If President Carter ever succeeds in firing David Gartner from the Commodity Futures Trading Commission, the White House may decide to tackle the tougher problems of staffing at Washington's most neglected regulatory agency.

There's already talk of dusting off the Office of Management and Budget study that calls for abolishing the five-member commission.

Early in the administration OMB recommended that CFTC be run by a single executive - like the Food and Drug Administration - rather than by five, politicially appointed commissioners.

The OMB report also called for carving up CFTC's turf, parceling out part of it to the Securities and Exchange Commission and part to the Department of Agriculture. That idea was quickly shot down by farm state congressmen who worked hard to create CFTC in 1974 and weren't about to see their handiwork dismantled.

But now - without making the commission the issue - the administration has the chance to reshape the CFTC and install a tough cop as its boss.

There's one vacancy on the commission now, another will open up this fall if Chairman William Bagley keeps his promise to retire, and if Gartner ever heeds the president's entreaty to quit, a third seat will be available.

As far as anyone at CFTC headquarters or on Capital Hill knows, the White House has done nothing about filling the seat of commissioner Read P. Dunn, whose term is up. Backed by the cotton industry - for which he worked for years - and the Farm Bureau (the voice of the rich farmers) Dunn is lobbying to keep his job. He apparently has no competition.

Nor are there any hot prospects for Bagley's job, although the Republican chairman of the commission has long said he would be quitting.

The administration's failure to seize on these opportunities to strengthen the CFTC infuriates the farm state congressmen who oversee the CFTC. These are the same congressmen who wrote the White House demanding Gartner's scalp because of stock given his children by the chairman of Archer-Daniels-Midland, a big company.

The Gartner appointment should have been the first step in shaping up CFTC. Instead of using the CFTC to pension off Hubert Humphrey's most faithful spear carrier, the White House could have put a presitigious regulator in charging policing the $1 trillion a year futures markets.

Previous CFTC members have either been people with close ties to the industry they regulate or no ties worth mentioning. Dunn and Robert Matrin, a former Cook Grain Company employee are in the former group: Bagley and Gary Seevers, a former member of the Council of Economic Advisors, are in the later.

As for Gartner, even if he can hold on to his job, he certainly cannot be the White House's white knight at CFTC although he sets longevity records every day it's been two weeks since the President "fired" him - there are growing questions about his effectiveness.

Questions raised about the "fructose connection" indicate the appearance of conflict of interest can be just as destructive as actual favoritism.

While on the staff of Hubert Humphrey, Gartner pushed the administration to raise sugar prices. Higher sugar prices were a big boon to Archer-Daniels-Midland, because it produces fructose, a corn sugar whose price is directly related to that of sugar.

Gartner says he - an Humphrey - pushed for higher prices because Minnesota is the second largest sugar beet producer in the country. But the obvious benefits to ADM raise the kind of questions that Gartner will have to keep answering as long as he remains on the CFTC.