Selecting Landrace Sweetcorn

Forgive me for this dumb question, but how do you select sweet corn for taste?  If I grow a bunch of different varieties of corn and everything crosses with everything, and I find one that is really delicious, well, I don't know that until I eat it.  Do I pull one cob from each of dozens of plants and keep track of which stalk each one came from so I can save the other ear on the stalk for seed?  It's hard for me to believe people do it that way.  

Peel open just the very top of the husk and take a tiny nibble, then hope the rest of the cob matures to plant seeds? I’m sure there’s a better way.

Sweet corn seed becomes viable at about 17 days after pollination. The earliest I can stand to eat sweet corn, at the very earliest watery stage is about 25 days. I think the best flavor is at about 32 days after pollination. The seed is fully mature by 40 days after pollination. It takes weeks after that for it to dry down if left on the plant.

So you could harvest plants at their regular harvest time, taste each cob, and save those you like for seed. I commonly harvest sweet corn for seed at about 40 days. I taste each cob. There can be huge differences in taste. Any that are spitters get dropped in the field. Any that taste extra good, get saved separately from the bulk seed.

I also take pruning sheers into the field, and cut off ends of cobs for tasting. If any are extra tasty, I tie a ribbon around the cob. I can taste a cob a number of times during the growing season.

When given plenty of space, a corn plant may produce several cobs. One can be for food, and the other for seed.

When the sugary enhanced trait is homozygous, the dried seed coat is finely wrinkled. Otherwise it's coarsely wrinkled.

The way I look at it, if you are working with an all sweet corn mix, then all of your corn will taste good.  If you have a preference for SU or SE, you can focus your genetics to your preferred level of sweetness that way.  Most instances of taste testing corn that I've seen have come from mixes that have incorporated flint/flour types into the mix to achieve other desired traits.  If your mix is a combination of sweet corn varieties only, then the most wrinkled seeds will be your sweetest.




 

Joseph Lofthouse wrote:Sweet corn seed becomes viable at about 17 days after pollination. The earliest I can stand to eat sweet corn, at the very earliest watery stage is about 25 days. I think the best flavor is at about 32 days after pollination. The seed is fully mature by 40 days after pollination. It takes weeks after that for it to dry down if left on the plant.

So you could harvest plants at their regular harvest time, taste each cob, and save those you like for seed. I commonly harvest sweet corn for seed at about 40 days. I taste each cob. There can be huge differences in taste. Any that are spitters get dropped in the field. Any that taste extra good, get saved separately from the bulk seed.

I also take pruning sheers into the field, and cut off ends of cobs for tasting. If any are extra tasty, I tie a ribbon around the cob. I can taste a cob a number of times during the growing season.

When given plenty of space, a corn plant may produce several cobs. One can be for food, and the other for seed.

When the sugary enhanced trait is homozygous, the dried seed coat is finely wrinkled. Otherwise it's coarsely wrinkled.

Thank you Joseph, that is exactly the information I was looking for.

If harvesting sweetcorn seed at the fresh eating stage, take care to dry it as quick as possible with plenty of air flow, so that it doesn't turn moldy.

Joseph Lofthouse wrote:If harvesting sweetcorn seed at the fresh eating stage, take care to dry it as quick as possible with plenty of air flow, so that it doesn't turn moldy.

Do you generally leave yours in the field to dry on the stalk, or harvest it and hang it to dry or something?  Sorry for the beginner questions, I save seed from things like squash and beans for a few years now, but I've never tried corn.  I'm on a new property and want to get my own landrace going.  I'm using your 'Astronomy Domine', High Carotene, and a couple random kinds I picked up from the store this year.

I'm drying sweet corn from the fresh eating stage now (picked July 4th) with the hope that it will dry without mold or insect damage.  First, I shucked the corn in a large batch for preserving.  I was very selective in choosing the best ears for the traits that I wanted to continue.  Then, I simply took a scrap piece of lumber & ran a bunch of screws through it, nails would work just as well too.  Next, I twisted the ears onto the screws vertically, and stored them in my very hot garage & occasionally put a fan on them.  So far, they've dried nicely with no mold at all.  I did cut the earworm damage off the tips initially, & once the kernels dried enough to flake off, I removed any that were cut in the process of cutting off the end.  I did this for two reasons: 1) The cut seed would not be viable, & I didn't want it in my mix, & 2) I thought that the moisture from the cut seed might encourage mold growth, so I eliminated that risk.  I've done this with two batches now, with the 3rd batch is being left to dry on the stalks (will compare results).

I don't think this method is inherently better for seed saving than just leaving it to dry in the field, but I needed the space to grow other things, and my research made me feel comfortable with trying it.  This method also allowed for me to eat & preserve the whole crop after selecting my future seed stock.  This wouldn't be a big deal with flint/flour/popcorn since the whole crop is already dry when you harvest it, but with a fresh eating sweet corn, there isn't really a good alternative that I know of for selecting your ears to save & eating/preserving the rest.  

While the seed is mature and can be dried at an earlier stage, I believe that the longer it stays on the stalk the better. It results in a seed with more food stored for the plant to use when it sprouts, making for an overall more robust and healthier seedling. I also think it makes for seed that will live longer in storage.

Ideally it should stay until the husks, and pretty much the entire plant is dry.  Unfortunately, that isn't always possible, especially as mentioned if your season is long enough, and you want to plant something else following your corn.

I have a couple of techniques that have worked well for me. It seems that once the seed is fully mature, the silks are nicely dry, and the tassels are dead the plant is finished growing. It still needs some water to keep it from drying too fast, but it doesn't need much of it and it doesn't need nutrients at all. Anything the seed needs can be drawn from the dying plant. So, one method I've used (in my small garden) is to clip off the tassel and maybe down a leaf or two and digging or pulling it up by the roots. Then I shove them in a big pot on the front patio with a bit of soil, pulled weeds or whatever around the roots and keep it watered. They aren't growing anymore, and they don't really even need light so you can shove a lot of plants into one big pot. It goes ahead and dries pretty much naturally this way, and you get really nice plump seeds.

My second technique is to leave the corn where it is to go ahead and plant something else under it. I generally plant a short season pole bean. When the beans sprout, I'll strip off some of the lower leaves of the corn. As the beans grow and the corn dries, I strip off more corn leaves. That way I use the dying corn stalks as bean poles, eventually harvesting the corn and stripping off the rest of the leaves. You can plant other things too like that too, but something nitrogen fixing is best and since it is the hot part of the year those corn stalks and leaves provide a little bit of shade at first.

Good points Mark,  I agree that fully matured seed would be best for a longer viable shelf life for the reasons you mentioned.  I do intend to compare this seed with the field dried seed when it's ready.  Prior to planting next spring, I will do germination tests to see if the seed is still viable.  If not, I can plant the field dried seed.  I like to read about others' experiences for comparison, but I also like to try things for myself under my conditions.

I have learned that with careful timing, I can grow a successful crop of early sweet corn to harvest before the surrounding field corns even tassel.  

I do like both of your ideas, and will try the slow drying stalk method on my next harvest, & the pole beans on my existing stalks that are still in the field.

How's your Aunt Mary's x Zapalote Chico coming along this season?  I harvested my early, cold hardy sweet corn, and had more worm damage than I'd prefer, despite the early season.  I definitely want to add some worm resistance to my mix, & am just curious how yours is coming along?

Thank you both, excellent information.

Cy Cobb wrote:How's your Aunt Mary's x Zapalote Chico coming along this season?  I harvested my early, cold hardy sweet corn, and had more worm damage than I'd prefer, despite the early season.  I definitely want to add some worm resistance to my mix, & am just curious how yours is coming along?

The Aunt Mary's x ZC did great, but I did not keep it as a new project itself. Instead blended it into my flint corn landrace. The Aunt Mary's because it grows so well here and has very flinty only slightly wrinkled, large seeds and 12 or less rows of kernels. The ZC because it is the source of the worm resistance.

Blending those two to make a worm resistant sweet corn would be a very worthwhile project but I think my gardens are really too small to make a serious attempt at breeding sweet corn.

I planted my corn early this year and wasn't planning on planting a late patch so figured I'd be skipping a year on selection for resistance. No worries, the worms showed up a month early this year, just in time to infect any susceptible plants.

Yes, the worms hit my crop hard & earlier than anticipated this year as well.  I don't remember if you previously posted the info, but do you have a link or source for those two varieties?  I'm interested in trying them out for my own sweet corn mix.  I had good tip coverage, but they still got in through the silks.  I'm not sure if it will help, but it can't hurt to try.  

Y'all are talking about tasting the corn raw, right? I sort of like sweet corn like that, but it's pretty different than after it's grilled or steamed. Are you basically just tasting for "good" vs. "bad" or are you looking for more flavor nuance and is there any concern that compounds changing with heat will give you something different with cooking? And is "good" just sweet?

Cy Cobb wrote:Yes, the worms hit my crop hard & earlier than anticipated this year as well.  I don't remember if you previously posted the info, but do you have a link or source for those two varieties?  I'm interested in trying them out for my own sweet corn mix.  I had good tip coverage, but they still got in through the silks.  I'm not sure if it will help, but it can't hurt to try.  

You can get Aunt Mary's from Southern Exposure Seed Exchange, but in their picture, you can see some yellow kernels, so their crop has been crossed up a little. It should be all white. I got a small sample of Zapalote Chico from the USDA GRIN, that was quite a process. I don't know of any commercial source for it.

If I was inclined to grow and keep an heirloom corn pure, Aunt Mary's would be it for sure. Best sweet corn I ever tasted, by far!