Yes, you can breed your own OP corn variety! It is fun and rewarding, but you need to know how. Some things are easy and some things are harder. Here is how you too can reclaim your heritage, affirm your God given right to save seed, and improve corn for yourself, our neighbors, and our descendants.

Getting Started

First you must begin with a good population. What makes a population good will vary from place to place and among different types of management. You need corn that will mature useful grain or forage for you under the rigors of your climate, soils, fertility, pests, and diseases. It needs to stand up long enough to be readily harvested. Your corn should be a good partner in your agricultural enterprise that is dependable and meets your needs! See how Dave Christensen breeds Painted Mountain corn in Montana. [Click Here]

There are relatively few OP populations to choose from that are available in large quantities anymore (SEE THE SEED SOURCES PAGE). Unless you have some good information you may need to do your own strip trials in smaller 2-4 row strip plots for a year or two to find which ones perform well in your location. The 1936 USDA Yearbook of Agriculture has a list of OP varieties that were once recommended in the United States (Table 1). Some of these are still available from the USDA National Plant Germplasm System (http://www.ars-grin.gov/npgs/searchgrin.html), though some may be partly inbred and some others are now extinct. The NPGS and some university breeders also have seed available of newer populations. What you want is a genetically diverse population that performs well for you, and like Dave you may have to build it using good planning and careful observation.

Crossing together the best looking varieties from your strip tests can often result in better performance than sticking to a “pure” variety which may be partly inbred. New mixed populations are called "composites." Recent research has shown that forming composites or mixtures of varieties can often increase yield by 10% or more over the pure parents. Dave Christensen's Painted Mountian is a composite of the best plants from the most adapted varieties in Montana. Anyone can easily form a new composite variety and then select out the best performing plants over time. Famous OP varieties like Lancaster Sure Crop, Reid's Yellow Dent, Krug Yellow Dent, and Falconer all began as composites on farms. Random mixing of seed from two or more good varieties (and especially three or four) will allow this to happen, but controlled pollination for one year will make sure that all the seed planted afterwards is actually of the intended pedigree. Planting alternate rows of two populations, detasseling one, and only saving seed from healthy plants in the detasseled rows will do the job right.

However, to form a high yielding composite as the basis of your breeding population you need some information first. Evaluation over years and learning about the hybrid vigor that can occur among certain population crosses is very important. If you are in a Corn Belt location, you may wish to form composites of some existing university populations that cross well together. The Iowa Stiff Stalk Synthetic (available from the USDA collection as PI 550481 - BSSS (R)C6) has superior hybrid vigor with many other varieties. Crossing to it can improve stalk strength and yield. Work in North Dakota and Ontario has shown that the 90-day maturity Stiff Stalk population from Guelph (PI 613074 - CG-Stiff Stalk (Combined S & RRS) C4) has very good general combining ability for yield and standing ability. Chances are also very good that the Stiff Stalk population (PI 517960 - PA Composite I (GLS)C1 (HY)) and Lancaster-type populations (PI 517962 - PA Composite II (GLS)C1 (HY) ; PI 517964 - PA Composite III (GLS)C1 (HY)) from Penn State could be crossed together to form a higher yielding composite.

The corn breeders of the early 20 th century warned against purchasing too few ears and purchasing seed in bulk. Since only a few ears are needed to plant an acre of corn, farmers would sometimes purchase just enough ears to do the job. However, in subsequent years inbreeding would drive down the yield of that seed because too few parents were involved. To avoid inbreeding problems it is best to have 100-400 parents (ears) to start with and in every succeeding year. It is best to purchase too much seed, stir it together well, and plant what you need the first year, saving the rest in reserve. Small quantities of seed can be acceptable to increase up to many bushels over a period of a year or two, but you cannot easily tell if the seed you are buying in the packet comes from one ear or a bulk of one hundred ears. Again, it is best to purchase as much as you can if it is a variety that appears to do well for you and to consider forming a composite if you think there is more yield potential in the population(s).

Table 1. List of OP Corn Varieties Recommended in the Different States by Their Respective Experiment Stations from the 1936 USDA Yearbook of Agriculture. [click here]

Breeding Methods and Seed Quality

The thing to remember about corn inheritance is that corn only inherits genes from its parents, not the way your management, rain, soil, rocks, your planter, pests, and other environmental factors have impacted them. A poor looking plant may have very strong offspring if it looked poor solely due to the conditions under which it grew. Similarly, a stupendous plant with a large ear may appear great just because it got extra fertilizer or had more space and its offspring may perform below average. When breeding corn, we want to select for good plants and make sure that they look good due to their genetics working within your environment.

Corn breeders have developed many different ways in which to make selections for improved yield, nutritional quality, plant standability, and disease resistance from good populations. The oldest forms (selection solely for ear type, mass selection among picked ears from the corn crib, simple ear to row selection) are fine for simply inherited traits like kernel color, ear shape, maturity, etc., but they work poorly for improving yield and other difficult traits. Listed below are the easiest, cheapest and surest ways to make selections yourself that can also improve yield.

However, just like in the old days, the quality of the seed you produce and of your field management will greatly impact your ability to obtain the best yields possible and to make good selections for the future. Well dried seed picked before a major frost from plants with excellent characteristics (large eared, well rooted, healthy, standing well, etc.) will give the best germination and uniform stand the following year. Using plateless planters or hand planting with a jabber will mean that you can get good stands even with less uniform seed sizes and shapes. Uniform stands make for the highest yields and the most efficient plant selections.

Recurrent Mass Selection for OP Corn [click here]

Why Stratified Mass Selection (as developed by Charlie Gardner)?

Two things determine the performance of a corn plant: genetics and environment. Soil, fertility, rocks, water, wind, insects, other corn plants, weeds, etc. all affect the performance of the plants you will be looking at, but these effects are not inherited! You should try to manage as best you can, but there will likely be some variations in the environment for each plant. If you only took huge ears from the rows on the outside of the field (very sunny) you would not make any more gain than if you took smaller ears from deep inside the field. Similarly, if there is a gap in the row those plants may look better than they are genetically simply because they have a little more light and water. Soil type in the field can also affect the fertility and moisture available to the plants. By mentally breaking the field up into smaller plots the comparisons among the plants within each plot are less likely to be affected by soil variations across the field and more likely to be affected by the genetics of the plants. Since plants do not inherit the environments but only the genes of their parents, this makes for faster rates of genetic gain. Stratified mass selection like this can make real gains in yield, especially if you harvest only the best ears from the best plants, the climate year to year does not vary too much and the population is genetically diverse (not inbred).

Modified Ear to Row Breeding for Corn [click here]

Why Modified Ear-to-Row Selection (As developed by John Lonnquist)?

This is clearly much more work than recurrent mass selection using stratified plots, but it may be worth it if time matters to you. By looking at several of the offspring from each ear under different circumstances you can get a much clearer idea of the genetic value of that ear with less interference from the environment where the mother plant first grew and where the offspring grow. Randomized row order helps give you a better idea of each ear row by allowing them to grow next to different ear rows each time. A little mass selection within each of the crossed ear rows in the third field also helps a little more, and bulk rows for pollination mean that many parents are involved for each ear, thereby helping to avoid inbreeding problems. However, the detasseling of unacceptable plants in the bulk rows (fathers) will help reduce the spread of those traits to the good performing, detasseled ear rows (mothers).

What Else?

One of the problems with selection visually is that we often take the biggest looking ears rather than the best ears that are high yielding AND acceptably dried down. Weighing the ears individually (mass selection) or in bulk by ear row (modified ear-to-row selection) right after picking and after a period of drying in the house or in a heated shed can allow you to judge the moisture content of the ears at harvest (wet weight – dry weight = lost moisture), though some can judge this pretty well by feel. Then you can consider maturity and dry down. If you also shell the dry grain and weigh it you will add to your list the actual yield of grain for each plant or row rather than the yield of grain and cobs. Remember, it is not ear length or any other ear trait but the actual weight of grain that determines grain yield!

Standing ability is also a problematic issue. In mass selection you MUST pick the ears before they are damaged by freezing, even though the stalks may weaken afterwards and fall over. If you are able to do your work in a breeding plot and not your production fields, you may be able to harvest just the best ears and also number them and the stalk from which they came (using large, colorful tags and permanent black markers). If the rest of the breeding plot is hand harvested you will still have seed for planting production fields the following year. However, you will be able to go back later and judge the long term standing ability of the plants from which you chose ears. Those from plants that fall down too soon after the harvest or which collapse when given a light kick are worth rejecting. Similarly, in modified ear-to-row selection you will have to make seed selections before frost, but you do not need to harvest the evaluation plots until later. Taking good notes on these at the normal harvest time will make it easier to decide which of the harvested rows are truly worth saving. In both cases, however, an excess of ears or rows must be harvested so that later selections among the ears can be made (by standing ability of their stalks) without reducing the number of saved ears too low.

PLEASE! If you have helpful stories and other information to share that would help others better select their own corn let Dave know!