A year ago I wrote about my Sumo seedling and how it compares to actual Shiranui This year I didn't get to tasting the fruits at the earlier time, and I can not confirm that my seedling is earlier. It might well be earlier, but I only started tasting the fruits in February. What is really different is the juice vesicles of my seedling fruits. They are always more firm than the ones from Shiranui fruits. The seedling fruit density is at about Gold Nugget mandarin level.
The Sumo seedling and Shiranui fruits vary in shape, rind thickness and the amount of sugar even when collected from the same tree. In the pictures below, two left fruits are from my seedling. The top left is from a tree grown in Vacaville, the graft was made directly onto a citrus rootstock (C-32 or C-35). Low left fruit is coming from a graft made onto Minneola Tangelo tree. Two right fruits are from the same tree of Shiranui grown in Isleton, CA.