[If] one preserves three [kinds of vegetables] in one barrel — R’ Eliezer says: One may eat based upon [the availability of] the first. R’ Yehoshua says: Based even upon the last. Rabban Gamliel says: Any vegetable whose species has disappeared from the field must be removed from the barrel; and the halachah follows his view. R’ Shimon says: All vegetables are alike regarding [the law of] biur. One may eat purslane until artichokes disappear from the valley of Beis Netophah.

One may eat based upon [availability in] abandoned [areas], but not upon [availability in] protected [areas]. R’ Yose permits [consumption] based even upon [the availability in] protected areas. One may eat based upon [the availability in] birdhouses, and upon the second crop, but not based upon [the availability of] the winter crop. R’ Yehudah permits as long as they have begun ripening before the end of the summer.