"It is advised for our citizens in Germany or planning to visit this country to be even-tempered, keep themselves out of political discussions and absent themselves from rallies held by terrorist groups ahead of the elections," said the Turkish foreign ministry in a statement published on its official website on Saturday.
It also said political leaders in Germany were using anti-Turkey rhetoric in their election campaigns and voiced the aim of blocking Turkey from becoming a member of the European Union.
"The political atmosphere in the aforementioned country is under the influence of far-right and racist propaganda," said the ministry.
"It is worrying that a chancellor-candidate political leader in Germany has recently made statements including clear racist elements and German officials took no measure about it."
During the televised event, Schulz made a proposal to halt Ankara's EU membership talks and freeze 4 billion euros ($4.68bn) in pre-accession funds.
Last month, Turkish President Recep Tayyip Erdogan called on ethnic Turks living in Germany to vote for those who are "not hostile to Turkey" in the elections.
Source: News agencies