1) HOW TO DETERMINE THE YEAR TO WHICH AN OLIVE BELONGS
QUESTION: The Gemara teaches that Chanatah (the time at which a fruit tree blossoms) determines the year to which the fruit of a tree belongs with regard to Ma'aser and Shevi'is. Rebbi Nechemyah says that this applies only to a tree which produces fruit picked at different times. The year for the fruit of such a tree cannot be determined by Lekitah, the time at which the fruit is picked, because the fruit is picked at different times and thus would belong to different years. Since the Chanatah for all of the fruit of such a tree occurs at one time, the Rabanan established Chanatah as the determining factor for Ma'aser.
According to Rebbi Nechemyah, the year for trees that produce fruit picked all at once follows Lekitah and not Chanatah. As examples of such trees, Rebbi Nechemyah mentions olive trees (Zeisim) and carob trees (Charuvim).
Why are olive trees included in the category of trees whose year is determined by Lekitah (according to Rebbi Nechemyah) or Chanatah (according to the Rabanan)? The Gemara earlier (13b) says that an olive tree's year follows the time at which the fruit grew a third of its eventual growth. As Rashi there explains, the Rabanan do not have the authority to choose a different time because the requirement to separate Ma'aseros for Zeisim is mid'Oraisa.
(a) TOSFOS (DH Kegon) says that the word "Zeisim" here is imprecise ("Lav Davka"). Both Rebbi Nechemyah and the Rabanan agree that the year of olives is determined by the time at which they grew a third and not by the time of Lekitah or Chanatah.
(b) The PISKEI HA'RID also writes that Rebbi Nechemyah and the Rabanan agree that the year of olives is determined by the time at which they have grown a third of their size. However, he adds that when Rebbi Nechemyah says that the year of olives is determined by the time of "Lekitah," he refers to the time at which they have grown a third of their size. "Lekitah" means the time at which the olives have grown a third of their size and are now ripe enough to be picked. (See Tosfos to 13b, DH Achar, who writes that Lekitah does not mean the time at which the fruit is actually picked, but rather it means the time of Gemar Pri, when the fruit becomes ripe and fit to be picked.)
(b) The TOSFOS YESHANIM explains, like Tosfos, that the Rabanan maintain that the year of olive trees follows Shelish (when they grew a third of their size) and not Chanatah. However, Rebbi Nechemyah maintains that the year of olive trees can follow Lekitah under certain circumstances. One who picks olives for their oil picks them one at a time. In such a case, the year of the olives is determined by when they grew a third, even according to Rebbi Nechemyah. In contrast, one who picks olives to eat picks them all at once. In that case, Rebbi Nechemyah maintains that the year is determined by Lekitah.
(c) The RITVA (13b) says the opposite of Tosfos (in (a) above). The Ritva writes that when the Gemara earlier (13b) says that the time of Ma'aser for olive trees is when they grow a third (Shelish), the Gemara there is imprecise ("Lav Davka"). Rather, olives are like all other fruits and their year is determined by the time of Chanatah (or Lekitah according to Rebbi Nechemyah) and not Shelish. When the Gemara (13b) quotes a Mishnah which explicitly says that Zeisim follow the time of Shelish, it means that when the olives have grown a third of their size they are considered ripe enough to be obligated in Ma'aseros if one wants to eat them. The Gemara there does not discuss how to determine to which year the olives belong. With regard to which year they belong (as far as Ma'aser and Shevi'is are concerned), the determining factor is Chanatah (or Lekitah).