In his 1983 book "Jews and Judaism in the United States", Rabbi Marc Raphael said: "in all the American colonies, whether French (Martinique), British, or Dutch, Jewish merchants frequently dominated.”
According to jewishencyclopedia.com: "The cotton-plantations in many parts of the South were wholly in the hands of the Jews, and as a consequence slavery found its advocates among them" http://www.jewishencyclopedia.com/articles/910-agriculture
Can someone provide concrete data on the matter?
No. According to The Historical Encyclopedia of World Slavery, in the section "Judaism in the Antebellum South" which begins at page 384:
About 5,000 Jews owned one or more slaves—about 1.25 percent of all the slaveowners
It says "a few" Jews owned plantations and lists Judah P. Benjamin as having a plantation with 140 slaves, Maj. Raphael J. Moses a plantation with 50 slaves and about 7 other Jewish plantation owners (Nathan Nathans, Ishaiah Moses, Mordecai Cohen, Isaac Lyons, Barnet Cohens, Champman Levy, "and various members of the Mordecai family").
Strangers & Neighbors: Relations Between Blacks & Jews in the United States basically has the same list of Jewish plantation owners and adds that a female, Abigail Minis, had a small plantation with 17 slaves and that Jacob Hart and Hart Moses Shiff owned shares of a plantation that had slaves.
There was Francis Salvador who had about 30 slaves and a plantation from 1774 to 1776 when he died in the Revolutionary War.
But definitely "no" Jews did not own most of the plantations that enslaved. 1% would be a good estimate since Jews represented 1.25% of slave owners.
See Index to Records of Ante-Bellum Southern Plantations: Locations, Plantations, Surnames and Collections for a catalogue of plantations and families that owned them.
