Vienna — As far as ordinary Bulgarians are concerned, the postponement of their President's imminent trip to West Germany was a non-event. The Soviet Union's Balkan ally was in the midst of a three-day celebration of the 40th anniversary of its liberation in World War II when Bonn announced the postponement.
At this writing, the news has yet to be published by the Bulgarian news media and little is likely to be said, if and when local papers do get around to reporting the story.
When East German leader Erich Honecker last week called off his own scheduled September visit to West Germany, set for a week after that of President Todor Zhivkov, it was not immediately certain Bulgaria would follow suit.
The Bulgarian visit would have had none of the extreme political sensitivity for the Soviets of the meeting between the two German leaders. It would have been concerned almost totally with bilateral relations and, for Zhivkov, economic matters of special interest to Bulgaria at a time of some economic difficulty.
West Germany is Bulgaria's biggest Western trade partner and one to which the Bulgarians currently are looking to most as a source of more trade and of new technology to boost a flagging industrial export potential.
Bulgaria has always been one of the Soviet Union's closest allies. But Bulgaria has in the last few years increasingly adopted distinctively innovative lines in domestic economic management that show substantial departures from the orthodox Soviet pattern on which its economy was founded following World War II.
This development reflects the same ''small nation'' claim to an individual approach, even within the bloc context, as the foreign policy attitudes of Hungary and, more recently, East Germany.
East Germany was determined to preserve a relationship between the two Germanys, despite the cold war between the superpowers. Hungary believes in more general terms that smaller nations have opportunities to exercise a mitigating role in the hope of maintaining a minimum of detente.
Bulgaria seems to have been like-minded. It briefly reported the calling off of the Honecker visit, but offered none of the condemnation of West Germany that was leveled by Moscow and some of its allies.
Following Bonn's announcement Sunday that the Zhivkov visit was now also in limbo, East European sources admitted to some surprise. But they said the decision should be seen as part of a Soviet ''general strategy'' in the state of East-West relations designed to tighten up the front displayed by the alliance as a whole.
It was not unconnected, these sources believe, with the expected meeting in New York, during the United Nations General Assembly, between Foreign Minister Andrei Gromyko and United States Secretary of State George Shultz.
The Soviet representative at Bulgaria's anniversary celebration, Mikhail Gorbachev, a key member of the Politburo, appeared to make it clear that the Soviet Union is wary, at this juncture, of any of its allies seeming to be accommodating toward the West.
The Bulgarians said nothing publicly before Zhivkov's expected West German visit. But there is no doubt that its postponement is a disappointment.
It must inevitably also mean something of a setback to new endeavors designed to raise one of Eastern Europe's smaller but most successful economies of recent years to new, more sophisticated levels, as this reporter saw on a recent visit.
Bulgarians can still be irritated by the traditional Western image of a backward Balkan nation - known to produce fine tobacco and luscious tomatoes and grapes but otherwise dependent on the Soviet Union.
These crops are still produced in abundance. But now there are also modern products of notably high standards - in machine-bulding, electronics and the like - which have established a considerable Bulgarian niche in world markets, including Western ones.
''Maybe we were once the poorest and least developed country in Europe,'' an official said. ''But since the last war, Bulgaria has been developed at a dynamic rate and in that short time has emerged definitely as a relatively advanced industrial and agricultural state.''
Steadily, in fact, through recent years, the Bulgarians have demonstrated concern to promote their image as a country which, while acknowledging that Soviets aid has been decisive for its development, has also learned to do many things for itself.
The figures, and the improving look of the country, do much to justify the claim.
Officials point out that Bulgaria's gross national product is 22 times greater than before World War II and the national income has been multiplied a dozen times. There has been some slowing down in the yearly growth rate of Bulgaria's industrial boom dating from the 1970s. The cause of this negative development is getting anxious government priority. But, at 4.5 percent, it is still a better figure than many advanced Western states can show.
No bones are made about Bulgaria's commitment to the USSR and to Comecon, the East-bloc ''Common Market.'' There is no thought of changing the country's market balance in which nearly two-thirds of its trade is within Comecon. Two-thirds of that is tied up with the USSR. Among other things, this means all of Bulgaria's oil, on special terms, and the technical wherewithal in developing a substantial nuclear energy capacity.
In trade with the West, most of the country's remaining 20 percent, Bulgaria has been careful to keep its debts in manageable proportions. But the more advanced technology in the West is freely recognized - particularly during the current campaign to increase significantly the quality of products with which Bulgaria might gain market access to Western markets.
In an undramatic way the Bulgarians were, in fact, among the front-runners in testing economic innovations within the bloc. In the 1960s, even before the start of the Hungarian reform, they experimented in a big textile plant with a measure of enterprise management, work incentives, and a curb on the ubiquitous controls by government departments.
Since then reform, however cautious, has turned the old Bulgaria upside down. From a country once 80 percent dependent on agriculture and earning only 20 percent of its income from industry, it has become one in which all the old proportions are reversed.
In place of the initial stereotyped collectivization, agriculture has been modernized in a network of 290 largely successful agricultural-industrial complexes. These average 32,000 acres, complete with their own manufacturing and food processing capacities and increasingly prosperous rural communities.
The private plots of farm workers are smaller and more circumscribed than those in some other East-bloc states. But an old anomaly has been largely removed. Farm incomes are now said to match those in industry. In addition, farmers have equal access to something they did not have before: social insurance.
Statistics from the UN's Food and Agriculture Organization bear out Bulgarian claims that agricultural growth in the 1980s is well up to and in some cases above the best Western standards. For example, per capita wheat production ranks first in Europe and yields per hectare are way above average compared with the world's big grain countries.
Agriculture is also providing the first test of a new ''public and state'' principle of management.
There is now no ministry of agriculture. Direct authority is exercised not by government, but by a national agro-industrial union, with strong elements of independent internal, elective management.
A similar arrangement is needed in industry, it is felt. New urgency has been given to this need by awareness of the slowdown of the momentum that had given Bulgaria one of East Europe's better living standards.