Rapidly Yellowing leaves...

[waylon]

1. Are you growing from seed or clones?
clones
2. How old are your plants?
~3 months
3. How tall are your plants?
4'-6'
4. What size containers are they planted in?
7 gallon smartpots
5. What is your soil mix?
100% coco
6. How often do you water and what type of water do you use?
once every 3 days, RO water with h&g nutes
7. What is the pH of your water?
5.8
8. What kind of fertilizer do you use and what is its NPK ratio?
H&G coco A+B
9. Do you foliar feed or spray your plants with anything?
H&G magic green every 2 weeks, DM reverse every 10 days
10. What kind of lights do you use and how many watts combined? (HPS, MH, fluorescent, halogen, incandescent "plant lights")
20 x 1000W HPS
11. How close are your lights to the plants?
1'-3'
12. What size is your grow space in square feet?
625
13. What is the temperature and humidity in your grow space
Day: 78-81 F, 40%-50% RH
Night: 65-68 F, 55%-68%
14. What is the pH of the soil?
5.8
15. Have you noticed any insect activity in your grow space?
Yes, bugs fly in and out of the coco and fly around the plants
16. How much experience do you have growing?
this is my second grow

i have a plant that is yellowing very rapidly and getting worse daily. last week this plant didnt have a single leaf that wasnt green and lush. Then one leaf at the bottom started to yellow, then it turned completely yellow and a few surrounding leaves started turning. Now a lot of the leaves going up the plant are yellowing. My first thought was nitrogen deficiency, but im following the H&G coco feed chart and my last feeding was at 1.8 EC. Im on day 26 of flowering. Im also seeing some yellowing starting on the bottom leaves on other plants in the room.

Any ideas? Thanks everyone for helping.

 

[lilredwagon]

A few of us have had symptoms like those this year. Check out this thread, might help isolate the problem. Hope it helps!
http://http://www.thcfarmer.com/forums/f57/phantom-deficiencies-rapidly-yellowing-leaves-rust-spots-necrosis-root-aphids-26050/

 

[Seamaiden]

Get Spectracide (since you said yes to the bugs), use it at the recommended dosage rate as a root drench, leave the root-zone soaked in this for 1-2 days. You'll probably have to do this twice, but it *should* kill them. I can't remember the dosage rate, or I'd say here.

 

[mellokitty]

aphids fly? really? (i guess there *are lots of different kinds of them....) (i've only been plagued by grey, green and black crawlers and only on my roses and mock orange, both outside)

can you describe the bugs a little better? fungus gnat larvae will wreak havoc on your roots, and the adults are little black things a shade smaller than fruit flies (which are generally red or brown, at least where i live)

 

[hiboy]

I have 24 sfvog going. 1 and only 1 of my plants have yellow leaves, not entirely but it stands out, didnt see any bugs in medium, and all plants share same rez water. Sometimes that just happens, all others are SUPER healthy. Dont think bugs would just go to that one. Im kinda stumped on this too

 

[mellokitty]

it's true, a lot of times there's just a runt.
but the OP says he's seen bugs, and sometimes they will just *colonise* one weaker plant.

 

[-hydrofarmer-]

i spray with this stuff call advid and u spray once all bugs are gone then u spray again the next day or so just to make sure

 

[Seamaiden]

aphids fly? really? (i guess there *are lots of different kinds of them....) (i've only been plagued by grey, green and black crawlers and only on my roses and mock orange, both outside)

can you describe the bugs a little better? fungus gnat larvae will wreak havoc on your roots, and the adults are little black things a shade smaller than fruit flies (which are generally red or brown, at least where i live)

Apparently they do. I had to learn that the hard way (best way to learn some things, I s'pose). And if you think fungus gnats are bad, you ain't seen nothin'. Root aphids are the motherest-fuckerest little high-fivin' motherfuckers I have EVER dealt with.

I would not, however, try to use Avid on them. That stuff is seriously toxic and must be used with extreme caution, and *all* PPE (personal protective equipment).

it's true, a lot of times there's just a runt.
but the OP says he's seen bugs, and sometimes they will just *colonise* one weaker plant.

I have to say, based on my observations of this last run, that you're correct. Except that I ran tables full of plants, several of each strain, and so I was able to gauge how each strain was affected. Mother of Thor was affected practically not at all by the root aphid infestation. Rhymes with Orange has no such moxie. Orange and Bubba Kush, as well as Blockhead, fall somewhere in the middle with Orange Kush performing a little better. All plants were colonized, but some moreso than others and it did seem to run along strain lines, if you get what I'm saying.

 

[hiboy]

Avid is serious shitz. i use to use it if i had to. Not even legal here in cali, make sure you cover up your skin and put on some kind of breathing protection. that stuff can do major damage. molecular dna stuff so i've heard

 

[mellokitty]

yes, i've heard about these root aphids this year, never had the misfortune of running into them (*knocking wood*). ditto red mites, although i've seen them outside (but never on my outdoor ladies, either). seamaiden, do you mind if i ask you: are you in the states? it seems these are 2 bugs my stateside friends complain about. in 15+ years of farming in BC, the worst thing i've encountered were thrips (<--i HATE those fucking things, they are my *nemesis*)

i don't tend to keep more than 2 strains in the same space, but i have definitely noticed an immunity trend as well: when half of your room is plagued with PM and the other half is like: "what's *their problem?" (a:HashPlant b:Dr.A NLxBlue) it becomes pretty clear, eh? ;p
as for colonising, there's one incident that sticks out in my mind: at a 60lighter in the interior where i worked for a summer, i went in to do my morning check one day and found 1 plant friggin *alive* with wee green caterpillars. they were 3 plants/light so they were big - all 6'+ - and this one plant was fucking *moving* like it was a fucking *ent. of course i went and grabbed the site boss; she was a 60+ grandma who'd been farming since the 60's, never seen anything like it. all the intakes were filtered, there was not 1 but 2 anti-contamination ante-rooms, and we all had indoor/outdoor clothes/shoes. and still this *one* plant (which, btw, wasn't close to an intake or the door). needless to say, we took it as a sign, pulled it and chucked it far away. still baffles me to this day. (we never did try to figure out what they were; we sort of had our hands full at the time)

 

[mellokitty]

AVID - deserved a separate post. it's bad news. most systemic neurotoxins are. there's a reason it's illegal in a lot of places.

according to the IPCS:
In a second study of the delta-8,9 isomer in mice (study 8),
the NOAEL for maternal toxicity was 0.1 mg/kg bw per day and that
for embryotoxicity and teratogenicity was 0.05 mg/kg bw per day.
Increased incidences of cleft palate and exencephaly were observed
over those in concurrent controls at doses of 0.1 mg/kg bw per day
and higher. Most of the anomalies were found at 0.1 mg/kg bw per day
in one litter, but the range observed in historical controls was
often exceeded (Annex I, reference 67). It is remarkable, therefore,
that no dose-response relationship was seen with respect to these
malformations. Its absence renders interpretation of these results
difficult, and the conclusion that teratogenicity occurred in the
absence of maternotoxicity in this study seems to be questionable.

what this means in English, is: at 0.1mg/kg bodyweight (less than half of the toxicity level for 'normal' animals) the pregnant moms started showing signs of toxicity (tremors, comas, etc.). at 0.05mg/kg bw said moms started having birth defects like cleft palate, exencephaly (<--when your brain forms outside your head. nice eh?) the scientist goes on to criticise the findings in the manfacturer-funded study, the results of which were used to compose its MSDS. (<- a chemical manufacturer bent the rules so they could market another poison? no *way*! lol)

in said MSDS, it states that ecotoxicity starts at 3.6 ppb (<-yes, that's a b, not an m) for fish (trout) and 0.34ppb (<- again with the b) for invertebrates. so when you use it and then take the safety precautions, you're effectively poisoning your immediate environment as well.

just a thought. ;p

 

[mellokitty]

OMFG -
waylon, i'm sorry about this digression about Avid, but it just occurred to me that if it has teratogenic effects on women, maybe it does on men, too? --and BINGO!:

3 exposure groups, all showing reduced fertility, fetal viability, resulting full-term pregnancies, testicular weight, sperm count, even water intake and body weight. the conclusion being that yes, avid has teratogenic effects on men as well.



holy crap that's a long link.

 

[Seamaiden]

But it's worth putting up.

So, moths/caterpillars can really do a number, but so far they're not the worst for me. Right now I'm battling against the after-effects of the root aphids, which is really persistent PM. I live at an elevation that's not quite agriculturalized the way the Central Valley is (yes, I'm in the states, California, Sierra Nevada, western scarp, east of Sact'o). I don't see the pests that people in the valley, Bay and metro LA areas see precisely because of this, but I have run across this in plants I've received from others who are in those areas. I've dealt with black spot, a previous issue with girls that came in with PM, the Borg (that single Avid application did the trick, and being pre-menopausal I'm fortunately not terribly concerned about my own reproductiveness, I still took every precaution indicated on the label, I'm a label-reader), caterpillars, which are most easily dealt with using Bt spray as well as Spinosad. And I'd have to say that the persistent PM is proving by far the most problematic, of any pest or disease I've dealt with to date.

It's like Brooklynellosis for plants, except it's not a guaranteed death sentence, just makes 'em shitty.

 

[mellokitty]

*still knocking wood about these root aphid things* (hopefully it's just too cold up here.... please please please)
sounds like a nightmare. i've only ever battled aphids outside, although, having a small child who likes to smell things, my options are somewhat limited. "pink solution" works great for a nontoxic option. the plants actually seem to like it. (i can't say enough good stuff about pink without sounding like i work for them - pm me if you're curious, i just discovered it over xmas when my mom got me some)

have you tried the skim milk cure for the PM? it's my be-all-end-all for PM, like i said before i have an aversion to systemics. works great.

 

[jakew215]

i use avid. and will continue to use. avid. you can test almost everything and it will most likely do some kind of harm at some point. just be careful with it... if you dont know what your doing dont fucking use avid.

there are tons of shit most people use that are harmful to humans IE cause cancer or whatever.

as for PM i use green cure, it seems to work well for me. but it wont get rid of the PM completely, i have to re-apply, but its gone for a few weeks right after i spray...

i just started running into an encounter with root aphids in my clone trays. they are like attacking the roots going through the rockwool into the perlite. i just got gognats and SNS203 to try and combat it. well see how that works.

 

[waylon]

thanks for the replies everyone. im thanking everyone and answering all questions and providing an update in a single post.

the symptoms seem like the root aphid issue, even though i cant find any evidence of crawling or winged aphids. the only bugs ive seen are fungus gnats, and ive looked at a lot of them under a loupe and im pretty sure i have not misidentified them. i couldnt look in the root zone, just an inch or two below the surface of the coco. i did 2 applications of spectracide (thanks seamaiden) to kill the gnats and whatever i couldnt see.

its now 7 days later and the problem has manifested itself in around 60% of the plants and it is not isolated to a particular strain. its getting much worse and spreading. it seems like there is now a mildew or fungus growing on the leaves, which is a new symptom. the problem is more aggressive now and attacking green leaves in addition to the yellowing ones. the good news is that the fungus gnats have dwindled to almost nothing.

 

[Seamaiden]

I think I can state rather unequivocally--those are NOT fungus gnats. If they're still around, they're still a problem because I'm almost positive (as in almost willing to bet money on it) they're root aphids. You'll have to treat everyone again. Those leaves are what I saw for a long time before I realized what a problem I had.

In fact, looking back at my OD hempy tub grow I now realize that the little flying bugs that were in the tubs (outdoors, where wasps and yellowjackets and praying mantises and hornets and all KINDS of bugs I have up here could get to them) weren't Super Fungus Gnats, they were root aphids. The "mystery yellowing event" that practically defoliated and I couldn't get them recovered from was likely caused by root aphids.

It's important to understand that once your plants are affected to this degree, they can't fight off anything. And so my lasting battle, the war I still wage, is against powdery mildew.

You will need to go nuclear on these things.



And to think, I teased lil miss lone for having bugs in her eyes. <hangs head in shame>

 

[mellokitty]

that is some serious necrosis you got there. looks crunchy.
the buggery thing about soil treatments is that if your roots already have significant damage the treatment itself (depending what you're using, i'm not familiar with spectracide) might do more damage. this combined with whatever havoc the pests themselves are wreaking can be very bad news.

i wouldn't give up on them just yet, (and if i wasn't a medigrower i *might* consider using avid at this point.) (personally i still likely wouldn't but if i was going to think about it it'd probably be about now) but i wouldn't dismiss the possibility that i might not be able to kill off the problem without it killing the plants themselves.

^that's not meant to be discouraging by any means, i just know from experience sometimes it's good to know when 'executive decision time' is close at hand.

*still knocking wood*

 

[Seamaiden]

I would not use Avid here, not for flowering plants and not for this.

Spectracide (triazicide) and Bayer Tree & Shrub (imidacloprid @ 1.47%) or Merit 75 (75% imidacloprid) are the way to go with this, in my opinion. If you go with the Merit you must allow time for it to get reduced to non-critical levels in plant tissues, that window is about 60 days. If you go with the Bayer you can allow less time, but it's still in the 30-40 day range.

Flooding my tables with Spectracide and leaving for two days, at the recommended dosing rate for soil and root drenches, is what finally did the RAs in. The remaining powdery mildew may be what does me in.

Neither Spectracide nor Bayer T&S seemed to cause any disruption to my flowering plants. It's been the PM treatments that have burned the living shit out of them, mostly because they have nothing left to fight with.

 

[lil miss lone]

Yes, buddy sorry to say it looks like you have the aphids, I've never seen damage that bad from just fungus gnats, and we have had both. The filthy buggers spread viruses too, so if you see no signs of bugs then your plants might be infected. Sick plants are very susceptible to things like pm and mold, pathogens that sort of thing.

If you still see bugs after the Spectracide treatments I'd try that Sevin (if your not in flower). Its toxic to insects but not humans, and is used on food plants everywhere. In flower I did a once weekly soil drench with either Azatrol or Azamax. (careful not to spray buds or leaves just bottom stem and medium surface). Azatrol won't kill them but it does a good job keeping them under control when you can't use anything else.

Good luck my friend.

Also, I would use a good root repair product like Hygrozyme with every feed from now on.