Even if he plowed the land for one day in the first and third years respectively, it should be sufficient to establish the presumption of ownership. Rather, everyone agrees that plowing is not sufficient to establish the presumption of ownership, and here the difference between their opinions is whether in order to establish the presumption of ownership one needs to possess the land long enough to grow major produce, which requires three months to grow, or only minor produce, which requires one month.

The Sages taught in a baraita: Plowing is not sufficient to establish the presumption of ownership. And there are those who say: This is sufficient to establish the presumption of ownership. Whose opinion is it that the baraita refers to as: There are those who say? Rav Ḥisda said: It is the opinion of Rabbi Aḥa, as it is taught in a baraita: If the possessor plowed the field for a year and sowed it for two years, or if he plowed it for two years and sowed it for a year, it is not sufficient to establish the presumption of ownership. Rabbi Aḥa says: This is sufficient to establish the presumption of ownership, which indicates that he holds that plowing establishes the presumption of ownership.

Rav Ashi said: I asked all of the great men of the generation about this, and they said to me: With regard to plowing, this is sufficient to establish the presumption of ownership. Rav Beivai said to Rav Naḥman: What is the reason of the one who says that plowing is sufficient to establish the presumption of ownership? Rav Naḥman answered: A person is not apt to have his land plowed by someone else and remain silent. Rav Beivai asked: And what is the reason of the one who says that plowing is not sufficient to establish the presumption of ownership? Rav Naḥman answered: The owner says to himself: Let each and every clump [shibba] of earth enter the plow. That is to say, the owner is amenable to having someone else plow the land for him, and then he will sow and harvest.

The residents of Pum Nahara sent a question to Rav Naḥman bar Rav Ḥisda. Our teacher, instruct us: Is plowing sufficient to establish the presumption of ownership, or is it not sufficient to establish the presumption of ownership? Rav Naḥman bar Rav Ḥisda said to them: Rabbi Aḥa and all of the great men of the generation say: With regard to plowing, this is sufficient to establish the presumption of ownership.

Rav Naḥman bar Yitzḥak said: Is it a novelty to enumerate great men who maintain an opinion without taking into account that of others? But what of Rav and Shmuel in Babylonia, and Rabbi Yishmael and Rabbi Akiva in Eretz Yisrael, who say: Plowing is not sufficient to establish the presumption of ownership?

The Gemara presents the sources for ascribing to these Sages the opinion that plowing does not establish the presumption of ownership. The basis for ascribing it to Rabbi Yishmael and Rabbi Akiva is the mishna, as the Gemara explained above. What is the basis for ascribing this opinion to Rav? As Rav Yehuda says that Rav says: This ruling that either a month or three months is sufficient use for the first and third years is the statement of Rabbi Yishmael and Rabbi Akiva, but the Rabbis, whose opinion is accepted, say: With regard to a field, its presumption of ownership is established by three years, from day to day. The phrase: From day to day, serves to exclude what? Does it not serve to exclude plowing, which does not establish the presumption of ownership?

What is the basis for ascribing this opinion to Shmuel? As Rav Yehuda says that Shmuel says: This ruling that either a month or three months is sufficient use for the first and third years is the statement of Rabbi Yishmael and Rabbi Akiva, but the Rabbis, whose opinion is accepted, say: He does not establish the presumption of ownership until he harvests three date crops, or harvests three grape crops, or harvests three olive crops. This indicates that Shmuel holds that plowing does not establish the presumption of ownership. What is the difference between the opinions of Rav and Shmuel? Abaye said: The difference between their opinions is whether three harvests of a young [na’ara] date tree, which produces a crop three times in one year, establishes the presumption of ownership.

§ The mishna teaches that Rabbi Yishmael said: In what case is this statement, that eighteen months are required to establish the presumption of ownership of a non-irrigated field, said? With regard to a white field, i.e., a grain field. But with regard to an orchard, harvesting three different crops suffices. Abaye said: From the opinion of Rabbi Yishmael we infer the proper understanding of a detail of the opinion of the Rabbis who disagree with him, and hold that three years of harvesting one crop is required to establish the presumption of ownership even with regard to an orchard: If one had thirty trees of one type in a field, and they were planted with a density of ten trees per each area required for sowing one se’a of seed [beit se’a], and one consumed the produce of ten trees in this first year, and of another ten trees in this second year, and of another ten trees in this third year, this is sufficient to establish the presumption of ownership.