I don't have any personal experience, but this is interesting. You might email him and ask how it's going, since the link is over a year old:

Here is a link that might be useful: Cashion on greening

There is no stopping Greening disease. The commercial growers do use a foliar nutritional spray to prolong the trees life but death is i
inevitable.

Sad to say, I believe my former glorious days of enjoying huge harvests from my 20 ft tall Ruby Red Grapefruit tree are over for good. Made more than a few friends with my luscious gifts, as the tree provided much more than I could use.
Had to cut it down 2 + yrs ago, then 16 months ago, with crossed fingers, I bought and planted another 5 ft tall Ruby Red. Alas, the few little signs of a fruit fell off fast and the tree is now slowly coming out of it's limbo phase and showing signs that's it's dying, despite lots of TLC.
Am still numb,..never expected such a disaster, here in sunny South Florida yet !

it is a sad situation for citrus. I'm planting other kinds of fruit trees.

Thanks for the responses.

Interesting link, Writersblock. This is a similar spraying combo that I've been told about at the nurseries--the ones who suggest organic feedings and azomite. I spoke with a citrus grower who uses micronutrient and oil sprays. She said it improves some trees, while others she had to cut. Unfortunately she didn't give me anything more specific. Wish I could get hear more stories from people who are trying these techniques, and try to get a better idea how much is true and how much is wishful thinking.

So sorry to hear about your grapefruit, Jofus. The trees I'm probably going to cut down are a Hamlin and a Dancy tangerine. I'm really going to miss them. I'm going to try sprays similar to what Writersblock suggests over the summer--unless I hear something that convinces me they just won't work.

I know what you're saying, Laura. I've been considering planting other fruit trees--mulberries, blueberries, persimmons, and so on. Still I'm going to miss the unity and "Florida feel" of the citrus trees.

Thanks again. If any of you have tried these oil spray/micronutrient regimens, I'd like to hear your experience and opinions.

Bill

Hi
can only add my bad experience . I had 5 citrus when I bought this house which produced well. During the "Citrus scab " problem all my trees were cut down even ground up the roots. including all my neighbors We waited several years and we all replanted and there is not one healthy tree in the bunch!! have one clementine left.
I'm using the area to grow winter tomatoes . Good luck with a solution!!! gary

Hi Bill and everyone,

I've been using the systemic products with Imidacloprid as the active ingredient. It is important to apply it after blooming is completed so as to not harm the already fragile bee population. It is not a cure and does not reverse citrus greening, but it does seem to slow the progression. Since first using it last spring, all of my citrus and my parents' citrus seems to have almost (but not quite) maintained status quo. I am no longer seeing the steady decline that I did when I first discovered greening. I am getting ready to apply it again this week. Blooms are done for 2014 so it is time.

Wouldn't it be great if they found a cure?

Carol in Jacksonville

Just be aware that imidacloprid is very, very, very bad for bees:

Here is a link that might be useful: Harvard study on imidacloprid and bee colony collapse

Holy cow, Writer, thanks a million for posting that link! I'm done with the Imidacloprid. Won't apply it and am so glad for the information. Also glad I read it before applying it this year (haven't applied any drench since 2013). I wonder how long the effects last in the plants? Yikes.... I feel terrible...

Carol

Don't feel bad. It kind of shocks me that places like IFAS haven't updated their recommendations. I noticed yesterday it's still listed as a primary pest control in their gardening guide, and for a lot of things that attack veggies that need bee pollination, too.

Almost forgot, after losing my Ruby Red grapefruit tree and the slow decline of it's small replacement, one fact eluded me.
Every day I walk past the closest fruit tree to my home, as I tend to all the others, a healthy looking Key lime tree.
I planted it 5 yrs ago and it's now 10 ft tall and is bristling with inch long sharp thorns and tangy key limes. Now isn't a Key Lime tree a citrus tree ,..or am I missing something here ?
This brash tree is somehow thumbing his ( her ) nose at all this Citrus Greening stuff. Just sitting there with minimal care compared to the others, loaded with fruits that turn a so-so cocktail into a great one,...IMHO anyway.
Just wondering if anyone else out there still has a healthy, thriving key lime tree or is this an anomaly ?

This post was edited by jofus on Mon, May 26, 14 at 17:06

Thanks again for the info.

Carol, I have read (mostly in UF publications) that even when commercial growers use systemics the trees around the edge of the grove still often get greening and have to be cut. The trees toward the center of the grove are the most protected. So they're using not only the pesticide but a "safety in numbers" technique, which is impossible for most home growers.

Jofus, that's really interesting about the key lime. I wish they were hardy here! I have some Rangpur lime trees (not really a lime) that I started from seeds. I'm been hoping they would be less susceptible because they're sort of wildish trees like key limes. We'll see. . . .

Thanks again,

Bill

Hi
My neighbors planted what was labeled "Key lime" while mine was labeled "mexican lime" looked a lot alike at least to me . Mine suffered a slow painful death while theirs looks very sickly but is still producing . has barely grown though.
gary

Thanks for the info, Gary. That's discouraging to hear, about the key limes/Mexican limes. Sorry to hear about your citrus trees. All of this is very sad.

Please note, the systemic pesticide will NOT prevent an infection (just posting this as some people I've talked to seem to think this.) It kills the psyllid when it ingests the pesticide when it feeds off the citrus leaf, however having already bitten into the leaf, the greening pathogen is introduced to the tree.

The systemic pesticide basically helps control infection of other trees because it kills the psyllid.

Mandarins, tangelos, and sweet oranges look to be more susceptible to the disease. Limes and pumelos less so.

Yes, the idea is to minimize bug bites. The pathogen doesn't seem to spread throughout the tree, but is localized to the infected shoot. Using the insecticides slows infections on new shoots by minimizing the vectors, but it really only slows the inevitable.

That said, greening has existed in Asia for decades and they still grow citrus. You just have to accept that trees won't be as long-lived as they used to.

Peaches aren't long-lived trees, either, so it's not an unusual proposition to replace trees more frequently than we're used to.

Oh, forgot to say that I use Keyplex Citrus as a foliar feed. It's kinda pricey and the only place near me that sells it is Miller's Hardware in Winter Park.

It does not reverse the damage on infected shoots, but it does seem to give healthy foliage quite a boost. I'm also trying invigorating pruning and granular feeding in smaller amounts at more-frequent intervals than generally recommended to try and keep nutrients more consistently available to the trees. So far, my trees are hanging in there, but a major scaffold on one of my tangerines is about gone and needs to be completely removed.

Here is a link that might be useful: http://www.keyplexdirect.com/our-products/207.html

This post was edited by TheTradition on Sat, May 31, 14 at 10:54

Sorry to be the bearer of bad news, but greening is a bacterial infection that spreads thought the tree unless excised... you know, cut off before it spreads farther. Wait too long and it spreads to the trunk and then to the rest of the tree.

I did a lot of reading a couple of years ago before I planted my trees, especially material from China. They have had this problem far longer than we have. Here's a synopsis of the strategy used by the more successful provinces. -->

Control the psylid like any other vector. Remove as many host plants as possible. Try to maintain buffer zones around groves that are free of host plants. They use pesticides sparingly on hot spots. Historicly the Chinese have been rather poor and could not afford to throw around pesticide like we do.

The Chinese claim that psylids do not fly far. Large groves tend to do better than smaller ones. The outer trees are considered sacrificial. If they are going to use insecticides, it is concentrated on the edges of the grove to reduce psylid penetration.

Nothing currently stops greening once it is in the tree. They practice aggressive pruning of any branch that appears to be infected. Prunings are burned, not composted. Any tree that starts to decline is cut down and burned, with special attention paid to peripheral trees.

The provinces that I read about did have commercial citrus production, but nowhere near the levels before.

Here in Florida they have been spraying groves with frequent, high doses of microneutrients. This keeps the trees going. But the disease is still there, spreading throughout the tree and providing an infection reservoir. Aggressive insecticide spraying has to be done to keep the disease from spreading even further. Not a cure, and an expensive stop gap in hopes that a tree antibiotic of resistant gene can be found.

Larry

Thanks for the information. Very interesting, the Chinese techniques. It's beginning to sound like this is going to be far more work than I'm willing to do, though I do love citrus. And if large groves do better than small ones, what chance do a few dooryard trees like mine have (especially when I'm in a neighborhood full of trees with greening)? My plan is go on with the organic feedings over the summer, see how the trees do, cut down the ones suffering the most, and replant with something else (not citrus).

Bill

An interesting short article on Biological control of Citrus Greening by using the Tamarixia radiata Wasp. (click on link below)

Also here is some info on the Tamarixia from UF (copy and paste into your browser) http://entnemdept.ufl.edu/creatures/beneficial/wasps/tamarixia_radiata.htm

~SJN

Here is a link that might be useful: Biological Control: Tamarixia

*crossing my fingers*

Here is a link that might be useful: Hope

Oh, that's encouraging. Hopefully at least one of those treatments pan out.

Thank you S_J_N!

Oh I hope it works!!!

SJN and Leekle, thank you for the info!

On the heels of the articles above came a morning report from our local news media that a treatment for Citrus Greening has been found. It appears that the information is moving mainstream:

UF team finds possible treatment for greening

Another interesting news story related to the subject:

State agriculture commissioner steps in between bee keepers and citrus growers

Carol

Here is a link that might be useful: UF/IFAS researchers find chemicals that treat citrus greening in the lab

Heard the reporting on this new research too, but they were clear that this is still in the experimental stage, that is, it worked in the lab & it's not clear whether it will be successful in the field.

But it gives me hope; they're working on it.

This post was edited by carolb_w_fl on Fri, Jun 6, 14 at 18:34

But if it causes severe liver damage in humans, what can be transferred through the fruit to us when we eat it from a ' benzbromarone treated' tree?

Well, they just got some more money for research:

ST. PETERSBURG, Fla. (AP) ��" Federal agriculture officials are allocating millions of dollars toward research to solve problems caused by the devastating citrus greening bacteria.

United States Agriculture Secretary Tom Vilsack told The Associated Press in a statement Thursday that $25 million in funding comes from the 2014 Farm Bill. Another $6.5 million will be sent to projects through a group formed to combat greening.