Yevamos 36

R' Yochanan holds that the one the owns the produce of a field is the real owner of the field. Tosfos asks : how does this fit into takanaos Usha that they decreed that a woman cannot sell her "Melug" fields. Although she holds the title of the field, but the husband keeps all the produce. So, according to R' Yochanan the woman anyhow doesn't have the main ownership to be able to sell the fields. Tosfos answers: that we could say that Takanus Usha was only said for the Shita of Reish lakish, that the one who holds the title is the main owner and not the one who owns the produce. Alternatively, the man's ownership is weaker than other ownership over the produce, because his whole ownership comes from being married to her. So we consider it somewhat more belonging to her. Alternatively, we consider his ownership weaker because it's only his because the rabbis decreed it to be. Another answer: they only decreed Takanas Usha in the case where the husband declines to receive the produce (but still would inherit her.) Rabbi Chaim Smulowitz If you ever though that Tosfos was beyond you. Think again. A few more free copies of Gemara and Tosfos: Sukka 2a-11a is still available at https://www.tosfos.ecwid.com