Legal Question in Business Law in California

I'm pretty sure this would be a violation. While you didn't ask whether the vendor of the "Apfel" would be trying for a U.S. trademark, the attitude of the law is revealed by the fact that trademark applicants in the U.S. are asked in the application process if their proposed name is entirely fanciful or if it really means something in a foreign language. Apple Computer would immediately notice this competitor and react strongly.

Unless Apple somehow forgot to register its mark in Germany, which of course is absurd, it absolutely would be a trademark violation. No "probably" about it.

The US Trademark Office (and other countries that are signatories to the international conventions) takes into account English (local) language translations of foreign words in denying trademarks that conflict with existing marks, so if Apfel is equivalent to Apple, then neither one would be permitted by a new company. If Apple sells its products in Germany, it would have registered the trademark there and no variation of its name would be permitted.