Aggressive mold from quarter pounder auto seeds

Plant Care Diseases
#1

I was stocking up on seeds a couple months ago, and for some reason I bought two quarter pounder auto seeds. I don’t usually just buy two seeds, so I don’t know if they were on special or why I bought just 2… They came in a test tube instead of the usual bag.

I marked up a sprout pad, planning to germinate 6 different plants. It looked like the quarter pounder seed was germinating 6 hours later, but when I looked closer, I realized it was a white slime mold coming out of the seed, so I tossed all of the seeds, the media, everything. The next sprouting I isolated the seeds, and no molds appeared, but I also didn’t germinate the second qp seed. Saving qp for last, I germinated it without incident.

One plant, gummi bear auto, turned a burgundy color. I thought it was just putting on a display, but it was also very stunted, despite the impressive other-worldly coloration and thick buds.

Gummi Bear was showing a color change on the trichomes, so I progressed her to harvest, and much to my dismay I found a mycelial mass in the heart of the plant. Other people had posted photos of larger green plants, I had a small purple plant, so I thought I had mishandled the plant when it was young. But it was stress from the heavy fungal load.

I did not see any signs of flowering of the fungi, but not all of them are visible, and it’s been 40 years since my last biology class. So I assume the entire grow room is compromised. No other signs of infection, so once the current harvest is complete, the entire building gets shut down and sterilized. The infected plant is being steralized to make it safe, and this is a rdwc system, so if anything is in the water it is everywhere… already ordered new buckets, and what parts are not new will be soaked in bleach. I live in the desert, so getting the room to 140ºf is possible, but I will want to chemically sterialize the flooring as it has a slab interfacing with the ground, so it would take fire to get the floor hot enough, and we aren’t doing /that/.

I always knew that sooner or later I would have to decontaminate the room, but I was expecting spider mites, not mold. This was a white fungal mass that originated in a “quarter pounder auto” seed. I had 2 qp seeds, and the first one took about 12 hours to go from wet to sending out a slime mold to eat all of the seeds being germinated. I got rid of everything, and started fresh, with no slime mold the second time. However the second qp seed was touching the first when I bought them, so it was probably infected, and I just couldn’t see anything.

I did not expect to get a mold infection like this, not in the 12% humidity of the desert. I work hard to get the grow humidity above 30-40%, so high humidity is not the main contributing factor in this infection. I had a clearly aggressive slime mold, and I underestimated what I needed to do to eradicate it. I probably should have torched the second qp seed, because if one was infected both had to be infected, they were in the same test tube when shipped to me. The QP plant does not appear infected now, nor anyone else, so they are probably resistant. Quarter pounder auto was supplied by someone that ships in test tubes, the only seeds I’ve seen shipped like that, so nothing else I have came from that breeder. So I’m reluctant to throw away my whole seed inventory.

Does anyone have any experiences with bud rot? How persistent is it? Were you able to grow an uninfected crop soon after?

#2

To my knowledge bud rot does not spread like wildfire like powdery mildew would. If you are running DWC or RDWC you are probably creating more humidity than people growing in soil would be creating thus a nice welcome home for bud rot depending on your temps. Bud rot got me twice because I live in the south and have big temp swings night and day. I added more air circulation and this helped me a bunch, I haven’t had a problem since. Though I also don’t ever close my tents…I leave the door open to allow air to flow in and out better. Still it is probably a climate problem or not enough air movement especially with all that water evaporating and creating extra moisture in the air. This is of course assuming you are growing in a tent. Hope this helps…Good Luck and Happy Growing!!

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#3

double post…

#4

Solid grow advice on humidity management, HansGruber. You’re spot-on about DWC systems cranking up RH levels. One tip from running commercial grows: VPD (Vapor Pressure Deficit) is crucial in hydro setups. Even with open tents, you’ll want dehumidifiers rated for your space plus oscillating fans at canopy level. We run 40-50% RH during flower with temps at 75-80°F to prevent botrytis. Those temp swings in the South are brutal - environmental control is everything in hydro.

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#5

Thanks for the detailed VPD insights, sneer9678. You’re dialed in on those hydro humidity specs. Running 40-50% RH during flower is textbook for preventing bud rot, especially in DWC where that water surface adds serious moisture. Those commercial-grade dehu specs are crucial - I’ve seen too many grows try to cheap out with hardware store units and pay the price. Smart move on the oscillating fans too - that air movement is non-negotiable for preventing microclimates.

#6

Yeah, I thought I got lucky, as I could only detect the infection in one plant, one that was clearly stunted, despite looking a glorious dark purple. It looked special, and was total rot. But I suspected strongly it was from the quarter pounder seeds. They were packed together, and the first one erupted with a slime mold. I have grown slime mold on purpose before, so I know what it looks like and how it acts… So the second seen in the tube I should have burned up. Instead I planted it. It had no infection… Or so I thought. It was the final plant to be harvested. Out of 4 plants, one was infection free, one was a total loss, one was a 1% loss, and the main carrier went without detection until harvest was complete. So is spread unevenly, and I could not acfford to toss it all, so I finished processing, and I discarded everything that was infected. I will use freezing for storage to arrest mold development.

And before you freak out about the mold, there was 25 or 30 years when all buds were molded, 1970’s to mid 80’s mold was a dominant flavor on the street. So while I agree the mold tastes terrible, I did not grow this to throw it away and replace it with $5,000 worth of retail weed. I don’t smoke it anyway, so I can control my exposure.

I think my primary concern at this point is to clean the room. I have a plan for that. This is a 5% humidity desert location, and no sources of water, except in my work space. So cleanup should be complete with what I can reach with a sprayer. I will scrape the room clean, then saturate all surfaces with benzalkonium chloride in a .4% concentration.

Benzalkonium Chloride is a disinfectant used by hospitals for many applications. surgeon scrub is .4% bzk. Bactine is .13% bzk. Eye drops and many other topicals have bzk. Benzalkonium chloride is a more refined version of a common mixture of cheaper compounds used for floor cleaning and other uses on the detergent aisle of the grocery store. I would not drink the stuff, but it is essentially a soapy compound that wets biological materials in a way that most single cell organisms and viruses (like covid) are rendered inert. While it may not directly kill a mold spore, it will coat it in soap that will stop growth, and I am not fearful of any ingestion hazard. I’ve worked in a hospital where they wiped the walls down with the stuff, cleaned the floors with it, etc. It leaves behind that hospital smell.

So the plan is to move everything out, clean the room meticulously, then wet down every surface with some “surgeon scrub” concentration bzk. Then all of the parts get a dunking, before going back in. Charcoal will be disposed of, and filter canisters will be wetted down. The blowers get to be dunked, then sun dried in the summer desert sun for a week or two. The bzk is likely to make everything sticky, but that is how it must be to be safe. I have such low humidity, I expect things to dry out really fast.

There will be a number of items I wipe down rather than dunk or spray. Things like my vpd computer, and the water quality electronics, and other things like that will get a wipe down, but really shouldn’t be breading grounds anyway. I was scheduled for all new buckets anyway to improve the plumbing (2" camlock based tank interconnects in a 2 stream “flowing stream” arrangement. It’s the same as I had before, but with some mods. I 3d print some of the components I cannot find injection molded. But yeah, all new gear is staged and ready to go. I have until october to get it all done. It is the part of the year it is too expensive to do sufficient cooling, the off season. The $1600 a month electric season. So after it is cleaned, the room with bake for 6 weeks or more.

I’m reasonably confident the room is going to be ok. But my seed library may need to be burned and replaced. That is the real loss here, I have things I can’t get any longer.

I’ve been growing since the mid 1970’s, this is the first time I have seen a slime mold (or any mold) come from a seed. I have seen seeds with root hairs some people think is mold, but no plants have ever molded. I was in 85% humidity with 4000-8000gr/m3 mold counts every other week all year long, never had a mold issue on anything other than the lawn and rose bushes. Come to the desert and 4 or 5 grows in, I got slimed, ray. I guess it can happen to anyone when you least expect it.

I’m fairly confident that I can put this behind me… but this was very unexpected. In the desert! I should have burned everything and all seeds when I saw the first one, but I was in a hurry.