i think my plant is diseased or maybe a fungal infection on leaves?

Discussion in 'First Time Marijuana Growers' started by 6700, Sep 1, 2013.

  1. #1 6700, Sep 1, 2013
    Last edited by a moderator: Sep 1, 2013
    symptoms: brown spots on leaves that appear to be getting larger, top leaves getting yellow. BUT: bottom and lower leaves are green and fine!
     
    here is my grow journal though i DONT have current pics on there (link)
     
    i am really stumped by whats happening. at first i thought it was a yellowing due to light bleaching from the 5w LED diodes. but now i believe i have some kind of fungal infection, heres why.
    1) i raised the light to 30"+, and it kept getting worse. my PH is normal, using very irregular and low amounts of nutrients, and its way too early for leaves to be dying from late in flower
    2) ONLY the top leaves of my plant are affected
    3) it doesnt look like any pictures i have seem except this(link). the yellowing occurs on the INSIDE of the leaf then spreads outwards, i have seen the opposite on most/all pictures online.
    4) when i first started growing about a year ago i had a plant with the exact same brown spots/yellowing, nothing i did seemed to affect it and it only got worse
    5) my jalapeno plants in another part of the house have something similiar! i feed them tap water!
    6)i remember when i placed the first cannabis plant with these symptoms near others that were only babies, some of them got the brown spots!
     
    so what do you guys think? i am open to all possibilities, thanks

     
  2. Pottasium defficient is my guess
     
  3. sounds like calcium deficiency or lockout due to low ph or salt buildup..Ive had it a few times from low soil ph and it generally doesnt affect bud development as long as you get some cal in it now and slow it down
     
  4. I'll grab a picture from your journal for this topic, so people can see
     
    [​IMG]
     
    Yellowing leaves starting from the top of the plant, and spreading from the inside of the leaf outwards, ticks a lot of boxes for iron deficiency, although I've not experienced it myself.  Apparently it can be a problem if the soil pH is higher, or if there's a phosphorous buildup.  Magnesium deficiency is shown by the lower leaves turning yellow, usually from the tips inward, then turning brown and dying, this doesn't really look like that.
     
    Any idea of your soil pH?
     
  5. sorry i will get pics tommorow, i plucked some leaves to take pics but they are dried up and broken
     
    it is not a defficiency of any kind i do not believe, because wouldnt the lower leaves be affected first? the lower leaves are still decently green, so i think for now i can rule that out, deficiencies i have seen start with the lower leaves. maybe not though
     
    my PH of water is just a little bit too high(under 7 or about 7 i believe) but i have started lowering it over the past 2 days.
     
  6. no some deficiencies start at top or middle...looks like magnesium since that dr bloom your using needs a cal/mag supplement...you can use epsom salt or cal/mag to correct it..you can also foliar feed epsom salt not sure on ratio but you can google it..I use a basic all in one like flora nova bloom to foliar feed if mine start getting light green
     
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  7. ok nice i didnt know that part, thanks at least its not a disease
     
  8.  
    Do you really think it's Mg?  It seemed strange, so I've looked up everything I can find, and The Cannabis Grow Bible (Greg Green, 2nd ed), various nutrient charts like http://www.420magazine.com/gallery/data/829/Cannabis_Nutrient_And_Deficiency_Table.JPG, or a good page linked by one of the mods http://www.greenmanspage.com/guides/plant_abuse.html all say that magnesium deficiency usually starts with the older leaves and develops into necrosis.
     
    The pic I grabbed from the grow journal shows that it's the the new leaves that are effected.  All the same sources above (and others) say that iron deficiency (which isn't fatal) looks similar to Mg deficiency but shows on the new leaves, and can be cause by either too high pH (if it is above 6.5 then it can be evident), or if there is an excess of phosphorous.  Incidentally, Dr Earth Bloom is very high in phosphorous.
     
  9.  
    yea i was thinkin mag or iron but you're right it looks like iron..didnt know mag starts at bottom my bad...either way a foliar feed of a complete nutrient will green em up until you can figure out if its ph or excess phosphorus
     
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  10. #11 6700, Sep 2, 2013
    Last edited by a moderator: Sep 2, 2013
    this has made me realize there could be something wrong with my tap water, if for example there is a lot of extra iron from a decaying pipe or something, and that is what is causing this in 2 different species of plants, then it might not be good to drink, im going to test it ASAP. this fits with something i have been seeing, when hot water comes from the faucet it is always cloudy, like you couldnt even see through it sometimes. i use a water filter myself for drinking (just a brita faucet unit) but i will get a test kit soon. my parents house is pretty old, i think about 50 years
     
  11. #12 Kubrick, Sep 2, 2013
    Last edited by a moderator: Sep 2, 2013
    Looks like mag to me. Mag def does show in new growth as it is a mobile element. You have 2 possible reasons for this. Either you haven't supplemented mag at all (if your base nutes don't have micronutrients) or you have a problem with your pH. If it is the latter, you can throw all the mag you want at it and it will not help. It will actually lock out absorption of other nutrients like Ca and K.You can foliar feed with epsom salts like others have said if it is a pH issue. If not you can get some CalMag+, it has a tiny bit of N along with Ca, Mg, and Fe. Since some think it could be iron as well this could be your best bet, just make sure your pH is in normal range for your medium. EDIT: I'm going solely by that pic so if that isn't recent please post another one.Are the veins of the leaves yellowing?Journal- http://d.pr/NLS6
     

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