Any chemistry nerds out there?
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@malte
That's an interesting question.There'd be a big difference in the pH of the solution, right?
I'm thinking that perhaps you'd run into the issue of not having enough acid strength, no matter how long you soak in acetic acid.
Do you know anything about the mechanism?
@folfdk I only know something from reading about it. I have no practical experience with chemical stratification and no significant chemistry background. I do understand the seed physiology sufficiently to get the basic logic (weaking a hard seed coat so the seed can take up water and physiological dormancy barriers can be overcome, e.g. cold).
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@folfdk I only know something from reading about it. I have no practical experience with chemical stratification and no significant chemistry background. I do understand the seed physiology sufficiently to get the basic logic (weaking a hard seed coat so the seed can take up water and physiological dormancy barriers can be overcome, e.g. cold).
@folfdk The general method is to soak the seed in 98% sulphuric acid for 30 minutes. Those kinds of concentrations are potentially dangerous and I wouldn't want to mess around with that without instruction from a professional.
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@folfdk The general method is to soak the seed in 98% sulphuric acid for 30 minutes. Those kinds of concentrations are potentially dangerous and I wouldn't want to mess around with that without instruction from a professional.
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Any chemistry nerds out there? I'm trying to experiment with seed scarification using normal 20% acetic acid as a substitute for the more advanced method using concentrated sulphuric acid. Is it possible to calculate how much longer I would need to soak the seed if I knew the concentration and time of sulphuric acid used?
@malte
Tried feeding the entire fruit to a large flightless bird in Mauritius, then collecting its shit? -
Any chemistry nerds out there? I'm trying to experiment with seed scarification using normal 20% acetic acid as a substitute for the more advanced method using concentrated sulphuric acid. Is it possible to calculate how much longer I would need to soak the seed if I knew the concentration and time of sulphuric acid used?
I think way more complicated than that. The key is to degrade the tough outer shell in some way. My understanding is that active anti-germination compounds are at the very surface and relatively easily reduced to an ineffective concentration by repeated washing.
If they are (also?) embedded in the outer cuticle, then the physical degredation of the cuticle would remove them.
Aside from inhibitors, the role of the hard cuticle is primarily to exclude water, to maintain stasis.
Rapid degredation of the cuticle with strong acid would achieve that.
Extended exposure to weak acid, rather than 'taking longer' might permeate over an extended period and literally pickle the seed, making it unviable.
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I think way more complicated than that. The key is to degrade the tough outer shell in some way. My understanding is that active anti-germination compounds are at the very surface and relatively easily reduced to an ineffective concentration by repeated washing.
If they are (also?) embedded in the outer cuticle, then the physical degredation of the cuticle would remove them.
Aside from inhibitors, the role of the hard cuticle is primarily to exclude water, to maintain stasis.
Rapid degredation of the cuticle with strong acid would achieve that.
Extended exposure to weak acid, rather than 'taking longer' might permeate over an extended period and literally pickle the seed, making it unviable.
@lionelb Not sure I'm following you. The point of scarification is to degrade the seed coat so that water can enter the seed (imbibition). Are you saying that chemical scarification is not possible or are you just saying that it is not possible with a weak acid?
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@malte
Tried feeding the entire fruit to a large flightless bird in Mauritius, then collecting its shit?@mrundkvist I don't fly and it's a really long way to Mauritius by land. Got any other chemistry hints on my question?
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@lionelb Not sure I'm following you. The point of scarification is to degrade the seed coat so that water can enter the seed (imbibition). Are you saying that chemical scarification is not possible or are you just saying that it is not possible with a weak acid?
I suspect that it will either be ineffective or that it will be so slow that the process will be qualitatively different. Only experiment will show.
Failure to germinate could be either failure to impact the layer or because of inactivation of the seed by penetration. An alternative reliable method applied afterwards would confirm which of those.
I am just suspicious of the idea that increasing the contact time would achieve equivalence.
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Maybe try it the natural way - eat them and shit them out! Isn't that how it works in nature?
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@EvilCartyen It is and and I am reminded of it eerytime I talk about the topic, because the joke inevitably comes up! @pms @folfdk
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I suspect that it will either be ineffective or that it will be so slow that the process will be qualitatively different. Only experiment will show.
Failure to germinate could be either failure to impact the layer or because of inactivation of the seed by penetration. An alternative reliable method applied afterwards would confirm which of those.
I am just suspicious of the idea that increasing the contact time would achieve equivalence.
@lionelb Great, this is why I'm asking. I curious if you have any theory as to why you think increased contact time could achieve equivalence. I might learn some chemistry.
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@pms This is an interesting idea. Any links on how such an aggregate looks like?
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@EvilCartyen It is and and I am reminded of it eerytime I talk about the topic, because the joke inevitably comes up! @pms @folfdk
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@pms I sand, clip, file and also bury some seeds for a whole year depending on the species. Would your colleague sand Cornus mas too? I would be happily surprised if that worked. The seed coat is really tough.
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@pms I sand, clip, file and also bury some seeds for a whole year depending on the species. Would your colleague sand Cornus mas too? I would be happily surprised if that worked. The seed coat is really tough.
@malte the seeds we discussed was wild pea seeds, pretty tough seed coat too. The sanding device is home made by another colleague. A box for the seeds and sandpaper fastened to a bit of some sort.
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@malte the seeds we discussed was wild pea seeds, pretty tough seed coat too. The sanding device is home made by another colleague. A box for the seeds and sandpaper fastened to a bit of some sort.
@pms Sounds like a realistic DIY project. I'm curious how it looks like. If you get a chance to ask your colleague for tips on how to make one, I'd love to hear.
