Despite the success of other orange varieties in many places, navel oranges fail in hot climates as far as I know.
The defect, as I understand, is due to the fall of the fruit in the early stages when it meets the hot and dry climate.
therefore, when these ‘Navel’ varieties (or some of them?) planted in those areas, the production will be low with a few fruits on the tree.
by reading UCR, Citrus Variety Collection; this is what I found:
Shamouti sweet orange, not navel orange but mentioned there, “Like the navel oranges in general, the Shamouti tree is sensitive to heat and aridity during the bloom and hence restricted in range of climatic adaptation, Thus, in very hot, arid regions production is low and the fruits are undesirably large …”.(; this proves what I say)
Trovita sweet orange, “Believed to a seedling from a navel orange fruit but does not have a navel …” & “… The tree is more productive under desert conditions. …”, but “juicier and milder in flavor than Washington navel”, (a navel but without a navel !?)
Robertson navel orange, “although it blossoms at about the same time as other varieties the young fruits develop more rapidly and pass through the fruit-setting phase earlier. The fruits thus escape the severe dropping associated with the heat and dryness …”
Frost Washington navel orange, “…popularity has increased until it is now more widely planted in California, Arizona, and Morocco than any other clonal selection of Washington.”.
Is there anyone who knows promising and successful navel orange varieties in those areas?