Black spots/streaks on tricho's

[EthnoGuy85]

What are these? My trich's get em all the time and are more prominent in the evening hours. Hardly visible during the heat of the day. Not rot or fungus and it doesn't seem to harm my cacti......

[bogfrog]

Possibly hail damage?

[AndyAmine.]

Ive been getting that lately for the first time, I was thinking it was from either too much water, some kind of fungal issue or from use of weed killer around the plants,

[bogfrog]

I've been seeing it in my collection also.

It seems to just be there all of a sudden, at first I thought it was a just a bit of dirt building up which would be causing the discolouration but it doesn't wipe off at all.

[AndyAmine.]

Yes, it seems to get worse where now I have like, black smut building up on the lower parts of badly affected limbs?

I just lopped the tops off a few of my fave specimens because of this hoping to save them from damage,

They didn't seem to be discoloured or soft inside either...

Dafuq? Chemtrails?

Edited August 23, 2013 by AndyAmine.

[Evil Genius]

Looks like a combination of being kept too wet in a too cold enviroment (wet feet) and maybe lack of nutrients. As indicated, the spots might be fungal as well but to me, this rather is a symptom than the actual problem. My cacti tend to get something like that very early in spring or very late in the season when its cold and wet. bye Eg

[gtarman]

I think it's just what happens in cold/wet...but I could be wrong. But I've seen it in a couple of my cacti too...all of us at the same time of year and the same hemisphere (Eg excepted EDIT: and OP..maybe I'm wrong), I reckon it would have to be.

Edited August 23, 2013 by gtarman

[AndyAmine.]

Yes, its been the coldest here in years.

[bogfrog]

Yes, it seems to get worse where now I have like, black smut building up on the lower parts of badly affected limbs?

Dafuq? Chemtrails?

..yep

Do you think its spreading from plant to plant or only affecting certain specimens?

I noticed it on almost all of my ex-partner's cacti, I assumed it was hail damage.

Seems to only be affecting a couple of mine, but I think I will quarantine them for a while just in case its contagious.

[EthnoGuy85]

Not hail or any other mechanical damage.

It's summer here and it's warm so I don't think it's cool weather either. Humidity is 50%+ almost year round and we've been getting rain but they dry out between showers.

I was thinking it may be from low soil ph. Which is then increasing the uptake of micronutrients. Because when the streaks start they come from the bottom up and you can almost watch them move up the plant.

I think I see an experiment coming up soon......

[Evil Genius]

Like mentioned before this is definately related to the lack of nutrients as well. A healthy plant with the correct soil type doesnt get these spots if they arent caused by a virus. And these very likely arent. The soil needs to be very mineralistic and has to have good drainage. If it doesnt, nutrients become unavailable to the roots. What kind of soil do you use? A cactus can get wet feet in summer too if the soil takes too long to dry out, you know.

[AndyAmine.]

Ill take photos of some of the more affected limbs tomorrow, see what you all think.

The cacti it has affected were definitely under fed until recently due to some neglect on my behalf and have had wet feet because they had rooted into the ground and its been wet and cold.

Its very unsightly and I have my fingers crossed that it doesnt progress to the weeping stage, that would suck.
Hopefuly it just heals up into some light marking but Ive given them some vitamin tonic, some manure and a drink of maxicrop, then follow up with some lime/sulfur in a few days to give them a head start.

I think a systemic may be the go though.

Also, maybe a silica sup?

[EthnoGuy85]

I use a small amount of coir, topsoil, composted cow manure and garden soil.

Then there's lots of perlite, pumice, crushed limestone, crushed lava rock and coarse builders sand.

I get a lot of rain so it has to drain and dry out fast. A good soaking dries up in two days as the clay pots wick the moisture any excess moisture.

Lime, bone meal, alfalfa meal, greensand, kelp meal and lots of organic slow release ferts are added in as we'll in very small amounts.

An article I read about tricho growing had a small bit about the streaking and a theory as to it's appearance.

"Pots tend to go a little acid when plants are wintering dormant. You can take advantage of this acid condition in the early spring with a “post dormancy” treatment for the first spring watering: 1 rounded teaspoon S.T.E.M. (Soluble Trace Element Mix, available from nursery supply companies) and 2-1/2 level tablespoons Epsom salt in 5 gallons of water. Soak pots with this solution; let them sit in the cool early spring weather, good sun, for 7-10 days. STEM and Epsom salt creates a temporary low pH condition (below 6.8) where trace elements will absorb rapidly. You will see thin dark blue (almost black sometimes) streaks moving up the creases in the stalk as the trace elements hits the chloroplasts. Cacti are typically heavy trace element feeders. "

[Optimystic]

yeah I foliar feed with kelp...im sure through the roots is a good way to feed them trace mins

and I do add a little kelp to the water maybe once per month, but I try an foliar feed them about 2 or 3 times a month
I've also mixed in a few handful of worm castings into most of the pots... planning to do that as well in open beds soon..

not sure if its visual placebo but foliar feeding seems to make the skin look really vibrant.. of course I do this like at 3 am

when the stoma are wide open, with a very diluted dose, just enough to cloud the water..

careful tho with kelp, some of the stuff on the market is very saline, I use a dry soluble freshwater type

I think I killed a brug with MaxiCrap.. I could be wrong but it had a saline look to it, but who knows

edit*

interestingly i've only seen that effect on Pachanois or very "Greenish" plants... I went to look and its only showing on one plant

and its on the older growth.. I have a cutting from the same plant next to it which doesn't appear to have it but I didn't look extremely close eh... its also where alot of sun has hit and the color has faded .. I have another Pach I could swear had that but now looks really healthy... Maybe more visible on the greenish less waxy colored columns? I dunno... but I really can't remember when on the other plant and now im not sure if I remember which plant lol... came and disappeared in a blink I guess

heres a pic.. I know this plant was grown in full open sun before arriving here and from a very old plant..

the new growth doesn't show any but its etoliated... it also shows a little of that pattern on the other side but not as much

and I wonder if the skin has been weakened a little by alot of sun, although its now in filtered all day sun

Edited August 23, 2013 by Spine Collector