Ornamental citrus trees from Florida are available for purchase in Canada in spite of a ban on the export of trees from that state. The authorities must have granted an exemption for export to this country since it has no impact on the U.S. citrus industry. However the trees could be diseased without showing any symptoms. Would it be prudent to avoid buying trees from that state in order to protect one's citrus collection?

I currently have three trees from Florida that were purchased in January 2006, before the ban was imposed. They appear to be healthy. Which diseases should I be aware of and watch out for?

The two diseases that got the quarentine placed on Florida are citrus canker and citrus greening (or HLB) the latter is transmitted by a small insect--the asian citrus psyllid that is unlikely to be found in Canada.

Florida has instituted many new regulations to protect the industry from any problems arising from nursery stock. All citrus nursery plants have to be grown and propogated inside a screened enclosure. As of Jan. this year, I cannot even give my citrus plants that I have grown from seed to anyone even inside the state of Florida due to a new law banning distribution of any citrus plants (even if they are free) if they were not propogated inside and enclosed screenhouse.

There is always some risk of importing some disease or pest whenever you get new plants, but due to the level of scrutiny, Florida's citrus plants may not be any more risk than others.

I think Skeet is correct about the danger of transmitting disease is minimal. However, if the tree has greening, you might not even realize it for up to three years. Further, if the Florida agricultural law that requires the production of nursery citrus trees be done in side a screened enclosure, if the trees being sold in Canada are one or two year old trees, than this new law might not help, as the law was only effective last month. Even though I believe, any danger to your collection is very minimal, I myself never ever purchase any trees out of Florida. With my collection (131 varieties) all it would take is just one (1) infected tree. - Millet

Actually, I think the law requiring a screenhouse for propagation went into effect in more than a year ago-- in Jan 2008 a new law was added to forbid transport and distribution of any not produced in a screenhouse, but Millet is right for container trees that are more than a yr old---they could have been produced before the laws went into effect.

Greening is a very serious disease of citrus and usually means death of the tree in the long run, but it also requires the presence of the Asian citrus psyllid to be spread to other trees.

Citrus canker is more of a cosmetic problem in the industry and it can be controlled to a certain extent with spraying, but it can spread through air at least a few hundred yards (during the canker eradication program FL cut down all citrus trees within 1900 ft of any known canker tree.)

Thanks for the replies. I'll just have to hope for the best. If I see a tree that I like I'd have little choice but to take a chance because of the very limited supply of citrus in my area.

Junglekeeper, all in all I think you will be OK. - Millet

The quarantine on citrus export is imposed by the USDA. I am sure that they have no authority in Canada, except that they might be able to stop shipment across US territory. I also believe I have read that shipments to Canada are permitted if the trees remained in a sealed container as it crosses the US, but it has been months since I read this and am not sure about how things presently stand.

I understand that Calamondins and Kumquats are exempt from the quarantine, as long as the nursery growing them meets certain requirements. These two are (were) suppose to be immune to canker. I do believe thay are taking a second look at calamondins, as they have found canker on some calamondins in at least one nursery.

You can go here and read the regulations for yourself. I could only get the link to work if I copied an pasted it. Once there, click on Deparment of Agriculture [PD]

http://www.usda.gov/wps/portal/!ut/p/_s.7_0_A/7_0_1OB?entqr=0&sort=date%3AD%3AL%3Ad1&ie=UTF-8&mode=simple&q=citrus+final+rule&num=10&ud=1&oe=UTF-8&navid=SEARCH&start=10

Ned

Thanks Ned, however, I cannot seem to get the link to work, even if I copy and paste. - Millet

Here is the updated link for the document search at USDA.
Direct link to the (.pdf) document in question: Department of Agriculture.

Millet, I tried it several times and it seemed to work ok for me. I did try something else. Just click on the highlighted part and a new window will oper at the USDA. In the search window there use the words citrus canker final rule. Then scroll down the page to link that says Deparment of Agriculture [PD]. Click on that and it should get you to the right place (I hope).

Ned

That's good, thanks Junglekeeper.

Ned

I heard yesterday that, effeciive January 11, all citrus trees are now included in the quarantine, including calamondins and kumquats (which had previously been allow). This applies to the entire state of Florida. A quick search yielded this news release.

Ned

http://www.aphis.usda.gov/newsroom/content/2008/01/cgfedord.shtml

Thanks, Ned. It seems exports to Canada remain, for better or for worse.

Quote:

If, in the future, scientific evidence demonstrates that nursery stock can be handled in a way that prevents the risk of spreading citrus greening, APHIS would pursue rulemaking to allow the interstate movement of these plants. However, until these requirements are established,nursery stock from areas quarantined for citrus greening only can be moved interstate for immediate export accompanied by a limited permit that prevents distribution to any citrus-producing states or territories.

My opinion is that there is little danger of contracting disease from nurseries meeting USDA's requirements. It is the trees purchased at shops along the interstate highways, and at flea markets, or received as a gift from a friend, and taken out of state by unsuspecting tourists, or by persons who don't understand (or don't care about) the problem such actions pose, that I see as the problem.

Ned