Kilayim, Chapter Six, Mishnah Nine
The final mishnah of chapter six continues to deal with things that extend from the aris.
1) A blossom which protruded from the aris, it is regarded as if a plumb line were suspended from it, directly beneath it, it is prohibited [to sow].
2) Similarly, in the case of [a blossom protruding from] a hanging branch [of a single vine.]
3) One who has stretched a vine-shoot from tree to tree, it is forbidden to sow beneath it.
4) If he made an extension [to the vine] by means of rope or reed, it is permitted under the extension.
5) If he made the extension so that the new [growth] might spread along it, it is forbidden.
Section one: If a blossom of a new vine sticks out from an aris it is forbidden to plant only directly beneath the blossom. Directly beneath is determined by the use of a plumb line, which is dropped directly from the blossom.
Section two: The same halakhah holds true for a blossom of a vine which protrudes from a single vine. It is forbidden to sow seeds only directly beneath this vine.
Section three: The following three sections deal with cases where a person extended a vine hung over one tree to hang it over another. If he simply extended the vine itself, it is prohibited to sow seeds underneath the vine.
Section four: If the vine was too short to be extended to the other tree and he used a rope or a reed to extend it, then it is permitted to plant seeds underneath the reed.
Section five: However, if he intends to train the vine to continue to grow onto the rope or reed, then it is prohibited to plant seeds directly underneath.