Q.Navel Orange Tree Now only producing a seedy lime like fruit.
I live in Lindsay, Calif. – orange trees are a main crop here. I had 3-4 years of navel oranges, and all of a sudden last year the tree seemed to turn to these useless, seedy lime like fruit. Is there a way to turn this tree back to producing navel oranges?

Certified GKH Gardening Expert
There are two possibilities that I can think of.
One is that the tree is extremely drought stressed, water deficient and possible nutrient deficiencies combined. Do you deep water at least once a week and fertilize in spring? A foliar fertilizer is also often used a couple times a year.
The other possibility, is that a sucker or suckers from the root stock below the graft, near the soil grade, has grown up to dominate the foliar canopy and suppress the naval orange fruiting top. The lime fruit could be from the root stock.
Inspect the trunk of the tree and see if branches are growing below a foot above the tree. There should be evidence of a graft. Anything growing below it is likely from the rootstock.
If you see that is the case, I would consult your extension agent or an arborist and see if it is still feasible to remove those dominant suckers.
https://www.gardeningknowhow.com/edible/fruits/oranges/growing-an-orange-tree.htm