Tetrazaolium Test

[12540dumont]

The two ways to find out whether a bean (or other seed?) is viable or not, are a tetrazolium test and germination test. Tetrazolium is a chemical that turns red in the presence of hydrogen ions. All living organisms release hydrogen ions every day and therefore, it was possible to see whether the lima beans were viable or not using tetrazolium. This is a result of metabolic activity.

Has anyone tried this?

[oxbowfarm]

When I was in school at CSU in Fort Collins, I worked at the state seed lab work-study. We did a lot of viability tests for the NSSL which was the next building over on campus. I did a lot of tetrazolium tests on tomato seeds one semester. You'd have to look up to protocol because I don't remember it, but basically you soaked the seed till it was fully hydrated and then treated it with tetrazolium after a certain time period. Then you have to dissect the embryo to determine viability. With tomato seeds we would section the seed longitudinally to try and cut the embryo in half on its long axis. Then you look at the embryo, if the whole thing isn't dyed pink its non-viable. A lot of times the radicle would be alive but the top would be dead or vice versa. That was actually a lot more common than them being all dead, just "Mostly dead". But then you'd need Miracle Max.

[12540dumont]

Thanks, it didn't look that hard, as long as you know which vessel has the poison and which has the brew that is true. I just have not been having much luck with some old seeds, and it might be worthwhile to spend the $20 to see if they are indeed mostly dead or alive and I need a different protocol.

[DarJones]

Would be better to ask about reviving seed Holly. There are ways to resurrect old seed under controlled conditions so long as they are still alive.

DarJones

[12540dumont]

Dar that's kind of the question.
I received some old beans and some old melons in the mail.

I started a flat of the melons using the peroxide method and nada, zilch, so I was wondering if they were too old. (Mostly dead).

I put the beans in a flat as well, everything else I planted on that day are up. I did the beans with fish emulsion. (soaked)

I looked up some of the tricks for starting old seed, but each of these flats and tricks takes up a bunch of time (which is one of the few things I can't get off the shelf), so I was wondering if Miracle Max needed to be called in.

Dar, I'd be happy to try anything else you can suggest. I'm about to toss the first batch of watermelons. I have 40 seeds left of 10 types.

I planted 5 of each on the first go. So I figure I have 8 tries left...

[DarJones]

Both beans and watermelons respond to nitrogen in the soil. Prepare some seed start mix by mixing a teaspoon of miracle grow 15-30-15 with a gallon of water and then using the water to thoroughly wet the seed start mix. Fill a cell tray with the seed start mix. Poke bean seed just into the top of the mix so that the hilium is down into the mix and the seed coat is still just visible on top of the mix. Put several seed in each cell, the only rule is that the seed must NOT be touching. Most of the seed will decay and fungi will grow on them. If the seed are touching, even viable seed will be killed. Set the seed in a very warm place to germinate. I tested an incubator at 85 degrees several years ago and got very good results. You can do the same thing with a small greenhouse. The important thing is that the beans must be exposed to light just as soon as possible. Weak seed won't push up through much soil. When they get light, they begin to produce energy which feeds the plant even if the cotyledons are dead. I've had bean seed germinate and grow with only 1/4 of a single cotyledon that was viable.

Watermelon seed can be done the same as beans. When you push the watermelon seed into the soil be sure the point is down. Check the seed regularly, I've had weak roots break the seed coat and I then removed the seed coat so the seed could finish germinating. Be gentle, it is very easy to damage weak seedlings. I had some 15 year old watermelon seed this year that germinated exactly 2 seedlings out of over 700 seed. That is the weakest and lowest germination I've ever been successful with for watermelons. I also germinated some cantaloupe seed from 1993 with 4 seedlings that grew out of about 40 seed planted.

One obvious fact, you can't germinate dead seed.

DarJones

[raymondo]

What Dar said. I've had luck with old beans by setting just on the surface, pushed in a millimetre or so, enough that the hilum and associated bits are covered. I hydrated the seeds first by soaking them in lukewarm non-chlorinated water with a single drop of fish emulsion in about a cup of water for no more than an hour before I set them them out.
I haven't tried old watermelon seed but old melon seed I've had luck with by doing the same soak, perhaps for a bit longer, then ever so carefully peel off as much of the seed coat as comes away easily starting at the pointy end. I don't force it. If it it doesn't come away, I leave it. These I then germinate on a damp piece of cotton like those make-up wipes which sits on a heat bed.

[12540dumont]

so okay, I'll begin again. I only have 40 seeds! I'm hoping for at least one melon. And of course a million beans!