(This thread is a continuation of the topic I started here on November 11th 2009.)
It is no mystery that seed germination can be induced, employing a technique known as "de-lidding". This is where the endocarp material covering the embryo is skilfully removed to expose the embryo.
As to why, and when you would attempt to induce germination is up to each individual, but in most cases, this is a very useful technique to employ, where you have seeds that are known to take a long time - perhaps a year or more - to germinate. Perhaps you're just curious to know if your seeds are still viable? Maybe you're fed up, monitoring small batches of seeds over such a long period of time, or worried that the embryos may be losing their viability, as you feed them either too much or too little moisture. Or perhaps like me, you want to induce germination as you head towards winter, so that you can raise a batch of seedlings in spring.
In my first experiment, I de-lidded 54 seeds of Lemurophoenix halleuxii. I started out with 60 seeds. Six of these seeds germinated without my help within the first few weeks of acquiring them, in mid-June 2009, but after nearly 5 months in a controlled environment, not one seed followed. So I began the experiment 8 days ago. Of the 54 seeds I de-lidded, 13 proved to be non-viable. I lost a further 4 seeds having discovered how important it is to guard against fungal attack when using this technique.
Removing the endcocarp material from certain seeds will inevitably expose some of the endosperm around the embryo, and this is where fungus will strike, if you are not vigilant. To avoid this problem do 3 things. Firstly, use a sterile germination medium such as vermiculite or perlite, or if you want to use your regular soil mix, cook it in the microwave first, to kill off any resident bacteria. Secondly, move your seeds after 24 hours to a different box. A change of substrate and "new air" seems to help. Thirdly, do not bury the embryo. Keep it above the surface of your germination mix, and mist your seeds at least twice a day. You can further prevent a fungal attack by using fresh water in a hand-mister, to "jet wash" the embryo close-up, from just an inch or a couple of cm away, when you move your seeds to a different box. So that's it. Some species can be de-lidded easily, without inadvertently exposing the endosperm around the embryo, in which case, these seeds can be germinated as normal, without the need for regular intervention.
Here are my 3 case studies. Others are also posting their experiences here, using the same technique, so please feel free to document your results.
Case #1 - Lemurophoenix halleuxii
All viable seeds de-lidded 3 days ago are continuing to grow healthily. Visible embryo growth started in less than 30 hours! One seed remains intact to see if and when it germinates on its own.
Case #2 - Corphya utan /macropoda
These seeds were a gift from Kris, I think more than a year ago. Only one seed germinated earlier this summer, so they were an ideal candidate. Photo A - 8 out of 10 seeds were viable after more than a year, and embryo growth was observed after 72 hours. After 5 days, the most vigorous seeds are getting ready to throw down a root! Photo B - labelled by Kris as Corypha macropoda although I understand this to be a synonym of Corypha utan. Still, they are most likely from a different tree, so they are being kept apart. These seeds were de-lidded 3 days ago, and 6 out of 7 seeds were found to be viable.
A.B.
Case #3 - Jubaea chilensis
These seeds were left over from a batch germinated last year, and after first removing the mesocarp, 3 out of 5 were found to be viable. Embryo growth was visible after 48 hours.