I brought the two trays with the Dact seed I had experimantally sowed onto cardboard in earlier this week and took some pictures yesterday and today. There is a marked difference between the two methods, with the seramis/perlite/sphagnum plus cardboard tray containing several large (3 - 5mm) plump protocorms with well developed shoots:
Whereas there were only a few small (0.5 - 1.5mm) protocroms in the cardboard only tray:
I have shown the distribution of (what I think are) the protocorms on the whole of the seramis/perlite/sphagnum plus cardboard tray below:
The protocorms on the cardboard only tray are too small to see at this scale but i think there are fewer than 10 compared to 40 plus on the other type of tray. On the other hand it is a lot less hassle, and certainly worth trying. I have started a second trial using a mixture of the bonsai products akadama and kanuma plus sphagnum dust plus cardboard soaked in 'cardboard juice', with four different species (Dactylorhiza spp. and D umbrosa, plus Himantoglossum hircinum (bit of a longshot!) and Anacamptis morio (which has germinated exceptionally well on B1) in seperate trays but all with the same treatment. They are currently chilling in the fridge, in a foil wrapped and clingfilm enclosed tray (see here, here, here and here). Whereas last time I used compost tea this time I only used 'cardboard tea'. I suspect that the compost contained a wide enough selection of fungi to provide one which would break down the cardboard whereas the cardboard tea would of course only contain whatever there is available in the air in my spare room! I should probably make another batch somepletely from scratch to test this, but I think I will just dilute the B1 innoculated agar from the next batch of seedlings I need to transplant (which should be soon!) and dribble that on the cardboard, to see if that does the trick... Not as scientific but the processing of the inorganic soil components is a bit of a long winded process.
This brings up the question of whether this is really worthwhile. If the only plants that can be successfully germinate in this method are those which can be successfully germinated and grown more quickly in vitro symbiotically, it is only worth doing if it is a lot quicker and easier (by virtue of being able to be done without sterile conditions). If the components require a lot of processing, this undermines its value. I wanted to try the bonsai ingredients to go back to the original method, but I have been surprised that the cardboard only method has been successfull at all and in the long run if more germinate I might opt to look at ways to make this method more successful.