Rot

[Mike]

I have had 3 cacti recently develop a rot problem - Eriosyce senilis, the hylocereus base of a moonglow gymnocalycium and a part of a Copiapoa humilis cluster. They are all recently acquired, say last 3 weeks, from different places, but I also repotted 2 of them (both had surprisingly small roots given the size of the plants), and fear I may have inadvertantly spread a fungus via a potting utensil.

I have cut out the rot, and used a rooting fungicide powder which seems to have stopped more rot, although the senilis will need a miracle to recover since it lost about 1/3 of its size, and all roots.

Is there any general preventative for this kind of thing, say some type of chemical or fertilizer to add to water for the cacti? I would hate to find this spreading, and I have repotted quite a few cacti. Any other advice is assuredly welcome.

Thanks Mike

[templegatejohn]

Hi Mike,

Rot is usually caused by poor cultivation (you cannot be blamed for this if you have only recently acquired the plants).

If you say that the plants have a poor root system, this would suggest that they have either been overwatered or the compost was poorly drained and became stagnated.

The rot is normally a type of fungus that enter the epidermis and quickly spreads until you either have what amounts to a hollow plant or a ball of mush.

You have done all the right things and will just have to hope for the best, particularly at this time of year when the growth of the plants is slowing down.

I don't know what you have over there in the way of chemical controls, but in England we have a product which is used to stop seedlings 'damping off,' in other words rotting. This is watered on to the compost before the seeds are sown and is then added to the water used when the seedlings are starting to grow. it is a powder that is mixed with the water and has a brand name which will probably be totally different over there. this is the sort of thing to be looking for. Green sulphur is also a good thing to have in the 'medicine chest' to put on wounds of areas that have been cut out because of rot.

Hope this is of some help. I am sure some of the guys/gals over there will be able to put you on to the right product.

John

[Mike]

Thanks John,

What is in the product you mention? For both some cacti cuttings and to stop the fungus when i cut it out, I have used something called Rootone, a rooting hormone with fungicide. It says to dip the cutting into the powder. Its active ingredients are napthaleneacetamide and thiram - no clue about them except it also says it is violation of federal law to use them in a manner inconsistant with its labelling.

mike

[daiv]

I have had similar experience with various cacti. It seems the best thing to fix the problem was to take the plant out of the soil and let it heal over just like a new cutting and then re-plant like a new cutting.

[templegatejohn]

Hi Mike,

The product is called Cheshunt Compound and comes in a small tin. The main ingredient is about 80% Ammonium carbonate, with about 15% Copper sulphate. It is the primary product over here to combat fungus and daming off.

Cheers,
John

[Blakes]

I have bought some stuff called 'Chinosol', this stops plants from damping off. It comes in little light green tablets that you dissolve in water. I used it when planting seeds. By the look of the labelling I think it has come from Germany. I live in the UK. Hope this helps!