Tosefta for Bava Metzia 75:4

[If someone] left produce at the place of an am ha'aretz, behold, they are presumed [to retain their previous status] for tithing and for Shevi'it (Dem. 3:4, cf. Y. Maas. V.1.8), and if they were subject to tithing, we may take Terumah (the priestly portion) and tithes from it for [produce] in another place (see Bava Metzia 38a:5), or designate Terumah and tithes for them. If they were from second tithe, we exchange them for money, and exchange the money for second tithe. If the [am ha'aretz said], I took [your produce] and left you old [produce or] tithed [produce], if you believe that he took it, we also believe that he purchased [the old or tithed produce], but if you do not believe that he purchased it, you do not believe that he took it. What are we talking about here? At a time that the [chaver] came an found the same type [of produce] that he exchanged, but if he left higher-quality [produce] (see Jastrow = "עגרון") and found lower-quality [produce], or [he left] lower-quality [produce] and found higher-quality [produce], behold, this is a concern, and for this [produce we do not presume it has retained its former status with respect to either] tithes or the seventh year.