Brown spots, purple stems, ahh

Discussion in 'Growing Marijuana Indoors' started by Summergirl1185, Aug 20, 2019.

  1. Hey guys,
    I'm 4 weeks and a couple days into flowering
    5 gal bucket fox farms ocean forest soil
    600 w led
    4 inch inline exhaust
    73 -76deg
    49-55% humidity
    6.3 ph of soil
    Have only fed pure unprocessed coconut water until a week ago
    Began to see purple stems up top only
    Had brown spots starting on upper leaves
    All spots appeared and became withered and crumbling in a day
    I thought it could be bugs when I first saw tiny spots so I sprayed the leaves with neem one time.
    Then started happy frog fertilizer and dusted surface before a good water
    A few days later added 1ml of calimagic to one liter ro.
    Starting to see new bud grow and pistils seem to be fattening back up. Also little swollen spots where stems meet.
    I assume after everything it was calcium deficiency.
    Shes still purple on top stems 20190816_114224.jpg 20190819_230018.jpg
    I'm hoping shes on the up and up now.
    Any thoughts, advice, or suggestions? Thanks in advance
  2. Looks like the same problem I am having figured it out ?
  3. I'm pretty sure mine is calcium deficiency
  4. Just mixing some up my self try it
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  5. P deficient.

    Red and purple are big indicators but should not be used solely to determine it. Red and purple are becoming more prevalent as more red/purple genetics are bred into different lines. / purple can also be triggered by cold ambient or cold soil, where it partially slows P uptake.

    But. You have dark green older leaves, with rust spots. I can see quite a few of your older leaves down low are affected.
    And your most affected leaves have a half green, half yellow look with rust spots, and the transition color has a blueish hue. Pretty much typical of a P issue.

    And P can just....wham....overnight your plant goes from a deep green to a duller green/yellow. That's when you have started approaching critical P shortage.

    And you are right around the 3-4 week zone when vertical/lateral growth pretty has much stopped completely, and flower formation is in high gear. This is when P demand increases drastically.

    Make sure your ambient doesn't get below 16°C. Make sure your soil is warm, and not getting a cold shock somehow. That should eliminate that as a cause, but seeing you are right at the right time for P to start really being in demand, I would say your mix is just short on it.

    If you really want to be precise, do a slurry test on your soil, runoff tests are iffy. Soil pH below 6 or above 7 can slow P uptake as it's less available to the plant.

    I am seeing the exact same symptoms, and I know for a fact it's a P shortage, because I got super stoned mixing my soil, couldn't remember if I put bone meal in my mix, decided to add about 1/4 cup per cubic foot of soil, to make sure I didn't O.D. it on P. Later looking at notes and thinking back....I realized that now I only had about 1/6th or 1/8th the amount of bone meal I should have....and I get all the same issues. Red streaking, rusty spotted lower leaves.

    I have my P issue under control right now as I am supplementing with Dutch Treat Bloom 0-10-10. I have managed to keep it from creeping up the plant and getting to that dull yellow death phase.
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  6. Dude great post. This happened to me (not as bad) last run and I had no idea what it was! This is really helpful.

    If I start seeing this issue, is it going to be on the bottom old growth first or the new top growth? Is there a pure form of P you can feed to correct it or would you have to use some sort of bloom booster?

  7. #7 PhenoMorph, Aug 21, 2019
    Last edited: Aug 21, 2019
    I find the streaking happens on higher stalks as a warning.

    You can see it on mine at the noding.
    You can also see two sort of warning stages of P shortage in the same picture. The plant on the left, up against the green pole, is a 'White Widow'. It has the streaking (all my plants do), but it also has deep dark green fan leaves. Then you see the two closest plants, those are 'Strong Stuff', and the one one kind of one back behind them, and to the right with a small gap between it and the wall, is also a White Widow (same height as the other White Widow) You can see it has advanced further with P shortage, and gone a dull green/yellow.

    As far as what to treat with, I tried adding mineralized phosphate, and bone meal to this mix before planting these ones, but I didn't add enough again, I guess. That's when I decided to just use Dutch Treat Bloom. I have since heavily amended my next batch of soil, and have started cloning moms to make new Mom plants (the soil my Moms are in is P short too).

    I have been jamming my plants with 0-10-10 @ 650 ppm continuously, for about 2 weeks now, and the dying leaves have stopped, and the dull yellowing has slowed. Newer growth on the stalks has stopped streaking as well. Not sure of any other better idea for P, sorry. I had to do what I had to do this round.
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  8. Sorry that's not the best pic to try and show it but you can see some plants are darker than others. My Strong Stuff are doing the same. About half of them are dark, half of them dull.
  9. Thank you for all your words of wisdom. This all started because I was feeding only coconut water and started molasses in flower. She was perfect until week 3 hit and went deficient. I gave her 1/2 cup of happy frog which is like 5-9-4 and I gave one tsp of calimagic. I dont want to over do it, but want to make sure shes fed! What should i do for next feeding? I do plan on putting some worm castings in there tomorrow
  10. Hey no problem. Yes, seeing you said only molasses and such I was like "oooooh!"

    It's tricky when you try to be a purist with organics. I try to stay away from bottled nutes myself, but once I realized my P amendment to this soil wasn't enough, I had no choice to buy a bottle. Dutch Treat is supposedly natural derived stuff just fermented and concentrated. Not too expensive either....24.99 CDN for a giant jug.

    Casting tea will help. Compost tea will help, but you need to get the P up a fair bit. High P bat guano into a tea would probably be good if you can find it.
  11. Here is two stages of P def: 20190820_185521.jpg

    Both plants are the Strong Stuff strain.

    The darker one was even darker, with deep, almost blue leaves, a week ago (early stage) The lighter green one was closer to yellow a week ago (later stage)

    The darker one is losing the blue/deep forest green and the lighter one is becoming more lime like. Hopefully there should be less of a difference in a week or two with the P dosages.
  12. This is my girl now 20190820_230048.jpg
  13. Yup. Very similar to mine. Looks more like my Moms that have been in P short soil for even longer.
    I mixed up about 180-200 gallons and I am trying to slowly raise the P levels as they stew. I re-use my soils so I amend the stuff that comes from just flowered pots, let it stew for a few weeks or a month plus, then it gets re-used later.
    Just taking a while to bring the P up to the N and K levels

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