WASHINGTON (AP) _ Scientists are developing new varieties of rustproof beans with the help of wild plants gathered in South America that resist the costly fungus.

''So far we've come up with 53 lines of beans that ward off all 55 identified races, or strains, of the fungus that causes bean rust,'' said J. Rennie Stavely of the Agriculture Department's Agricultural Research Service.

Many of the rust-resistant lines began with wild beans found by USDA plant explorers in Guatemala and other Latin American countries.

''Several years ago we found that many strains of wild and cultivated beans resist one to as many as a dozen races (of rust),'' Stavely said in a report on his work in the February issue of Agricultural Research magazine.

''A few resist most of the 55 races. So at first we bred plants that combined resistance borrowed from several of these strains. The final product has resisted all 55,'' he said.

Rust can cost $250 million in losses in the United States in a bad year, said Stavely, a plant pathologist with the Microbiology and Plant Pathology Laboratory in Beltsville, Md.

He and colleagues at the research service and five universities released 17 highly rust-resistant beans from 1984 to 1988 and 36 lines since then. At least five new lines are expected out this year, Stavely said.

The 53 lines consist of 12 bush-type green snap beans and 12 yellow wax beans for freezing or canning, seven navy dry beans, two pinto and two great northern beans.

Commercial breeders turn the new lines into varieties that can be marketed. A rust-resistant variety of the popular Slenderette green snap bean showed up this winter in supermarket frozen-food cases. Stavely and a Rutgers University scientist released the original line to breeders in 1986.

A majority of the new beans also ward off most North American strains of bean common mosaic virus, the crop's worst virus disease, said Matt J. Silbernagel, a scientist based at the Vegetable and Forage Crops Production Research Laboratory in Prosser, Wash.

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WASHINGTON (AP) - The Agriculture Department this month increased its estimate of 1991-92 world cotton production to 92.2 million bales, 400,000 bales greater than January's projection.

''This is nearly 3 million bales greater than the previous world record cotton production set in 1984-85,'' the department said in a report on the world cotton situation.

''The increase this month is primarily the result of a larger-than- anticipated crop in Pakistan, which was raised by 800,000 bales to 8.8 million bales,'' it said.

''Accordingly, the world cotton stock estimate rose this month by more than 800,000 bales.''

In contrast, the world consumption estimate for marketing year 1991-92 declined by 540,000 bales to 85.6 million bales.

''The reduction brought estimated consumption down below the previous record established in 1989-90 of 86.7 million bales,'' the report said. ''The reduction this month is due primarily to decreases in the estimates for the former Soviet Union and Turkey.''

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WASHINGTON (AP) - Milk production in the 21 major dairying states during January totaled 10.7 billion pounds, almost the same as production in the same states in January 1991.

December revised production at 10.4 billion pounds was slightly below December 1990, the Agriculture Department said in a recent report.

Production per cow in the 21 states averaged 1,283 pounds, 32 pounds more than January 1991.

The number of cows on farms in the 21 states was 8.31 million head, 205,000 less than January 1991 and 17,000 less than December 1991.