Date: 11 Av 5573
From: Rabbi Moshe Sofer
To: Rabbi Lipman Katz
The responsum discusses the halachic permissibility of having a non-Jew graft an apple branch from a wild apple tree onto another apple tree, considering the prohibitions of 'amira l'nochri' (telling a non-Jew to perform a forbidden act), 'lifnei iver' (placing a stumbling block before the blind), and 'kilayim' (forbidden mixtures).
Source: Shu"t Chasam Sofer Collected §25