yellow leaves burnt tips

Discussion in 'Sick Plants and Problems' started by medmaryjane, Jan 6, 2010.

  1. I noticed one of my plants that are in the 4th week of flowering starting showing leaves that have yellow leaves and burnt tips. Here is the info on my grow:

    What type of medium; Promix/Perlite
    What brand and type of soil? Promix
    Indoors or outdoors? Indoors
    What strain? Not sure
    How old are the plants? 4 1/2 weeks into flowering
    What type of lights and how many watts? 400 watt HPS air cooled
    How far from the lights? 12 inches
    What is your watering frequency and source of water? about once every 8 days, city water that I let sit for 2 days in barrel before using
    What, how much and when was it fed? NPK? 1/2 strength Big Bloom, Tiger Bloom, bushmaster
    What is the medium/runoff pH and PPM if in hydro? 6.5, 500 ppm
    What are the temps and humidity in the room? temp 77 degrees, humidity 30%
    What size pots? 5 gallon
    Any bugs? Look real close. no
    Any other pertinent info? They are clones from my mother plants. They look really good and are developing huge buds, but I am worried about this leaf problem. Here is a pic:

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  2. im no expert but from research this is a normal nitrogen def that happens during Flowering my $0.02

    Just an idea
     
  3. Are they spots or the leaf turning yellow, if its more spotty bunch of little tiny spots, might be bugs. Could be phosphorus def? Do you know the NPK of your nutes?
     
  4. Man after I look at it more, Im starting to question it being a P def. Im not 100% :S Do you maybe have pics of the full plant too.
     
  5. There are no spots, but the stem is purple. And there is blackening on the edges. I have been feeding them quite freq, so It might be overnuting.
     
  6. Well if its not genitics of the plant, purpling stems are generally caused by temps below 55ºF or phosphorus def. or could even be from stress or LST or something there of. But like you say could be over fert. that would be a form of stress cause purple i would think as well.
     

  7. Here are some more pics of the plant. It is now 5 weeks into flowering.

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  8. Oh man no, lol Looks great! Too me it looks about normal. All the larger fan leaves will start to turn yellow as a N def. Don't try to correct this while they are flowering, plants dont require as much Nitrogen in flowering stage as they did in veg. But yeah nothing really looks out of the ordinary to me.

    The First pic of just the leaf looks like its something with nutes or bugs, but the later pics of the full plant the yellow leaves, to me, look like lack of nitrogen, the plant is sucking it out of the fan leaves, which is good.

    What is the temp and humidity?
     
  9. i literally have the same leaves on my plant that is also midway flowering. after seeing your post i believe what your seeing as well as myself is just the natural cycle of leaves dying off.

    I would keep a close eye on it though
     

  10. The temp at the plant level is 77 degrees, humidity around 30.
     
  11. alright yeah man looks good, if you wanted might be able to raise the humidity up a little, 50% i think you can have flowering. but yeah, I wouldn't be worried, things look good! well done.
     
  12. Thanks
     

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