An old short-handled hoe sits conspicuously on a snelf in Cesar Chavez small shrine-like office at La Paz, the United Farm Workers' headquarters tucked away in the Tehachapi Mountains at the foot of California's vast, fertile Central Valley. An aide tells a visitor that Chavez keeps it close by to remind him of his roots in the fields.

This back-breaking tool of stoop labor is also a symbol of battles won - of the union's glory days when its crimson and black banners, cries of "Huelga!" and nationwide lettuce and grape boycots appeared to signal a social revolution within the multibillion-dollar agricultural industry.

Now, the short-handled hoe is banned in California. The state has a law - landmark legislation for the nation - that sets up machinery for union organizing. The Teamsters have withdrawn from the fields, leaving the UFW free from other union competition.

But the union's long march is not over. The UFW has moved into the less glamorous, highly technical world of nuts-and-bolts unionism, and its record so far is less than inspiring.

"They're social activists and agrarian reformers, not union leaders," said a grower who is well-regarded by the union and considered pro-UFW by many of his fellow ranchers. "They'd still prefer to tell off a grower than do the mundance work of trade unionists," he continued. "Unfortunately there's nothing they enjoy more than a good day of picketing. They're dedicated people, impeccably honest . . . but, my God, sometimes you're negotiating with nuns in miniskirts."

Alan Kistler, organizing director of the AFL-CIO, sees it differently, contending that Chavez is, at heart, a true unionist. "They're now facing tasks that other unions have dealt with over time . . . Cesar's got to do it all at once," said Kistler.

Says Chavez: "All we did in the past is strike and picket . . . now we have to build a union."

Chavez' union-building - an ambitious program ranging from teaching English to Mexican, Filipino and other foreign-born field workers to creating a cadre of well-trained bargaining specialists and union administrators - will be conducted against this backdrop:

Although the UFW has won most of the union representation elections that have been held under California's 1975 farm labor bargaining law, it has contracts covering only about 30,000 of the roughly 300,000 eligible workers. This is about half what the union claimed as its contract coverage in the early 1970s.

It weathered a crisis that threatened financing of the new law's enforcement but overplayed its hand in pushing unsuccessfully in 1976 for voter approval of a constitutional amendment to solidify the union's advantages under the law.

It has slowed down its organizing activities because of a huge backlog of uncompleted contract negotiations, which the union blames on grower recalcitrance and official footdragging and the growers attribute to poor bargaining by unskilled union negotiators.

Chavez' traditional liberal and church allies were angered when he went to the Philippines last summer and reportedly made statements favorable to the Marcos regime. A brief stir also arose when a top union official resigned the previous year to protest what he called "red-baiting" against leftists within the union.

More recently, Chavez had ducked the furor over proposed enforcement of the 160-acre U.S. limitation on federally watered farms in the West, a controversy that pits agrarian reform principles against the reality of fewer jobs for union members. There are also reports of tensions within the union between Hispanics and Filipinos and between those who stress social activism and those who advocate a more orthodox union approach.

The impact of all this may be exaggerated by some UFW critics, but it points to a potential for future strains as the union moves further into the idealism-corroding world of modern American labor-management relations.

Finally, the UFW suffered a major setback - in real and symbolic terms - when workers at the vast Giumarra vineyards, the largest family-owned producer of table grapes in the nation and the scene of a violent UFW-Teamsters confrontation in 1973, rejected Chavez' union last fall.

On the record at least, the union blames everyone but itself for the loss: the Giumarras for unfair labor practices, the U.S. Border Patrol for making raids in search of illegal aliens during the election campaign, the state Agricultural Labor Relations Board apparatus for timidity, footdragging and obstructionism.

But the fact of the loss has hurt the union and emboldened many growers.

"It could have turned the tables for Chavez," said Harry Kubo, president of the Nisei Farmers League and a leader of the growers' fight against the 1976 ballot initiative. "It's very difficult to come back from something like that. You have to have enthusiasm, drive, momentum. When you lose, you lose a lot more than an election."

Because of the Giumarra vote, defeat of the ballot initiative and other factors, "there isn't the anxiety there once was" about the UFW among growers, said Martin Zaninovich, a Delano-area grape grower and director of the South Central Farmers Committee.

A source more friendly to Chavez said: "Cesar's probably right in some of the charges he's made, but the fact remains that he lost an election that he should have won . . . He's got to survive in a tough, cruel world."

At Giumarra and elsewhere, the union's problems result in part from its earlier successes.

Since Chavez moved to the fore of farm labor organizing in California in the early 1960s, both wages and working conditions have improved dramatically.

According to UFW figures, grapes, which were picked for 85 cents to $1 an hour before the 1965 Delano strike, now pay $3.35 an hour under union contract. Lettuce, paying $1.50 to $1.60 an hour before the Salinas strike in 1970, now pays $3.55 an hour. Many non-unionized growers will pay the UFW wage, or more, to keep the union out - a tactic not uncommon to industry as a whole. Moreover, many have health plans and other benefits, often as a result of previous UFW organizing efforts. Workman's and unemployment compensation are now available, partly because of UFW pressure.

"We matched them point by point," including hourly pay of about $4, vacations and a medical plan that included $700 in pregnancy benefits, said John Giumarra, speaking of last summer's unsuccessful UFW organizing campaign at the family's 8,000-acre vineyards in the southern San Joaquin Valley. The UFW had organized Giumarra's fields in 1970 but lost them to the Teamsters in 1970 when the powerful trucking union, accused by the UFW of offering sweetheart contracts to the growers, all but drove Chavez from the fields.

"They may not be adequate from my standpoint, but wages and fringes are a lot better than they were," said state Assemblyman Floyd Mori (D-Alameda), chairman of the joint committee that oversees operations of the ALRB. "So what has the union to offer that's all that much beter?"

Mori said growers are showing "a lot more sophistication" in dealing with the union, a point underscored by Giumarra's extensive use of Spanish-language radio, cartoons and other tools of the Chavez trade to blunt the union's propaganda offensive.

Similarly, the push for better wages and benefits has helped intensify pressure for mechanization of the fields, which in turn threatens the very jobs that the UFW is attempting to put under contract.

UFW lobbyist Michael Linfield testified last fall that mechanization would result in loss of 123,000 farm worker jobs over the next decade.

For instance, looking at two crops the UFW has focused on in the past, the union forecasts that the number of jobs in lettuce will drop from 16,700 to 5,400 and jobs in wine grapes will decline from 29,700 to 6,800 (mechanization of table grape harvesting is not foreseen).

Some agricultural economists like Refugio Rochin at the University of California at Davis contend that mechanization has peaked in terms of affecting the fulltime farm labor force, although it may reduce seasonal employment, especially for women and young people. But Chavez argues that it will have a "disastrous effect" in displacing workers and says the union is working on proposals to give workers an opportunity to share in profits made off the machines.

Meanwhile, the immediate problem is negotiation contracts. The UFW has 90 contracts that have been negotiated and 115 in negotiation, as well as 80 bargaining units that are awaiting certification, according to the union's own count. The union could triple in size if it could just get all its supporters under contract. Meanwhile its organizing has slowed to a trickle, to less than 1,000 a month, according to Chavez.

"The union is groping around in its negotiating, it's not as sophisticated as some older unions in the effectiveness of its bargaining," said Mori.

To grapple with this problem, the union is creating a school within its rambling La Paz headquarters complex, an old tuberculosis sanatorium on 280 acres of sun-baked hills that were bought and donated to the union by a wealthy well-wisher.

Here the union will train "specialists" to assist the ranch committees in bargaining, with the eight-month curriculum ranging from labor history to agribusiness economics ("That's something we know nothing about," says Chavez). Also, there will be training in union administration and contract servicing. A separate program, financed by a $500,000 Labor Department grant, will provide English-language training for about 1,500 migrant and seasonal workers.

Some growers are skeptical that Chavez can pull it all together, but the UFW's history is replete with premature obituaries. "Remember," says John F. Henning, executive secretary-treasurer of the California Labor Federation, "he did something no one else could do. He organized the farm worker."