Classical plant breeding is now perceived as old fashioned, less quick, less effective, and less responsive than genetic based techniques. But the fact is that classical plant breeding is more efficient, it doesn’t take any more time, and it allows you to move the body of traits quickly and effectively toward the intended outcome. Using classical breeding techniques, you can juggle multiple traits simultaneously and transform your crops in multiple ways, versus genetic modification (GM) which looks at one trait at a time. Using GM, it takes a lot longer to make multiple changes in a population. So much of genetic modification is based on ownership of genetic material, while classical plant breeding is not. And the cost of classical plant breeding is miniscule compared to the cost of genetic transformation. Further, classical plant breeding uses appropriate technology that’s been around for a long while and doesn’t have massive negative impacts on the land.
Why breed on your farm? Breeding allows for specific adaptations to the environment, allows for adaptation to your cultural needs, and allows for control of your seed source.
It also allows you to identify which traits are important to you. You can breed for texture, taste, crack resistance, color, beauty, or disease resistance and select for quality traits, and/or for environmental adaptation, and/or for cultural adaptation, and/or for long-term adaptive advantage (to maximize genetic diversity), and/or for high-quality seed.
It is important to choose the right crop. Is it important to you? Do you love it? Does it resonate with you? You cannot breed a crop out of obligation. Also, consider if you can produce seed in your climate and whether the crop fits into your system, your seasons, and your wet and dry times.
Always start with trials. There is great expertise right here in Hawai‘i—people at the university who are willing to help you conduct variety trials. Trials allow you to evaluate varieties for their potential for plant improvement as breeding parents. Doing the research for your trial will help you to identify if there is a variety that already works or a variety that almost works. You might find that there are two varieties, which when combined, might work. Start with something that has good genetic variation already, and really get to know your crop.
To make a strain cross, grow 50–100 plants of each variety. Select 20–30 of the best individuals before flowering, then remove the other plants. Harvest bulk seed from each variety. Allow the progeny to inter-mate for 1–2 seasons. Plant them near each other, and see which does better. Harvest the less preferred strain, and collect seed from the preferred strain.
You can use either progeny selection or mass selection in breeding your plants.
In mass selection, plant a large population under uniform conditions. At the end of the season select 20 plants from each of the four corners of the plot. In several generations you will have a new variety.
Progeny selection is a bit more involved. Select 50 plants from the population (save the best only), let them inter-mate, save seed in individual brown lunch bags, plant 50 individual rows (row #1 gets seed from bag #1, and so on), times two repetitions next season.
In the second season, select 15-20% of best families (rows) based on both repetitions. For example, 7–8 rows out of 50 might be really good. Eliminate the other 42–43 rows before they flower. Then eliminate 30–40% of the poorest plants from the selected 7–8 rows. Allow the remaining plants to inter-mate. Collect bulk seed within families (by rows). Selecting seed by rows lets you control the maternal genetics (versus mass selection where all families are mixed). Next, plant the selected families (2 repetitions), evaluate those 8 rows, bulk their seed as a variety if satisfied, or repeat family selection if necessary. This is a 3–4 year process to create a new variety. If we really want to be prepared for the future, we need to increase genetic variability. Leave as much variability as you can in the plants you select.
To find plants that are disease resistant, you can create a disease nursery, doing everything possible to make the plants susceptible to disease. Choose susceptible varieties of plants and plant alongside a resistant variety (control). After you determine which varieties are resistant to disease, cross the resistant variety with good tasting varieties. Soon you will have new varieties that are flavorful and more disease resistant—all for very little investment of money.