Before eating a fruit that grew on a tree one recites the Beracha of "Borei Peri Ha'etz." Halacha defines "tree" for purposes of this Halacha as a plant whose stalk and branches remain intact all year round, even after all the fruits are removed. If a plant collapses after losing its fruit, then even if its appearance resembles that of a tree, one would not recite "Borei Peri Ha'etz" over its fruit, but rather "Borei Peri Ha'adama."
In light of this principle, the Poskim (Halachic authorities) discuss the issue of whether or not one recites "Borei Peri Ha'etz" over papaya. A papaya tree remains intact all year round, and after its fruits are removed it grows taller and the following year produces fruit from its new growth. After four or five years, the tree collapses and must be replanted. Seemingly, since the tree remains after the fruit is removed, we should, indeed, consider it a "tree" for the purpose of Berachot, and the proper Beracha over papaya fruit should be "Ha'etz."
However, the Ben Ish Chai (Rav Yosef Chayim of Baghdad, 1835-1909) writes that the work "Kol Eliyahu" brings another source citing a Tosefta that imposes an additional qualification that must be met for a plant to be considered a "tree" in this respect. Namely, it cannot produce fruit within a year of its planting. Since trees generally require more time to develop before yielding fruit, a plant that begins producing fruit within a year after it is planted cannot be classified as a "tree." As the Ben Ish Chai observes, a papaya tree begins producing its fruit within the first year of its planting. According to this Tosefta, then, a papaya should not warrant the Beracha of "Ha'etz."
However, considerable controversy exists concerning the veracity of this Tosefta, and it therefore cannot serve as a definitive source on this matter.
Another possible indication emerges from testimony cited in the work "Chesed Le'Avraham" that Maran (Rav Yosef Karo, author of the Shulchan Aruch, Tzefat, 1488-1575) and the Arizal (Rav Yitzchak Luria, 1534-1572) partook of eggplant within the first three years of its tree's planting. Now the Torah prohibition of Orla forbids eating fruit from a tree during its first three years. That these Rabbis partook of an eggplant tree within its first three years indicates that they did not consider an eggplant tree a "tree" for purposes of Halacha. One explanation given is that eggplants grow already during the first year of the tree's planting, and Halacha therefore does not consider this plant a "tree." Accordingly, a papaya tree would likewise not be classified as a "tree," and its fruit should warrant the Beracha of "Ha'adama," rather than "Ha'etz."
It should be noted, however, that the "Chesed Le'Avraham" merely records that Maran and the Arizal would partake of eggplant within the tree's first three years. The explanation given for this practice is speculation, and thus this testimony cannot definitively prove the status of papaya with respect to Berachot.
Yet another factor involves the fact that a papaya tree is hollow, rendering it different from most other trees. This difference perhaps sets it apart from regular trees with respect to Berachot, such that it should require "Ha'adama," and not "Ha'etz."
As far as practical Halacha is concerned, the Ben Ish Chai, Chacham Bentzion Abba Shaul (Israel, 1924-1998) and Chacham Ovadia Yosef all accept the view that over papaya one recites "Borei Peri Ha'adama." The work "Birkat Hashem" writes that nevertheless, if one mistakenly recited "Ha'etz" over a papaya, he does not stop eating to recite "Ha'adama," as he may then rely on the arguments raised in favor of reciting "Ha'etz."
Summary: Before eating papaya one should recite the Beracha of "Borei Peri Ha'adama"; if one mistakenly recited "Borei Peri Ha'etz," he continues eating without reciting "Ha'adama."
