don't know much about loquat.. but this is what it says.
Propagation: Generally seeds are used for propagation only when the tree is grown for ornamental purposes or for use as rootstock. For rootstock the seed are washed and planted in flats or pots soon after removal from the fruit and the seedlings are transplanted when 6 to 7 inches high. When the stem is 1/2 inch thick at the base, the seedlings are ready to be top-worked. Loquats can be propagated by various grafting methods, including shield-budding or side-veneer grafting and cleft-grafting. The use of loquat seedling rootstock usually results in a comparatively large tree with a high canopy. Cultivars grown on quince rootstock produce a dwarfed tree of early bearing character. The smaller tree has no effect on fruit size and gives adequate fruit production with the advantage of easier picking. Loquat cuttings are not easy to root. Grafted trees will begin to bear fruit in 2 to 3 years, compared to 8 to 10 years in seedling trees.
http://www.crfg.org/pubs/ff/loquat.html
pete