Secretary of Agriculture Clayton Yeutter said yesterday he would recommend that President Bush veto the 1990 farm bill unless Congress substantially cuts agriculture program proposals made by the Senate.

He said the Senate version of the bill is $5 billion over current budgetary guidelines.

Sen. Patrick Leahy (D-Vt.), chairman of the Senate Committee on Agriculture, Nutrition and Forestry, said the Agriculture Department had "cooked up new numbers." He accused the Bush administration of trying to stall the farm bill to give the administration more leverage in its attempts to reduce agriculture subsidies around the world in four-year-old trade negotiations underway in Geneva.

The exchange marked the re-entry of the Bush administration into the battle over the farm bill, the legislation that will regulate the nation's agriculture for the next five years. Senate debate on the bill could begin as early as this afternoon. The House of Representatives will introduce the bill next week.

"From a budget standpoint, the cost of the bill is excessive," Yeutter said in a 13-page letter to Vice President Quayle, who is president of the Senate.

"If {the farm bill} were sent to the president prior to the conclusion of the budget summit and does not achieve substantial, multi-year savings . . . and if price and income supports are not made more market-oriented . . . then the secretary of agriculture and the president's other senior advisers would recommend that he veto the bill," Yeutter wrote.

Yeutter said mandatory spending requirements in the Senate version of the bill -- for crop subsidies and other programs -- would cost $5 billion more than the $54 billion budget baseline recommended for the next five years. New programs written into the bill, Yeutter said, "could result in over $3 billion of additional outlays.

The letter was sent on the same day the mid-session review of spending was released. The review showed an overall federal deficit of $218.5 billion for Fiscal 1990, $118 billion over guidelines. But agriculture, the review said, was expected to finish the year $3.6 billion under budget.

Yeutter acknowledged lower projections for agriculture, but said "the instability of commodity markets dictates that we must consider the variability as well as the absolute dollar spending for these programs." The letter analyzed various crop subsidy programs and described how the program costs could rise suddenly if the Senate's farm bill recommendations were passed.

"The administration and the Congress are committed to the reduction of the federal deficit. To that end, spending restraint will be required," Yeutter said. "Meeting budget constraints is completely consistent with our goal to develop legislation that builds on the market-oriented, competitive course of the 1985 {farm bill}."

The letter marked the lengthiest administration comment on the farm bill since Yeutter in February issued the Agricultural Department's so-called "green book" analyzing farm programs but making no spending recommendations.

"At the eleventh hour, USDA {the Agriculture Department} has cooked up new numbers," Leahy said in a statement. "The reality is that the Senate farm bill is over $6 billion less than what the president proposed in January.

"The administration's veto threat is a thinly veiled effort to kill the farm bill so the administration can cut a back room deal in Geneva," Leahy said. Leahy and other Democrats in Congress have suggested that Yeutter and the Bush administration wanted to stall the farm bill to give negotiators more leverage in promoting free trade policies at ongoing talks under the auspices of the General Agreement on Tariffs and Trade.