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Seed Storage - · Hydroponics Daily

• 0:00
  Hello and welcome back to Hydroponics Daily with me, Dr. Russell Sharp.
• 0:04
  Today's episode is about seed storage, which most hydroponic growers will be interested in.
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  It's important to note that not all seeds can be stored.
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  A large proportion of seeds are what scientists term recalcitrant,
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  and this means once they dry out or they're stored in the cold, then they die.
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  So it and as most seed
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  storage techniques involved keeping seeds dry and
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  cold then this would be essential so make
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  sure that the seeds you're trying to store is not recalcitrant first
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  most crop species though are not recalcitrant many tropical tree fruit crops
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  are recalcitrant so mango mangosteen coconut all large seeded tropical fruits
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  they're all recalcitrant and And then closer to home,
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  the oaks are all recalcitrant, horse chestnuts,
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  sweet chestnuts, black walnut,
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  hazel, and many, many of the maple species.
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  So sycamores, Japanese maples, things like that.
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  And then some small seeded species like ivy, heterohelix, fantastic scientific
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  name, that is also recalcitrant, so you cannot be stored.
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  So once you've ruled out recalcitrant seeds, you might also find that your,
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  the plant you're growing grows into a third category and that is intermediate
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  where they don't store very well long term so they can be dry stored for a short
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  period of time and that includes coffee,
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  coffea arabica, lettuce which is
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  a you know fairly common crop so and parsnips
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  so if you've had parsnips and lettuce seeds in your
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  seed box for a long time
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  then probably worth buying some new ones parsnips are
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  notoriously poor at germinating and that's
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  why you're on the packet it should recommend to plant
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  at least two or three seeds at
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  every point you want a parsnip plant you can always thin them out later if they
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  were if they were stored better than you thought they would but that's that's
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  the recommendation and you'll also find cat lettuce and parsnip seeds always
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  come foil-packed to really maintain their viability,
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  whereas not the majority of seeds come foil-packed, like spring onions,
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  that wouldn't come foil-packed normally. That would just come in a paper bag.
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  Envelope and then if your seeds do prove
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  to be good for long-term storage then you
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  might have to consider that long-term storage might not be good
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  for your seeds and that's because seeds
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  in storage suffer from mutations
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  they can't recover from mutations like
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  a living organism that's growing can and so
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  mutations build up over the years and this
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  is why when you when you bring out seeds from
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  long long-term storage they can often have deformed
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  growth now when it came to melons and
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  cucumbers and i think pumpkins they used
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  to say that long-term storage was better because you produced a
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  better crop but the it's found
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  from subsequent studies with commercial cultivation that
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  this is not true and that the ionizing radiation from
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  the universe and from human activity
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  causes long-term damage to the seeds so
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  if you're growing a crop that's prone to mutations
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  then yes it might be might be able to store it for 10
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  20 30 years but you've got to ask yourself is that
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  the best what best seed to buy should
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  you actually be buying in fresh seed every year
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  people do experiments with ionizing radiation
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  though for producing interesting mutations.
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  And in fact seeds are often taken up to the international space station and
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  the chinese space station did you know the chinese have got a space station
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  they have and they take seeds up there and then they bring them down and then
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  work out whether they're good for certain crops and things like that and and
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  give them to schools to do experiments with.
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  Often that's a lot of the seeds that go up there are just for schools to play
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  around with and compare to seeds that have stayed their entire time on the surface of the earth.
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  When it comes to the ideal conditions to keep seeds in when they're in storage,
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  you want to dry them out as much as possible and store them at refrigerator temperatures.
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  You also want to keep them in the dark because many seeds are what are termed
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  photoblastic and that means that germination is improved or is promoted by light.
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  Lettuce is a good example of that.
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  It was first discovered, phytochrome, the pigment that involves photoperiod,
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  was actually discovered in seedlings and it's also involved in germination.
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  So you want to keep them dark, you want to keep them cold, but the problem with
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  keeping the things cold in say a refrigerator is they can also get damp.
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  So you want to make sure they're well sealed or they're with silica gel. and
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  then you also want to
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  keep them make sure they're clean because any microorganisms that
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  grow on them are going to reduce their viability they're going to feed off the seed
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  coat and certainly any insects so
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  the big killer of seeds is weevils weevils
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  are beetles that have evolved to feed just on seeds so you want to really make
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  sure there's no access for weevils to get in there and um and any fungi can't
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  grow on them if you're able to get your seeds down to.
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  Maybe like you know the moisture content down to like five to seven
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  degrees celsius five to seven percentage you
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  can actually freeze your seeds but you do need to make sure
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  they're very dry that is the technique that's used by
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  the seed banks around the world so in the uk we've got
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  wakehurst placed which is the national seed bank for what you might have heard
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  of kew gardens they're probably the biggest botanical gardens in the world and
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  they store a vast quantity of the world's species of seeds mainly native species
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  and obviously it's funded by the UK taxpayer and UK farmers,
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  private sector but don't expect to have access to that if you work in the private
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  sector you know f was right you know private sector how dare we actually make use of the resources.
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  Or that our country has actually developed over the
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  centuries no you're not allowed to access any of those seeds
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  to commercialize them they have to be just kept for the scientists
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  at kew gardens to look after for some future.
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  Even though the on their remit and.
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  The way they talk about it they say they they help you know
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  improve the uk gdp and
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  help industry it's an absolute nonsense in my
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  eyes it really annoys me that the seed banks like wakehurst
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  place and you're not allowed to get seeds from them if you're from
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  the private sector in america there's also seed banks
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  they are under threat because of federal government
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  funding cuts i believe so those freezers
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  could be turned off and the seeds ruined there's also this fall barred
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  seed bank that stores all the crop species and
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  varieties that's up on Svalbard which
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  is an island north of Norway very far north
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  of Norway up in the arctic circle it's actually threatened though
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  by climate change ironically in that
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  the ice is retreating from around
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  the seed bank and they've had to actually keep the freezers on
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  for longer whereas normally they were they were going to rely on
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  the the background cold temperatures so there's
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  seed banks that's my high horse about seed banks what I think of seed banks so
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  you obviously do not need a seed bank you can use a freezer or you
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  can just use a fridge if you can't get your seeds dry
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  enough you also want to make sure you're just storing
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  the seed and you're not storing any husk or what we call chaff because that's
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  going to decompose as well in storage so just make sure you you know what the
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  seed is and what the the outer coat is you know that might sound simple but
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  you think of a peanut and you know you might think the whole thing the hole.
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  Casing is part of the seed when and stuff like that
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  so i'm not sure if it is i don't know peanut what part
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  of the peanut do you eat i don't know that's a really bad example russell what
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  can i think of that's a good example i'm going to say
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  acorn but that's not a good example because that's a recalcitrant seed coriander
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  coriander is a good example that's got a husk and inside that
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  the seeds but with coriander often it's you sometimes
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  you get it and it's still in the husk so probably not the best example either
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  there but yeah i'll move on it's important when
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  you dip into a packet of seeds that you seal it
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  up straight away and you put it back in
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  a sealed container because often seed packets come sealed
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  and then you might just want to roll it up make sure you
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  put some sellotape over it or ideally put it in a plastic bag
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  and also that you hand when you get the seeds
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  out your hands are not wet and covered in wet grown media
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  and things like that it's tempting you know i know
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  it's tempting to when you get the seeds out you know you get a
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  few more out get a few more you don't want to waste any seeds but if
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  you're putting seeds back in to the seed packet that have
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  been exposed to your wet hand that's really the the worst
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  case scenario how long can a seed
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  last for in storage well that depends on who you believe there are reports of
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  sacred lotus seeds that have laid buried in silt deposits in dry lakes in china
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  and japan successfully german a thousand years after they were dug up.
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  The reports of Arctic lupine, which sounds like a lovely plant.
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  From the permafrost dating back from 10,000 to 15,000 years still being viable.
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  However, the world record for seed resurrection is currently held by the narrow-leaved campion.
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  Another, sounds like it's another
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  delightful plant that, and one for your borders, herbaceous borders.
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  And that was buried in Siberian permafrost. And that was brought back to life.
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  And that was thought to be 32,000 years.
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  So I doubt your refrigerator would last 32,000 years or your freezer.
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  But this, you know, in the Siberian permafrost, this amazing plant was still
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  going strong with the mammoths and the saber-toothed tigers, its mother, the seeds.
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  Probably other amazing animals that no longer exist, and amazing plants.
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  So many of the plants grown in hydroponics will last at least 10 years in storage,
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  so tomatoes and other things like that you don't need to worry about,
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  as long as they're stored well chilies they'll all survive many many years in
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  storage and so just make sure you keep them as dry as possible and don't expose
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  them to light keep them away from microbes and keep them nice and cool or frozen
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  if you've got the facilities to do so.
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  I'm not sure if there's any work that's been done on techniques to improve seed
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  storage that you could do like chemical treatments or,
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  very, very ripe fruits will produce a seed that is extremely dormant.
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  And I think this is one of the reasons why really hot extreme chilies often
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  struggle to germinate when you get them, in that they're taken from really ripe extreme fruits.
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  Whereas if you were taken, seeds will often be viable when they're taken from
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  green fruits and will have much lower dormancy levels.
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  Now, however they have lower ability to
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  storage in storage i don't think that's ever been
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  done it would be a very very long experiment sort
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  of lifetime experiment to do so i don't think
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  anyone's rushing out to get that experiment i don't think anyone's going to
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  be and when the results come in i don't think anyone's gonna whoa the
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  results are in this was an amazing experiment and we found out so much from.
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  It so yeah you're not going to get much kudos from doing that experiment
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  even though it would be interesting to know so yep you
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  can you can often harvest seeds from
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  very very unripe fruits that's something to consider be
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  interesting to look at that with the big black
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  mama chili seeds i've got growing this year i'll harvest
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  from see some seeds from very from
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  various stages of ripeness and store them
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  over the winter period this year and
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  then next year i will germinate them
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  and i will report back whether the the unripe
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  extreme chilies were had a a
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  lower did they did they germinate faster basically and
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  could we reduce the time it takes to grow extreme chilies
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  by doing that because one of the big constraints in growing extreme
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  chilies is just the time it takes for them to germinate and
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  the high temperatures required if we could produce extreme chilies that germinated
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  at much lower temperatures much faster than the seeds would be you could get
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  a harvest in in certain situations where you couldn't like a cold greenhouse
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  in the uk or in say ohio in america.
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  And you the people who grow the chilies would
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  get a lot less returns or refunds because often people
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  will be complaining going i bought these chilies and they
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  didn't germinate none of them germinated and then the
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  companies will give them the refund and then 10 days
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  later this person who complained and was on twitter moaning
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  all their seeds will germinate so i think
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  that's actually a really valuable trial so i'll definitely
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  do that this year and report back that's been hydroponics
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  daily for today seed storage and everything that goes
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  into it and we'll probably do another seed episode tomorrow
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  because i think there's a lot to cover that we haven't already covered on hydroponics
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  daily please share this podcast if you found
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  it you found it useful in any way really trying to grow the listener base and
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  it's really encouraging and to know as it goes up the charts and that people
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  are listening and obviously the more the more that happens the more effort i
• 14:04
  can put into every episode at the end of every working day but thank you very
• 14:07
  much for listening so far and see you again tomorrow thank you.