פירוש על ברכות 69:5

ACCORDING TO THE ONE WHO TAUGHT, [AS A RULE]: A FOURTH-YEAR GRAPEVINE ETC. Tosfos is showing us how this dispute affects us even today. And nowadays we hold that the status of fourth year fruits are in effect even outside of Eretz Yisroel. However, it is in effect only for vineyards and not for other trees. For whosoever is lenient in Eretz Yisroel, the Halochoh is like him outside of Eretz Yisroel. Since there is a position that maintains that even in Eretz Yisroel, only fruit of the vine is subject to the laws of the fourth year, we outside of Eretz Yisroel follow that opinion.
What do we do with vineyards of the fourth year? And the fruit of the vineyard of the fourth year nowadays, we transfer the sanctity to the amount of a p’rutah,¹The rule is that when one transfers sanctity from an item that is worth one hundred dollars to a coin worth a penny, the transfer is effective. One is initially not allowed to do this, because he is cheating the Temple Treasury fund, but if he did do it is valid. Nowadays when there is nothing one can possibly do with the fourth year fruits, it is permissible to initially transfer the sanctity to a very small coin. a very small coin, and one grinds it and throws it into a river, so that nobody should accidentally violate its sanctity. And so is it clearly stated in the Sh’iltos of Rav Achai (Parshas K’doshim Simon 100).

That the second hillul can also show that the benediction is required over fruits.

See p. 18 n. 5.