Citrus Greening and damage

General Fruit Growing
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Has anyone had any success dealing with Citrus Greening (HLB / Huanglongbing)? I didn’t see many posts about it.

I live in Florida and I was aware of it before I planned to plant, but it was not yet in my area. In spring 2020 I planted a Sugarbelle mandarin due to it being one of the most tolerant varieties at the time.

At the end of 2022 we had a great harvest of very tasty fruit. At the end of 2023 we had another big harvest but about half of the fruit was small and not sweet. I assume I had too many fruits and that was why they didn’t all ripen. After harvesting I did a hard pruning of the tree. I also tried to thin a bit during the year. The harvest at the end of 2024 was again still pretty big, but not good, just a few fruits were semi-sweet and none were big.

I figured that there was something going on and after a bit of consultation it was determined that my citrus trees do have Greening.

I also have a Jackson Grapefruit planted at the end of 2021. In spring 2024 it flowered for the first time and 8 fruit set, but all fell off by wintertime.

I corresponded with my local extension and they gave me a few things to do.

They let me know of a quick home test to see if Greening is likely: https://crec.ifas.ufl.edu/media/crecifasufledu/extension/plant-pathology-/greening/pdf/HS37500.pdf - beyond just visual cues.

The first thing they suggested trying was additional fertilizer: https://sfyl.ifas.ufl.edu/media/sfylifasufledu/lake/docs/fruit-production/pdf/Citrus-Fertilizer-for-HLB.pdf I purchased a fertilizer similar to this and am overloading them to see if it helps.

The second thing they suggested was using oak leaves: Oak Leaf Compost for HLB? - UF/IFAS Extension Lake County I made a 5 gallon bucket of the tea for each tree twice and then mulched underneath the trees with the oak leaves.

Another thing I had heard from a different source was trace nutrients were very important. Sources like Green Sand, Azomite, or Kelp were important. I am trying using this, and this.

I’m going to give them another year to try and produce and see if this helps. Otherwise I think I may move on. I’m very sad as the Sugarbelle especially is still a beautiful tree and the fruit was very good. I think best case though is that they told me the two trees might have a few years. They are both cultivars that are tolerant of greening but it only buys them a little extra time.

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Here is a picture of it from back in February before the last oranges were harvested along with two harvests for reference. The oranges when healthy were much bigger and sweeter, but coloration was the same.

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This was gonna be my first suggestion. Citrus are big feeders, and one of the signs that they aren’t fed enough is sour fruit. I can’t really see the leaves to see if it has greening, but I don’t see any green splotched fruit and they look in good shape, so thats a good sign. With the pictures you sent, I would just say its nutrient deficient.

This is what young citrus do. They are very good at knowing when they can’t support a fruit, and will just abort them. If you ever repotted a citrus while it was blooming and see all the fruitlets fall off a week later, its the same reason. Plant didn’t feel like it could sustain the fruit and itself.

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Thank you! I’m sorry I wasn’t more clear in the first post. My trees were confirmed as hlb positive by my local extension. It is greening. Its not terribly visible on the leaves, especially from far away, but you can see the splotches.

I’m passing on what I’ve learned so far to help anyone else fighting it. Perhaps something will give a little reprieve.

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