Author Topic: Clever tricks for dealing with low populations of corn ?  (Read 675 times)

Yaz

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Hi!

I'm new to deliberate plant breeding, but have been seed saving for the last 5 years or so, mostly from various curcubits, nightshades, and legumes. I don't worry about purity, mostly saving from "whatever grew best" and enjoying the crosses that occasionally show up.

This year I decided to plant Painted Mountain Flour corn, with the idea that I could 1) make corn flour, and 2) play more with plant breeding with something that crosses more readily by selecting for a white and red version (and, as always, a selection that grows and produces in my climate/heavy soil).

I haven't had much luck with corn in the past, but figured the very early and cold tolerant Painted Mountain was a good bet.  I mentally allocated about a third of my new tilled garden to the project, ordered seeds, and figured i had plenty of space for variability.

Then I did some reasearch on Painted Mountain and realized why my corn always struggles - I've been planting far too closely - 6" apart, 18 " rows (0.75 sq ft/plant). Oops.

With 3 sq ft/corn plant, I can fit about 54 plants in my garden (6 rows of 9), about 1/4 of the 200 recommended to maintain diversity. My seed buying and starting this year was bigger than my garden and I am tired of tilling sod, so expanding the corn patch isn't an option this year.  I am stubborn, so I still want to at least try to save seed and get started this year.

Can anyone give me any suggestions for ways I can approach this? Here's a few things I've thought of:
  • If I halve my seed spacing for the first and last row, I could have about 18 extra plants, and accept lower yield from those rows
  • If I quarter my seed spacing for the first and last row, and consider them "pollen donors" only, i could have 36 extra plants. 
  • I could add closer spaced seeds at the end of each row (maybe add about 12 -24 plants)
  • I could plant at the larger spacing, save seed this year, then next year plant half saved seed, half previous years seed. (or half seed from another supplier).  Then each following year plant half 1 year seed/half 2 year seed). 

Are any of these logical solutions? What would you do?

spacecase0

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #1 on: 2020-05-16, 08:23:39 PM »
closer spacing gets you more plants, and if you are not looking for production, it is likely ok as long as you get them enough water.

the idea of growing seeds 2 years from your original seeds and them mix the first 2 years for year 3 works

also remember to get seeds from each cob for replanting, don't just mix them all together, some cobs might not get replanted that way.
remember that seeds collected from the bottom of the cob will give you shorter season corn, middle of the cob will not change the growing time of the corn, and top of the cob will give you longer season corn.

also, choose seeds that look different if you have a really low population, it will help with the required diversity.

« Last Edit: 2020-05-16, 08:29:17 PM by spacecase0 »

William S.

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #2 on: 2020-05-16, 09:47:51 PM »
I can grow 200 painted mountain plants in 200 square feet no problem. Bed five feet wide (I have long arms) and plant one kernel per square foot. I am sure if you give them plenty of space they'll be huge plants and you can save several years seed and mix it to get the population size.
Western Montana garden, glacial lake Missoula sediment lacustrian silty clay mollisoil sometimes with added sand in places. Zone 6A with 100 to 130 frost free days

Ocimum

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #3 on: 2020-05-17, 06:45:18 AM »
...
remember that seeds collected from the bottom of the cob will give you shorter season corn, middle of the cob will not change the growing time of the corn, and top of the cob will give you longer season corn.
...

I am intrigued: Is it the smaller the seed, the longer to maturity? Because a big seed has a head-start?

Yaz

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #4 on: 2020-05-17, 11:14:12 AM »
That's neat about the place on the cob being related to maturity date - I assume the bottom kernels are pollinated first and therefore pollinated by the first plants to release pollen? Is that the logic?

I made a blood sacrifice to the black fly gods and went and planted the corn this morning. The plan was to plant next weekend but the weather looks good and I realized I wont have time next weekend.

Since you think a mixed year population will probably work, I did 3 rows of full spacing and three rows of half spacing to see what the difference is (~75 seeds),  and really just see if it's worth growing.  The seed is from a large seed company so I suspect it isnt too inbred.  A few weeks ago during a several hour long mind numbing conference call, I sorted the half pound of seed I bought by colour, so planted only white, white and red striped, other colours with red stripes, red kernels, and all the "unique" kernels (mottled, gradient coloured, different shades etc).

I have another 75 seed packet I bought from an independent Canadian grower/ seed company and didnt plant. I will assume the genetics are different, and plant ~ half that seed and half my seed next year (and try to actually have 200+ plants)

I am tempted to go over to my dads and till up his garden, which hasn't been used in a few years, (2020) and do a second planting with a bigger population of mixed leftover seeds there. But there is an almost zero percent chance he will water it, I dont feel like weeding it, the black flies are even worse there, and August is often rain free, so probably a bad idea.
« Last Edit: 2020-05-17, 11:16:11 AM by Yaz »

Ellendra

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #5 on: 2020-05-17, 12:07:51 PM »
You have plenty of space to grow 200+ plants. Just not all at the same time :)

Take your seeds and divide them into batches, with each batch being enough to fit the space. Start with one, and grow each batch separately, one batch per year. When you save seeds, make sure you take a little from each plant. When you run out of your original seed, start mixing in some saved seeds. There are lots of mixing algorithms you can use, but the main idea is that each planting has seeds from plants that didn't all grow from the same batch. That way you get the same diversity as a huge patch, but in smaller bites.
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spacecase0

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #6 on: 2020-05-17, 03:43:43 PM »
I am intrigued: Is it the smaller the seed, the longer to maturity? Because a big seed has a head-start?
it has to do with when it is grows and is pollinated.
the ones at the base are first, so they tend to grow shorter season like they were.
some people say that they also have stronger roots, but I have never tested that.
opposite for the ones at the top of the cob.

so I mark my cobs as to when they silk, then get seeds from the appropriate place to bring my corn back to silking (and tasseling on each plant when it silks) all at the same time.
right now they are about 3 weeks apart for all of it, so it takes more water than it needs to and does not give me a larger harvest of the longer season either.
fixing a corn variety can take a few years.

my suggestion to anyone trying to make a good corn variety with limited space,
especially if you someday plan on living off of it when you get more room someday,
grow 2 types that are very similar but from different sources.
then cross them when you get the additional space.
you will not run into inbreeding depression that way.

I almost lost a variety because I only started with 36 plants,
I grew at least 200 plants and saved seeds from all of them in years after.
took 4 years to fail (or was it 5 ?), but it happened.

Yaz

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #7 on: 2020-05-29, 10:27:53 AM »
Well... I may have been counting my corn seedlings before they sprouted... looks like about 50% germination or less, with the corn that did germinate up about 15 or 20 cm already. I am debating if it makes sense to try and fill the holes in the rows. Would corn planted 2 weeks later make a huge difference and not allow the patch to cross pollinate?

Oh... and I discovered my order from the small scale producer shorted the Painted mountain seeds, so unless I reorder from somewhere next year, I wont have the genetic variability I was hoping for.

Ferdzy

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #8 on: 2020-05-29, 04:56:33 PM »
The best-laid plans of mice and men, gang aft aglay. Especially when you are dealing with seeds, more's the pity.

nathanp

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #9 on: 2020-05-29, 05:20:00 PM »
Quote
unless I reorder from somewhere next year, I wont have the genetic variability I was hoping for.

That isn't a bad idea anyway if you are looking for genetic diversity.  Ordering from multiple seed sellers may offer a different genetic mix.

Yaz

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #10 on: 2020-07-06, 08:45:10 AM »
Documenting here, as I tend to lose garden journals.

Currently have aproximately 64 corn plants growing, mostly short/small - hard to tell in some cases if things are a tiller or another corn plant since I planted in clumps. It's been a drought here (more than a month since last rain) and unseasonably hot since I planted, and I've not watered enough, probably. Every time I water, the corn seems to jump 6" overnight. Tallest corn is now chin height (on my 5'4 self), most (likely the second batch) is probably waist height or shorter. The biggest corn has been tasselling for a few weeks now, but I see no signs of silks forming, but the beginnings of cobs on some of the largest plants. Oh, and there are definitely bugs crawling in the smaller corn cobs.

My corn does look nicer than the commerical corn I see while driving - farmers don't typically irrigate here, so the corn is less than waist high (maybe knee high), and I suspect from the close spacing most is grown for silage.

I am considering if I should introduce another/different flour corn into the mix next year for diversity (Cherokee White?), possibly one developed for the hot/humid climate of the east, rather than the cooler/drier climate of Montana. It gets tricky, as the growing season here is still short. I'd prefer not to "lose" this year of corn selection for my climate, but also don't want to kill it with inbreeding. Or perhaps just presoak the seeds, and start it earlier when there is (usually) more water/cooler temps.

reed

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #11 on: 2020-07-06, 09:33:33 AM »
I also struggle with eliminating genetic depression in small populations but have developed a few tricks. One is to cross varieties that are significantly different in many ways. I settle on a few traits that I want and look for varieties that have those but are as different as possible in other ways and I try to include several, not just the same one from different sources.  One small pack of seed each, of say, five different varieties well mixed in the patch I think would give you a nice start to begin selection.

I have a theory too that maybe one reason small populations of corn are so prone to depression is because a higher percentage of the seeds are selfed, that is the mother and father are the same plant. I fight that by detasseling particular plants that for what ever reason I favor as a mother plant. Then I try to pollinate it with several others that have good traits. Those plants then make a high % of the next season planting.

I didn't like Painted Mountain in my garden. It tended to grow only 4 feet or so before maturing and ears often overshoot the husks which leads to all kinds of bug and mold problems in my climate. Cherokee White is a very large, very long season corn, so crossing it to PM would introduce a lot of diversity I suspect but the difference in DTM would make timing a little tough.


 

Woody Gardener

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #12 on: 2020-07-07, 08:08:12 AM »
reed:
"I have a theory too that maybe one reason small populations of corn are so prone to depression is because a higher percentage of the seeds are selfed, that is the mother and father are the same plant. I fight that by detasseling particular plants that for what ever reason I favor as a mother plant. Then I try to pollinate it with several others that have good traits. Those plants then make a high % of the next season planting."

I agree but rather than detasseling I grow 3 white 'Moonshiner' corns that are heat and drought resistant and grow well in poor, heavy soils like mine. They are 120 days seed to harvest and lack the phytonutrients and high protein and oil of colored varieties in orange, blue/black, and Harmony Grain that are 80-110 day corns.

White is recessive to all colors so any colored kernels on the white 'Moonshiner' cobs are a cross.

reed

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #13 on: 2020-07-07, 08:30:45 AM »
White is recessive to all colors so any colored kernels on the white 'Moonshiner' cobs are a cross.

Yep that would work real well but not in my project cause the blue color is in the aleurone and I'm working to eliminate aleurone color. I want a variety of colors but each individual ear a single color. I pulled some great flinty, colorless aleuron seeds out of Harmony. Eventually I also want to eliminate variation in endosperm but like you said, since white is recessive I don't think that will be too hard to do.

Richard Watson

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Re: Clever tricks for dealing with low populations of corn ?
« Reply #14 on: 2020-07-08, 01:29:59 PM »

remember that seeds collected from the bottom of the cob will give you shorter season corn, middle of the cob will not change the growing time of the corn, and top of the cob will give you longer season corn.




I dont understand how this works, can you explain please.
Changeable year round climate, less so summertime, warming winters - just under 500mm average yearly rainfall. 20 years of soil improvements plus sub soil top soil reversal means my garden beds are about half metre deep. Below that is 100's of metres of alluvial out wash from the Southern
alps.