FROM GREAT Depression days to these recession days, one Washington institution has consistently provided this city with a taste of the country--the Montgomery Farm Women's Cooperative Market. For half a century, this white-clapboard, green-shuttered building in the 7100 block of Wisconsin Avenue has attracted a loyal following who come to purchase fresh and home-canned produce, meats and baked goods from some of the same women who sold them to their mothers and grandmothers.

Here you can watch the seasons change without glancing at the calendar. Easter hams and potted lilies give way to lilacs, bundles of asparagus and baskets of dark red strawberries; these, in turn, are replaced by the peas, beans and melons that overlap the arrival of fleshy tomatoes and heaps of milky corn. Then come the months of apples with the tang of childhood memories, the cider, pumpkins, pork sausage and mincemeat pies of autumn and winter.

This venerable market, celebrating its 50th birthday this year, sells only the produce that's in season on nearby farms. You will never find a tomato here in June or a banana anytime. What you will find is some of the finest quality food in the Washington area, from brown eggs to sweet butter to country hams and bacon.

Some aspects of the Montgomery cooperative have not changed in the intervening years since a group of women banded together to keep the wolf of the Depression from their farmhouse doors. You will still find, among others, "Big Mildred" and "Little Mildred," Mrs. Russell Watkins and Mrs. Irving Watkins.

But elements of change are in the offing: Urban sprawl has spilled houses, highways and shopping malls across the fields and orchards of farm after farm throughout Montgomery County. (The National Agricultural Lands Study, published by the federal government last year, predicts that at present rates of loss, Maryland could lose 44 percent of its "prime and unique" farmlands in the next 20 years.) In addition, the women, a surprising number of whom have been there from the beginning, are growing older, and many of their families have sold acreage on which they once grew food.

Another change has been the addition of a flea market that occupies the front yard from spring through fall. Leon Carrier, manager of the market, explains that in a time of rising taxes, the two days of market operation are no longer sufficient to produce needed income. But some food sellers worry that customers will spend their money before they come through the door.

Yet the farm women still come every Wednesday and Saturday. Mrs. Russell Watkins, who has been selling at the market for 48 years, still lives on the farm where she was born more than 70 years ago. She sells eggs, an occasional fresh turkey, exceptionally good fruit preserves and apple butter and what some consider the market's best roasting chickens. She talks about retiring, taking life a bit easier. She and her husband have raised their own family and six foster children from their farm earnings, but Watkins says she is tired now.

Mrs. Irving Watkins, whose glass cases display frying chickens, brown eggs and a year-round selection of pork products such as scrapple, sage-spiked sausage meat, smoked and unsmoked links, spareribs for summer picnics and fresh ham for winter roasts, has missed only two Saturdays in 39 years. She was absent the day her son, Roger, was born and the day her husband died.

Roger Watkins, himself the father of a teen-ager now, remembers hearing of the market's beginning as "the only way anybody on a farm around here had of converting anything into cash." He took over the Damascus farm when his father died and says that these are bad times for farmers. "I don't care how hard a fellow works, a farmer in Montgomery County today will not make interest on his investment. But to me, it's the life I know best. It's all my mother knows."

"Since Ada Main retired, I think I'm about the oldest one here," Joyce Burke said one Saturday. "I'm not sure I like being the oldest." Burke's stall sells home-baked ham that's great for summer picnics, and fresh liver that she picks up at a slaughterhouse. In the fall and winter she has ox tails for soups and stews, and in summer she sells vegetables and flowers like those in a grandmother's garden. One Saturday in May, there were jugs of old-fashioned peonies with a fragrance evocative of Decoration Day in New England. She sold them at $5 for a fat bunch whose buds continued to unfurl for nearly two weeks.

Ada Main, of whom she spoke, was a market landmark who retired last winter at nearly 80. Main had spent 43 years of Saturdays at the market, nearly as many years of rising at 4 a.m. on Fridays to bake the soft, heavy wheels of pound cake that drew customers to her stall from all over Washington.

Frances Renn, a 37-year veteran of the cooperative, sells plants, seedlings, cut flowers and, in December, woods-sweet Christmas greens and wreaths.

Harold Mullinix, whose farm has been in the family for five generations, sells beef raised on his own corn, oats and hay. At his corner stall, you can buy "country cuts" such as a flavorsome boned and rolled shoulder clod (neck meat nearest the shoulder) that makes lots of juice for gravy. Mullinix will sell you a hind quarter for your freezer or a hefty steamship round for your party.

While many produce items sold at the cooperative are considerably less expensive than their supermarket equivalents, the emphasis here is more on the quality of the food than on the price. Apples, cider and pumpkins seem especially good buys, and beet greens were selling recently for $1 for a grocery bagful, but you will pay $2 a pound for Mullinix's ground chuck and $2.50 a pound for the shoulder roast. The important factor is the first-rate quality of the beef or of the chickens sold at other stalls at 95 cents a pound. The difference in flavor is immediately apparent.

The Cox family sells a mixture of produce and prepared foods at a popular stall whose customers form the only orderly line in the market. The Coxes offer apples far into the winter, farm-churned butter in sweet and salted versions, hams, ham hocks to boil with greens, locally made cheeses, fried chicken, salads and thick squares of chocolate fudge that summon memories of late nights in the kitchen with a wooden spoon, marble slab and sticky fingers. The pies here are excellent; a long sign-up list at holiday time demonstrates the popularity of the pumpkin and mincemeat varieties.

Carrier says it's becoming difficult to find new farmer vendors to replace those who leave, to maintain the balance between produce and prepared food that he wants to keep.

Prepared foods--from Inger Dvorak's Norwegian cakes to Mrs. Johnson's biscuits and the kung pao chicken and steamed dumplings at the family stall called Judy's--now constitute much of the fare at the cooperative.

One popular stall that sells prepared goods is "Joyce's Sin City," a stall just inside the door. Joyce Berthoud, a former social worker, faces ranks of customers who stand four deep waiting to buy fruit salad, lemon cakes, Jamaican meat pies and casserole dishes. Some customers even bring their own serving dishes in which to carry off the food for a party.

Some stalls assemble their wares from several sources, choosing the best maple syrup here, the best peaches there. One such enterprise is owned by Chunil and Rick Marquez, who deal with 12 to 15 suppliers for the sophisticated fare they offer: croissants, black rye bread, fudgy midnight layer cake, tortes, deep-dish quiches that cause traffic jams in the far left corner of the building.

Margaret Finzel makes a first-class chicken salad, and the carrot cake she bakes has created so many fans that several customers have ordered cakes to carry on trips out of the country. But customers also go to her stall for Romaine Baugher's pies--raspberry, cherry, blackberry and blueberry, all made from fruit harvested at the family's Westminster, Md., orchards. And Baugher's apple dumplings are another favorite.

For many regular customers, the fun of the market is the unexpected. Standards such as barnyard chickens, blackberry jam, old-fashioned varieties of apples, new potatoes, pots of rosemary and savory, glossy cabbages and baby carrots are all very fine. But one week there may be oyster plant, cushiony red raspberries or seldom-seen gooseberries. Perhaps even clumps of woods ferns for transplanting. There may be masses of yellow zinnias in back-porch coffee cans or kohlrabi fit for a still life.

If you miss a week at the market, a season could slip by you. KOHLRABI AND NEW POTATOES (4 to 6 servings) 1 pound kohlrabi, peeled and sliced 1 pound tiny new potatoes 2 tablespoons fresh sweet butter 2 tablespoons flour 1 cup milk Salt and pepper to taste 1 teaspoon celery seed Pinch caraway 1/4 cup sharp cheddar cheese

Boil kohlrabi in salted water until tender, then drain. In separate pan, boil potatoes in salted water until tender. Drain and peel potatoes. Combine kohlrabi and potatoes in a bowl. Make a cream sauce, using fresh sweet butter, 2 tablespoons melted and stirred over low heat for a couple of minutes with 2 tablespoons flour, then a cup of milk gradually whisked in. Season with salt and pepper to taste, 1 teaspoon celery seed and a pinch of caraway. Stir until it boils and simmer for a few minutes. Pour sauce over vegetables and put the mixture into a 1 1/2-quart baking dish. Sprinkle with 1/4 cup sharp cheddar cheese, and bake at 450 degrees for about 20 minutes. STEWED OYSTER PLANT

Scrape and wash salsify, or oyster plant, and slice lengthwise or across. Stew slices until tender in salted water; drain and put in saucepan. Cover with milk. To one pint of salsify add a tablespoon of butter rolled in as much flour as will adhere to it, season with salt and pepper. Bring to a boil and let stew for five minutes. GREEN PEA PANCAKES (Serves 4) 2 cups green peas Salt, pepper and sweet butter 2 eggs, beaten 1 cup milk 1/2 teaspoon baking powder 1/2 cup flour Oil for pan

Boil green peas a few minutes until cooked, drain and mash while hot. Season with salt, pepper and sweet butter and let cool. Add beaten eggs and milk. Sift together baking powder and flour. Beat into the mixture of peas, eggs and milk. Mix well. Heat oil in a frying pan and drop batter by spoonfuls. Cook as you would griddle cakes. FRUIT PUDDINGS (6 servings) 1/2 cup sugar

1 tablespoon butter 1 cup flour 2 teaspoons baking powder 1/4 cup milk 2 egg whites, stiffly beaten Butter for pan 1 to 2 cups berries or peeled and diced peaches, sweetened to taste Whipped cream for topping

Cream sugar and butter together. Sift flour and baking powder together and stir into sugar, then add milk. Fold in egg whites. Fill buttered individual pudding cups 1/3 full of fresh berries or peaches, which have been sweetened to taste. Put a large spoonful of the batter on top of fruit, set over water in a covered pot or pan, bring water to boil and steam for 30 minutes. Serve hot with whipped cream. FRIED CORN 6 ears fresh corn Salt and pepper 6 slices bacon

Cut corn from ears and squeeze out "milk" from corn cobs. Season lightly with salt and plentifully with pepper. Fry bacon until crisp. Remove bacon and put corn into pan with bacon drippings. Stir well, then let set over very low heat until a brown crust forms on the bottom. Turn corn into serving dish and sprinkle crumbled bacon over the top.