BONN, West Germany (AP) _ Czechoslovakia and Bulgaria have applied to belong to the World Bank and could become members of the U.N. loan fund by the fall, its president said Wednesday.

World Bank President Barber Conable said he expected the two East bloc nations will ''doubtlessly be accepted by the time of the annual meeting,'' which is scheduled for late September in Washington.

The World Bank, or International Bank for Reconstruction and Development, is a specialized agency of the United Nations set up to further economic development through guaranteed loans and to train member-state officials toward that end.

World Bank officials meet annually with the International Monetary Fund. The IMF director, Michel Camdessus, said last month that he hoped Bulgaria and Czechoslovakia would become members of his organization this fall.

Each of the World Bank's 153 members also belong to the IMF.

The IMF promotes monetary cooperation, currency stabilization and trade expansion, and is charged with working out balance-of-payment difficulties in the international community.

Conable, who attended an annual meeting of the Federation of West German Industries on Wednesday, met with West Germany's Minister for Economic Cooperation, Juergen Warnke, on Tuesday.

He said Warnke told him that West Germany's plans for unification with East Germany haven't reduced the country's commitments to international development.

Conable said the World Bank intends to actively take part in reconstruction of East European economies in support of democratic changes taking place there.

He said the bank has earmarked $2.5 billion for economic development and environmental projects in Poland, and that an additional $5 billion was being made available in loans to Eastern Europe over the next three years.

A representative office will be set up in Warsaw in July, Conable said. ''We're going to have a big program in Poland,'' he said.

Also Wednesday, the World Bank and the Polish government reached agreement on a key $300 million loan to assist economic reform, a Polish finance ministry official said.

The so-called ''structural adjustment loan'' provides not only funds but represents World Bank approval for the shock reform program undertaken by Poland's non-Communist government, Deputy Finance Minister Marek Dabrowski said.

Final World Bank approval is anticipated by the end of August, Dabrowski.

Conable also made general world debt problems a theme of his remarks.

He said he hoped that the seven major industrialized country, the United States, Canada, Japan, West Germany, Britain, France and Italy, will decide on new ways to deal with world debt at their annual economic summit in Houston, Texas next month.

''No successful way of dealing with that has been found yet,'' the World Bank leader said.

Another major issue at the Houston meeting includes funding to curtail ''environmental degradation,'' in the world, Conable said.