my navel orange tree produces 5 to 8 pound oranges, last year had 2 of them, this year has 12. What is wrong with the tree, they are unedible.
With the scant amount of information you supply, no one will be able to give you an educated answer. Three questions I would ask are, how old is the tree, currently what size is the tree, and have you trimmed or pruned the tree? - Millet
Your citrus tree is old enough to produce fruit, and somewhat old enough to produce higher quality fruit. As the tree ages, the fruit will become better year after year. However, because oranges, in fact all citrus varieties, produce blossoms, followed by fruit, **ONLY** on new growth, any pruning WHAT SO EVER (even a minimal pruning), greatly reduces, or possibly eliminates fruit production for the following year. There are many threads on this forum that discusses pruning and citrus trees. Citrus trees are either rarely, or NEVER pruned. Good luck to this tree next year. I would also ask what is the yearly fertilizer program that you give this tree? - Millet