Mother Earth News, Sep/Oct 78
How to Choose Parent Plants
Once your vegetables are established - in late spring or early summer - select only the finest specimens for seed production ... the ones that are most robust, have the shiniest leaves, are least bothered by insects, and seem truest to type. And don't judge merely by a single criterion - giant fruit, for example - but consider each plant's overall vitality. Remember, sickly plants yield fewer viable seeds ... and tend to produce sickly offspring to boot!
Next, after you've chosen your "parent" stock, clearly mark each plant in some fashion (with ribbons or stakes or what have you) to set them apart from your "ordinary" eatin' vegetables. If you're anything like me, you'll thoroughly enjoy selecting plants for such desirable traits as earliness, sweetness, hardiness, shape, color, productivity, and resistance to drought or pests. In effect, you will be developing your own strains ... and chances are they'll be better adapted to the environmental conditions in your own particular garden than any commercial variety you can buy.
Mother Earth News, Sep/Oct 1987
Bring new pleasures and superior plants to your garden
By Nancy Bubel
Be sure to mark your parent plants with stakes, bright labels or wild-colored cloth strips. This is especially important if more than one family member is likely to be picking vegetables. It's no fun to find that your earliest-ever pea pods just disappeared into the soup pot. ... Be sure to choose your parent plants carefully, selecting seed only from superior examples. What should you look for? Whatever's important to you. If you'd like early tomatoes, save seed from the first fruit that ripened. If it's size you're after, save seed from the plant that produced the most large fruit. And consider the plant as a whole in addition to individual qualities.
With most cross-pollinated crops, you should save some seed from five or more individual plants (even if you only need a small amount of seed). If you repeatedly keep the offspring of only one plant, over time the inbred seed will most likely run down, i.e., lose vigor and become more susceptible to disease or other problems. Self-pollinators don't lose vigor from their natural in breeding, so you can safely save only one plant's (or a single fruit's) seed from them if you wish.