gardenweb88, I have not heard about this "infestation". Are you perhaps referring to Citrus Greening (i.e., HLB)? I have absolutely no information about this. However, in a small area of Los Angeles county bordering Orange County, there was a discovery of an HLB-infected tree in someone's back yard (the person had grafted HLB-infected pummelo budwood to this neighbor's existing citrus tree.) This happened last spring, and there was a quarantine in that area, door to door inspections, sprayings, etc. No further spread of HLB has been found or reported. Is that what you're referring to? HLB does not turn the insides of fruits black, but it will cause misshapen and sour fruit, and will eventually kill the tree entirely within several years of infection. A very, very serious disease that the citrus industry is frantically trying to find controls/cure for. It has decimated Florida's commercial citrus crop, and California is trying to keep HLB out of our state. You may be able to find inspected and clean citrus at another nursery close to you. It is worth checking other nurseries out.

Many other great options here in S. California. What is your Sunset zone? We really don't use USDA zones here in California as they are essentially worthless. If you can provide your Sunset zone, we can offer up some good suggestions. Apples, pears, stone fruit, mangos, bananas, grapes, berries, dragonfruit are a few suggestions.

Patty S.

The staff member at the nursery indicated that the infestation was a bug that didn't have an effective pesticide available. He might've just been simplifying the issue in his telling to me. I'm in Los Angeles county bordering Orange County, so the HLB that you describe might be what the nursery staff member was talking about. He did talk about the devastation in Florida's citrus plants.

I'm not familiar with how to determine sunset zone.

This post was edited by gardenweb88 on Mon, Apr 8, 13 at 1:57

Citrus canker and greening are the "major" things that are worrisome in Florida. I never heard of any mystery bug turning anything black... sound like some April fools crap.

All these quarantines are only delaying the investable, they either need to find a cure or grow cultivars resistant to it. This supposed California Nazi-raiding of home growers and nurseries is not going to fix anything.

HLB is like the AIDS virus of the citrus world and is a bad character; there is no cure and infected trees can live for years, spreading the disease. The vector is almost invisable and has a 2-mile flight range. Any resistance will have to be bred for each varietiy, as a resistant rootstock will not impart that resistance to the cultivar. Desert wholesale nurseries like Young's can still ship but moving trees or backyard fruit out of a quarantine area is prohibited. I'm afraid I agree with your inevitable assessment, but it doesn't hurt apples!

gardenweb88, it sounds like he was referring to HLB, then. It doesn't turn your fruit black, though, but it is fatal, and not treatable. If you live near or in Whittier, this would be what he was referring to. The lifespan for an infected tree is approximately 5 years, but for the few few years, the tree will be asymptomatic, yet infectious. The disease is spread by a vector insect, the Asian Citrus Psyllid. Fortunately for us in California, there has been no reported spread past this one find. So, we are remaining hopeful. You still may be able to find citrus at other nurseries that are closer to you, so don't give up quite yet. And, apples are a great alternative, or addition to fruit trees in your garden. Applenut can give you some excellent advice on good apple cultivars. I have about 12 or 15 different apple varieties, and a few based on applenut's recommendations.

Applenut, there has been some good research with regard to the development of resistant cultivars, and that reseach has come out of Texas A&M University, with the lead researcher being Dr. Erik Mirkov. But, considering the many thousands of citrus cultivars we have, trying to breed for resistant cultivars is not the only solution, unfortunately. Great for commercial citrus growers, who focus on perhaps 15 different citrus varieties, but for the dooryard or hobbyist grower, we are hoping for some of the other research to provide better options. And, within that, examining certain citrus cultivars and citrus relatives that show some degree of increased resistance (although all do succumb, eventually). There are several (about 20 to 25) different research projects worldwide being undertaken around HLB, and the focus is mainly on three fronts: in controlling the vector, developing resistant cultivars, or addressing the infection (C. Liberibacter asiaticus), directly. One of the most fascinating research projects is being conducted I believe in Japan. It takes the Tristeza virus, de-pathogenizes the organism, then uses it like a "silver bullet" to carry in an organism into the tree that will kill C. Liberibacter, and continue killing it, if the tree gets reinfected. You literally inoculate or vaccinate the tree. Fabulous for those of us with many rare and unusual citrus in our collection, where there would be little to no hope of ever seeing a resistant cultivar developed. Plus, commercial growers would not have to replace their trees, just inoculate them to protect them. There are actually several quarantine areas scattered about California, but only quarantined due to the ACP. The Whittier area is quarantined for both HLB and ACP.

Patty S.

Here is a link that might be useful: Breeding for HLB Resistance PowerPoint

I just read an article about Citrus Greening and the Asian Citrus Psyllid that transmits it in a recent issue of Scientific American. The article was quite gloomy about the prospects of fighting greening and didn't include anything about the Japanese research with the Tristeza virus you mentioned, hoosierquilt, so thanks for sharing it.

Well, most of the research right now is flying under the reporting radar, shazaam. But, there are some really incredible, mind-blowing things going on with HLB research. Mainly because it is such a devastating disease and threatens to devastate the entire world's commercial citrus industry. In order for Florida citrus to continue, they have basically had to figure out how to get as many viable crops in 5 years, as at that point, the tree is no longer able to produce acceptable fruit. So, essentially, Florida citrus growers are having to replace their trees every 5 years. I cannot even imagine that, but that is the current reality for commercial citrus in Florida. A few unusual things to note regarding HLB: First, is that this organism ultimately kills its host. That is unusual, as it would also ultimately spell the demise of the organism as well, if nature were to take its course. Secondly, the "C" in C. Liberibacter asciaticus stands for "Candidatus". Candidatus is the scientific classification that is included in the taxonomic name that indicates a bacterium cannot be maintained or grown in a culture. It is an interim taxonomic status for noncultivable organisms. So, the researchers have had to study in situ, which makes researching very difficult. Great minds are at work right now, I would very much love to be involved in the research, as I find it indeterminably fascinating.

Patty S.

gardenweb88,

Here is the link to help determine your Sunset zone.

Here is a link that might be useful: Sunset climate zones: Los Angeles region

UC Riverside is rearing and releasing natural enemies to ACP called Tamarixia. It isn't a cure for the HLB, but they will help out in slowing down the spread. Hopefully Texas A&M or some school will find a cure in the meantime.

Be on the look out for the new 'good' insect, Tamarixia. See link below for more info.

Here is a link that might be useful: Article of UCR releasing Tamarixia

This post was edited by Avocado101 on Thu, Apr 4, 13 at 1:20

CDF had a display of a yellow sticky trap where they had circled an ACP, and for the life of me I couldn't distinguish it from the whiteflies, gnats, and specs of dust on the rest of the card; I have no idea who the lucky person is who gets to stare at all those traps trying to find one.

My thought is if they just prolong the infected tree's life, it's just a carrier for that much longer. I wouldn't want anything but clean trees around my orchard. That's fascinating about the Tristeza virus, I wonder how they inject it; graft an infected limb on? Meanwhile I'll carry on with apples, which also do well in tropic areas where they don't have to worry about banana wilt or yam decline.