Tosefta על פאה 7:7

One who plants an orchard in order to dedicate it [to the Temple] is exempt from orlah and from the fourth-year vineyard (i.e., the laws forbidding benefiting from fruit in the first three years, or four years for a vineyard, and see Y. Peah VII.7.2, adding "and from [the laws of] defective clusters"), but he is liable in shevi'it (the seventh year of the agricultural cycle, when working the land is prohibited). From what time is a person permitted to harvest his vineyard (per Vilna Man. delete "בשביעית" = "during shevi'it")? From the time that he knows his fruit (i.e., whether each grape cluster is going to be normal or defective), because [at that point] the vineyard is already liable in (the laws of) the growth of defective clusters.