Quote Originally Posted by Lars.Kurth View Post
I think the weather at the moment does not help: too warm and I would not be surprised if many bacteria make it from outside into the greenhouse. With temperatures between 8-15C the heating does not kick in often enough which helps create conditions that make it easy for bacteria to multiply.

I did find that "Bayer Rose & Ornamental Spray Garden Insecticide Fungicide" has helped stop the spread a little, but some orchids really don't like this stuff. Dendrobiums drop leaves, so do some Aerangis a day after application. So this can't really be used in a preventative matter. I am hoping that Python 27 helps (I am going to the US next week and will bring a bottle back).

This is partly my fault: I started getting some leaf spots in October and didn't take them that seriously. I just thought my fungicide regime would deal with it. Many of the plants which got leaf spot, then developed soft rot (probably creating an opportunity to infect). As a result the disease got a few weeks headstart.

My problem is that I can't change my conditions much. My greenhouse is too full and it is almost impossible to ensure that water droplets don't make it to other plants. At least I know now what to look for next year.
Ditto Lars! have also been using bayer fungicide systemic. Very difficult to intervene when its to complicated stopping water splashing/ dripping from plant to plant. My grow room (inhouse) is consistently 16oc - 18oc minimum 24 - 28 oc day max with most mounted/ hanging/ suspended.

I too think that I did not take the infection mystery that hit my stanhopea collection autumn time and its metamorphasized or dominoed from there but cant be too sure. Certainly cross infection or poor quarantine at a time when it was pratically party time for bad pathogens. On the Stans leaves I had yellow/ brown spots develop on foliage and pretty much isolated and then rapidly radiated outwards killing leaves. After a short period soft rot escalated and my grow room is well aerated so its my spraying that was the key. Bulbs rotted and stunk grotesquely and so on and so on with leaves stems etc etc.

The victims started to syphon off with less death rate but still after half my prided tropical/ exotic/ epiphytes was killed. Noticed another ( brassia) in last 24 - 48 hrs.

My problem lyes now with the phytotoxicity effects of using excess chemicals. At this point I can live with the losses but strongly debate any further future investments as the obstacles increase in severity from a dry/ reasonably warm enviro attracting spidermite to a moist cooler situ resulting in this. Abit of a shame for a great hobby that has been a great experience but seems a lose lose/ catch 22 situation. The fungicides and all the other *!?^%cides will hopefully stabilize current situation but will now have to watch as my heliconias, nepenthes, epiphyllums and remaining orchids' leaves dry up, crisp and die!

Its a complicated one for sure and sorry for moaning on your thread. lol