Once George Tanimoto plopped a few Chinese gooseberry roots into his California soil, something big began to take shape in the golden West.

Tanimoto's gamble 25 years ago, inspired by a county extension agent who was begging farmers to try the unusual plant, led to his becoming one of the country's biggest growers of Chinese gooseberries, cultivating 65 acres of them.

That was one of the ways that the Chinese gooseberry, commonly known as the kiwi fruit, became a major and profitable crop around Gridley, Calif.

The kiwi's success with American consumers is one of the results of a Department of Agriculture program that searches the globe for fruits, grains and vegetables that might adapt to this country's soils and please its palates. Named by New Zealanders after a native bird, the kiwi was introduced from a USDA experiment station at Chico, Calif.

But there's another driving force at work here. A growing taste for different foods, an influx of refugees and immigrants from Latin America and Southeast Asia since the 1960s and the desire of many farmers to try different planting practices all have played a role in introducing crops and foodstuffs.

Take millet, a grain native to west Africa that researchers see as an important future crop for U.S. farmers. Millets now are grown in the Plains states, mostly for use as bird feed and as a livestock forage crop.

But according to Glenn Burton, a USDA scientist who has pioneered millet research since 1936, pearl millet may one day be grown in areas of the United States where water is scarce and irrigation-pumping costs are prohibitive.

"We already have identified a dwarf gene and an early gene for the pearl millet," Burton said from his office at the Coastal Plain Experiment Station at Tifton, Ga. "It will be several years before we can release the seed, but we think there will be a place for it in dry parts of the country . . . . It would be a late-summer crop, well adapted to deep sands and short enough for harvesting with the combines that farmers have available today."

Burton's early work with millets resulted in hybrids that brought dramatically higher crop yields and wider use of the crop in India and elsewhere. He says he believes that pearl millet, his specialty, will catch on here.

"It won't be an extensive U.S. crop, but I foresee it being used primarily as a poultry feed," he said. "It has a high protein and lysine content; it wouldn't use as much fertilizer as other grain crops, and it generally is more resistant to pests than other grains. It can grow at low fertility levels with little water."

Private studies financed by the Rodale Research Center, near Emmaus, Pa., offer similar hope for amaranth, a stunningly beautiful ancient grain plant that turns to brilliant burgundies and golds. Rodale's studies and its introduction of varieties of amaranth suitable to U.S. soils have put 700 acres into commercial production.

Amaranth already has caught on among health-food devotees as a high-nutrition grain. But the Rodale researchers see it as a crop that will become attractive to western or southern farmers faced with water and energy-cost problems. It needs little moisture and grows rapidly in hot weather.

Rodale's revival of amaranth, once a staple of early American civilizations, has drawn worldwide attention and inspired the Agency for International Development and the National Academy of Sciences to underwrite an amaranth development project in Third World countries.

George White, a plant-introduction specialist at USDA's research center at Beltsville, said, "I think you're going to see more and more amaranth in health-food stores, but I don't know if it will catch on as a major crop. But in addition to its grain value, it can be used as a vegetable -- the leaves are much like spinach."

White noted, however, that new crops do not just pop up overnight. "The advent of a new crop is a very slow process . . . . It requires much research and study to determine adaptability and potential usefulness."

One of his colleagues, researcher Robert J. Knight, based at the USDA's subtropical horticultural laboratory in Dade County, Fla., agrees. But he can't suppress his excitement over the carambola, a fruit he says "is about to take off."

Knight helped introduce varieties of carambola into this country from Asia, where it has grown for centuries. About the size of a cucumber, the golden fruit looks like a five-pointed star when sliced. Knight is breeding carambola varieties that will have less acid and thus be sweeter.

"The USDA first brought this to Florida in 1923, and, like so many other things, it has evolved very slowly. But we have found it easy to grow in Florida. And a farmer can get a couple of crops a year with it," Knight said.

The carambola is one of a number of tropical fruits increasingly grown in Florida. A Rare Fruit Council International was set up in 1955 to promote tropical fruits in south Florida -- a campaign abetted by the infusion into the area of immigrants with a hankering for succulents from their native Latin America.

For example, the mango, is now grown on 2,000 acres in Florida and is getting popular across the country. And the mamey (pronounced mah-may), is raised on 300 acres. According to Knight, it's a fruit "some Cubans here would sell their grandmothers to get."

Janelle Smith of J.R. Brooks & Son, a tropical-fruit wholesale firm in Homestead, Fla., said, "We find the mango moving into new market areas because of the coverage given it by food editors. It has become chic and 'in' among many consumers -- and it's an excellent fruit, besides."

"Another one that seems ready to take off," Knight said, "is the anonas family . . . . The cherimoya is one, the sugar apple is related to that, and the cross between them is the Florida atemoya."

These exotics, however, are a small part of the new crop picture. Pushed by Congress, the USDA is taking a hard new look at guayule (why-oo-lee), a flowering shrub that grows wild in the Southwest and can produce rubber identical to prized Asian rubber. Researchers are looking at ways to cultivate guayule on a large scale in desert areas.

"It's hard to predict how this will turn out. Interest in it has run in cycles," USDA's White said. "It was researched vigorously during World War II, but then it was shelved. Now, with the emphasis on new crops, it is getting another look."

Another plant apparently destined for success as a crop is the jojoba (ho-ho-ba), which has come into common use in shampoos. Grown in pre-Hispanic America, jojoba was "rediscovered" 50 years ago as the source of a high-quality lubricant.

It is much like sperm-whale oil, a rare commodity since the whale was labeled an endangered species, and is viewed as an effective substitute if it can be cultivated on a commercial scale.

USDA also is doing research on such curiosities as crambe (krahm-bay), a member of the mustard family; domestic rapeseed and meadowfoam, both oil crops; and euphorbia, the "gasoline plant" that grows wild in California and is being tested for adaptation in the Southwest. If the tests are successful, euphorbia could be refined into gasoline, scientists say.

Laboratory and field studies of these and dozens of other unusual plants, some of which are used commonly in other countries, are going on with an eye toward a distant, more varied American agriculture.

Some agricultural researchers, instead of looking ahead, are looking back to find the future. At Ohio State University, for example, they're studying recently discovered teosintle grass -- the ancient Mexican forefather of today's hybrid corn -- to seek qualities that might improve corn.

Even the tobacco plant, a heavyweight of the colonial American farm economy that has fallen into some disrepute, may find new use. A scientist from the Agricultural Research Service, using molecular genetics to grow a new tobacco, has developed a technique for extracting a tasteless, colorless, odorless protein that is as nutritious as milk and can be stored easily.

Holy smoke! They may get tobacco out of the fire and into the frying pan.