The National Plant Diagnostic Network

Since the events of September 11, 2001, there has been greater emphasis on and concern about the threat of bioterrorism and the potential for our agricultural crops and natural ecosystems to be attacked.

Another concern is the potential for accidental or natural introductions of new pests and pathogens. There is a long history of pests and pathogens being introduced into new areas, and new problems in Missouri created by these introductions.

You may be familiar with introduced pests and pathogens such as Dutch elm disease that destroyed many of the elm trees that used to line our urban streets, or the multicolored Asian ladybeetle that now invades homes in vast numbers in the fall.

As global trade increases, the potential for new introductions also increases, particularly with the importation of plants and plant products from around the world. While it would be very difficult to prevent all possible introductions of new pests, if we can quickly detect a new introduction before it is able to become established in a new area, we may be able to eradicate or contain the new organism before it has a chance to become an expensive situation without simple solutions. For this reason it is critical that we have a way to rapidly detect, diagnose and respond to intentional and accidental introductions of pests.

To respond to these types of threats, the University of Missouri Extension Plant Diagnostic Clinic is part of the National Plant Diagnostic Network (NPDN) made up of experts from the nation's land grant universities and State Departments of Agriculture. This network was created by the U.S. Department of Agriculture as a way to utilize the established links land grant universities have with growers via the cooperative extension service, and experts in plant science and integrated pest management.

Funds and training materials provided to members of NPDN allow diagnostic clinic staff to train first detectors, people who work closely with various plants in Missouri and would be most likely to detect new plant problems, so they are able to quickly and efficiently submit samples of new plant problems to a diagnostic clinic.

Other new procedures help quickly prepare for an emergency situation resulting from new introductions. A new database connects the diagnostic labs so that data from across the country can be stored in a central location and quickly analyzed, providing better quality and uniformity of information associated with samples and better record keeping and reporting of pest outbreaks.

New equipment has also helped to improve diagnosis. For example, digital cameras attached to microscopes allow photos and information to be seen and communicated quickly over the Internet to other experts anywhere in the country.

Although NPDN has been developed recently, beginning in 2002, it has already proven useful. An important example of this occurred in 2003, when an aggressive strain of the bacterial disease called southern wilt was accidentally introduced to the United States with geranium cuttings from Kenya and Guatemala. The bacteria that causes this disease, Ralstonia solanacearum race 3 biovar 2, has the potential to cause disease problems in solanaceous vegetable crops, such as tomatoes, potatoes and eggplant, in addition to ornamentals. However, the quick detection, identification, containment and eradication of the pathogen prevented establishment and no additional outbreaks have been detected at this time.

For more information about NPDN see http://www.npdn.org/. You can also go to http://www.ncpdn.org for the North Central regional information, the regional portion of NPDN that includes Missouri.

If you have plant or insect samples you are concerned about, you can submit them to the plant diagnostic clinic. Please see last month's Missouri Environment and Garden (February) or go to http://agebb.missouri.edu/pdc/ for more information on submitting samples.

BSimeon Wright, Plant Diagnostic Clinic Coordinator, (573)882-3019