SikkimRex Posted March 6, 2006 Went down South for the weekend, and as we all know, it rained like a MOFO. When i returned, I have found that all my cactus have this black sliminess happening under the surface, just in 3 days! We had them under the verandah, but some sideways rain may have got them. I was thinking that they just got too wet, and was going to remove the pebble mulch and leave them in the sun to dry out, and hope for the best... Dunno what else to do... Also, last week I pyrthrummed for the scale, as per other posts I had read... but this happened just after.. a link? I dunno... can any of you experienced dudes recommend a strategy? Are they all gone - is it too far gone? A scared parent... Rex Share this post Link to post Share on other sites
AndyAmine. Posted March 6, 2006 Ouch, that looks nasty, I would use a fungacial spray ASAP and get it into the sun today.. thankfully we have a break in the rain. I would probably go wiht Copper Oxy or Mancozeb plus. Share this post Link to post Share on other sites
strangebrew Posted March 6, 2006 (edited) Definately sun. I'd put mancozeb on as well but am unsure if it actually does anything, nothing has ever gotten worse for me after applying it put it that way. Edited March 6, 2006 by strangebrew Share this post Link to post Share on other sites
AndyAmine. Posted March 6, 2006 Ive also found that regular supplements of a good quality Silica solution like dutch Master or that other one I cant rememeber right now. Seems to toughn up the skin and makes it less prone to infections that eat the skin. in fact I swear Ive seen the little silica crystals in the flesh of other plants Ive used it on so it really does work/. Share this post Link to post Share on other sites
Tripitaka Posted March 6, 2006 Also, last week I pyrthrummed for the scale, as per other posts I had read I always believed that pyrethrum applied to Cacti destroyed their cellular structure? Share this post Link to post Share on other sites
Salviador Posted March 6, 2006 Is it possible the bigger pebbles on top of the mix act as a barrier to letting the humidity out? My monstroses have been out in constant rain for the past 4 days and they look great! Share this post Link to post Share on other sites
SikkimRex Posted March 6, 2006 Also, last week I pyrthrummed for the scale, as per other posts I had readI always believed that pyrethrum applied to Cacti destroyed their cellular structure? Hmm. Thats a worry. Can anyone else confirm this? I am sure that others on the fourm have suggested Pyrthrum for scale on cactus.. Thanks for the reply about anti-fungal all - cant do any harm - so I will have a go. It just looks like DEATH to me... BUT I MUST SAVE MY BABIES! Can they survive these kind of ailments? Share this post Link to post Share on other sites
AndyAmine. Posted March 6, 2006 Damn it, this is the 2nd time Ive had to write this reply for some reason.. Anyhoo, Yes they should heal up into a scar after a month or so, no problems, as long as you can keep them nice and dry and increase the air flow. From my experinaces in a S.E.QLD high humidity environment, I dont use any kind of top dressing at all, it slows down evaporation and I belive it causes a couple of other problems but I am still confirming it., Pyrethrum is probabaly one of the better things to use in regards to potential damage but should still be washed off after a few minutes.. then keep repeating it every few days until the infestation is underhand. The big ones to avoid is white oil things with Alcohol or hydrocarbons in them, they will burn the shitter out of your cacti... Share this post Link to post Share on other sites
nate123 Posted March 6, 2006 Pyrithrium is one of the Safest insecticides to use, unfortunately it will burn Trich's. Most cacti handle it fine but trichocereus develop scar tissue where it has been applied UNLESS it is washed off a few minutes after application. Most san pedro at cactus nurseries around her are completely corked around the base because of greenhouse pyrithrium bombs. Won't burn them if it is washed off ten minutes after application. Share this post Link to post Share on other sites
SikkimRex Posted March 7, 2006 Thanks Guys! Its just so sad. But now andy if you reckon they may come good, I will stick with them. I was gonna cut them into lots of little cuttings. I wish I had known about the washing off the Pyrethrum part. Now I do. Its all good (breathe). I gotta tell ya- its 20 years since i did plant protection in my hort course, and all this stuff has just washed away. Just more evidence that I gotta get out of the office.. I wonder if they have refresher courses for horticulture? Tanks again! Rex Share this post Link to post Share on other sites
Rev Posted March 9, 2006 I'd put mancozeb on as well but am unsure if it actually does anything, nothing has ever gotten worse for me after applying it put it that way. yes it ceratinl inhibits black rot with and without the result speak for themself withy its stopped init tracks at early stages, without sometimes it stops but also sometimes it gets bigger and causes collapse. no biggy when yo have a dozen of each variety or more but if its your only one its a tragedy ive never seen pyrethrum burn trich cacti. i use it in the rare instncae of scale insect infestation. NO white oil Share this post Link to post Share on other sites
zee_werp Posted March 9, 2006 Is mancozrb a vrand name? If so, what is its active ingredient, for those of us outside Aus? Share this post Link to post Share on other sites
strangebrew Posted March 10, 2006 (edited) Mancozeb is the active ingredient. It makes me think that there must be more than just the one menace floating around affecting Trichocereus because mancozeb didn't seem to stop the spots I was getting on new grow this season. Bacteria maybe? Edited March 10, 2006 by strangebrew Share this post Link to post Share on other sites
Rev Posted March 19, 2006 (edited) stop or remove? i havent found mancozeb to clear up a cactus. its just inhibits the fungus long enough that the cactus walls it off and sheds it The only reason i treat now is if its a rare form, and cos if you keep on top of it the incidence drops and teh rate of new infection is less black death remains a problem only for really susceptible plants like T scop and its hybrids some years are bad some years are good and the next few years will tell me if the cumulative effects of teh the steps ive taken to reduce incidence are paying off. Ive never used a systemic fungicide on my cacti yet but i do have a big bottle of carbendazim, the metabolite and replacemnt for benomyl http://www.google.com/search?hl=en&lr=&q=c...im+&btnG=Search i got it to make selective agar - allows mushroom growth but inhibits mould. if my collection were smaller i might consider trying to treat with it. generally i dont like systemics tho. Edited March 19, 2006 by Rev Share this post Link to post Share on other sites
strangebrew Posted March 19, 2006 Stopping new spots from forming I should have said. It didn't seem to have any preventitive properties in this case. In the end I just left them alone, they kept coming but never got bigger, but I am in a dry environment. Share this post Link to post Share on other sites
Rev Posted March 19, 2006 i am in a wetter environment and they are still no concern here just spots not like black rot that starts like blistering paint Share this post Link to post Share on other sites
