Anthracnose Fungus

[Gee.S]

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[Azuleja]

These are from AZ too. What do you think? The first arrived badly spotted. The second was a replacement that looked fairly clean but quickly showed problems in all the little wounds that occur during shipping. I've had them many months now and removed numerous leaves, at times thinking they were finally clean. This post was a reminder that apparently I need a better fungicide. I've been trying to avoid stripping their leaves a second time. Persistent and frustrating.

[Gee.S]

Azul, I wonder if you might be best off just slicing off the affected lower leaves with a nice sharp knife. Have you treated the soil (don't mind me, I really don't know much about anthracnose fungus)?

[Azuleja]

I took off the worst leaves again this evening. Without unpotting, it's hard to get them trimmed completely. No, I haven't treated or changed the soil since I potted them. I resprayed with fungicide rated for anthracnose (tebuconazole) and will repeat weekly for 3 weeks, per label instructions. I wasn't taking it too seriously but realized I need to handle it while the weather's on my side.

[Stone Jaguar]

Azuleja:

Like Gee, I would recommend removing severely damaged leaves with a blade sterilized between plants. I favor Cleary's 3336 as my weapon of choice, sometimes combined with Daconil if I'm drenching. Without a good ag-chem arsenal, proper anthracnose can be very challenging to control in wet climates or during long rainy periods in seasonally dry climates. For potted plants with some non-specific, athracnose-looking spotting, I find that a thick past of mancozeb and water dabbed on with a small paintbrush - on both sides of the leaf if the lesion has gone through - will normally contain and dry up something that has not really caught fire.

Normal precautions for use of ag-chem always apply for fungicides as well.

[mcvansoest]

I'd barefoot the plants and inspect the roots as well as change the soil and get rid of the soil in those pots, the soil may not have been the source in the first place but by now it probably has acquired some spores from the infected leaves. If after treatment and changing of the soil the issue persists it might imply that your watering frequency is too high.

[DesertDweller]

I sometimes have something similar on plants shipped to me, am quite certain being in a box for a few days is conducive to fungal growth, so doesn't really surprise me. That said, I've never really had a problem so long as I kept them out in the fresh air and liberally applied Daconil. I take off any questionable leaves when they first arrive, but once potted, I try not to disturb them if I can help it. Any leaves that start to show symptoms after potting, I usually just liberally spray (read: daily) at first. For small stuff (say a single spot on a leaf), I use a soaked q-tip to apply the Daconil more precisely, but still spray in the general vicinity at least. Ultimately the impacted leaves succumb, some sooner, some much later, shriveling off and dying. At that point I still spray them until they're crispy critters and can be easily yanked away without un-potting. This has worked for me so far, but YMMV of course.

[Azuleja]

With the plants above I took off the worst leaves, removed and replaced the top layer of soil and sprayed with multiple applications of the fungicide I have. The spotting hasn't progressed, but if I boxed and shipped them who knows. I now believe if there is even slight infection present, being packed in a stuffy box can cause it to progress rapidly, especially in leaf wounds.

I recently lost a beautiful sansevieria that arrived rotting at the base. I cut off the affected area, dusted with sulphur and dried it a week before planting. It still progressed all the way to the core. It wasn't anthracnose, but slimy rot dissolving the plant tissue. Thankfully most plants arrive healthy.

[Spination]

Yes, been there and done that with a Sans too. It's a 50-50 prop you can cut off the obviously infected area, whether the disease has progressed inside the plant or not. All you can do is try to save it, and hope. It's definitely frustrating when all one's best efforts are for naught.