All citrus trees produce buds. Depending on the climate and other criteria, buds will either turn into floral buds, producing flowers, or remain foliage buds producing leaves. Various stress situations such as enough cool temperatures or drought can differentiate a foliage bud into becoming a floral bud. Therefore, if your area does not get enough cool weather (650+ hours <65-F during the fall and winter) to differentiate the buds into flower buds, you can stress the buds by withholding all moisture from the tree until you notice a wilt of the leaves, then water thoroughly. In the tropics where the weather never gets cool enough to induce the tree's buds to differentiate into floral buds, it is the dry season that accomplishes the bud change. I take it you fertilize these trees 3 times during the growing season each year.