Harvest/dry/cure - Battling powdery mildew

[SpicySativa]

Hey everyone.
I've got some plants that have 2, 3, and 4 weeks left of flowering (Space Queen, Jack the Ripper, then White Widow). I've been battling a very minor case of powdery mildew using a potassium bicarbonate spray (Bi-Carb Old fashioned fungicide). It's been working ok just with a weekly spray (other than the pistil damage). None has showed up on any of the buds or sugar leaves, just a couple shaded fan leaves here and there. I plan to do one last spray of bi-carb a couple days before harvest.

My question is, if there are no visible patches of mildew when I harvest, would it be safe to do a regular slow hang dry and cure? Or do I NEED to do a quick dry, or dry at very low humidity?

I have a dark area, lots of fans and a dehumidifier. How do you handle this kind of situation to make sure PM doesn't rear it's head during drying and curing?

Thanks for any help!!!

[oldmac]

Hello SpicySativa,

Powdery mildew needs humid conditions to grow, so I'd crank up the dehumidifier, get a little fan action going and dry it that way. The lower the humidity the faster the dry time, so maybe that becomes a fast dry.

Bi-Carb Old Fashion fungicide is safe to use on vegtables, so it is pretty safe to use but I'm not sure I'd want to be spraying my smokeables/vapeables so close to harvest.

Since PM is a fungi that is spred by spores it is usually easy to get rid of once and for all. You did not say if you are growing indoors or out....if indoors you need to clean every bit of your grow/flower area with a mild bleach solution. Then control your humidity levels in the future. If outdoors you need to figure out where the spores are coming from; dead or old mj plants around, or an mj plant you planted that was infected or feral hemp (ditch weed). Because PM is pretty much order/family specific your spores are from some form of cannabis.

Good luck with the problem, hope you either find the source or get cleaning for the future.
OM

[SpicySativa]

Thanks for the reply!

The plants are growing indoors in soil in a 2.5' x 3.5' x 6.5' cabinet that I built. It's got an air cooled 400 watt HPS with a 450 cfm Vortex and a carbon filter. Inside I've got 2 of those 6" Air King clip on fans blowing on the tops, plus a 10" desk fan and 3 computer fans moving air under the canopy.

As far as where the PM came from, they are clones from a dispensary.... So...

[MEDEDCANNABIS]

Thanks for the reply!

The plants are growing indoors in soil in a 2.5' x 3.5' x 6.5' cabinet that I built. It's got an air cooled 400 watt HPS with a 450 cfm Vortex and a carbon filter. Inside I've got 2 of those 6" Air King clip on fans blowing on the tops, plus a 10" desk fan and 3 computer fans moving air under the canopy.

As far as where the PM came from, they are clones from a dispensary.... So...

indeed, im convinced growing from seed is the best option anymore.

[oldmac]

Well that would explain it SpicySativa. :(

As MEDED says, there is growing from seed, but another option if you want to continue getting clones from a dispensery is to purchase a small sulfur burner. So as you get your clones and transplanted treat the heck out of them with sulfur. A few times, early in veg and you will be better off. Again keep your humidity lower if possible.

good luck and good growing
OM

[SpicySativa]

Yeah, it's a real trade off with these clones...

I have my humidity in check now (dehumidifier). Earlier in this grow I
thought I could wing it on the humidity cause I had so damn much air moving around. I was wrong.

[copobo]

one application of eagle 20 in veg will solve your PM problems forever. Anymore, the only time I need to do this is when I bring in a clone which doesn't happen much.

It's non-organic, but it's also non-mobile, so if you only use in veg you shouldn't be getting any chems in your smoke.

you can get a big jar on ebay for ~50-60 shipped and that will be enough for the rest of your life. It's something like a 1/4 tsp to 2 gallons if I remember correctly. So, buying a repackaged ounce or two is enough to break the cycle - by spraying everything in veg once now, then once the day before you flower...

[oldmac]

Hey there copobo,

Do you really grow MEDICAL mj and provide patients with meds grown with such stuff? :wtf:

Eagle 20EW is designed for use on ORNAMENTALS and TURF. You have no idea how much of the nasty stuff will be retained by a mj plant, as there is nothing available in the scientific literature to asure someone that the final product is safe to vape, smoke or ingest.

SpicySativa is allready using a product (see his OP) that he has found to work, is safe to use on vegatables that can be consumed. I suggest he just uses that, if it's just a few clones at a time, but even then early in veg. My concern is its use so close to harvest. Sulfur burner is better if you have a large room of clones or plants infected with PM, it gets in all the nooks and crannies where spores my linger.

I've been suppling mmj to patients for nearly 25 years, and it is mostly cancer patients or patients in hospice care. I would never, ever use such nasty, unsafe shit on what's suppose to be meds. Or for myself.

OM

[SpicySativa]

I just wish the bi-carb didn't damage the pistils so much... Even at half strength it turns them brown and shrivels a few. I've been pulling them out of the cab at lights on, spraying them down (in the shower) then blowing on them with a nice fan for half an hour or so o dry before they go back under the lights.

You think the pistil damage will have much affect
in the end? The calyxes are still nice and frosty, and seem healthy.

[SpicySativa]

Have any of you dealt with the burned pistils from potassium bicarbonate spray? They look pretty sad with all the prematurely brown pistils, but the buds are still swelling up. Hope they turn out OK...

[oldmac]

I just wish the bi-carb didn't damage the pistils so much... Even at half strength it turns them brown and shrivels a few. I've been pulling them out of the cab at lights on, spraying them down (in the shower) then blowing on them with a nice fan for half an hour or so o dry before they go back under the lights.

You think the pistil damage will have much affect
in the end? The calyxes are still nice and frosty, and seem healthy.

Hey Spicy,

It is just cosmetic damage. Since you are just growing these and not breeding your girls have no need for thier pistals since they use them just to collect pollen.

In fact if a plant in your flower room went hermie, those girls with the burnt pistals can't get "pregnent".

Alls good.
OM

[SpicySativa]

Funny you mention that about the pollination... I think one of my ladies is batting for both teams. I don't know which one it is, but I see a few seeds forming here and there. Lame.

[polishpollack]

Oldmac, there was a lady that handled alot of medicine, along with consuming some and she died. It was thought that she was exposed to too much Avid. This was a few years ago. Shit's for real, plant treatment can make you sick.

[oldmac]

Funny you mention that about the pollination... I think one of my ladies is batting for both teams. I don't know which one it is, but I see a few seeds forming here and there. Lame.

But I'm willing to bet you won't find seeds where the pistals are burnt! ;)

Hey polishpollack,

All too true. Someone who is relatively healthy, but just got a cancer diagnosis and starts chemo or radiation has thier immune system compremized by the treatments. Something they could shrug off before now becomes life threatening.
OM

[Rusty Trichome]

one application of eagle 20 in veg will solve your PM problems forever. Anymore, the only time I need to do this is when I bring in a clone which doesn't happen much.
oldmac already covered the medical issue associated with additives and cures, but here's the label for the stuff. (read the precautionary statements section)
http://www.cdms.net/ldat/ld6DG005.pdf

With proper grow room controls, you should never be in a position of having to use a product that put's your health, or someone elses health in jeopardy.

Bad shit, likely best to keep it out of your grow rooms.