Systems and methods for disambiguation of agricultural input are disclosed. An example disclosed method includes determining a first probability for a second product specifier. The first probability indicates a likelihood that the second product specifier is correct. Additionally, the example method includes, in response to determining that agricultural input identifiers for a manufacturer associated with a portion of the first product specifier are in a variety database, modifying the first probability with a second probability. The example method includes, in response to determining that the agricultural input identifiers for the manufacturer associated with the portion of the first product specifier are not in the variety database, modifying the first probability with a third probability different from the second probability. The example method includes comparing the modified first probability with a threshold, and associating the second product specifier with the vehicle location when the modified first probability satisfies the threshold.