Agriculture is big business in Virginia.

The state's largest industry, agriculture reaches beyond the cornfields (employing 50 percent of the state's manufacturing work force) to produce one of the most delicious examples of American cuisine.

To celebrate this economic and culinary coup, the Virginia Agribusiness Council sponsored the first Virginia Food Festival August 11 at the State Fairgrounds in Richmond.

"We've been making some of these foods since colonial times," said J. Carlton Courter III, director of member relations for the council. Group members, he said, decided to pool their resources and "have some fun" with the products they make.

Thunder-threatening clouds notwithstanding, 5,000 people from all over the state, many in blue jeans and cowboy hats, ambled from tent to tent to taste the best of Virginia.

Hot dogs made from turkey meat -- representing the sixth largest turkey production in the country -- went over well despite some initial reluctance. But no one hesitated to line up for beef and pork barbecue. Beef cattle are Virginia's top agricultural industry and pork ranks fifth, so vendors were kept busy dishing up more than 9,000 barbecue sandwiches.

The state's egg and dairy industry served dessert -- wholesale milk is the state's second largest commodity. Twelve people had spent the previous day making thousands of crepes, which were stuffed with apples and topped with vanilla ice cream and chopped peanuts.

Alpenglow -- a preservative-free drink made from Virginia apples -- was a sparkling alternative to the milk, beer and iced tea also served at the festival. But the natural spring water from Surry County offered a welcome reminder of just how good plain water can taste.

The feast ended, traditionally enough, with Virginia soybeans and peanuts.

Soybeans, it was noted, have an image problem. "Everybody knows soybeans are the coming protein source for the American farmer," said one soybean farmer, "but how many people know what a soybean plant looks like, let alone how the bean is used?"

This was no gourmet affair. But food lovers were treated to a taste of Virginia-style food that--complemented by the recent growth of a new wine industry, and highlighted by several new restaurants that treat Virginia ingredients with a "continental" touch--make up one of the finest regional cuisines in the country.

The following recipes feature some of these indigenous foods. VIRGINIA PORK BARBECUE (10 to 12 servings) 6 to 7 pound boneless boston pork butt (allow one pound of raw meat to yield 1/2 pound cooked barbecue) Barbecue glaze (recipe follows) Barbecue seasoning sauce (recipe follows)

Prepare charcoal fire. Wipe pork with a damp towel and place, fat side down, on the grill. (Use a barbecue meat thermometer if you wish to determine when the pork has cooked thoroughly.) Cook 1 1/2 hours then turn the meat over and baste with barbecue glaze. Continue cooking and basting for another 1 1/2 to 2 hours. Total cooking time should be about 3 1/2 hours.

When the meat is cool enough to handle, chop or mince the cooked pork butt and mix with barbecue seasoning sauce to taste. If you are using a commercial sauce, adjust it by adding 1 pint of vinegar, black pepper and crushed red pepper to taste, to 48 ounces of commercially prepared sauce.

The meat should be lightly moistened with sauce. Serve hot, on buns or with corn on the cob and cole slaw. BARBECUE GLAZE

A barbecue glaze should contain nothing that will burn as it cooks over a charcoal fire: no tomato paste, sugar or worcestershire sauce. Instead, mix to taste and according to the size of the roast: hot melted butter, vinegar, salt, black pepper and red crushed pepper. Heat and mix together and use to baste meat while cooking. BARBECUE SEASONING SAUCE (Makes about 2 quarts) 2 pounds onions 1 1/2 cups vegetable oil 1/2 cup cider vinegar 4- to 5-ounce jar prepared mustard 5 ounces worcestershire sauce 1/8 teaspoon black pepper, or to taste 1 tablespoon salt, or to taste 1 tablespoon chili powder, or to taste 3 tablespoons hot pepper sauce, or to taste 1 6-ounce can tomato paste 1 12-ounce bottle ketchup 3/4 cup water 3/4 cup cooking sherry 1 head garlic, cloves separated, peeled and mashed 1/4 cup brown sugar 2 tablespoons lemon juice 1 cup applesauce

Grind onions or whirl in blender with vegetable oil. In a large pot, combine all ingredients. Stirring from time to time, cook over low heat, uncovered, for 3 to 4 hours. Serve over sliced or minced beef or pork. Cover and refrigerate. Keeps 1 month. For longer storage, freeze. PARMESAN PEANUTS 2 tablespoons oil 1 pound unsalted peanuts 1 teaspoon garlic salt 2 tablespoon grated parmesan cheese

Heat oil in shallow baking pan in 350-degree oven for about 5 minutes. Remove from oven, add peanuts and stir until coated with the hot oil. Return to oven for about 5 minutes. Remove from oven, sprinkle with parmesan cheese and garlic salt and stir to coat with cheese.