For R' Meir says: That which is customarily counted dooms [a mixture] to burning. But the Sages say: Nothing dooms [a mixture] to burning excepting only six things. And R' Akiva says: Seven. And these are they: walnuts of Perech, pomegranates of Badan, and sealed barrels, and regenerations of beets, and stems of cabbage, and Greek gourd. R' Akiva says: Also loaves of a householder. That which is subject to orlah [is forbidden as] orlah. [That which is subject] to kilei hakerem [is forbidden as] kilei hakerem.