Tosefta על ביכורים 1:10

One who purchases from a poor person, and so too a poor person to whom they gave slices of bread or figs, he takes tithes from each and every one. With [respect to] dates grown in the valleys (Bikkurim 1:10), he tithes from one on behalf of everything. In other places [where the dates are of lower quality], he takes tithes from each and every one. With [respect to] figs in years of satisfaction (see above) he takes tithes from one on behalf of everything, but in the other years he tithes each and every one.