The Supreme Court agreed yesterday to review a ruling that Arizona's labor law for farm workers is "unconstitutional entirety."

The justices granted an appeal by Gov. Bruce Babbitt, the Arizona Farm Bureau Federation and growers' associations to hear argument on the ruling, handed down last April by a panel of three federal judges in Phoenix.

Approximately 30,000 to 40,000 farm workers, most of them migratory, grow and harvest citrus fruits, lettuce and other seasonal crops in Arizona.

Federal labor laws exclude the workers from coverage. Arizona adopted its Agricultural Employment Relations Act in 1972, expressing a legislative Act in 1972, expressing a legislative intent to make the workers "free to organize" and choose unions to represent them.

Over the next five years, however, workers petitioned for only seven elections. By contrast, under the California counterpart law they petitioned for nearly 400 elections in five months.

Cesar Chavez's United Farm Workers National Union denounced the Arizona law as the growers' "brainchild." The three-judge panel called it "a complete perversion of the expressed intent of the legislature."

The court took these other actions: Company Cafeterias

The court agreed to review a ruling that the prices companies charge at in-plant cafeterias and food-vending machines are "terms and conditions of employment" subject to bargaining under the National Labor Relations Act.

The ruling was handed down last February by the 7th U.S. Circuit Court of Appeals in a dispute between Ford Motor Co. and the National Labor Relations Board.

The dispute arose at Ford's Chicago Stamping Plant, where the United Automobile Workers represents about 3,600 production workers. The plant has two cafeterias and five vending machine areas. While these facilities are air-conditioned, employe locker rooms - where workers must store food brought from home - are not. They become hot in summer.

ARA Service, Inc., operates the cafeteria and machine facilities for Ford, receiving free space, equipment, utilities and maintenance, plus a $52,000 annual subsidy.

Since 1967, the company and the union have bargained over the quality of ARA's service. In a letter to the UAW, Ford said that it "recognizes its continuing responsibility for the satisfactory performance of the caterer." At the same time, Ford consistently has refused to bargain about the prices ARA sets with the manufacturer's approval.

The issue came to a head in February 1976 when food prices went up five cents to 10 cents an item. More than half the workers, bringing lunches to work, began to boycott the cafeterias and machines. The boycott ended with the arrival of hot weather.

Meanwhile, the UAW filed an unfair labor practice charge. It won in the NLRB, which filed a complaint that the appeals court upheld. Ford must bargain not on every proposed change in food prices, but on unilaterally affected price changes challenged by the union, the court said. Cosmetics

The court let stand a ruling that the Food and Drug Administration was empowered to order labels on packaged cosmetics to list the ingredients. Such disclosure has been in effect for about two years. Power Tax

In a case affecting about 10 million consumers in Arizona, Southern California and Texas, the court agreed to review a ruling upholding a New Mexico tax on electricity generated in the state with strip-mined coal for sale in neighboring states.

The tax - 0.4 of a mill per net kilowatt hour - costs out-of-state power suppliers about $5 million a year. But, says New Mexico, producing the power inflicts $12 million in environmental damage on the state while burdening the state and local governments with population and socio-economic problems that cost an additional $27 million. Natural Gas

The court agreed to review a ruling upholding the McCombs Group, a Texas natural-gas producer that, after certifying in 1953 that it would sell supplies to the interstate United Gas Pipeline, stopped doing so - without seeking government approval - in 1966. McCombs claimed the field was depleted - but since 1971 has been supplying E. L DuPont de Nemours & Co. from the same field. Joining United, the Justice Department said the abandonment wasn't in good faith.