Sudden Yellow/Browning Of Leaves

[Sirus]

SOIL:

How long has this problem been going on?
4-5 days that I have noticed
What STRAIN are you growing?
DNA Genetics LA Woman Feminized
What was the establishing technique? (seed or clone?)
seed
What is the age of your plants?
7w 3d above soil
How long have they been in the soil mixture they are in now?
4-5 weeks
How Tall are the plants?
18" possibly
What PHASE (seedling, vegetative or flower) are the plants in?
12/12 day 18
What Technique are you using? (SOG, SCROG etc)
na
What size pots are you using? (Include how many subjects to pot)
2.5L
What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?)
4 part FFOF, 2 part FFLW, 3 part EC, 3 part Perlite, and 2 tblsp dolomite lime per gal. 1 part = 1 gal
What Nutrient's are you using?
FF with 1 tblsp mollasses every other watering
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful*
FF. Full str Big Bloom, 1/2 str Beastie Bloom, 1/2 str CaMg, 1 tbl Mollasses
How often are you feeding?
every other feeding, once a week
If flowering, when did you switch over to using Bloom nutrients?
Currently on day 18 of flower, started using Open Sesame 1 week prior to 12/12 switch.
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)
Big Bloom, Beastie Bloom, CaMG, molasses
What is the TDS/EC/PPM of your nutrients used?
350
What is the pH of the "RUN-OFF"?
will check next watering, pH adjusted to 6.5 for last feeding
What method of pH test was administered? Using Strips? pH pen?
pen
How often are you watering?
every 3 days
When was your last feeding and how often are you feeding?
last feeding was 5/22, every other watering
What size bulb are you using?
AgroSun gold MH 400W and Hortilux Super HPS 400W
What is the distance to the canopy?
25"
What is your RH Factor? (Relative Humidity)
35-45%
What is the canopy temperature?
mid to upper 70's, been a couple days recently where the max temp is 85, this is for a couple hours when the lights kick on and its still nice and hellishly hot outside.
What is the Day/Night Temp? (Include fluctuation range)
upper 70's day/ upper 60's night. I noticed the curling after a heater malfunction and she spent the night around 54F
What is the current Air Flow? (cfm etc.)
170cfm Vortex w/filter, a/c blowing directly into port at bottom of tent (unknown cfm)
Tell us about your ventilation, intake exhaust and when its running and not running ?
controlled by C.A.P. controller, runs 75% of the time as its hot as all hell, I ducted an air conditioner to help with the temps.
Is the fan blowing directly at plants?
the a/c when on does make the leaves move, but its not sitting directly in front of the vent.
Is the grow substrate constantly wet or moist?
no
Is your water HARD or SOFT?
distilled
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?
distilled
Are you using water from a water softener?
na
Has plant been recently pruned, cloned or pinched?
not for weeks
Have any pest chemicals been used? If so what and when?
no
Are plant's infected with pest's?
no

LA Woman- She has been my whippin post for sure, everything I have thrown at her she has appeared to take in stride. At least until now... I noticed N toxicity starting to kick in about a 1 1/2 weeks ago or so. Since that time she has recieved no additional N. Three days ago (prior to feeding) I noticed major yellowing/browninsh burnt appearance on the oldest/biggest fan leaves. One so bad I pruned it as it was defitinly done for. Temps have been in the mid 80's for short periods of time over the past few days but nothing extreme. Past 3 waterings have been the standard watering (1tbl Mollasses, 1/2 str CaMg) x2 and one feeding (1tbl Mollasses, 1/2 str CaMg, full str Big Bloom, 1/2 str Beastie Bloom). I was reading in the infirmary that when experiencing N toxicity in dry conditions leaves can take on a yellowing burnt appearnce. Prior to last watering they only went 2 days before my usual "hand" test and I made them go another day. It was the next day when watering when I noticed the major change in leaf appearnce. 3 old fan leaves affected so far, one was pruned, another got some cut off. These pics were taken the following day. Any input would be greatly appericated!

 

[pushlimits]

Hey bro. If I am reading this correctly, your plants are 7 weeks old from the time the seed opened. If this is the case, your plants are root bound. The container is only 2.5L. Almost 2 month old plants should have much more soil then that. They need transplanted.

 

[Sirus]

I don't remember the exact date I transplanted but they were about 3 weeks old, so they have been in these pots for about 4 weeks. I can mix up a batch quick if they need to be transplanted.

 

[Sirus]

An update, not good unfortunatly... So the problem continues with my LA Woman. The yellowing is starting to spread. With N deficency is it common for the tips to turn brown and brittle like they are? Temps have been in the upper 70's low 80's. The is proper ventilation, probably a little too much. I notice there is no neg pressure with the a/c blasting in the tent.

A new development I noticed with her as well... A good size brown spot on a otherwise green leaf, one other leaf has a pin head size spot on it.

Since I am only 3 weeks into 12/12 I fear she is headed for disaster. They will probably be due for watering Sunday, they were watered with straight distilled Wednesday.

Any ideas out there?

 

[Sirus]

yea so pics would be nice..

 

[High Country]

Might not be a nutrient issue. Check for early signs of spider mites.

 

[Sirus]

Thanks for the quick response HC. I will read up on spider mites so I know what I'm looking for.

 

[pushlimits]

That's Fungus Bro. Get some sulfur spray quick!!! Look it up I had to battle that nasty shit a few times. This is the time of year it really comes out.

 

[High Country]

I had a recent run in with spider mites that led me to dispose of 24 mums. I initially thought there might have been a nutrient issue but the yellowing of the leaves continued until I could see the webs of the mites.

By this time the plants were stuffed. I culled all the mums, bombed the grow room. Luckily I had 40 clones on the go and they are OK. A sulphur based spray will help eliminate mites, aka THE BORG.

 

[pushlimits]

Fungus; I'll put money on it (well you know what I mean). Either way sulfur spray will work for both mites and fungus. like High and I said. I have had that nasty shit before dude "black spot fungus"- look it up. Hope this helps

 

[Sirus]

Thanks for the input PL . It looks like I'm off to find some sulfer spray tommrow. Will it damage the flowers, I'm 21 days into 12/12?

So this looks readily avalible Safer® Garden Fungicide Can this be applied when the lights are on?

 

[Justin_Credible]

Thanks for the input PL . It looks like I'm off to find some sulfer spray tommrow. Will it damage the flowers, I'm 21 days into 12/12?

So this looks readily avalible Safer® Garden Fungicide Can this be applied when the lights are on?

Hey bro...just got your message...
The black is fungus, check the back of the yellow leaves. If you see no mites (white dots eggs, black dots live mites) on those lowers (which I do not think you have bro-seph) it is a cal-mag issue. Yellowing with rust color is cal-mag. Tear off those leaves because she will keep trying to repair them, thus putting valuable bud production elsewhere. I agree with these guys on the black mold and sulfur, and no I would not ever spray anything period with lights on, even water. Small dose of cal-mag added to nutes, or large dose (read back of bottle) added to water usually takes care of that yellowing rusty problem for me. Good vibes bro, u'll be fine.
BTW bro, u can get sulfur spray at any home depot or hardware store. Also can get it in crystal form and mix and spray yourself.

 

[Sirus]

Thanks for the input JC Looks like I'm off to the store in the am.. gonna have to pull this operation off under a green led flashlight, this should be interesting..

Give the big guy my best and blaze one for me!

 

[Justin_Credible]

Thanks for the input JC Looks like I'm off to the store in the am.. gonna have to pull this operation off under a green led flashlight, this should be interesting..

Give the big guy my best and blaze one for me!

Yeah, I've been there...taping green plastic over my headlamp so I can go in during the day and do my treatments. Have fun with it...she will be fine.

 

[Sirus]

Got some fungicide spray, gonna be putting it on in a couple of hours 2pm'ish. Lights are scheduled to turn on at 7p, is this gonna be enough time? Should I just let the two T5's turn on and then hit the HID's later?

 

[rubbanutz420]

The black in fungus...for sure...The yellowing leaves at the bottom of the plant, in my opinion is not a big deal aslong as its not moving up the plant.....After 2 weeks in flower I usually remove all the lower leaves and branches anyways....shit that doesn't get alot of light gets removed....Get that fungus under control with a sulfur spray or burn sulfur and you should be good to go...good luck

 

[Sirus]

Thanks Rubba I sprayed LA today, hopefully within a couple days I will start to see some improvement. I only did the top of the leaves, and only the ones showing signs of the "black fungus" and neighboring ones. I will throughly inspect the other three tonight for signs of further contamination. I also plan to prune the yellowing leaves from all the ladies tonight.

Will the sulpher spray hurt the actually flowers? I don't want sulfer soaked pistils. Or does this stuff flush out?

 

[Work2much]

You're early enough that it won't hurt the finished buds. You could probably fit in one more light spray in 4-5 days just to be sure.

 

[grapeman]

pfft

 

[Sirus]

Checked on her once the lights came on... I am seeing crystal'ish looking residue from the spray, is this normal? I also think Chocolope caught some so I am going to spray her tommrow as well. Should I prune the leafs that have the fungal growth or leave them be? Lastly, should I be looking for a reversal in leaf apperance or just lack of spreading to determine effectivness? Thank you everyone for the help.