back / zurück
Abgeschickt von Scott Durkee am 06 Mai, 2002 um 21:48:52
Antwort auf: Re: C. acaule culture von Robert St-Jean am 01 Mai, 2002 um 22:09:51:
I don't have magical answers on this but I can summarize what I have experienced growing roughly 1500 of these from seed so far and flowering about 200 to date.
C.acaule has evolved in a niche environment dominated by extremely acidic soils (ph 4.0 or so) and in the process has developed less defenses against the organic activity that occurs in more neutral soils. As a result, as the ph rises the plant can be more easily attacked by the increasing activity of soil pathogens. The low ph seems to be the critical factor in that it controls the soil activity indirectly. I do not believe that it is the plants in-ability to take up soil nutrients at higher ph levels that kills the plant, because I've grown very robust seedlings in sterile culture at ph values of 5.8 to 6.0.
In addition, I've monitored several flats of C.acaule seedlings in my greenhouse and have found a high correlation to general health of the plants and the ph of the media in the flat. As the ph rises, so does the incidence of seedlings that suffer from stem rot and other adverse effects.
Other factors include a need to keep the mix highly aeriated and a little on the dry side. Wet, compacted mixes cause crown rot on this species very quickly. And like most Cyps, the plants like cool roots and dappled shade.
More details can be found from my published article in the AOS journal from September 2000 at the following link:
back / zurück