Rustica disease ID on late harvest leaves

[Arden_Rock]

Hey FTT,

First post here, but I’ve been browsing the forum as a resource for the past year. Thank you all for the great discussions and information.

This is my second year growing Rustica in my backyard in coastal San Diego County (Zone 10A). This season I grew four varieties: Hopi, Limonka, Isleta Pueblo, and Brasilia 7. Because I’ve been traveling a lot and was also curious to see how much natural color-curing would occur before harvest, I came back to find that most of the leaves had fully browned and dried on the plants.

Here’s the issue: many of the leaves show small dark brown spots or translucent patches. In most cases there’s no soft texture or mold-like growth I can rub off. On one plant that received less sun, however, I definitely see black mold-like growth on the leaves. My question is: are these all stages of the same disease, or could the dark spots simply be damaged areas that later became susceptible to mold?

I’d love help with two things:

1. Identifying what disease or issue I’m dealing with.
2. Whether these leaves are still safe to consume. I am not concerned with appearance since I will likely be Perique-style pressure-fermenting them.

I’ve attached two photos of the obviously moldy leaves, along with others showing the different types of discoloration. The pics are all from the Hopi plants, but some of the Limonka and Isleta also had similar issues.

I'm hoping they're still useable, or I will be harvesting a big learning lesson this year.

Thank you

-B

 

[deluxestogie]

Welcome to the forum. Feel free to introduce yourself in the Introduce Yourself forum. You may wish to scan through the topics in our Index of Key Forum Threads, linked in the menu bar.

Tough question. The conspicuously moldy leaves (the final 2 images) look like Aspergillus niger. If it's just a few leaves like that, then I would be inclined to toss them. The other leaves show a much more widely dispersed pattern that differs from the ones with obvious mold. I don't think those are mold, though I could be wrong.

If your intention is to combust the final tobacco, then the good news is that aflatoxin, even if some is in the leaf, will mostly burn, or just waft away in the smoke. My advice for leaf that may contain aflatoxin is that it is safe for pipe tobacco or for cigar filler or binder, but risky for wrapper. Essentially, if you intend to have the tobacco in moist contact with your mucus membranes (mouth; nose), then the aflatoxin becomes a significant risk. So no smokeless use, and no cigar wrapper.

Bob

 

[Arden_Rock]

Thanks Bob! Good to know about the relative safety of aflatoxin when combusted. I’ll move forward with processing these and keep the batch for smoking. I’ll have enough healthy looking leaves for snuff making as well.

Open to any other opinions or observations on what the spots could be. I had a lot of hornworm and other hungry bugs this year and many of the leaves have had their excrement making contact, wonder if that could have contributed, but thinking about it further there were plenty of leaves that were not in contact.

Cheers

 

[StoneCarver]

I grew Hopi this last year too. Mine had spots like that. Well, idk. The spots on my plants were mostly white but they were the same size and spaced similarly. The spots were not evident prior to color curing. Some leaves I dried green to rule out mold during color curing and those too had spots. So, my guess is that its something that occurred whilst the plant was growing iow prior to priming leaves. I was wondering if its a disease or bug bites. My plants were heavily infested with some bug that looked like a cross between an aphid and stick bug. The infestations really picked up when the plants started budding and the bugs were mostly only on the buds. There were also a lot of little green stink bugs on my plants again mostly only on the buds. Smoking the leaves doesn't seem to have harmed me h-h-harmed me.

BTW: your leaves are much bigger than any of mine were. Well done. Also, the lower leaves on my plants often browned whilst the upper part of the plant continued to grow similarly to your experience. I cut leaves off as they browned. I'm guessing that the seeds brought a virus or mold spores with them that these plants are highly susceptible to, particularly considering we are on opposite ends of the continent. Your other plants that showed this spots may have picked it up from the Hopi. I'm wondering if using tissue culture techniques to sterilize the exteriors of the seeds will help break this cycle.

 

[deluxestogie]

Welcome to the forum, @StoneCarver. Feel free to introduce yourself in the Introduce Yourself forum. You may wish to scan through the topics in our Index of Key Forum Threads, linked in the menu bar.

the seeds brought a virus or mold spores with them

Tobacco seed pods and the chaff from incompletely cleaned tobacco seed may transmit pathogens. Properly cleaned Nicotiana tabacum seeds have never been documented to transmit pathogens. The seed of Nicotiana rustica is about twice the diameter, though, again, I am unaware of pathogen transmission via cleaned seed.

Bob

 

[StoneCarver]

When I received my order of tobacco from Whole Leaf Tobacco, there was a note that mentioned "sunspots" on the tobacco and that its harmless. I'm wondering if that's what we are looking at on this Hopi N. rustica.