Orange marks on Loph

[GoOnThen]

I noticed a couple of orange marks on this Loph and I am concerned that it is the start of orange rot.

Cheers

Got

[George]

I have done some research and I'm starting to think it's a kind of blight or mold.

It's a discoloration of cactus alkaloids/tissue when it comes into contact with cerain microbes on the non sterile surface of the plant, the soil or the air. some larger patches on a plant even develop little white flecks/microscopic cocoons sitting on it that looks like it might be mold spore. I think it's simmilar to fruit molds like with pears or apples.

weather you cut a loph and leave it in the open or rot has damaged tissue from the inside out, this discoloration seems to be constant with non sterile exposed tissue.

I have some loph's with some of the same damage, some even in the exact same potting transplanted at the same time, one has it the other is spotless.

In my case heavy rains and wettness has encourage this disease to take hold but I do believe it's a mold or bacteria. I'm trying to use a fungicide atm to see if I can notroll infected plants.

So far it seems as though they have responded positively but It's a little early to tell. I'm testing colloidal silver and lime-sulphur. The infections seems to dry aout and flake or cork and discolor in bad cases. I'm hoping it's not just my mind playing tricks on me. Some infections flake leaving a hole but then there's healthy green skinned tissue underneath.

Edited April 23, 2011 by George

[M S Smith]

"Rust" can be a killer. Good luck!

DISEASES OF CACTI AND SUCCULENTS

Cactus Anthracnose (fungus - Colletotrichum (Gleosporium) spp.): This disease affects several kinds of cacti, Cereus, Echinocactus, Mammillaria, and particularly Opuntia (prickly pear). Infection results in a rather moist light brown rot which shows many light pink pustules on the surface. Spots are small at first, later enlarge and become covered by the small spore-producing pustules. Large areas may be affected, sometimes destroying entire plants. No satisfactory control is available, other than removing and destroying diseased cladodes as soon as noticed. In the greenhouse, soil from infected plants should be removed and benches disinfected. Spraying with a copper fungicide may help in checking the disease.

Charcoal Spot (fungus - Stevensea (Diplotheca) wrightii): Charcoal spot is a common and destructive disease of Opuntia in Texas. Small spots, usually one-fourth inches or more in diameter, appear first. The spots are surrounded by a ring of small raised dots that are the fruiting structures. Spots later enlarge, but remain separated. There is no control for infected plants. Remove and destroy diseased specimens.

Dry Rot (fungi - Phyllosticta concava and Mycosphaerella spp.): Small black circular spots develop first, which later increase in size until they reach a diameter of one or two inches. Further advance is checked by the development of callus tissue. Minute fruiting structures are seen in the infected tissue. The disease is in part physiological, influenced chiefly by soil moisture. Remove and destroy diseased specimens.

Scorch or Sunscald (fungus - Hendersonia opuntiae): This disease is common and serious on prickly pear cactus (Opuntia). Spots at first are distinctly zoned, later enlarging until entire cladodes turn a reddish-brown and finally die. The center of the disease area is grayish-brown and cracked. Other fungi may also be present in the diseased area. No practical control has been developed.

Cotton Root Rot (fungus - Phymatotrichum omnivorum): Several members of the cactus family are susceptible to attack by the cotton root rot fungus. Infected plants die. When pulled from the soil the brown strands of the fungus can be found growing on the root surface. No control practice is available. For additional information, see the section on Cotton Root Rot.

Soft Rot (bacterium - Erwinia carotovora): The bacterium enters tissue through natural openings and wounds. Under conditions of high humidity, the bacteria reproduce quickly, spreading to healthy parts of the plant. Diseased tissue is watery, soft, black and deteriorates rapidly. If environmental conditions turn dry, the development of the disease may be checked. The best control is to avoid wounds, treat broken surfaces right away with a copper fungicide and avoid having plants in places where humidity is high.

Nematodes (Meloidogyne spp.): Most of the cacti and succulents are susceptible to infection by root knot nematodes. Infected roots show small galls which are typical of the disease and serve to identify it when clean, washed roots are observed. Fumigate or sterilize soil before potting. for additional information, see the Root Knot section.

Other Diseases (fungi): Other fungi known to cause disease on cacti are Fusarium oxysporum (Fusarium rot), Macrophomina phaseolina (Charcoal rot), Septoria spp., Helminthosporium cactivorum, and Aspergillus alliaceus (Stem and branch rot).

Scab (physiological): Particularly common on prickly pear cactus. Rusty colored, corky areas appear on the stems. Scab is thought to be a form of edema, resulting from overwatering and poor ventilation. Increase light and decrease humidity for control.

Stem Rot of Cacti (fungus - Drechslera cactivorum): Basal or top rot of seedling cacti that turns cactus into a shrunken mummy covered with brown spores. First symptoms are yellow spots. It can completely rot a plant in four days. The fungicide Captan should give some control.

A couple other links:

http://www.cactusmuseum.com/diseases.asp

http://web1.msue.msu.edu/imp/modzz/00000237.html

[mutant]

In my experience there's little to do to avoid it, seasonally,it normally hold back the plant and scars it it can be a killer if wet yeah.

regrafting to slower stock is one option.

some other strains seem to be more hardy , I think caespitosas, which are commonly grafted are more prone to it..

just saying...

[GoOnThen]

Thanks for the replies

I have put it in my shed to keep it dry for the moment.

I am thinking of giving it a fungicide treatment but I am unsure which to try and would I use a diluted dose.

Cheers

Trevor

[George]

A small infection like that should be sorted by just giving it some direct sunlight for some time. It looks like skin infections and not something from the inside of the plant.

Molds cannot survive a certain amount of UV sun exposure so make use of that if the weather allows and if it won't in turn burn your loph.

You could use a small brush to limit the amount of fungicide you use and only apply it to the infection. Sulphur dusht, lime sulphur, store baught fungicide should all do.

I'm starting to think that Peyote keepers and cactus greenhouses are made for each other. Plus then you can add some ario's to that collection and less surprises.

[mutant]

^^ agreed

fungicide is not necessary. I have saved a lopho graft in much worse state by applying a combo of 2 fungicide though... I have saved the particular strain [my first one, came as small pups from a friend] and orange rot always appears some times over the growing period. Those I grafted on slow growing echinopsis are the only of the strain that don't catch orange rot....

[GoOnThen]

Thanks George and Mutant.

The graft has been getting about 6 hrs sun over the summer but it was only getting 2 to 3 hours direct sun recently.

I have now moved it to a shelted sunny spot and I will watch it for a few more days

I have on hand sulphur dust and copper based or mancozeb fungicide any thoughts on the best to use if things dont improve ?

Cheers

Got

[mutant]

I had used mankozeb plus another fungicide I dont remember and it was successful. It was the first time I used synthetic chemicals to protect any of my plants and I made it a bomb!

[trucha]

Use ConSan 20 if you don't live in CA. (Use PhySan 20 if a person lived in CA. ConSan 20 is not presently sold inside of the State of California due to state label requirements.) You are in Oz so it might have a different brandname?

Read and follow directions to protect your eyes and lungs. Both are quaternary benzalkonium chlorides so can be corrosive but nothing else works so well that does not leave toxic residues. Spray it, paint it on or soak cuttings in it. Repeat soon if it does not work completely.

I've had success using savlon (chlorhexidine) and also betadine when those were all that were around but ConSan is better.

[GoOnThen]

Thanks Trucha

I have had a bit of a search and it dosnt look like ConSan 20 or Physan 20 are avalible here.

Cheers

Got

[trucha]

There might be something else with the same active ingredients.

They are fairly common disinfectant agents. Good luck!

[George]

None here in ZA it seems. Maybe some weird FDA issues.

It might be limited to industrial use but no common off the shelf products.

Other names I have found:

Roccal D

Quat 20

There might be some koi fish sore treatments but I don't think it's going to be worth the price.

Edited April 27, 2011 by George