Detecting Surprise Diseases

Detecting Surprise Diseases

Diseases are always on the move, and it’s impossible to predict which diseases will show up in the greenhouse. Growers can, however, learn from the diseases that show up elsewhere. At SAF Pest Management Conference next month, Colleen Warfield of the University of California will share information about unusual disease problems encountered in the last year. And she’ll tell you what to watch for in the year ahead.

What is the significance of your topic to growers?

“For most growing operations, it is fairly predictable that certain plant diseases will occur every year and on a particular crop. And wouldn’t it be nice if those were the only diseases we had to worry about?

“There are two things that the floriculture industry is really good at–introducing new plant materials and sharing plant pathogens. Of course, the sharing of plant pathogens certainly isn’t intended. In fact, an incredible amount of resources go into protecting and selling high quality plant materials.

“But just like the flu shot that may not protect you from all the viral strains that may come your way (think about that plane ride home during the holidays!), it is also unrealistic to believe that you can keep every plant pathogen at bay.”

So how can growers best arm themselves to protect their plants against obscure diseases? 
“The best protection you have for preventing disease losses is to arm yourself with information. Looking at what diseases were unusual, problematic, or more prevalent in the previous season is often a good indicator of what is to come. Any time you can recognize a disease problem sooner, the greater chance you’ll have for successful control.”

Can you give us a snapshot preview of what attendees can expect from your presentation?
“Most growers, understandably so, are not going to speak up in a public setting and say, ‘I lost 30 percent of my celosia crop last year due to some nasty, leaf spot disease. By the way, does anybody know what that was?’

“Instead, I think most growers would prefer to experience, in the privacy of their own mind, what I call ‘ah ha’ moments. I will be presenting and showing images of a diversity of plant disease problems that were confirmed by diagnostic labs in 2008. A cross-section of plant pathologists from around the country have generously shared some of their diagnoses with me.

“As a result, I think most growers will see at least one disease they encountered last year in their own operation; not necessarily something they submitted for diagnosis, but something they may have been curious about yet never had diagnosed.

“It may be comforting to know that your operation wasn’t the only one battling the problem. Misery loves company, right? It is not unusual for the same disease problem to show up in multiple greenhouses in a given region or even on a national scale. It can also be very beneficial for anyone working in the floriculture industry to know what diseases showed up on a given crop, or which were more prevalent last year. This information is particularly helpful for growers who are contemplating or planning to grow that crop this season.”

What are you most looking forward to about the conference yourself?  

“I can assure you I will be having plenty of my own ‘ah ha’ moments throughout the conference. This conference provides an incredible forum for the exchange of information and ideas between growers, industry reps, educators and researchers who all share a common interest. And the realization that each of these groups is critical for the continued success of our industry inspires a wonderful spirit of cooperation and collaboration. I wouldn’t want to miss it!”

Warfield is scheduled to present on surprise diseases from 1:30-2 p.m. on Saturday, Feb. 21. The conference takes place from Feb. 19-21 in San Jose, Calif.

For more information on Pest Management Conference, presented by Society of American Florists and Greenhouse Grower, visit

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