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[Greentoe]

The biggest seedling graft I have now has a brown spot on it. I sprayed it with ga3 on the 1st so that was 11 days ago now. Since then it grown a lot and just a day or two ago I noticed a slight brown spot on it. It has gotten larger since then. Does anyone know what might be causing this or how I can fix it? Any advice would be greatly appreciated.
Thanks

[New Wisdom]

If it's mushty then it's rot. The only thing you can do about that is cut off the rotted part and hope it keeps growing.  Is it still in high humidity?

[Greentoe]

No it's been out if high humidity for a few weeks now.

[New Wisdom]

Is it mushy?

[Greentoe]

Ya it is just a little bit. I suppose I should go ahead and cut it off.

What do you think's causing it to rot? I wouldn't think it'd be from over watering the pereskiopsis since I have other grafts that are growing on pereskiopsis that's directly in water.

[New Wisdom]

I would get a few more opinions first before chopping away at it. I can't say for sure without seeing it.  And it could be something that was in between the scion and stock when you grafted that didn't show up until now.

[Greentoe]

I would get a few more opinions first before chopping away at it.

Ya that sounds like a good plan. I'm really not looking forward to cuttings it up. It was doing so good.

[Greentoe]

So after looking at it some more. I came to the conclusion its definitely rot. I went ahead and cut it off, making sure I removed it all. It ended up being a pretty large chunk. I'm hoping it bounces back, but if it doesn't I have plenty more seedlings to graft in its place.

I still dont know what caused this. If anyone has any ideas please let me know so i can try to avoid this happening again in the future.

Thanks

[New Wisdom]

The only thing I can think of is non sterile blades/surrounding while grafting. Also it could have been the GA3 spray if you were doing that.  One time I sprayed a small ariocarpus seedling graft with GA3 and it got rot the day after.  I'm not sure why that would make it rot though.

[Sunshine]

Its was probably either a fungi/bacterial infection, too much water, or most likely all three. When you graft a cacti and give it a lot of water it bloats and the skin gets thinner making it easier for pathogens to infect it. Even if you used a sterile blade when you grafted it, spores and bacteria are everywhere and it is inevitable that some will make its way onto/into it.

If it were sunburn or damaged caused by too much light it would have been more even most likely. I think you did the right thing amputating it before it spread any further. I highly recommend that you treat the exposed areas with some sort of antibacterial powder to prevent future infections.

There are lots of natural things you can use that will help prevent future infections without harming the graft. A lot of herbal oils have antimicrobial properties and sulfur powder has antimould properties. If I were you I would make a paste and smear it on.

I don't think it was your fault that this happened to be honest. Sometimes its just sheer bad luck. You could try being more clean when you make grafts in the future and use some type of antibacterial. I'm just spit balling but maybe neosporin would work for this purpose. I'd have to check the ingredients, but it would be awesome if it did. Its cheap and readily available. Hell, we could probably use it in place of Vaseline to hold on grafts and hold in moisture.

1 Like chums of chance likes this.

[TBM]

The only thing I can think of is non sterile blades/surrounding while grafting. Also it could have been the GA3 spray if you were doing that.  One time I sprayed a small ariocarpus seedling graft with GA3 and it got rot the day after.  I'm not sure why that would make it rot though.

Could be coincidence? I'm not sure if GA3 could cause rot. Maybe some contamination in the water used to dilute the GA3?

[New Wisdom]

It didn't affect any of the other plants I sprayed it with. So I don't think it was the GA3. But maybe when the skin soaked it up it opened the pores up to pathogens possibly.  I'm not really sure how it works when they soak stuff up from their skin but maybe it's like opening a door for other stuff too.

By the way greentoe. If the rot doesn't keep spreading then it will pup out of an areole most likely and abort the current scion.  We'll see though I guess.

[Sunshine]

I doubt GA3 was the cause. Correlation does not equal causation. It probably already had a bacterial infection which just happened to appear after the treatment.

[Sunshine]

Are you saying you think the GA3 opened up the stomas New wisdom? I don't think that was the problem. Plant stomas are open anyways. Since it only happened a day later I doubt that it had anything to do with the GA3. In my experience GA3 takes at least a couple days to start working. The infection was most likely already there before you treated it. Had it happened a few days later and had you been giving it lots of water it would be possible that micro tears formed due to bloating and excessive growth and allowed the plant to be infected, but I doubt that due to the time frame.

[EDIT] I'm not quite sure how GA3 and other hormones are absorbed either. But I know it can only be absorbed 2 ways;
Either through the cell wall
Or through the stomas.

[New Wisdom]

I don't know. I was just hypothesizing.

1 Like happyconcacti likes this.