The Office of Management and Budget, spreading its tentacles further and further into federal programs, seems to be reaching out toward the Agriculture Department's marketing order system: the network of directives in which USDA tells fruit and vegetable growers where and in what quantities they can sell their crops.

Agriculture likes the system, but some free-market economists on the president's staff aren't quite so enamored of it. At the behest of the regulatory reformers, USDA earlier this year set up a task force to study the orders' effects on productivity and efficiency.

But now the OMB, invoking its authority to review all federal paperwork, has told Agriculture Secretary John R. Block that it wants a report on the paperwork the system generates. Some people at Agriculture view this as a way the White House could try to revamp the entire system. OMB officials say only that they'll wait for the paperwork report, due at month's end, before deciding what to do.

HIGHER STANDARD . . . The government's rule requiring private employers to crack down on sexual harassment of employes is on the latest hit list of regulations scheduled for "reconsideration," primarily because the guidelines have been criticized for being too vague. But Defense Secretary Caspar W. Weinberger has told his 3 million employes that similar rules won't be relaxed at the Pentagon.

To make things clear, Undersecretary Lawrence Korb has issued a formal definition of what is taboo: "sexual advances, requests for sexual favors, and other verbal or physical conduct of a sexual nature."

WHOOOOSH . . . Confident that its friends in Congress will save it from the budget crunch, Amtrak is making ambitious plans. President Alan Boyd has signed a contract to see if Japan's 150-mph bullet trains could run on some U.S. routes, including the Los Angeles-San Diego and Dallas-Houston runs. The 150 mph "Shinkansen" trains could shorten trips by 30 percent or more.

TAKING AIM . . . General Dynamics leads defense contractors in a lobbying effort designed to sink a venerable Pentagon dreadnought: Adm. H. G. Rickover, designer and commander of the Navy's nuclear fleet. Rickover, well beyond the standard retirement age of 65, will be forced to retire in January unless the Navy extends his active-duty commission.

Contractors (such as General Dynamics' Electric Boat facility) that have been stung by the admiral's complaints of "profiteering" are pushing Pentagon and White House officials to kick him out. Among other charges, critics say Rickover is really 83, not 81, as the official biographies state.

The admiral has few friends at the Pentagon, but could survive, congressional sources say, if President Reagan gets involved. "How can a 70-year-old president fire anybody for being too old?" a House Democrat asked.

SIGN OF THE TIMES . . . Along with the standard forms and the welcome-aboard handshakes, new employes at Voice of America headquarters (17th Street and Pennsylvania Avenue NW) are routinely shown a film on how to avoid being raped.

DON'T BLAME ME . . . Stung by critics, Reagan's men are falling back on an old Jimmy Carter refrain: progress is slow because economic problems are so tough.

"We never promised a quick cure," Commerce Secretary Malcolm Baldrige told New York businessmen this week. And Baldrige found a scapegoat: "We are beginning to understand just how much damage has been done by . . . the previous administration. It will take longer than expected to repair."