
Microbes Protect Potatoes from Storage RotBy Ben Hardin September
30, 1998A bacterium patented by the Agricultural
Research Service to reduce Fusarium dry rot in stored potatoes has proven 50
percent more effective than a synthetic chemical now used to control rot in
commercial storage bins. The chemical, thiabendazole (TBZ), is the only
federally registered fungicide for potatoes destined for human consumption. Scientists with ARS, the University of
Idaho and United Agri Products, Inc., of Greeley, Colo., conducted research
on potentially protective bacteria under a cooperative research and development
agreement (CRADA). They tested the bacteria on potatoes stored in bins for four
to eight months at four North Dakota and Idaho sites. The most outstanding bacterium tested, Enterobactercloacaestrain S11:T:07, reduced dry rot an average of 21 percent in contrast to 14
percent by TBZ. Researchers noted a 17 percent drop in dry rot when the
S11:T:07 strain was applied to potatoes infected with TBZ-resistant strains of
the fungus Fusariumsambucinum in an earlier pilot study. When
TBZ was applied instead, dry rot increased 7 percent. ARS scientists at the National Center
for Agricultural Utilization Research, Peoria, Ill., are researching
improved formulations of S11:T:07, one of 18 beneficial bacteria they've
patented as dry rot inhibitors. The scientists have shown the microbe can be
produced in a liquid culture system compatible with industrial fermentation
practices. Dry rot fungi plague the potato industry worldwide, causing a dark tissue
discoloration on the potato that eventually forms a dry, crumbly rot. Annual
losses in stored potatoes in the United States are estimated at more than $100
million. ARS is seeking to license the 18 patented bacteria or form cooperative
research agreements with private firms to develop biocontrol products based on
the beneficial microbes. The agency is the lead scientific wing of the
U.S. Department of Agriculture. Scientific contacts: David A. Schisler and Patricia J. Slininger,
USDA-ARS National Center for Agricultural Utilization Research, 1815 N.
University Street, Peoria, IL 61604, (309) 681-6567, fax (309) 681-6427,
[email protected],
[email protected]. U.S. Department of Agriculture | |