Pediocactus Knowltonii not looking too great.

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Stuart
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Pediocactus Knowltonii not looking too great.

Post by Stuart » Sat Feb 13, 2021 9:08 pm

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Has anyone any thoughts on this Pediocacatus Knowltonii ? It's been gradually looking worse during the past few months, first going from a nice green to a grey-green colour and then producing all this yucky brown growth. I would have grafted it ages ago and I take off a few offsets to graft each year. The ones I've grafted this summer still look fine in a different grenhouse but this one looks unhappy to say the least. It's quite solid, no sign of any rot. It can't be cold, although I keep the greenhouse at about 4C, in habitat it lives under snow in the winter and they are fine in an unheated greenhouse. Does that only leave a virus as the only answer?

Stuart
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fero
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Re: Pediocactus Knowltonii not looking too great.

Post by fero » Sun Feb 14, 2021 12:13 am

It reminds me of the orange rust type markings on ortegocactus . even the epidermis is a similar blue green .
with that one they recommend the brightest spot to try control it. this is a link to "life's "ortegocactus page they are suggesting it helps it to blend in with the surrounding lichens . at least you have some good replacments.
https://www.google.com/url?sa=t&source= ... 3259518793
I would put it on a top shelf and see what happens.
also give a very close inspection ,which I'm sure you have already , just in case of wee red beasies. which it most likely isn't.
NickHitchcock
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Re: Pediocactus Knowltonii not looking too great.

Post by NickHitchcock » Sun Feb 14, 2021 8:54 am

I have what looks like exactly the same orange growth on 2 young Matucana, they are next to 3 others, I sprayed twice with rose clear and it seems to have stopped the orange stuff from getting worse and it has not spread to the ones next to them.
Northampton and MK member

Very much on a steep learning curve, just love the huge variety and how different succulents can be from one another.
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iann
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Re: Pediocactus Knowltonii not looking too great.

Post by iann » Sun Feb 14, 2021 9:03 pm

Could you bear to take a head off and dissect it? Would be good to know now if you have a systemic infection or just some skin damage. If I spotted damage like this, I'd normally suspect cold damage first, then mites, but cold damage is unlikely and it doesn't look like mites.
Cheshire, UK
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Ali Baba
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Re: Pediocactus Knowltonii not looking too great.

Post by Ali Baba » Mon Feb 15, 2021 10:40 am

The other thing you might consider is a nutrient deficiency, do you feed it with a fertiliser that contains micronutrients?
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