Rootstocks Tolerant to Citrus Greening

[Millet]

The University of Florida's  Lake Alfred breeding program has found several rootstocks that appear to tolerate greening better than existing trees, Grosser told several hundred growers at a Thursday morning seminar in Bonita Springs.

A commercial citrus tree is a combination of two varieties. A rootstock is designed primarily for the soil conditions in an area. A scion produces a specific fruit variety, such as a Valencia orange or a white grapefruit, is grafted onto the rootstock.

Tolerance means the rootstock has a lower frequency of greening infection or, if infected, the disease has less an effect on tree health, Grosser said.

The greening-tolerant rootstocks are ready for widespread field tests, at least an acre of plantings in various parts of the state, he said. That's the next test before one or more of the rootstocks can be released to growers for general use. - Millet

[GT]

Good news, Millet! Thank you for sharing.

[Scott_6B]

Here's a bit of additional info on work to find better rootstocks and on screening of current citrus germplsasm for HLB tolerance.  Some of Dr. Grosser's observations are highlighted in the presentation.  It is interesting to note that Poncirus shows some resistance/tolerance to HLB.

http://www.citrusresearch.org/wp-content/uploads/Stover_Ed_Is_there_useful_resistance_HLB.pdf

And some more recent updates.

http://www.growingmagazine.com/article-10650.aspx

And a bit of news on research focused on learning about the bacterium Liberibacter asiaticus that causes HLB where they have now sequenced its genome and are beginning work on identifying means to control the bacteria. 

http://www.heraldtribune.com/article/20140114/ARCHIVES/401141033?p=1&tc=pg

[Tropheus76]

Wow, great news. So maybe in 15 years or so after it is released and the commercial groves quit gobbling(as they should grumble grumble) the new stock as it becomes available maybe we will get it in the residential markets. I haven't noticed it in any of my trees but I foliar spray and fertilize the crap out of my trees on a weekly basis, so they had better not show any signs.