Halakhah do Orla 1:5

And one who redeems a fourth year vineyard - [if] he wants he redeems it [as] grapes, [and if] he wants, he redeems it [as] wine; and so [too,] olives. But with other fruits, he redeems them before they change from their natural state. And the redemption is that he say, "These fruits are desanctified upon this money" - and behold, they are desanctified with this. And he [then] brings up the money and consumes [that which is purchased with it] in Jerusalem. And Shmuel said in the Gemara (Kiddushin 11b) that consecrated things worth a maneh (a hundred large coins) that is desanctified upon the value of a perutah (the smallest coin) is desanctified (is effective) - but not less than the value of a small coin, as it does not have the legal status of money, for any [purpose]. And the same is the law for the fruits of the fourth year. And a fourth year vineyard does not have [the law of] forgotten [grapes] and the corner (Mishnah Maasrot 5:3), nor fallen grapes and bunchless grapes. And we do not separate the priestly tithe and the [other] tithes from it, but rather it all goes up to Jerusalem, or he redeems it and brings up the money and consumes it in Jerusalem. And the law of that which they, may their memory be blessed, said from when do we count the new year for fourth year plant, and so [too,] (Talmud Yerushalmi Orlah 1:1) that everything that is obligated in orlah is obligated in the fourth year. And in the commandment of orlah (Sefer HaChinukh 246), we will write about this at length, with God's help - and we will write which tree is obligated in it, and what [part] of the tree. And from it, we will learn to the fourth year. And the rest of all of its details are elucidated in the last chapter of Maaser Sheni (see Mishneh Torah, Laws of Second Tithes and Fourth Year's Fruit 9).