Among the characteristics of trifoliate orange—Poncirus trifoliala—rootstock for citrus is its supposed dwarfing effect on tree size. However, many of the Valencia, Washington Navel, and grapefruit trees budded on trifoliate orange rootstock are large and productive. Frequently, the trees that exhibit varying degrees of dwarfness are immediately adjacent to large trees.

The above progress report is based on Research Project No. 1604.