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Abgeschickt von Camiel F. de Jong am 22 April, 2003 um 11:48:35
Antwort auf: Rate of success von François Pageau am 21 April, 2003 um 14:25:58:
I completely agree with Uta. Then again, I should, as we trade a lot together;). However, I have some things to add. For most seedlings the seramis-perlite-Vulca mix is adequate or any other inorganic mix provided that it has good water retention properties. It is important that soil conditions remain fairly constant. When seedlings (and also adult Cyps) experience large fluctuations in moisture content they are weakend and subsequently killed by molds. Therefore, the bigger the container they are grown in the better. I use containers of around 60 by 40 cm and 20 cm high. I drill in holes at 2-3 cm from the bottom and fill this layer with the 1 cm mesh beads used for hydro culture. On this layer I put the mix. This way always some water remains at the bottom and the mix remains moist. In winter frosts tend to uproot the seedlings so that they are exposed to the weather. If this happens they dry out and are killed. I lost a lot of seedlings this way.
In spring I water the plants from time to time with the following solution:
KH2PO4: 125 mg/L
MgSO4.7H20: 60 mg/L
KNO3: 125 mg/L
Ca(NO3)2: 250 mg/L
FeEDTA: 35 mg/L
I add spore solution from Nitsch medium. As I grow seedlings in vitro and I prepare all the media myself it is easy for me. I realise, however, that this is difficult to achieve for the regular grower. Diluted solutions of commercial fertilizers such as Wuchsal or MiracleGro may be used but to my knowledge they do not contain calcium or magnesium and this should then be added in other ways. These salts could be bought at a agro retail center and be added to the !dilute! commercial fertilizer.
I'm under the impression that the calcium renders the seedlings more resistant towards infection by strengthening the cell walls. The magnesium is added as this is vital for chlorophyl production.
Before applying a new feed the containers should be watered profusely to rinse out remaining unused feeding solution.
For fast growers, like reginae, 250 mg/L ammonium nitrate is added when the shoots start to emerge. When the shoot is full-grown it is left out. When Botrytis (Grey mould)is spotted on dead parts of the seedlings treatment with chlorothalonil will help to control damage. Damping off is another problem that is not easily controlled when it occurs. Damping off seems less frequent when plants are deflasked (rinse off all agar, goes best with sieve and shower) and stored for a while in the fridge in plastic bags with a few drops of water. It is best to store the bags with the seedlings in a polystyrene box in the fridge. The polystyrene box buffers temperature differences in the fridge preventing condensation on the bags. This condensation dries out the seedlings.
Exceptions to the deflasking procedure outlined above are arietinum and acaule. I grow both species succesfully in a mixture of (50/50) (v/v) sphagnum peat and coarse sand. Do not use sea sand. It contains salt and shells (lime).
Acaule should be watered with water to which 1 small spoon vinegar per liter water is added to keep the pH below 4.5. I use cidar vinegar as recommended by Scott Durkee from the Vermont Lady Slipper company. Seedlings should be protected from rain to prevent the vinegar from flushing out. In case watery laesions appear on the leaves, soil pH is too high and must be corrected at once. Having done so, the laesions will dry out and do not spread out further. Acaules should not be fertilized.
Arietinum can be watered with normal water but no fertilizer should be applied as I just found out. This weekend some seedlings I deflasked last year and of which one already had a small flower bud, developed stem rot at the base and toppled over 4 days after fertilization.
Starting material is very important. Buy seedlings that have multiple roots of at least 5 cm long, show no signs of browning, and have well-developed buds. Seedlings that have done bad in vitro will in most cases also do bad ex vitro.
One last thing: I estimate my average succesrate at around 70% survival first year out of flask. However, this may be as low as 0% in some cases like when seedlings become uprooted during frosts and as high as 100%. However, Cyps are relatively new in horticulture. I experience huge differences between seed batches from the same species both in in vitro amenability and compatibility to the conditions I grow the seedlings in. For example:
Seeds from yatabeanum from Kodiak Island were raised to seedlings. Upon deflasking the seedlings did not do very well and now I hardly have any left. Another batch of seed from far east Russia did not germinate very well but the resulting seedlings thrive ex-vitro. For the coming two decades it is up to us Cyp pioneers to select plant lines that do well under conditions we apply to them both in vitro and ex vitro. Achieving this will result in artificially propagated high quality plants that will thrive in our gardens. Up till then it will remain pioneering with ups and downs but then again, when it would have been easy we would probably not have bothered growing Cyps!
: I have started to grow cypripedium just out of flask about three years ago. I was used to grow paphiopedilum and phragmipedium out of flask when I started.I am not satisfied with the rate of success for the first years out of 20 seedlings only six survived for two years they are still surviving when planted outside .
: All of the reginae (20) were planted outside the second year. This was too much risk they all died.
: I have tried with different species and the survival rate has been below 30% .
: This year is supposed to be different because I have started 15 differents species in february.I am trying
: to see how the temperature influence the growth at the begining ( first two month ) those growing at 10- 12 C are doing better than those at 18-20 c what I was told but I needed to see if it was true.
: Californicum, flavum,kentuckiense seems to grow easyly under both conditions.
: I would appreciate if the experts ( those who have a lot of experience) would share a little about what would be a good rate of success for different species. Hopefully with learning how to grow these beautiful plants better I can stop killing the seedlings.
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