Author Topic: huanglongbing disease  (Read 1073 times)

Kalopa Guy

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huanglongbing disease
« on: March 18, 2025, 01:55:08 AM »
Kinda wondering if any hobbyists on this forum has encountered this in their  backyards yet.  AKA / Citrus Greening Disease
Wondering if maybe USDA / Fla. St, Dept of Ag  is stepping up to save the industry. 
Pretty sure death nell there for Fla Citrus.   next Ca... headed to Hawaii zero doubt.
Maybe contact congressional reps and demand exemptions to USDA /UDAID cuts to research and plant quarantine.


Artocarpus

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Re: huanglongbing disease
« Reply #1 on: March 18, 2025, 05:39:11 AM »
Yes, all my citrus is gone. A couple of years ago I put in key lime doing well so far. I believe these new plants have been modified to be resistant. I believe that part is already done if not mistaken.

booeyschewy

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Re: huanglongbing disease
« Reply #2 on: March 18, 2025, 05:41:59 AM »
California implemented a program to avoid it and it appears to have worked. It’s slammed Brazil and seems that citrus is dead here so they’re moving to new areas where it will probably take hold again. Tough disease

JakeFruit

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Re: huanglongbing disease
« Reply #3 on: March 18, 2025, 06:37:10 AM »
No, it's been spreading in California for a year or more https://www.cdfa.ca.gov/citrus/pests_diseases/hlb/regulation.html

Calusa

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Re: huanglongbing disease
« Reply #4 on: March 18, 2025, 08:09:18 AM »
Yes I've lost a Minneola and a couple of Dancy's to greening. Honestly, I believe those trees were already infected when I got them. I am now experimenting with a Tango (tangerine) and a Sugar Belle tangelo, which were protected by a psyllid-proof screening canopy from the beginning until Milton ripped them off last October. Oh well the trees had outgrown them anyway.

So now they are at the mercy of the citrus gods. They are supposed to be HLB resistant (Sugar Belle) and HLB tolerant (Tango). So far, so good, no sign of any disease or major pests - they both gave my back yard that heavenly aroma the past few weeks and are now loaded with baby fruitlets.

Kalopa Guy

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Re: huanglongbing disease
« Reply #5 on: March 18, 2025, 08:44:05 AM »
The plant hopper (asian citrus psyllid)that spreads it carries the bacterium. Control the plant hopper and control the problem good luck with that, homopterans are impossible to eradicate difficult to control. Luckily modern science has gene editing technology that should be of help. Only problem is that means cutting and chipping susceptible trees and planting genetically modified ones, developing new resistant cvs is going to take decades. I wonder if the Chinese have done any work on this. It's their darn disease.

Kalopa Guy

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Re: huanglongbing disease
« Reply #6 on: March 18, 2025, 09:56:51 AM »
Didn't think of that, I guess if you have uninfected plant mtl and keep it screened that would work. There is a millionaire in Kohala Estates who has a giant screened poly house with mangos inside. A few years ago I tried that with my cannabis it kept every thing out except the 2 spotted spider mite. Funny how $ solves many problems. Really sad how modern agriculture is increasingly moving indoors.

Yorgos

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Re: huanglongbing disease
« Reply #7 on: March 20, 2025, 12:46:24 PM »
I lost a star ruby grapefruit, moro orange, meyer lemon and a ujukitsu lemon to HLB in 2020.  Then the ice storm Uri hit Feb '21 and took out the rest of my trees.  I replanted in 2022(of course!) and things are developing.  I hope the cold of Winter Storm Uri (Feb '20) followed by Winter Storm Elliot (Dec '22), and the latest Jan '25 cold will set the ACP populations back to give the upper Texas Gulf Coast a breather at least.
Near NRG Stadium, Houston Texas. USDA zone 9a

a_Vivaldi

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Re: huanglongbing disease
« Reply #8 on: March 20, 2025, 07:22:11 PM »
Interesting, do cold weather events have a significant impact on ACP numbers? I had read a study at some point suggesting they could colonize as far north as zone 7 or 6 iirc, but this suggests that they probably can't, or at least not reliably or in great numbers.

FruitGrower

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Re: huanglongbing disease
« Reply #9 on: March 20, 2025, 07:39:17 PM »
Kinda wondering if any hobbyists on this forum has encountered this in their  backyards yet.  AKA / Citrus Greening Disease
Wondering if maybe USDA / Fla. St, Dept of Ag  is stepping up to save the industry. 
Pretty sure death nell there for Fla Citrus.   next Ca... headed to Hawaii zero doubt.
Maybe contact congressional reps and demand exemptions to USDA /UDAID cuts to research and plant quarantine.


I had HLB wipe all my citrus out the first time I tried growing them in 2016. In 2020, I started growing them again under protective screening and I have no signs of infection on any of my trees (~30). Though the screening does present its own set of problems, it's better than watching them slowly die from hlb.

bussone

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Re: huanglongbing disease
« Reply #10 on: March 21, 2025, 09:49:00 AM »
Interesting, do cold weather events have a significant impact on ACP numbers? I had read a study at some point suggesting they could colonize as far north as zone 7 or 6 iirc, but this suggests that they probably can't, or at least not reliably or in great numbers.

In theory, psyllids can feed on poncirus and zanthoxylum (I don't think they can do it on rue), so could get pretty far north. In practice though, they don't favor either species and neither one seems to be harmed by it, and the density of available plants starts getting pretty thin once you hit zone 8.

As a practical matter, the number of psyllids goes way down and the number of psyllid predators stays at the same amount.

Alippincott

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Re: huanglongbing disease
« Reply #11 on: March 21, 2025, 02:56:53 PM »
I thought I remembered hearing that Calfornia has been doing a good job keeping it in control by releasing sterile Psyllids. I cannot find the source, but hopefully it doesn't spread too fast. I just recently grew out a bunch of rootstock and grafted onto them to put in my yard.

pineflatwoods

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Re: huanglongbing disease
« Reply #12 on: March 21, 2025, 09:07:27 PM »
Oranges are toast- rootstock is taking over already on those.
Grapefruit- they're still alive- but nursing them back to health probably won't be an option
i have a key Lime- that is doing ok- hasn't fruited in a while.

Meyer lemon is growing protected from psyllids.

Tango Tangerine has also resisted HLB.
All plants were acquired in 2022.

I've seen far fewer psyllids recently for whatever reason. I even used to see them on non citrus in really bad infestations. Citrus leaf miner picks up the slack- another awful pest. Key Lime seems to resist it best.

I notice Citrus is like apples up north- seems to attract every known insect pest to man.

LoPresti

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Re: huanglongbing disease
« Reply #13 on: March 21, 2025, 09:44:18 PM »
I see or hear about people here in California buying citrus tree’s from Florida often enough. Thanks to Etsy and Ebay. It’s not a good feeling but those people never seem to care.

Tropheus76

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Re: huanglongbing disease
« Reply #14 on: March 25, 2025, 01:10:39 PM »
My in the forest experiment seems to be working ok. I have Sweet tangerine, Naval, Persian Lime and something else in an oak woods clearing. Went completely underwater for two days during one of the hurricanes last year. They didnt care. Something else interesting, since the deer eat the leaves so often, I dont get leaf miners :P Out in my yard I still have some of my older citrus up and kicking. My pommalo and Yuzu lemon are chugging along just fine. About 12 years old. My 9 pound lemon looks like heck but still produces heavily and I have to prune it every two years so I can mow under it. On the other side of the house I have another naval orange and pink lemon who while they arent growing, they both put out tons of blooms each year and leaf miners aside, look fairly healthy. In a pot under my eaves on the east side of my house I have a Centennial Kumquat and that thing produces like a beast. Been there about 3 years, big and bushy, even the leaf miners leave it alone.

On the bad side, my oldest tree which was there when I moved in 13 years ago  and I was never able to ID, it is pretty much finished. I just havent gotten around to removing it.

Yorgos

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Re: huanglongbing disease
« Reply #15 on: March 28, 2025, 10:53:58 AM »
Interesting, do cold weather events have a significant impact on ACP numbers? I had read a study at some point suggesting they could colonize as far north as zone 7 or 6 iirc, but this suggests that they probably can't, or at least not reliably or in great numbers.

My comment was based on ACP being a South Asian insect and thus cold sensitive.  Based on this article that may be a fond dream:
https://citrusindustry.net/2017/08/31/impact-of-temperature-on-psyllid-survival/
Near NRG Stadium, Houston Texas. USDA zone 9a

a_Vivaldi

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Re: huanglongbing disease
« Reply #16 on: March 28, 2025, 11:27:32 AM »
Quote
Field observations and laboratory studies conducted by David Hall have shown that ACP can survive sub-zero temperatures as low as 21 F for several hours. While the air temperature in a grove may decrease into the low 20s for a short period of time during a freeze event, ACP may survive inside the tree canopy where temperatures are slightly warmer than the surrounding air temperature. In Florida, air temperatures are commonly measured in the grove via a standard thermometer mounted approximately 4 feet above the soil surface, which will be colder than inside the protected tree canopy.

To me this is encouraging. While ACP might occasionally invade zone 7, 8a and northern parts of 8b , the typical winter should kill them or at least severely reduce the population. My understanding is HLB has a fairly low transmission rate, it takes a while for it to spread from tree to tree. So if the disease vector is only occasionally present, spread of the disease would be hampered. Add to that the fact that most wild and even cultivated citrus in zone 8 are to some extent resistant to HLB (wild trifoliate, cultivated trifoliate hybrids), and you decrease further the chances that whatever ACP do invade zones 7 or 8 will actually carry HLB.

Not saying I don't think HLB can't spread into zones 7 or the harsher parts of zone 8, just that to me it seems like the spread would be significantly slower and easier to control.

One thing I'm curious is, to what extent does feeding on trees with MaSAMP (the peptide in finger lime that can kill HLB bacteria) affect ACP? Are the ACP feeding on that tree ingesting and absorbing MaSAMP, and in high enough quantities to clear the HLB they might be carrying?

LBurford

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Re: huanglongbing disease
« Reply #17 on: March 28, 2025, 11:42:03 AM »
Didn't think of that, I guess if you have uninfected plant mtl and keep it screened that would work. There is a millionaire in Kohala Estates who has a giant screened poly house with mangos inside. A few years ago I tried that with my cannabis it kept every thing out except the 2 spotted spider mite. Funny how $ solves many problems. Really sad how modern agriculture is increasingly moving indoors.

The Chestnut blight came in on Chinese Chestnuts and killed billions of Chestnut and Chinquapin trees. One third of the forest east of the Mississippi River was wiped out. 

Galatians522

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Re: huanglongbing disease
« Reply #18 on: March 28, 2025, 07:26:12 PM »
I don't know about the finger lime, but I was just at a meeting where it was mentioned that curry leaf contains an antibacterial substance that kills HLB in the gut of psylids who feed on it. It is a favored host plant for ACP but the trees to not seem to suffer from HLB.

JakeFruit

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Re: huanglongbing disease
« Reply #19 on: April 02, 2025, 01:09:25 PM »
I don't know about the finger lime, but I was just at a meeting where it was mentioned that curry leaf contains an antibacterial substance that kills HLB in the gut of psylids who feed on it. It is a favored host plant for ACP but the trees to not seem to suffer from HLB.
I have a bunch of curry leaf, never noticed any of those tiny critters on them. I have citrus inches/feet away that definitely get infested periodically. I haven't noticed any HLB yet, but that's probably just dumb luck or my inability to identify it.

 

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