The Diamante citron (Citrus medica cv. Diamante − Hebrew: אתרוג קלבריה or גינובה) is a variety of citron named after the city of Diamante which is its most known cultivation point. Diamante is located in the province of Cosenza, Calabria, on the south-western coast of Italy. This is why this variety is sometimes called the "Calabria Esrog", the Hebrew name for the citron.
The Diamante citron was one of the most important varieties candied by the largest factories at Livorno Italy; it was gathered from Liguria, Naples, Calabria & Sicily and then shipped into England and the United States.
Genoa was known to supply citron for the Jews since the times of the Tosafists, along with Sanremo, Bordighera, and the rest of Liguria. The city is located in the region of Liguria which has a long history of citron cultivation, thanks to the massive mountain chain (Apennines) which protects it from turbulent winds. Genoa has also a known history of banking, and they may have also traded the citron grown in the rest of the country, being a well established Seaport as well.
Although little is known about the Genuese variety they used to grow, Volkamer indicated that it was very similar (besides the taste in which the Genuese was reported to be not as good) to the one illustrated by him as well as by Ferrari as the Cedro Ordinario. Therefore, it is considered to be of oldest Ashkenazic tradition for the Jewish ritual during the Feast of Tabernacles.
Most adherent to the Diamante variety of Calabria are still the Chabad's who's late Rabbi's were always in support for this traditional variety. Among the other Hasidic sects it is most used by the Satmars.
Kashrus Supervision 
While Calabria is at the southern point of Italy, and its climate most Mediterranean, it is the most suitable for the citron. Even though, during the winter it is still too cold for the citron, and this is why the farmers need to protect them with blue or green plastic covers. Most of the citron trees in the area are grafted onto foreign rootstock, to save them from freeze and all different kinds of illness. This practice renders their fruits non-kosher for the Sukkot ritual, and therefore in order for a mashgiach to certify a citron as kosher, he must first carefully inspect the tree to confirm it was not grafted.
A Jewish delegation comes from Israel to Santa Maria del Cedro every year between July and August to choose the best fruit to be used in the holiday for the Jewish community. The selection of the best fruit is a virtual ritual. The mashgichim, each followed by a peasant carrying a box and a pair of scissors, go to the citron farms at five in the morning. The mashgiach proceeds slowly looking left and right. Then he stops and looks at the base of the tree, right where the trunk comes up from the ground. A smooth trunk means the tree has not been grafted and the fruit can be picked. The mashgiach lies down on the ground to examine better the lower branches between the leaves.
|Citrus • Succade • Hybrid • Grafting • Chimera • Etrog • Sukkoth • Four Species
Once the good fruit is found, the mashgiach shows it to the peasant who cuts it off leaving a piece of the stalk. Then the mashgiach analyses the picked citron one more time and if he decides it is worthy he wraps it in oakum and puts it in the box. The farmer receives the agreed sum for each picked fruit. Then the boxes are sealed and sent to the Lamezia Terme airport with a final destination Tel Aviv.
Although Diamante is also growing in Puerto Rico, Sicily and Sardinia, their citrons are not used for the Jewish ritual, since no kashrut certification was present at tranplantation. Seeds and cuttings of inspected trees were planted in the Israeli village of Kfar Chabad, with the hechsher certification by major kashrut organizations.
The methods for tree checking to verify if the tree is grafted or not, were established by a board of rabbis in Israel by 1877 as described in Kuntres Pri Etz Hadar which was published in Jerusalem a year after.
Other citron varieties 
- Different Citron varieties used as Etrog, are the Greek Citron, the Balady Citron, Moroccan Citron and Yemenite Citron.
- Citron varieties, or hybrids not used for the ritual, are the Fingered Citron and Florentine Citron.
See also 
- The Cultivated Oranges and Lemons
- The citrus Industry citation by Google Books
- The Citrus Industry online in name of Georges Gallesio
- Traité du citrus By Giorgio Gallesio in French p. 256
- Orange Insects
- an Easter Holiday in Liguria
- Cedro ordinario illustration of Nürbergisches Hesperides oder gründliche Beschreibung.
- Malum Citreum Volgura from Hesperides sive de malorum aureorum.
- Oekonomische Encyklopädie
- A world known statement by rabbi Yosef Yitzchok Schneersohn
- Discovery Jewish Italy – academy article
- Ansa Mediterraneo- RELIGION ROME JEWISH LEADERS VISIT COSENZA CITRON FARMS
- Isaac, Erich. (1959). Influence of religion on the spread of citrus: The religious practices of the Jews helped effect the introduction of citrus to Mediterranean lands. Science, 129: 179-186.
- Article by Rabbi Tzinner about Yanove Etrog
- Etrog in Hebrew Wikipedia
- HaLevanon 11 - no 7, HaLevanon 12 - no 4, page 2 gives a detailed list of cultivation areas and shipping system of ritual citron in Italy.
- The wanderings of plants and animals from their first home; By Victor Hehn, James Steven Stallybrass, digitized by Google Books
- The Citron that the Chabad Rabbeim used
- ChabadPedia about Calabria citron
- The Diamante Variety described by The Purdue University
- The Citrus Variety Collection by the University of California
- Citrus Pages with pictures
- Chabad Website.
- The Mesoreh about the Calabrian Etrog
- Center for the Study of Jewry in Calabria and Sicily
- Essential Oils
- A study on glutamate oxaloacetate transaminase isozymes of citron cultivars
- A DNA Comparison study
- Postcard from Calabria
- Zitrus Freunde