CORVALLIS - Many home gardeners may wonder what hybrids are, as they shop for seeds and vegetable starts in the spring. And they want to know if hybrids are better than standard, open-pollinated varieties.
Next time you visit your local seed store or catalog, take a look at the name and description of each variety. If it is marked with "F1" or "hybrid," then it is a hybrid variety, according to Bill Mansour, Oregon State University vegetable crops specialist.
If it is labeled "heirloom," "open pollinated" or has no special markings, then it is most likely an open-pollinated or standard variety. Most lettuce, bean and pea varieties for home gardeners are open-pollinated, while most cabbages, broccoli, tomato, cucumbers, melons and Brussels sprouts are hybrids. Hybrid summer squashes, cucumbers, melons, corn and carrots dominate the garden seed market.
What is a hybrid, anyway?
A hybrid is the result of pollination of one genetically uniform variety with pollen from another specific genetically uniform variety, explained Jim Baggett, professor emeritus of horticulture at OSU. A seed company chooses parent varieties that will produce first generation offspring (F1 hybrids) with the special characteristics they desire.
"Hybridization, or crossing, is done in a very controlled manner so that all of the plants grown from the hybrid seed will be the result of the desired cross and will be genetically identical," said Baggett, who has bred dozens of new varieties of vegetables for the Oregon agricultural industry and home gardeners, including several varieties of snap peas, tomatoes and green beans. "The pollination is often done by hand, which results in expensive seed."
In some crops, less expensive methods can be used to make hybrids.
"In corn, for example, the male and female lines are interplanted in the field," he said. "The tassels are removed from the female or seed parent, or a self-sterile female is used. Pollination is done naturally by the wind."
Hybrids may be bred to be more widely adapted to environmental stresses such as heat, cold, disease or drought. They have more uniform characteristics than non-hybrids, making crops more predictable in quality. Sometimes hybrids can be made to produce earlier or higher yields, have higher germination rates or more cold tolerance.
"Because they usually have hybrid vigor, they may yield more than open pollinated varieties," said Baggett.
But hybrids do not "breed true." They do not produce seeds that will grow into plants exactly like themselves, because in the next generation, the genes have segregated into many new combinations, explained Baggett.
What this means to the home gardener is that reliable seed cannot be saved from hybrid plants. Seed for hybrid varieties must be purchased year after year from the seed companies or nurseries, unless you want to gamble and grow an array of offspring.
On the other hand, standard, or open pollinated varieties are more or less stabilized in their characteristics. They remain fairly consistent, producing seed that will grow into plants more or less like their parent plants, though less uniform than hybrids.
Standard varieties either self-pollinate or are pollinated by wind or insects. Standard, open pollinated varieties most often produce viable seed, so home gardeners can more dependably collect and save their own seed. Sometimes, due to genetic mutations, offspring of open pollinated plants can be significantly different than their parents. Commercial growers often term these plants "rogues," and cull them from their fields.
Most U.S. production farmers want their whole crop to mature at once and be of uniform color and size - hybrids help them do this. If you are a home gardener who wants to save and trade seed with friends or an heirloom gardener who is interested in saving and preserving old varieties, then some open-pollinated varieties will be for you. Most home gardeners grow both open pollinated varieties and hybrids.
Some seed companies that sell a good number of open-pollinated varieties include: Nichols Garden Nursery, 1190 North Pacific Highway, Albany, Ore. 97321-4580; Seed Saver's Exchange, 3076 N. Winn Rd., Decorah, Iowa 52101; Territorial Seed Company, P.O. Box 157, Cottage Grove, Ore. 97424-0061.