November 2004

Ralstonia Again By Bridget White

On October 8, the USDA’s Plant Protection and Quarantine division announced the presence of Ralstonia solanacerarum race 3 biovar 2 in a Quincy, Fla. greenhouse, and the industry collectively held its breath. Not again, we all thought. The last incident, less than 10 months ago, destroyed a top-level supplier, left hundreds of growers with no crop and focused the attention of the U.S. government on our business practices. No one wanted a repeat.

Well, it doesn’t look like we’re getting one, and I’m not sure if that’s good or bad. (Turn to page 8 for complete details of the story, and sign up for GPN Weekly at www.gpnmag.com to get weekly alerts about happenings such as this). The good news is that it doesn’t appear that any of the geranium suppliers shipped the disease into the country. The bad news is that it may have come from a local, endemic source…at least I think that’s bad news. The long-range implications are convoluted at best.

My opinion

At the magazine, we hear lots of rumors. So we spend a lot of time talking to researchers, informed sources, breeders, government in both Florida and Washington, and anyone else we think has some information. A lot of what we hear are just theories and what ifs. And since an editorial is the only appropriate place to cover such things, here goes. The following are a few of the possible outcomes I came up with for the recent Ralstonia outbreak.

1. The area of Florida where this incident occurred is one of the heaviest tomato production areas in the United States, and tomatoes are a known carrier of r3b2, as well as the other more common strains of Ralstonia.
2. When tomatoes show signs of wilt, they are tested for Ralstonia but do not have to be sent to Beltsville for race and biovar typing. If Ralstonia is found, plants are destroyed without ever knowing what is really wrong with them.
3. We have heard several times that the disease was found in the greenhouse’s retention pond and a local stream. If true, this outbreak would make more sense, and the source would be tomato production and not the greenhouse.
4. Would this also mean that Ralstonia had been present for a long time in the United States without our ever knowing about it?
5. We hear that USDA has decided to test wilted tomato plants and local water sources for r3b2 (when asked, USDA would not comment). The target area for the testing is still unclear. I would hope the testing is extensive. The pathogen has shown itself hardy in climates ranging from dry to wet and warm to cold.
6. Many expect that r3b2 will be found in local water sources, and USDA will have to decide how to respond. Possibilities include decertifying the United States as Ralstonia free, an action that would cause the collapse of the lucrative seed potato business and is therefore unlikely, and/or imposing a quarantine to try to control the spread of the pathogen.
7. A quarantine could take several different forms — local, state-wide or regional — and could be limited only to known hosts (though that has been complicated by a recent rumor that hydrangea plants in Quincy are showing symptoms) or widened to…? At any rate, there is a potentially tremendous threat to our industry if the right approach is not enforced. Florida produces a lot of product that is shipped throughout the country; imagine not having that resource or having it severely limited.
8. Now for the good news. SAF and ANLA were already petitioning the USDA to remove r3b2 from the bioterrorism list, and if the pathogen is confirmed to exist naturally in the United States, the chance of that happening increases dramatically. It would mean a little less government scrutiny for our industry, and that is always good.

I know this is a lot to think about, and that’s what I wanted to accomplish. GPN is always very careful about publishing only what we can directly verify, but there is so much to think about with this disease — things that may only be supposition at this point.

We don’t know where this latest Ralstonia outbreak is going to take our industry, but we need to start thinking about it. We should be involved when the issue first comes up so we can shape the outcome; the last thing we want to have to do is react to a government decision.