Ten years ago, if you didn't have your own backyard strawberry patch, the best place to find the tasty little fruit was in grocery stores or supermarkets.

Now "pick-your-own" plots abound in metropolitan Washington suburbs, and more are opening up for business every year. These scattered fields, where you pay by the pound or quart for strawberries you pick yourself, are fast becoming the most popular means of getting strawberries to the table.

Fruit specialists at the Beltsville Agricultural Research Center say the "pick-you-own" method should provide the bulk of consumers' strawberries before too long, and they are conducting extensive experiments to catch up with the growing demand for "the perfect suburban strawberry."

None exists as yet, but the Beltsville researchers say they are only two or three years away from producing a berry that is more suited to suburban growing conditions.

The research center, part of the U.S. Department of Agriculture, last week held a Strawberry Day in the fields and kitchens of the sprawling institution. A taste test, in which only one person participated, showed that the most appetizing-looking strawberry ended up with the lowest rating; and a not-very-distinguished-looking berry got the highest.

"The disproves one strawberry myth," concluded Dr. Miklos Faust, chief of the Beltsville fruit labs. "The berry that looks the best doesn't always taste the best." Faust wore a tee shirt featuring a bright red strawberry on the front.

When consumers shop for strawberries, they look for those that have the most appealing shape, size, color, flavor and firmness. When researchers choose strawberries, they look for all these qualities and more besides.

For a strawberry to flourish in the generally overused and diseased soils near major population centers, where most "pick-your-own" plots are located, the fruit also should be disease resistant and not require many sprays, according to Faust.

It should have dark green leaves, bear a maximum amount of fruit on a minimum amount of runners, have a high vitamin content, freeze well to provide a year-round supply, bear fruit all summer long and resist molding in containers, among other qualities.

Many of these characteristics already exist in the 80 or 90 varieties now available in supermarkets, Faust said. And researchers are nearing the point where a strawberry that produces all summer long will be available in "pick-your-own" plots.

"We're only two or three years away from introducing a strawberry that will bear fruit all summer long, maybe even into September," said Fraust as he checked some of the 50,000 plants in the center's agricultural fields to find berries to compare. "But it probably will be 15 years before we get a plant that won't need to be sprayed."

The years of research being put into strawberry production is to benefit the small farmer as well as the consumer, Faust added. He said five acres of a "pick-your-own" plot can support a small family that sells strawberries to pickers. The small farmer, not able to conduct research on his own, can choose the variety that best suits his region and purpose.

It takes at least 10 years to develop a strawberry variety, a comparatively short time compared to other fruit development such as apples, that can take 30 years, Faust said.

The researcher starts out with 60,000 or 70,000 plants, artificially pollinates them with the desired characteristics of a father plant to combine the best of each. The seeds from this breeding will be planted and left to determine which are the strongest. About 90 per cent of the plants will die, Faust said. From the remaining 7,000 or 8,000 plants, about 120 with the most desirable characteristics will be chosen. More experimentation is done to produce one plant that exhibits the best qualities of all the others.

As Faust rummaged through the research center's plants, he picked out some that were as large and red as small ripe tomatoes and others that appeared similar to raspberries. Many of the plants were well known varieties available commercially. Most however, had only numbers for names, still considered by fruit specialists as unborn strawberries.

The most typical types of strawberries for this area are the Early Glow, Red Chief and Guardian varieties. Some of the charateristics of these varieties are being bred into new varieties to form a new, ideal type.

Faust said the ideal berry would be oen that is "large, juicy, sweet, flavorful, grows easily, resists disease, has a high productivity and is long-bearing."

"The ones available now are perfectly acceptable and quite tasty," he added. "But there's no reason we can't try to come up with one that retains the high quality of current varieties while requiring less spraying for disease resistence."