Conversations about landracing field corn

So, I have my ideas, but wanted to get some opinions about corn spacing, specifically "flower/flint/dent types" & how it affects yield.

I'm not a market grower, but have plans to grow a diverse collection of field corn this year.  Most of what I've read say plant 12" between plants & 36" between rows.  Some say as little as 6-8"/24-30".  One account said as much as 20-24" between plants if lack of water is a concern (which also somewhat aligns with the wider spaced clusters of corn that arid desert farmers used).  Another university study for commercial type growing of landrace indigenous corn summarized the sweet spot as being 9" between plants & 36" between rows if fully irrigated.

I see the commercial fields around me with no irrigation, just natural rainfall, but those plants are bred to be planted like 4-6" apart with no weed competition & all the nitrogen & fertilizer inputs they can handle.  I understand there is a calculation there for maximum rate of return, but I'm not really concerned with that.  I get the concept of how you grow your corn generation after generation will shape the future crop.  That said, how would you go about incorporating a lot of diverse seed into your initial crossings/grex?  Plant closely the first few years to get the maximum number of seeds in the ground for wide pollination, or just start multi-year successions at the recommended for best yield spacing, saving seeds from each years' best? (No additional fertilizers & maybe weeding 3 times.)

In the interest of trialing more initial seed, would 9" spacing between seeds hinder the plant health/block pollination too much, or could it actually help identify the thinner weaker, less competitive plants for rogueing?  Is it too much to expect good cross-pollination given the typical leaf structure?  Would you start rogueing the weaker 1st year plants as soon as you can tell they aren't going to be competitive (retaining the soil nutrients for others), or do you let them contribute pollen to the grex the first years knowing they may produce better under next years' conditions?  My gut says if it's underperforming, I don't want it adding pollen to the mix that I'll just have to cull later, so I'd either pull it if young, or detassel it to still get a food harvest without adding weak genes.  Is there a potential benefit to letting the weak plants pollinate the mix?  

Just some overthought musings while I'm waiting to plant, but hoping for some experienced advice here.  I'm open to other concepts from those who've done it as well.

I have tried tight spacing and wide spacing. Both produce plenty of corn, so it is a question of goals, advantages and disadvantages.

Narrow spacing in rows helps with mid to late season weed control, via shading. However, it makes weed control harder because it doesn't allow you space to walk and it's harder to get the hoe where you need it. Narrow spacing usually produces a higher production, especially if you have rich soil and plenty of water. But the ears will be small so harvest is somewhat annoying, plus you lose 'bragging rights' from having only small ears!

Wide spacing will often reduce production, unless it's a dry year. On the other hand, if you are doing any sort of intercropping, it's almost mandatory to have wide spacing.

Last year I went with very wide spacing, hills 4-5 feet apart, 1-3 stalks per hill. I got 60 bushels/acre with an open-pollinated variety, which I am very happy with, especially given how dry it was. However, this was non-organic, used NPK fertilizer and gypsum. The wide spacing allowed me to get all around the hills on every side, so it seemed like weed control was actually much easier then corn planted in rows. Also allowed potatoes, squash and beans etc. plenty of light/space to grow, so had good results from intercropping.

I read some papers by a Greek agronomist who tested pollination in spacing similar to what I used last year. According to him, it greatly reduces cross pollination, so most of the seed came back self pollinated. He claimed that by doing this year after year it allowed him to strongly select for the traits he wanted without having to go to a lot of trouble covering silks or hand pollinating. He also claimed that a few years of doing this allowed him to create open-pollinated varieties that yielded just slightly less than hybrids used for comparison.

This coming year I will use the same hills/spacing, but no NPK fertilizer.

Thom Bri,

That's an interesting result regarding the mostly self-pollinated example.  Were you able to tell from your own wide spaced growing if that held true for you as well?  I recall a past Joseph Lofthouse post in which he illustrated that beyond 3 feet (if I remember correctly) the cross pollination dropped significantly.  I'm sure this is naturally variable depending on if there are calm pollination days vs swirling winds vs straight-line winds during pollen release, but it makes sense.  

I saw a YT video recently of someone who was growing a small flour or flint corn variety (Possibly Roy's Calais?) in small clusters as traditionally done.  His "saved seed" selection criteria was pretty much the same logical process that most of us use, but his philosophy was to keep the best ear from each cluster rather than the best ears of the entire patch.  His theory was that by doing it this way, he could account for differing concentrations of soil nutrients from one cluster to the next since all roots from that cluster had equal access to the same pool of nutrients.  At first, I thought this was a bit odd, then the more I thought about it, the more sense it made if your goal was to maintain a large amount of quality seed for a specific variety.

I'm very excited to see how my own corn does this year, & find very interesting the different ways people grow their corn & why.  As I develop my own plans, I can see me modifying from year to year which method I want to use for specific goals.  At least for the first few years until I find the right balance that I like...Thanks for the link!

Cy Cobb wrote:Thom Bri,

That's an interesting result regarding the mostly self-pollinated example.  Were you able to tell from your own wide spaced growing if that held true for you as well?  

I believe there was still a lot of cross-pollination, but, most of the hills had more than one stalk.