That is strange and I have never heard of such a thing. I can't help but wonder what is different for the unproductive sections of the tree...lack of sunlight, sprayed with pesticide during bloom, ????
I suggest you try contacting your County Extension Office to see if they have any way of assisting. They are experts in your local situation and may be aware of something unusual that might be going on with grapefruit tree in your area. Their contact info is:
St. Johns County Extension, 3125 Agricultural Center Drive, St. Augustine, FL 32092-0572
Phone: (904) 209-0430
Thanks for the question. Please stop in again soon!
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