Do the laws of Arla apply to the tree of a gentile? May a Jew eat the fruits of the first three years from a gentile owned tree?
The fruits of all trees contain the Biblical Arla prohibition, whether the tree is owned by a Jew or a gentile, and whether in Eretz Yisrael or the Diaspora. [Even the Arla fruits of a gentile in the Diaspora is Biblically forbidden. Some Poskim however rule that the Arla fruits of a gentile in the Diaspora is merely Rabbinically forbidden.]
 Michaber 294/8; Tur 294/8; Tosafus Kiddushin 36b; Rosh 62; Ran 15a; Mordechai 501; Semag Lavin 146; Rabbeinu Shimshon Arla 3/9; Rashba 1734; Rambam Maaser Sheyni 10/5; Radbaz 580; Birkeiy Yosef 294/6
Other opinions: Some Poskim rule that the Arla fruit of a gentile is not prohibited for a Jew. [Pirush Hamishnayos of Rambam Arla 1/3; See Beis Yosef 294 and Birkeiy Yosef ibid; The Rambam in Mishneh Torah ibid retracted from this opinion]
 Aruch Hashulchan 294/11
 Chasam Sofer 286, brought in Pischeiy Teshuvah 294/7