According to University of Florida Institute of Food and Agricultural Sciences citrus breeder Jude Grosser, new Sugar Belle hybrid rootstock LB8-9xS13#16 has quite a history.
Before HLB became the dominant scourge of Florida citrus, Grosser was heavily invested in trying to solve blight. Lee had a great interest in blight, because in several of his most productive blocks the annual tree loss to blight was about 12 percent.
Citrusindustry.net quoted Grosser as saying: “Evidence was showing that pummelo x mandarin hybrids had superior blight tolerance as compared to other rootstock categories, so I made a lot of pummelo x mandarin hybrids."
"Orie was in a hurry to plant rootstock hybrids to test for blight tolerance, and he had just planted a large block at the Alligator Grove. He suggested we plant trees in between each of the planted trees. We made cuttings from about 125 new rootstock hybrids and we tried to get at least seven liners for each rootstock. We grafted them all with Valencia and planted them one year after the original grove was planted — about 12 years ago.”