinking my hard water is the root cause of my issues. I have a Hanna tds/ppm/ph meter and the ppm and tds are waaaay high for water straight from the tap.

    Have a RO unit en route hopefully that will filter some shit out... And before anyone says anything I know I probably need a softener too. ;)

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