Heat stress without the heat

Discussion in 'Growing Marijuana Indoors' started by AloeRuss, Nov 11, 2013.

  1. Hello all
    I have a situation.
    Have few dozen girls in 16x10 grow room.
    AC thermostat is set on 71. Have 2 thermometers in two different places of the room. They both display 74-75.
    I noticed that when the thermostat shows 72 (right before AC kicks) thermometers display 77-78.
    However, all those temps are well within the range for growing.
    Most of my girls display the following.
    The bottom foliage is nice and green.
    Leaves on the top is curling inwards on the edges. Also a lot of leaves surfaces becomes rugged, uneven and feels like it will be crispy pretty soon.
    I can't post the pick but I think I described it well.
    Any suggestions or advice on how to proceed from here?
    Thank you much!
     
  2. well if your temps are for sure in order, I would say your plants are either having some kind of problem with nutrients, or they might be getting stressed out. Either they are deficient in something (hence the new growth is being affected), or maybe when your AC kicks on, if it happens to be pointed at the tops of plants it might be stressing them with the cool air.
     
    hard to say for sure without pictures.
     
  3. Are either of your thermometers positioned in a way so that they read/reflect what the temperature is at the top of the plant canopy?

    If they are, then it sounds as if you've got some kind of micronutrient deficiency. As dish' has already pointed out, pictures would help immensely. Do you have pictures, and just can't figure out how to post them?
     
  4. How is your humidity? As waktoo asked, make sure you're getting an accurate temp reading. Make sure they aren't getting blasted by fans; wind burn can cause that sorta thing as well as moisture stress.
     
  5. Try giving full details of your grow...there's a form in a thread pinned to the front page of the sick plants subforum; copy and paste it and answer the questions.
     
  6. Not that you haven't considered this already, but although heat may not be an issue, I've had experience with light burn. What's your light setup like?
     
  7. Attaching picture.  
    Please ask me if you have any other questions..
     
     
     

    Attached Files:

  8. Again, you need to list the full details of your grow.
     
  9. It's in soil
    Sunshine mix #4
    Indoor
    Loui
    Plants are 35 days old
    1000w hidrolux bulb
    20 inches from the light
    Water them approx once every 2 days
    Temperature is 75-77
    Humidity is 60
    5 gallon pots
    Some spider mites
     
  10. #10 CoLoKiD, Nov 12, 2013
    Last edited by a moderator: Nov 12, 2013
    It's the spider mites!! I use AZA max as a preventative. 15ml per gallon once every two weeks. But if you are trying to get rid of them you will have to use more. You can use this up until last three weeks of flower. Or you can Mighty Wash until he last two weeks of flower which is foliar only. If you have mites use ASAP because they multiply FAST!!! And possibly over watering. I only have to water 1/2 gallon per plant every 3-4 days
     
  11. No mate. The leaves in the picture does not show mite problem. None of those leaves have mites on them either.
    I have to deal with mites in few of other gardens.
    This one is the cleanest.
    I used avid 15 days ago, floramite last week and I have 2000 ladybugs crawling around.
    Anyone else?
     
  12. Looks over watered and some light stress..that's a very powerful light bulb.. id raise it maybe another 10 inches or so...
     
  13. #13 CoLoKiD, Nov 12, 2013
    Last edited by a moderator: Nov 12, 2013
    Overwatering and mites! Even if you treated 12 days ago it doesn't bounce back that fast. Give it time.
     
  14. Thank u mates.
    Any of you professors want to chime in?
    This leave trying to tell me something very loud, I just haven't done this long enough to understand.
     
  15. Over watering. 5 gal pots shouldn't need water every other day. A pot that needs water should feel light when tipped up on it's side.
     
  16. But that's not what the leave is telling me, mate.
    It's rolling up like it's loosing water. Not droopy like it would be.
     
  17. Is the damage only directly below the lamp?
    Or uniform accross the top of the canopy?
    Are the lower leaves getting effected in the same way?
    Can you take a photo showing the whole plant and light but with the light off so we can see real colours?
     
  18. Moisture stress; one due to overwatering (the droop) and two possibly light stress (the canoeing).
     
  19. I will try to get the picture a bit later.
    The damage shown is mostly under the light and the bottom foliage looks very good. The way it should.

    I want to restate the wired lady bug behavior that will tell something to the more experienced.
    They all are hiding behind the duct. They moved from where the food, water, warmth and light is to hide in the dark. What from?
     
  20. I will try to get the picture a bit later.
    The damage shown is mostly under the light and the bottom foliage looks very good. The way it should.

    I want to restate the wired lady bug behavior that will tell something to the more experienced.
    They all are hiding behind the duct. They moved from where the food, water, warmth and light is to hide in the dark. What from?
     

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