The Twisted Leaf Necrosis Mystery

Kinch

Kinch

Well-Known Member
Greetings community. I hope everyone is doing well.

I have fairly healthy indoor plants still vegging at Week 15, but I have a leaf growth issue on the Blue Dream (shorter on the left in picture one). The main symptom is spotty necrosis and twisting fan leaves. (picture two).

Pink and Blue Week 12.JPG leaf delete.jpg
New growth is strong at the top after light feeding two weeks ago (ratio 24-8-16), but the malformed and crippled leaf growth predates the feeding.

The Pink Nepali (taller) next to the Blue Dream has shown no similar symptoms. They have both had the same diet, light schedule and watering schedule since late July when I obtained them as clones. I used the screen of green method to keep the plants short and grow multiple cola sites. They live in a grow tent with carbon-filtered air and ph'd water, though I have sunned them outside a bit when flushing them.The Blue Dream (afflicted plant) has shorter inter-nodal distances on the branches and is much more dense than the Pink Nepali.

My best guesses are

1. bad reaction to low water levels earlier in veg cycle
2. nutrient deficiency
3. disease (though I'd expect the Pink Nepali to also be infected)

Any thoughts?

Kinch
 
myke

myke

Well-Known Member
I assume your new to growing,spider mites are the cancer of cannabis.By the looks of it you have a big problem.Theres lots of info around here but since there not budding yet there garbage.Super clean everything and start again.If you have other house plants id be checking those.
Not what you wanted to here i know,sorry.
 
Kinch

Kinch

Well-Known Member
Ugh. Thanks for the diagnosis. I just found the telltale webbing.

Disappointing? Yes. I even used neem oil as a preventative this grow. Maybe it was too little too late or improperly emulsified.

I get the impression that spider mites are bad in CA. Never noticed the issue in my outdoor Illinois grows, but I only checked those plants twice a month.

Thanks again,
 
myke

myke

Well-Known Member
Kinch said:
Even clones from professional cannabis shops will import pests? I'm inclined to believe my garage grow space has too much outside exposure.
Click to expand...
Ya there everywhere outside. All it takes is one stuck on your shoe.
 
kovidkough

kovidkough

Well-Known Member
Kinch said:
Even clones from professional cannabis shops will import pests? I'm inclined to believe my garage grow space has too much outside exposure.
Click to expand...
I suppose the place you aquire a clone does matter but they are still human thus open to error, all it takes is an uninformed employee
 
GeneBanker

GeneBanker

Well-Known Member
I have a pair of shoes and clothes just for entering my grow for just this reason. I’ve had thrips once and it was enough for me.
 
F

F80M4

Well-Known Member
Here's what you do. No need to reset or anything. Go buy Horticultural oil and ONLY horticultural oil. Buy a 1 gal sprayer. You gonna fill that baby up with lukewarm water and put in 120ml of the horticultural oil and mix that. Next thing you do spray the walls and floors. Tip the plant over to its side leave it on the ground like that and you are gonna Spratly the living shit out of it. Make sure you hit the stem too. Do to all your plants. After that stand them back up and spray the tops. The oil dries up quick and the leaves will look Shiney. Come back later roughly an hr or so and pluck off all the dead leaves, leaves with bite marks etc. Once you finish quickly spray the plant again the wall the floor everything. Don't spray your light obviously. Shut it off and clean it and put it back. Now you are done. You sprayed twice in 1 day. Repeat again everyday for 1 week.
 
Kinch

Kinch

Well-Known Member
F80M4 said:
Here's what you do. No need to reset or anything. Go buy Horticultural oil and ONLY horticultural oil. Buy a 1 gal sprayer. You gonna fill that baby up with lukewarm water and put in 120ml of the horticultural oil and mix that. Next thing you do spray the walls and floors. Tip the plant over to its side leave it on the ground like that and you are gonna Spratly the living shit out of it. Make sure you hit the stem too. Do to all your plants. After that stand them back up and spray the tops. The oil dries up quick and the leaves will look Shiney. Come back later roughly an hr or so and pluck off all the dead leaves, leaves with bite marks etc. Once you finish quickly spray the plant again the wall the floor everything. Don't spray your light obviously. Shut it off and clean it and put it back. Now you are done. You sprayed twice in 1 day. Repeat again everyday for 1 week.
Click to expand...
Follow up on the spider mite advice from @F80M4 :

I took the advice and, instead of doing a reset, I tried to salvage the plants. I've had some success with the techniques F8 outlined. I treated the grow as a lost cause and learning experience, assuming the Blue Dream and Pink Napoli were dead. I wanted to experiment with mite control methods.

Here is what I did over the last month to combat the infestation:

1. First, a hard spray down with hose outside. There was some branch damage, but damaged leaves were blasted off.
2. Hand/trimmer defoliation of severely damaged leaves
3. Intensive, daily Neem oil spray for 3 days at 1-2 times per day (at lights off)
4. Intensive, daily Monterey horticultural oil spray daily (for a week) followed by hort spray every two then three days as infestation dissipated
5. light defoliation of residual damage leaves every couple days after initial stripping of infested leaves
6. weekly hand vacuum at top of plants (from a safe distance) to draw out any spider mites trying to travel by wind
7. Horticultural oil spray of entire grow tent interior and surrounding grow area once a week over three weeks
7. Switched to 12-12 light on Dec 2, 2020 (in the middle of this treatment)

The horticulture-oil therapy seems to have destroyed the mite population. Under the scope, there is no sign of live mites anymore. Eventually, there was no sign of mite eggs in my sampling.

Pic 1: stripped lower leaves on Blue Dream
Pic 2: new flowering growth after recovery on Blue Dream
Pic 3: the Pink Nepali and Blue Dream in recovery

At week 3 of the treatment, the new leaf growth showed no sign of mite damage and early budding is smallish but green with healthy pistil formation. You can see in the pics that I left a couple of the damaged leaves on at the top but stripped away most of the leaves from the lower half.

Thanks for the advice, F8. Fun experiment. I might even get some buds from the effort. Perhaps mites are not a death sentence? @myke

Ego
 

Attachments

Corso312

Corso312

Well-Known Member
Kinch said:
Ugh. Thanks for the diagnosis. I just found the telltale webbing.

Disappointing? Yes. I even used neem oil as a preventative this grow. Maybe it was too little too late or improperly emulsified.

I get the impression that spider mites are bad in CA. Never noticed the issue in my outdoor Illinois grows, but I only checked those plants twice a month.

Thanks again,
Click to expand...

Very easy to deal with.. Fill up a garbage can of large container with very sudsy dawn dish soap.. Very foamy... Dip that plant upside down and submerge for 20 minutes... Then pull it out and spray off everything... Then do it again 3 days later.
 
F

F80M4

Well-Known Member
Kinch said:
Follow up on the spider mite advice from @F80M4 :

I took the advice and, instead of doing a reset, I tried to salvage the plants. I've had some success with the techniques F8 outlined. I treated the grow as a lost cause and learning experience, assuming the Blue Dream and Pink Napoli were dead. I wanted to experiment with mite control methods.

Here is what I did over the last month to combat the infestation:

1. First, a hard spray down with hose outside. There was some branch damage, but damaged leaves were blasted off.
2. Hand/trimmer defoliation of severely damaged leaves
3. Intensive, daily Neem oil spray for 3 days at 1-2 times per day (at lights off)
4. Intensive, daily Monterey horticultural oil spray daily (for a week) followed by hort spray every two then three days as infestation dissipated
5. light defoliation of residual damage leaves every couple days after initial stripping of infested leaves
6. weekly hand vacuum at top of plants (from a safe distance) to draw out any spider mites trying to travel by wind
7. Horticultural oil spray of entire grow tent interior and surrounding grow area once a week over three weeks
7. Switched to 12-12 light on Dec 2, 2020 (in the middle of this treatment)

The horticulture-oil therapy seems to have destroyed the mite population. Under the scope, there is no sign of live mites anymore. Eventually, there was no sign of mite eggs in my sampling.

Pic 1: stripped lower leaves on Blue Dream
Pic 2: new flowering growth after recovery on Blue Dream
Pic 3: the Pink Nepali and Blue Dream in recovery

At week 3 of the treatment, the new leaf growth showed no sign of mite damage and early budding is smallish but green with healthy pistil formation. You can see in the pics that I left a couple of the damaged leaves on at the top but stripped away most of the leaves from the lower half.

Thanks for the advice, F8. Fun experiment. I might even get some buds from the effort. Perhaps mites are not a death sentence? @myke

Ego
Click to expand...
Glad everything is working! Horticultural oil all the way non stop is the way! Not a fan of neem oil tbh. For some reason the horticultural oil sticks on the pot, stem and stuff and if there is any lone survivor they die. 10/10 everyone that I recommended using HO the way I tell them. No more spider mites. Too many people have techniques to "control" but my technique kills them for good.
 
myke

myke

Well-Known Member
Being able to take them outside and having an empty tent to disinfect is a big plus,Going forward whats the plan?Can you still spray?Glad you were able to get ontop of this.
 
Kinch

Kinch

Well-Known Member
myke said:
Being able to take them outside and having an empty tent to disinfect is a big plus,Going forward whats the plan?Can you still spray?Glad you were able to get ontop of this.
Click to expand...
Yeah, the removable design of the grow tent was key. That initial blasting may have knocked off most of the active mites while the Neem oil dousing immediately afterward suffocated the embedded larva and nymphs.

Thanks to @F80M4 I've become an evangelist for Horticultural Oil. It was the dreaded two-spotted spider mite that Robert Bergman says are especially resilient to insecticides. I've read that using a combination of oils/soaps is best. If one brew doesn't kill the entire colony, the other will and therefore prevent re-population. Not enough data to confirm that with this little experiment. The combo was effective but Hort Oil alone might do the trick.

@myke asks what's next for the recovering plants, and I'm not sure. There have been no signs of live mites under the microscope, no eggs or feeding damage on the newly flowering branches, but I'm still cautious. Anything I put in the tent now gets a coating of Hort oil, of course. The plants will get a hand vacuuming once a week to suck off any hidden mites. I may treat the plants with Hort Oil again, but it is now week 4 of flowering, so I don't want to coat the buds that I will eventually smoke. If I do spray again, I'll focus on the fabric pots, soil surface and defoliated stems below the budding canopy.

I'll certainly let everyone know if there is a re-infestation. Thanks for all the wisdom. Wish I could buy all of you a beer.
 
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