Curious on corn genetics, selecting shorter plant height

[Dewdrop]

In short, I'm curious if Country Gentleman sweet corn can be selectively breed, with or without outcrossing, for a shorter plant height to about 5 feet.  Traits I want to hopefully keep (if not linked to plant height in genes) include the same or similar taste, sweet corn, thick cobs with smaller kernels to eat, tight husks (corn earwigs are well established here), and ideally also keep the 'shoepeg' zig-zagged kernal arrangement.        

Questions:
1 Would it work to select only the shortest plants for seed, or would that also select against vigorous growth?  Would it be better to aim for about average height instead, or to cull out the tallest corn plants?   
2 Assuming the corn plants must be grown outdoors, any tips for selecting for shorter corn plant height?
3 Would it be a bad idea to simultaneously 'wean off watering', whilst doing this project over seasons?  I currently water my garden on an as needed basis.  It would be nice it I could happen to end up with a more drought-resistant corn.    
4 Is corn plant height linked to cob thickness or kernel size?    
5 Are there any short 'shoepeg' corn? 
6 Is the Country Gentleman corn likely to produce more than 2 cobs per plant if I space them out 'properly', rather than my spacing of 4" last time in a row? (I know rows are not ideal, but I've apparently 'gotten away with it' by 'rubbing the tassels together' to pollinate the silks below)       
7 Are there any shorter sweet corn plants that produce over 2 cobs per plant reliably?  How far apart did you plant the seeds and what state or country did you grow them? 
8 Are there any shorter corn plants with tillers? 
9 What is the difference between saving seeds from 25 out of 100 corn plants compared to a few seeds from each individual corn plant?  How do you organize so many seeds when it's time to dry and store them?      
10 Any other tidbits of information that may be relevant?  Any constructive criticism?      

The reason I want to select for shorter height is for fun, and based off my experience with a good wind gust blowing down my unsupported corn plants the other year.  Yes I could simply try to hill the corn, or see if it will be enough to grow beans on as additional supports, but I think I would rather play with and grow something that eventually reaches my needs, or grow what already does.  I have acquired a taste for Country Gentleman corn though, especially when buttered and eaten as corn on the cob.    
           

[walt]

#1.  Can you tell the difference between a dwarf and a runt?  I think you can.  Make sure the plant is strong with typical leaves.  Or let me put it this way.  It sounds like what you want are shorter internodes.  The rest of the plant you seem happy with.  So concentrate on shorter internodes.  Don't go for fewer leaves.  Or maybe one or two fewer leaves.  Look your plants over carefully, then decide.

#4.  I don't think the two are linked.

#9.  I would be ok with saving seeds from 25 plants.  But do be careful to use only the best.  Good selection can overcome some inbreeding.  But on;y with careful selection.

[flowerbug]

plant the seeds a bit deeper to help with getting blown over. i'm not much into growing any kind of corn here (way too many raccoons, local farmers all grow GMO corn and we don't have enough buffer space anywhere) but i also would plant more than a single row if possible as they will help protect each other.

those are my thoughts, otherwise i'm interested in how this turns out for you. keep us updated!

[nkline]

Jan 20, 2020 23:41:21 GMT -5 Dewdrop said:

In short, I'm curious if Country Gentleman sweet corn can be selectively breed, with or without outcrossing, for a shorter plant height to about 5 feet.  Traits I want to hopefully keep (if not linked to plant height in genes) include the same or similar taste, sweet corn, thick cobs with smaller kernels to eat, tight husks (corn earwigs are well established here), and ideally also keep the 'shoepeg' zig-zagged kernal arrangement.        

Questions:
1 Would it work to select only the shortest plants for seed, or would that also select against vigorous growth?  Would it be better to aim for about average height instead, or to cull out the tallest corn plants?   
2 Assuming the corn plants must be grown outdoors, any tips for selecting for shorter corn plant height?
3 Would it be a bad idea to simultaneously 'wean off watering', whilst doing this project over seasons?  I currently water my garden on an as needed basis.  It would be nice it I could happen to end up with a more drought-resistant corn.    
4 Is corn plant height linked to cob thickness or kernel size?    
5 Are there any short 'shoepeg' corn? 
6 Is the Country Gentleman corn likely to produce more than 2 cobs per plant if I space them out 'properly', rather than my spacing of 4" last time in a row? (I know rows are not ideal, but I've apparently 'gotten away with it' by 'rubbing the tassels together' to pollinate the silks below)       
7 Are there any shorter sweet corn plants that produce over 2 cobs per plant reliably?  How far apart did you plant the seeds and what state or country did you grow them? 
8 Are there any shorter corn plants with tillers? 
9 What is the difference between saving seeds from 25 out of 100 corn plants compared to a few seeds from each individual corn plant?  How do you organize so many seeds when it's time to dry and store them?      
10 Any other tidbits of information that may be relevant?  Any constructive criticism?      

The reason I want to select for shorter height is for fun, and based off my experience with a good wind gust blowing down my unsupported corn plants the other year.  Yes I could simply try to hill the corn, or see if it will be enough to grow beans on as additional supports, but I think I would rather play with and grow something that eventually reaches my needs, or grow what already does.  I have acquired a taste for Country Gentleman corn though, especially when buttered and eaten as corn on the cob.    
           

1- You may not make 5 ft, but you should be able to shorten it some.

2- Count nodes, less nodes=probably shorter genetics, you can likely lower ear height which will help with wind as well.

3- I wouldn’t wean off water yet.

4- Probably not

5-Yeah I came across a short inbred for field corn that had a shoe peg segregate (I used it for a breeding cross, oops).

6- 4” is too close, they should have more ears, and be shorter if spaced properly.

7- Likely yes, more fertilizer will also help, nitrogen especially.

8- Yes northern flint backgrounds especially; this includes a lot of sweetcorns.

9- Genetic selection doesn’t really happen if you use all the plants, disposable condiment cups they hold 2oz and have clip on lids. I dry the corn on the cob blowing a fan on it at room temp, but I don’t do sweet corn.

10- I would breed it to a sweet corn with a plant type more like what you want, the first generation; then back cross it to country gentleman, and go from there.

[reed]

There are some short growing sweet corns. Blue Jade is one, it's a very small plant and very delicious, it tillers quite a bit and makes three or more small ears. I think it is Burpee that has a short hybrid they advertise for growing in containers, I don't know much about it though. It may se or sh2 or something you might not want.

I myself like to blend rather than hybridize. So to make a shorter version of Country Gentleman I would cross it to Blue Jade (and any others I could find of a short nature) with CG as the father. And in a separate spot do the opposite, CG as mother. Keep in mind what ever grows from that or those F1's will be of consistent type(s). Grow as many of those F1(s) as you can and save seed from as many as you can. That said these would be fairly wide crosses so you don't have to have a tremendous amount, ten would probably be fine is that is all you have space for.

Then I would just let the F2s pollinate each other at random. Space them at least 8" apart so they have room to demonstrate their actual potential. With water and ferts it doesn't matter too much, as far as the genetic blend goes except to make sure it is consistent so they all have equal conditions. Select from there, (by comparison) plants that meet your criteria.

After that just a simple continuing to grow your new corn, selecting each year for the plants that look like CG except shorter. As years go by selecting plants that are more and more similar to one another you will be bottlenecking your population to a some degree so will need to increase the number you save seed from each year.


I like doing it this way cause then I don't have to mess with so much tedious control of the project, after making the first F1 crosses you don't even have to mess with detasseling any, just select what you like. One thing that might screw you up on the first cross is maturity times of the different ones. Unfortunately the only way I have been able to tell for sure if two kinds will match up is to grow them and find out. If you have space you can do multiple staggered planting of each to increase chances they will match up.

There might be faster ways with controlled backcrossing and the like but for me that takes too much tedious effort.

[Dewdrop]

Thank-you so much everyone!  I didn't realize to check how tall or short the corn nodes were.      

This year may be an interesting year for me to try selectively breeding corn (by de-tasseling the undesired taller ones) and saving their seeds, but enough for me to practice with anyways.     I apparently have 11 older seeds left over from being mailed in for the year 2018. They were sitting on a closet shelf in the seed packet for about two years before I sealed them inside a canning jar, so hopefully they don't have too much trouble germinating.   I might try planting them 1 foot apart, rather than 4" apart to thin out to 8-12" like the directions on the seed packet says.  I can always improvise with the empty space later.  I don't know if it matters whether to thin corn sprouts by distance or by their height.        

I have plenty of seeds from 4 corn plants (out of about 40 corn plants total) when I was practicing seed saving the other year, unfortunately they were right beside each-other, so those seeds will probably be added very sparingly towards seed-saving.    
I may unintentionally get some cross-pollination from some shorter yellow sweet corn elsewhere in the same garden. I think yellow corn kernels are dominant over white, so the first generation of yellow seeds should be easy to select for or against.     

Is keeping the same taste tricky?  Would it keep relatively the same taste if the F1 Country Gentleman-Golden Bantam corn is breed back to the Country Gentleman corn?  Would it likely drop the 'shoepeg' corn kernel arrangement?      

[DarJones]

Shoepeg is a fairly complex trait to re-select. I've had to resort to a backcross to Country Gentleman to regain the trait. At minimum, you will have to bag each ear and self-pollinate (or backcross) to gain any ground. I should mention that I am attempting to combine shoepeg with se+ to improve kernel tenderness. There may be an issue with linkage between se+ and shoepeg.

IMO, selecting from your existing seed - given the small amount - will be unlikely to produce a significantly shorter plant. It would be better to deliberately cross to a shorter corn followed by selection and perhaps a backcross to get the height desired into a shoepeg background.

[Dewdrop]

Edited: Thanks DarJones. I forgot to check my seed stash before ordering seeds for this year, opps.    I completely agree with you that my corn population of my old 11 seeds (or rather how many actually grow) is way too small. 
I think I will manually cross-pollinate the CG (SU-corn) to the yellow corn, and back-cross it and see if the shoepeg shows up.  Luckily, I have my pick out of a total of over 100 of Golden Bantam (SU-corn) and Idaho Chief (I think) sweet corn plants to cross pollinate with.  It's just a question of timing with tassels and silks, I remember the timing worked out the other year.    Hopefully the back-crossed corn will taste ok, I know I didn't like the CG cob with roughly half (I suspect) GB-pollinated kernels.... it was edible but nothing like the bi-color corn of 'Peaches and Cream' I also like the taste of.    
        
I will just have a lot more corn to eat, I mean cull , this year.  I need to figure out again this year how much garden space I can maintain, since I expect to be busier this year outside the garden.    

[reed]

Jan 27, 2020 0:49:17 GMT -5 Dewdrop said:

Is keeping the same taste tricky?  Would it keep relatively the same taste if the F1 Country Gentleman-Golden Bantam corn is breed back to the Country Gentleman corn?  Would it likely drop the 'shoepeg' corn kernel arrangement?      

Selecting for flavor is the rub with sweet corn. You have to taste it to see and it's hard to save it for seed after that. Some people open the ears and cut off the top to taste and then close and seal it back up as good as you can to finish drying down for seed. Just go ahead and eat the ones that are less to you liking. I always ended up with a lot of bug and mold issues when I tried it but I don't know how else it could be done. 

[Dewdrop]

Thanks reed, I didn't know some folks tried cutting off the top of the corn and saving the remainder for seed. I know this garden has a very healthy population of corn earworms, but luckily the chickens are willing to help keep them in check come harvest-time.  I really should try to add a bit of mineral oil or PAM (nonstick) spray to the silks, but I keep forgetting to do so. The only loss is less corn in the freezer and on the plate, but we get some well-fed chickens for a day or two. Most of the time they are on the tips or top 1/3 of the cob that I can simply snap off. Sometimes we can cut off the bad corn kernels, on the cutting board. A few whole cobs go right in the chicken run if the damage is too spread out to selectively cut off.  Based on a casual observation, feeding them to the chickens seems to reduce the next year's corn earworm population/damage by roughly 1/3, but we also keep the chickens out of the garden itself.  I guess I could eat one cob and leave the other for seed, especially if the corn plants consistently produce at least two cobs per plant.

Does it matter in saving the top or bottom cob for seed? I can see the timing in eating the top cob working really well. I tend to have a harder time picking the second cob in it's very best time to eat, but I manage to get it while its decent anyways. It seems like the top cob is mature a bit quicker than the second cob. Mebe the top cob puts out silks sooner and has a head start?

[prairiegardens]

Has anyone tried Yukon Chief? I understand it to be a smaller (4-5 foot), very early corn generally with multiple (smaller) cobs, the reviews have been positive but nothing said about flavour..have ordered some for this year and hoping the taste will be at least decent. It isn't shoepeg though.

[nkline]

If the plant runs short on nutrition/water it will cannibalize the second ear to feed the first. They should taste similar if picked at a similar stage, but that is part of the selection battle too.

[prairiegardens]

Saltspring Seeds has Yukon Chief this year much to my astonished glee, they are bringing some to the local seed swap March 1 for me. They actually carry a number of interesting varieties of veggies that I haven't seen elsewhere. I had first run across Yukon Chief on Sandhills but if I can get what I'm looking for in Canada then it seems a good thing to support the locals(and save the exchange rate..money saved means I can buy more seeds!)

[Dewdrop]

Hmm, I seem to have more questions again.

Questions:
1 How often do you have to outcross corn? When is it more optimal to outcross?  
2 How many corn plants do I want to introduce for the outcross(for a population of 100 plants)? What if I intend to backcross the seeds from the outcross?    
3 Would the plants dna/genetics be 'different'/re-arranged enough in one variety of corn was divided into groups to focus on different traits (like shorter plant height or more tillers)? What if one plant variety was grown in different environments (near mountaintop vs. in a valley)?
4 Should I locally adapt seeds for a year before selecting for plant height?

[nkline]

Feb 9, 2020 18:45:38 GMT -5 Dewdrop said:

Hmm, I seem to have more questions again.

Questions:
1 How often do you have to outcross corn? When is it more optimal to outcross?  
2 How many corn plants do I want to introduce for the outcross(for a population of 100 plants)? What if I intend to backcross the seeds from the outcross?    
3 Would the plants dna/genetics be 'different'/re-arranged enough in one variety of corn was divided into groups to focus on different traits (like shorter plant height or more tillers)? What if one plant variety was grown in different environments (near mountaintop vs. in a valley)?
4 Should I locally adapt seeds for a year before selecting for plant height?

I’ll take a stab
1. You just don’t want to self it more than a couple generations depending on how broad based your starting population is.
2. I read this question multiple ways, so here’s a few answers; you need multiple planting’s of a parent likely the male to sync pollination, try 10 days before, 5 days before, same day, 5 days after, 10 days after, if you have zero clue. I would consider country gentleman to likely be a little inbred, so then it just comes down to how inbred the other parent is. If you cross two inbreds you will get one plant type and the next generations is where it gets interesting. I would at least do 5 of a cross, and keep track of the female, one might kick out genes you don’t like and you can scrap everything coming from that female line. If I were doing it I would try at least 5 cg females/ yukon chief males (if that’s what you decide on) but would plant the Yukon chief 5,10,and 15 days after maybe more than that. Then back cross using your hybrid as the seed parent probably 20 female plants/ cg males planted 15,10,5 days before the hybrid females. From there select for plant height and adaptation to your environment keeping seed from the top 20 plants out of 100 maybe do this three years keeping everything open populated. From there I would narrow down ear taste, type, color and other things keep 20/100 still all open pollinated.
3.Yes, but your project would take forever
4. No, throw out poorly adapted as you go, and if you can, kill the poorly adapted plants before they contribute to your gene pool