ETROG (Heb. אֶתְרוֹג), citrus fruit among the Four Species used on Sukkot. The Bible describes what is usually rendered as "the fruit of a goodly tree" (peri eẓ hadar; Lev. 23:40), traditionally interpreted as being the etrog (Citrus medica). The word etrog, the name by which this fruit is known in talmudic literature, derives, according to one view, from the Persian torong, according to another, from the Sanskrit suranga, meaning "beautifully colored." Some maintain that the etrog tree, along with its name, reached Ereẓ Israel only during the Second Temple period, even as it was brought to Greece from its native land, India, only after the campaigns of Alexander the Great. Others contend that "the fruit of a goodly tree" is to be identified with the Pinus or Cedrus, called dar in Sanskrit; others say that what is meant is simply any beautiful (hadur) fruit. There is evidence that the etrog was known in ancient Egypt; its use as one of the Four Species on Sukkot was probably responsible for its wider cultivation in Ereẓ Israel in olden days, for neighboring countries set no great store upon its fruit, which is not particularly good. Indeed, even during the Hasmonean period, which abounds in evidence of its cultivation in Ereẓ Israel, the etrog was not grown in Italy and is not mentioned by Pliny (23–79 c.e.) among the products of that country.
The etrog was formerly unique among the fruit trees of Ereẓ Israel in requiring constant irrigation for its growth, whereas the others were only occasionally irrigated, and then only to increase their yield of fruit. This fact is adduced among the various proofs that "the fruit of a goodly tree" (peri ezhadar) is to be identified with the etrog, eẓ hadar being interpreted as eẓ hiddur, that is, the tree which requires water. Since the etrog was the only *citrus known in Ereẓ Israel in the mishnaic and talmudic period, the question of the permissibility of an etrog from a grafted tree for the performance of the religious rite did not arise until comparatively recent times.
The etrog was a conspicuous ornamental motif among Jews during the Second Temple period, appearing on coins of Simeon and other Hasmoneans, and it is often depicted on the walls of synagogues and in mosaics. When Alexander Yannai once acted contrary to the halakhah in the Temple, "all the people pelted him with their etrogim" (Suk. 4:9; Tosef., ibid. 3:16; Jos., Ant., 13:372). In the mishnaic and talmudic period, when the etrog was widely cultivated in Ereẓ Israel, it was comparatively cheap, a large etrog selling for two perutot (Me'il. 6:4). An especially beautiful etrog, which was in great demand for the festival, cost very much more, at times as much as the price of three meals (tj, Suk. 3:12, 54a). There were periods (for example during the Hadrianic persecutions) when etrogim had to be brought from far-flung places in Ereẓ Israel (Tosef., Dem. 3:14). Various uses were made of the etrog; its thick skin was eaten either pickled in vinegar or boiled to a pulp (Suk. 36b; Ma'as. 1:4), and a perfume was extracted from its peel (Suk. 37b), which was also highly valued as an antidote against snake-bite (Shab. 109b).
Today, the etrog is not extensively cultivated in the world, and is grown primarily for the citronate that is extracted from its peel. There are many strains of etrog. In Israel the small strain is predominant; the large strain was brought to the country by the Yemenites (cf. Suk. 36b, about a large etrog which was carried on the shoulder). In addition to the sour etrog, there is also the sweet strain (cf. Shab. 109b). With the increase in the species of the genus citrus, the etrog was crossed with other citrus plants, which probably accounts for the present difficulty of growing an etrog which has not been grafted on a lemon or hushhash stock, the ungrafted variety being vulnerable to pests and diseases, and its pittam (the protuberance, the pistil) usually being atrophied. Whereas in ancient times the pittam was a conspicuous mark of the etrog's excellence, there are those today who are particularly anxious to obtain only an ungrafted etrog, which usually has no pittam. There are several distinguishing signs by which the grafted and the ungrafted etrog can be distinguished. The skin of the latter is generally rougher than that of the former, and, according to some halakhic authorities, the seed of the latter lies longitudinally within the fruit, and that of the former, latitudinally. Until the end of the 19th century the center for the cultivation of etrogim was the island of *Corfu, from where they were exported to Jewish communities in Europe. Later these began to use the etrogim of Ereẓ Israel. Today the etrog groves in Israel supply local needs and also export many etrogim abroad.
V. Loret, Le cédratier dans l'antiquité (1891); Loew, Flora, 3 (1924), 285ff.; S. Tolkowski, in: jpos, 8 (1928), 17–23; J. Feliks, Olam ha-Ẓome'aḥ ha-Mikra'i (1957), 66–70.