A spirit of defiance moves across the southern Philippines

Six hundred miles south of Manila in Mindanao's lush rural province of South Cotabato, moderate opponents of the regime of President Ferdinand Marcos are beginning to speak out after more than a decade of public silence.

They are doing so at some personal risk.

Here, as in many rural settings throughout the Philippines, the government rules with a firm hand. In 13 of South Cotabato's 17 towns, the particulars of daily life such as the funding and construction of schools, roads, and sanitary facilities, are controlled in large measure by mayors loyal to President Marcos's ruling New Society Movement (known by its Tagalog initials of KBL). Local police, who are members of the Integrated National Police Force, act at the behest of commanders whose allegiance is also with the Philippine President.

Shock waves of protest that have rumbled across the nation since the assassination last August of opposition leader Benigno ''Ninoy'' Aquino Jr. have been slow to arrive here. In Davao, a city 50 miles north of the provincial border, they arrived on Sept. 21, the widely commemorated 11th anniversary of the imposition of martial law. ''Yellow Fridays'' - rallies in memory of Aquino - have since been observed regularly on Davao's confetti-littered streets.

South Cotabato's first antigovernment protest did not occur until Dec. 1, more than three months after the assassination, and several days after nationwide celebrations of Aquino's 51st birthday.

In 95-degree heat, 7,000 people stood motionless for more than five hours at a run-down grandstand in Koronadal while a dozen speakers - including the late senator's brother, Agapito ''Butz'' Aquino - took turns lambasting the Philippine President. The town's opposition mayor, Ishmael Esuino, spoke forthrightly.

''Deep in your hearts you may fear that we are inviting trouble to this very peaceful place,'' he told the crowd.

''But when on Aug. 21, on making his first step on Philippine soil, our hero Senator Aquino was mercilessly shot, then we lost all tolerance - for the loss of our freedoms under martial law, the transfer of powers from civilian to military authority, the rigged elections, the graft and corruption. We have become indignant and will no longer mind the threats of arrests and detentions.''

The rally's featured speaker was ''Butz'' Aquino, who has become a leader of the Manila-based Justice for AquinoJustice for All (JAJA) movement.

Some local residents were not certain who he was - or for that matter, who his brother was. Others wore yellow T-shirts emblazoned with slogans that have become standard among Manila's ''Aquinistas:'' ''I'm mortgaged to the IMF''; ''We love Marcos - Just Kidding''; ''Who killed my hero?''

Spontaneous rallies followed in the towns of Polomolok and Tupi, where several hundred people pledged allegiance to the JAJA credo of ''Truth, Freedom, Justice, and Democracy.'' And in General Santos, a port of 150,000 on Mindanao's south coast, 10,000 ignored advice from KBL politicians to stay away from the town's first JAJA-sponsored rally.

''I have been able to criticize President Marcos openly because I have relied on the people of Koronadal, not the military,'' Mayor Esuino explained later. ''When we build roads, for example, we use materials and labor donated by our people.''

The mayor said that prosperity was the key to the new spirit of defiance in his town. Many have prospered in recent years thanks to the success of the government's land reform program and high levels of agricultural productivity. Koronadal sits on a wide plain between low mountains that is rich with alluvial soils. The region's principal crops, yellow corn and rice, can be cultivated profitably on plots as small as one or two acres.

''Other towns in the province are poor and must rely on Marcos, the KBL, and the military,'' Esuino said. ''The position of their mayors is that we have to be 'practical.' The mayor of the next town, Polomolok, is an oppositionist, but he would not show his face at the rally for Ninoy (Aquino). He was afraid.''

The pressure on Esuino has been considerable. The mayor said an emissary from South Cotabato's powerful pro-Marcos assemblyman, Jose Sison, advised him that Sison would introduce a bill designed to divide Koronadal into two districts if antigovernment rallies were held. Esuino's bodyguard, a member of the police force, was ordered not to appear with him at the rally.

The spirit of defiance new to Koronadal has strong historical roots in neighboring Muslim communities. South Cotabato, settled by evangelical Christians in the 1930s and '40s, is less than 10 percent Muslim. But nearby provinces are predominantly Muslim. In these areas and elsewhere on the island, factions of the secessionist Moro National Liberation Front (MNLF) continue to wage an armed struggle against the central government. In 1979 MNLF leaders reportedly made a pact with Senator Aquino before he went to the US for medical treatment: They agreed to keep the peace until he returned to rally the nation against Marcos.

Guerrillas of the communist-led New People's Army (NPA) have also engaged government troops in sporadic fighting in Mindanao. The NPA's forces, while well-organized and often respected by small farmers, have no historical claim on the island. The estimated 5,000 to 7,000-man force is scattered across the Philippines, with units hopping from one island to another to avoid well-armed concentrations of government forces.

A resurgence of NPA and MNLF activities was anticipated in the wake of the Aquino assassination. In South Cotabato, political instability has encouraged the rebels to join forces, according to local sources. Their new organization, local sources say, is called the Koronadal Revolutionary Council.

Widely held perceptions of a range of social and economic injustices feed the radical cause. One focus is the presence of US-owned multinational corporations.

One such corporation is a pineapple plantation managed by Dole, Philippines, and spans an estimated 25,000 acres between Polomolok and General Santos, a distance of 30 miles. Dole rents most of the land from local owners, many of them small landholders. According to a prominent lawyer in the province, the plantation is farmed by 10,000 laborers who are paid approximately $150 per month, about twice the nation's minimum wage.

One local planter charged Dole with evading Philippine taxes by shipping the product to Hong Kong, through a subsidiary, where the product is sold at a much higher profit.

''The feeling here is that a reasonable portion of the final profits should be reported for taxation purposes in the Philippines where the income is really derived,'' he said. Benjamin R. Labayen, acting deputy minister of agrarian reform, said that to his knowledge this was not the case, and that as far as he knew, Dole was paying a fair price to landowners in the area for the right to grow pineapples on their land.

The government's military presence here is another focus of dissent. A well-known attorney in General Santos, who also wished not to be identified, described how government soldiers regularly meet fishing boats at the city wharf to confiscate a portion of their catch. Each soldier, he said, usually takes several pounds of fish. What remains is shipped by truck to other cities. Along the way, he said, soldiers set up checkpoints at which fees are exacted from drivers. ''There are often as many as 20 checkpoints,'' he said.

A third grievance concerns the plight of squatters in South Cotabato's urban areas. Rogelio Garcia, a lawyer in General Santos, represents some of the city's 5,000 squatter families. Earlier this year the government's Ministry of Human Settlements began to demolish squatter dwellings. The displaced have been resettled on a 346-acre tract 10 miles from the center of town. According to Garcia, the government has not yet fully provided the new community with basic services such as running water, electricity, transportation, and education.

Former Mayor Luis Santos of Davao predicts that current antigovernment sentiment in southern Mindanao will at least precipitate ''a mass exodus'' from Marcos's KBL party in next May's legislative elections.

Another possible consequence, Santos said, is armed rebellion ''if the current experiment with democracy'' fails to produce tangible results by mid- 1984. Santos said he was prepared to lead such a rebellion to relieve Mindanao of its ''poor-cousin status.'' But, he added, he preferred to work for reform through legal means.

Hilario de Pedro III, a Koronadal lawyer who heads the local JAJA organization, said he was hopeful that the Marcos government could be overcome without bloodshed. But de Pedro said the recent alliance of local MNLF and NPA forces - ''a combination of NPA brains and Muslim brawn'' - could prove troublesome.

''We are surrounded by the MNLF and the NPA,'' he said. ''They are hiding in the more politically repressed towns and in the mountains. Their presence is alarming. It threatens our opportunity to get rid of Marcos through peaceful means.''